RespiratoryCare Practice Exam PDF

RespiratoryCare Practice Exam Gary Persing, TMC Q&A + Rationale 1) A patient receiving positive expiratory pressure (PEP) therapy through a mouthpiece at 10 cm H 2O has minimal secretion production. Course crackles are heard during auscultation. The respiratory the...

RespiratoryCare Practice Exam Gary Persing, TMC Q&A + Rationale 1) A patient receiving positive expiratory pressure (PEP) therapy through a mouthpiece at 10 cm H 2O has minimal secretion production. Course crackles are heard during auscultation. The respiratory therapist should recommend which of the following? A. Decrease the PEP to 5 cm H2O. B. Discontinue the treatment and begin percussion and postural drainage. C. Increase the PEP to 15 cm H2O. D. Administer the treatment with a mask instead of the mouthpiece. Correct Answer is C Rationale: PEP therapy is indicated for patients with retained secretions. Positive pressure applied during exhalation aids in the mobilization of secretions. Generally, PEP levels of 10 to 20 cm H 2O are used. If the PEP used does not result in the mobilization of secretions, the PEP should be increased. 2) A heated humidifier is delivering 26 mg of H2O/L of gas to an intubated patient. Which of the following statements concerning this situation are true? 1. A humidity deficit exists. 2. The patient's secretions may become thicker. 3. The heater temperature should be decreased. A. 1 only B. 1 and 2 only C. 2 and 3 only D. 1, 2, and 3 Correct Answer is B Rationale: Whenever the amount of H2O being delivered to the patient is less than 44 mg/L, a humidity deficit exists. This decreased H2O delivery can result in thickening of pulmonary secretions, with an increased potential of mucous plugging and atelectasis distal to the plugs. Because cooler air cannot hold as much H2O as warmer air, decreasing the heater temperature increases the humidity deficit. 3) The respiratory therapist is administering acetylcysteine (Mucomyst) via a handheld nebulizer to a patient who suddenly becomes short of breath. Which of the following is the most appropriate recommendation at this time? A. Have the patient take deeper breaths. B. Add racemic epinephrine to the nebulizer. C. Stop the treatment and administer albuterol. D. Stop the treatment and administer cromolyn sodium. Correct Answer is C Rationale: A common complication of acetylcysteine administration is bronchospasm. When respiratory difficulties occur during a Mucomyst treatment, suspect bronchospasm and administer a bronchodilating agent. 4) An intubated patient's secretions tend to become thicker and harder to mobilize in which of the following conditions? 1. Absolute humidity of 18 mg H2O/L of gas 2. 48 mg of H2O/L of gas 3. Relative humidity of 100% at 25° C 4. A H2O vapor pressure of 47 mm Hg A. 1 and 2 only B. 1 and 3 only C. 2 and 3 only D. 2 and 4 only Correct Answer is B Rationale: For delivery of 100% saturated gas at body temperature (100% body humidity) , the gas must be holding 44 mg of H2O/L of gas to have an H2O vapor pressure of 47 mm Hg. Thus, choices 1 and 3 result in a humidity deficit. Although choice 3 indicates a relative humidity of 100%, it is at only 25° C, not at body temperature (37° C), so inadequate H2O is being delivered and the body has to make up the deficit. This causes the airway to dry out and make secretions thicker. 5) Which of the following is the most appropriate ventilator VT setting for a female patient who is 5 ft, 5 in tall and weighs 85 kg (187 lb) ? A. 450 mL B. 600 mL C. 800 mL D. 900 mL Correct Answer is A Rationale: The ventilator VT should be set at 8 to 12 mL/kg of ideal body weight. Calculation of ideal body weight is as shown: Male: 106 + (6 × [ (height in inches - 60]) Female: 105 + (5 × [height in inches - 60]) In this problem, the woman is 65 inches tall. 105 + (5 × [65 - 60]) = 105 + 25 = 130 lb In other words, you add 5 lb for every inch over 5 ft to a base of 105 lb to obtain the ideal body weight. To change pounds to kilograms, divide by 2.2: 130/2.2 = 59 kg Using 6 to 8 mL/kg of ideal body weight, the most appropriate volume is 450 mL. 6) During O2 rounds, the respiratory therapist notices a nebulizer delivering very little mist to the patient's aerosol mask. Which of the following could cause this problem? 1. Inadequate flow from the flowmeter. 2. A plugged capillary tube. 3. Excessive H2O in the aerosol tubing. A. 1 only B. 1 and 2 only C. 2 and 3 only D. 1, 2, and 3 Correct Answer is D Rationale: Inadequate flow to the nebulizer results in an overall decrease in total flow and less mist output. If the capillary tube is plugged, H2O is prevented from being drawn up the tube for aerosolization to occur, with less resulting mist output. Finally, H2O build-up in the aerosol tubing results in an increased resistance to gas flow; therefore, gas flow decreases, along with total mist output. This usually occurs on heated nebulizers because of the temperature change from the outlet of the nebulizer through the cooler tubing, which results in H2O condensation in the tubing. 7) Chest film results reveal that a patient has consolidation in the left upper lobe. For selective suctioning of the left mainstem bronchus, the respiratory therapist should recommend which of the following? A. Have the patient turn the head to the right during suctioning. B. Use a Yankauer suction device. C. Use a whistle-tip suction catheter. D. Use a coude-tip suction catheter. Correct Answer is D Rationale: A coude-tip catheter is a catheter in which the tip is angled to the left for selective suctioning of the left mainstem bronchus. 8) A patient receiving volume-controlled ventilation has a PaO2 of 54 mm Hg on a PEEP of 8 cm H2O and an FIO2 of 0.50. After increasing the PEEP to 12 cm H2O, the cardiac output decreases from 5.2 to 4.0 L/min. The most appropriate action is to do which if the following? A. Discontinue PEEP and increase the FIO2 to 0.70. B. Increase PEEP to 15 cm H2O. C. Decrease PEEP to 8 cm H2O and increase the FIO2 to 0.60. D. Maintain the current settings and measure cardiac output in 1 hour. Correct Answer is C Rationale: Because increasing the PEEP level from 8 to 12 cm H2O resulted in a reduction in cardiac output, the PEEP should be returned to 8 cm H2O and the FIO2 should be increased to 0.60. The general rule of thumb for the examination is to increase the FIO2 to 0.60 before increasing PEEP. 9) This set of ABG results was obtained on a patient in the ICU on a 2-L/min nasal cannula: pH 7.22 PaCO2 27 mm Hg PaO2 78 mm Hg HCO3- 12 mEq/L BE – 13 mEq/L The correct interpretation of these ABG results is which of the following? A. Partially compensated metabolic acidosis B. Uncompensated metabolic acidosis C. Fully compensated respiratory acidosis D. Uncompensated respiratory alkalosis Correct Answer is A Rationale: The acid pH is the direct result of the decreased HCO3-level. The patient is hyperventilating to decrease the PaCO2 so that the pH returns to normal levels. Because the pH is still low, it is considered a partially compensated metabolic acidosis. 10) The following data are collected from a 2-month-old infant with respiratory distress syndrome (RDS) who is on pressure control ventilation: Mode SIMV Ventilator rate 40 breaths/min Inspiratory pressure 24 cm H2O FIO2 0.60 PEEP 4 cm H2O PaCO2 36 mm Hg PaO2 41 mm Hg pH 7.42 HCO3- 23 mEq/L BE -1 mEq/L On the basis of these data, which of the following should the respiratory therapist recommend? A. Increase PEEP to 6 cm H2O. B. Decrease rate to 35 breaths/min. C. Increase FIO2 to 0.70. D. Increase inspiratory pressure to 30 cm H2O. Correct Answer is A Rationale: The normal PaO2 for a newborn is 50 to 70 mm Hg; therefore, hypoxemia is present. The same rule applies to newborns as for adults when hypoxemia is present and the patient is on 60% O 2 or higher. Do not increase the O2; instead, add or increase PEEP. Reducing the ventilator rate increases the PaCO2 and decreases the PaO2. 11) Postural drainage and percussion have been ordered for a patient with cystic fibrosis with right lower lobe atelectasis. While in the Trendelenburg position, the patient's heart rate increases from 74 to 100 beats/min and the respiratory rate increases from 18 to 28 breaths/min. The patient becomes agitated and states, “I can't breathe when my head is down.” The respiratory therapist should do which of the following? A. Continue the treatment with the patient sitting up. B. Explain the importance of this position to improve his lung condition and continue the therapy. C. Recommend replacing chest physical therapy with fluttervalve oscillation therapy. D. Recommend replacing chest physical therapy with incentive spirometry. Correct Answer is C Rationale: This form of therapy has been shown to be beneficial in the treatment of cystic fibrosis, especially for those patients who cannot tolerate the postural drainage positions indicated for treatment. 12) The following electrocardiographic (ECG) rhythm is observed on the patient's oscilloscope monitor after endotracheal (ET) suctioning: Which of the following is the most appropriate action to help prevent this from occurring? A. Decrease the suction pressure. B. Hyperoxygenate the patient. C. Use a larger suction catheter. D. Limit the time that the catheter is in the airway to 15 sec. Correct Answer is B Rationale: This ECG strip indicates sinus bradycardia, a fairly common side effect of tracheal suctioning. The sinus bradycardia is the result of vagal nerve stimulation. Hypoxemia caused by suctioning may lead to other cardiac arrhythmias. Increasing the O2 level before suctioning helps compensate for the hypoxemia so that arrhythmias are less likely to occur. 13) The following ABG values are collected from a 32-year-old patient receiving 50% O2 via aerosol mask: pH 7.44 PaCO2 35 mm Hg PaO2 60 mm Hg HCO3– 23 mEq/L BE -2 mEq/L The respiratory therapist should recommend which of the following? A. Place the patient on a nonrebreathing mask. B. Increase O2 to 70%. C. Place the patient on a CPAP mask. D. Decrease the flow to the aerosol mask. Correct Answer is C Rationale: The ABG levels reveal mild to moderate hypoxemia. Oxygen percentages over 50% to 60% should be avoided because of increasing the possibility of oxygen toxicity. 14) These data are collected from a sedated, paralyzed patient on volume-controlled ventilation in the assist-control mode: Mode Assist-control Rate 10 breaths/min VT 600 mL (0.6 L) FIO2 0.40 ABGs pH 7.29 PaCO2 50 mm Hg PaO2 77 mm Hg HCO3– 27 mEq/L BE +3 mEq/L Which of the following ventilator settings would decrease the patient's PaCO 2 to 40 mm Hg? A. VT = 700 mL; rate = 12 breaths/min B. VT = 900 mL; rate = 15 breaths/min C. VT = 800 mL; rate = 8 breaths/min D. VT = 750 mL; rate = 10 breaths/min Correct Answer is D Rationale: Use this equation: Desired VE = [VE (current) × PaCO2 (current) ]/PaCO2 (desired) = (6 L × 50) /40 = 300/40 = 7.5 L (desired VE) A VT of 750 mL (0.75 L) and a rate of 10 breath/min is a VE of 7.5 L. 15) An alert, spontaneously breathing patient has a PaCO2 of 33 mm Hg and a PaO2 of 55 mm Hg while receiving 70% oxygen. Which of the following is the most appropriate way to increase the patient's PaO2? A. Increase the FIO2 only. B. Intubate the patient and increase the FIO2. C. Apply continuous positive airway pressure (CPAP) at 60% oxygen. D. Apply CPAP at 100% oxygen. Correct Answer is C Rationale: A PaO2 of 55 mm Hg on 70% indicates refractory hypoxemia, which does not improve with higher levels of oxygen. Application of CPAP is necessary to improve oxygenation by alveolar recruitment and by opening the alveoli and increasing the surface area for better gas exchange. Once the alveoli are open, oxygen diffusion into the blood increases, resulting in an increased PaO 2, often to the point that the FIO2 can be reduced. A level of 0.70, as in this question, can be damaging to lung tissue, so reducing it to 0.60 while applying CPAP is appropriate. Mechanical ventilation is not indicated at this time because the patient is ventilating adequately. The primary problem is hypoxemia, resulting in hyperventilation. Once the PaO2 is increased, the patient's need to hyperventilate will diminish with a rise in the PaCO2. 16) The physician writes an order for a patient to receive 15 L/min of an 80:20 helium-O2 mixture from a premixed heliox cylinder via a nonrebreathing mask. For the patient to receive this flow through an O2 flow meter, the flow must be set at approximately which of the following? A. 8 L/min B. 12 L/min C. 15 L/min D. 24 L/min Correct Answer is A Rationale: An 80:20 mixture of heliox diffuses through an O2 flow meter 1.8 times faster than 100% O2. To determine the correct flow rate setting, divide the desired flow (15 L/min) by 1.8. 17) The following data were obtained from a 75-kg (165-lb) male patient on volume-controlled ventilation: Mode Assist-control Ventilator rate 12 breaths/min VT 600 mL PEEP 10 cm H2O FIO2 0.50 ABGs pH 7.37 PaCO2 41 mm Hg PaO2 82 mm Hg HCO3- 26 mEq/L BE +1 mEq/L Which of the following is the most appropriate action to take at this time? A. Decrease FIO2 to 0.40. B. Increase VT to 700 mL. C. Decrease PEEP to 5 cm H2O. D. Maintain current settings. Correct Answer is D Rationale: These ABG results indicate normal values. Therefore, no ventilator changes are necessary. 18) The following data have been obtained from a 70-kg (154-lb) patient with pneumonia who is receiving volume-controlled ventilation: Mode SIMV Ventilator rate 8 breaths/min VT 550 mL FIO2 0.35 Total rate 14 breaths/min Pressure support 5 cm H2O ABGs pH 7.47 PaCO2 33 mm Hg PaO2 79 mm Hg HCO3- 25 mEq/L On the basis of these data, the respiratory therapist should recommend which of the following? A. Increase FIO2 to 0.45. B. Decrease SIMV rate to 4 breaths/min. C. Decrease VT to 500 mL. D. Place patient on 30% flow-by. Correct Answer is B Rationale: The patient's ABG levels reveal alveolar hyperventilation, a sign that the ventilator rate or VT is excessively high. The VT fits for the patient's weight (6 to 8 mL/kg of body weight) and, because the patient is being weaned (SIMV rate = 8 breaths/min) , the most appropriate choice is to decrease the rate to 4 breaths/min. 19) A 54-year-old patient enters the emergency department with mild chest pain and shortness of breath. Oxygen is started at 3 L/min per nasal cannula. The ABGs drawn 30 minutes later are as follows: pH 7.36 PaCO2 44 mm Hg PaO2 62 mm Hg HCO3- 24 mEq/L BE 0 mEq/L The respiratory therapist should recommend which of the following? A. Increase O2 flow to 5 L/min. B. Intubate the patient and institute mechanical ventilation. C. Place on continuous positive airway pressure (CPAP). D. Maintain current O2 therapy. Correct Answer is A Rationale: The patient is still hypoxemic on 3 L/min of O2. Choices b and c are too drastic and not necessary at this point, so an increase in liter flow to 5 L/min is most appropriate. 20) While monitoring vital signs on a patient on a ventilator, the respiratory therapist observes a blood pressure of 175/100 mm Hg. Which of the following should be recommended at this time? A. Administer nitroprusside. B. Decrease the tidal volume (VT). C. Increase inspiratory flow. D. Administer dopamine. Correct Answer is A Rationale: Nitroprusside sodium (Nipride) is a potent, fast-acting, peripheral vasodilator, which reduces peripheral arterial resistance, thereby decreasing blood pressure. 21) The physician orders 40% O2 for a patient with dyspnea. Which of the following devices delivers this O2 level most consistently? A. Nasal cannula at 5 L/min B. Simple O2 mask at 10 L/min C. Partial rebreathing mask at 12 L/min D. Air entrainment mask Correct Answer is D Rationale: The air entrainment mask is a high-flow device, which delivers a more consistent O2 percentage than low-flow devices. Normal spontaneous inspiratory flow is 25 to 30 L/min. Because the maximum liter flow available on low-flow devices, such as the cannula and simple and partial rebreathing masks, is 6 to 15 L/min, which is less than the patient's flow demands, any inspiratory flow needs of the patient above this flow range decrease the percentage delivered because the patient is inspiring more room air. The actual percentage of O2 delivered by a low-flow device is never known because it fluctuates with the patient's VT, respiratory rate, and inspiratory time. 22) You are suctioning a patient with pink frothy secretions who has a PCWP of 23 mm Hg and a PAP of 20/10 mm Hg. This assessment is consistent with which of the following conditions? A. Pulmonary embolism B. Cardiogenic pulmonary edema C. Pulmonary hemorrhage D. ARDS Correct Answer is B Rationale: The pink frothy secretions indicate pulmonary edema. The pulmonary wedge pressure (PCWP) is elevated, resulting in a backup of fluid in the lungs. Because the edema is the result of a cardiac abnormality, it is cardiogenic pulmonary edema. 23) A patient's chest radiograph reveals moderate pulmonary congestion. Other data are as follows: PCWP 22 mm Hg PAP 40/21 mm Hg Qt 3.5 L/min On the basis of this information, the patient most likely has which of the following? A. Noncardiogenic pulmonary edema B. Pneumothorax C. Cardiogenic pulmonary edema D. Pulmonary embolism Correct Answer is C Rationale: These data reveal an elevation of both the PAP and PCWP, with a reduction in Qt. The radiograph shows excessive lung fluid (pulmonary edema). If wedge pressure increases (as a result of left heart failure) , this causes a backup of blood into the lungs, leading to increased capillary hydrostatic pressure, which causes pulmonary edema. In this case, it is termed cardiogenic pulmonary edema because it resulted from cardiac problems— namely, left heart failure— as evidenced by an increased PCWP. 24) During manual ventilation, minimal resistance is found during compression of the bag, with little rise in the patient's chest. Which of the following should the respiratory therapist do to correct this problem? A. Increase oxygen flow to the bag. B. Inflate the cuff on the patient's ET tube. C. Add a reservoir to the bag. D. Allow a longer time between bag compressions. Correct Answer is B Rationale: If the ET tube cuff is not inflated, gas being compressed from the bag will leak around the cuff, most likely from the patient's mouth. With a leak that large, the bag will not pressurize when compressed and, because little air is entering the patient's lungs, the chest will rise very little. 25) The physician wants a patient with a tracheostomy to be able to talk and still maintain the airway for suctioning. He wants the respiratory therapist's recommendation for the airway that would cause the least amount of airway resistance. Which of the following is the best choice? A. Tracheostomy button B. Uncuffed tracheostomy tube C. Fenestrated tracheostomy tube D. Cuffed tracheostomy tube Correct Answer is A Rationale: A tracheostomy button rests on the anterior wall of the inside of the trachea, not in the lumen of the trachea, for minimal airway resistance. 26) The respiratory therapist is preparing to transport a patient on a 4-L/min nasal cannula from the oncology ward to the radiology department. The E cylinder used for transport contains 1500 psig. How long will the contents last running the cylinder down to 500 psig? A. 52 min B. 1 hour 10 min C. 1 hour 45 min D. 2 hours 10 min Correct Answer is B Rationale: Use the following equation: (Cylinder pressure × 0.28) /flow rate = minutes remaining in the cylinder The “catch” to this question is that the cylinder is not run to empty, but to 500 psig. You must subtract 500 from the tank pressure before multiplying by the E cylinder factor of 0.28: [ (1500 – 500) × 0.28]/4 L/min = 280/4 = 70 min, or 1 h 10 min Note: Although subtraction of 500 psig from the actual cylinder pressure is suggested for the calculation of the time left in a cylinder, unless the question is stated that way on the examination, do not subtract the 500 psig. 27) A patient with severe COPD enters the emergency department in moderate respiratory distress on a 4-L/min nasal cannula. His ABG results are as follows: pH 7.23 PaCO2 85 mm Hg PaO2 48 mm Hg HCO3- 35 mEq/L BE +12 mEq/L The most appropriate recommendation is which of the following? A. Decrease flow to 2 L/min. B. Place the patient on mask CPAP at 4 cm H2O and 60% O2. C. Begin noninvasive positive pressure ventilation. D. Place the patient on a nonrebreathing mask. Correct Answer is C Rationale: Patients with severe COPD have hypercapnia (high PaCO2 levels) , even at their best. The therapist must look at the pH to determine whether an acute hypercapnia is superimposed on the chronic hypercapnia. Normally, the patient's pH level is between 7.30 and 7.35. If the pH is below 7.30, acute respiratory failure should be suspected. Rather than intubating and beginning mechanical ventilation, try noninvasive ventilation first, if given the choice. This often buys more time to treat the underlying factor that has led to the acute failure. If possible, avoid intubation and ventilation in patients with severe COPD because they can be so difficult to wean. If the choice for noninvasive ventilation was not given, mechanical ventilation must be the next choice. It is not appropriate to decrease the liter flow to 2 L/min because the patient's respiratory drive has not been reduced by the current oxygen flow, as evidenced by a PaO2 of 48 mm Hg. If the PaO2 is above 70 mm Hg, reducing the flow is appropriate. 28) The respiratory therapist is calibrating a transcutaneous PO2 monitor before setup on a neonate. The barometric pressure is 747 mm Hg. At room air, the monitor should read: A. 0. B. 75 mm Hg. C. 147 mm Hg. D. 157 mm Hg. Correct Answer is C Rationale: To calculate the partial pressure of O2 in room air, use the following formula: PO2 = (PB -H2O vapor pressure) × 0.21 (747 mm Hg-47 mm Hg) × 0.21 = 147 mm Hg in which PB is barometric pressure. 29) The following data have been collected on a ventilator patient in the assist-control mode: Mode Assist-control Vo2 200 mL/min C (a-v) o2 5 vol% Hb 14 g/dL pH 7.43 PaCO2 37 mm Hg PaO2 85 mm Hg VT 650 mL Rate 10 breaths/min FIO2 0.45 PEEP 6 cm H2O This patient’s QT is which of the following? A. 2 L/min B. 3 L/min C. 4 L/min D. 5.5 L/min Correct Answer is C Rationale: Note this equation: QT = O2 consumption (VO2) /[ (Cao2- Cvo2) × 10] = 200/50 = 4 L/min Note that much of the data listed are not necessary to calculate QT. This is common in an examination. 30) A 24-year-old male patient weighing 65 kg (143 lb) is receiving mechanical ventilation after diagnosis of a drug overdose. His chest radiograph is consistent with pulmonary edema. Pertinent data are as follows: Mode SIMV Rate 15 breaths /min ABGs pH 7.41 PaCO2 38 mm Hg PaO2 49 mm Hg Tidal volume 500 mL FIO2 0.75 HCO3- 26 mEq/L PEEP 8 cm H2O Pressure support 5 cm H2O BE +1 PIP 52 cm H2O Sao2 83% Plateau pressure 41 cm H2O Which of the following changes should the respiratory therapist recommend at this time? 1. Change the mode to pressure control at 35 cm H2O. 2. Increase the FIO2 to 0.85. 3. Increase the PEEP to 12 cm H2O. 4. Increase the rate to 20 breaths/min. A. 1 and 3 only B. 2 and 4 only C. 1, 3, and 4 only D. 2, 3, and 4 only Correct Answer is C Rationale: The patient's ABG results reveal adequate ventilation with hypoxemia on an FIO2 of 0.60 and a PEEP of 8 cm H2O. The pulmonary edema has reduced lung compliance, as evidenced by the elevated plateau pressure (41 cm H2O). This high pressure is damaging to lung tissue and may result in a pneumothorax. The patient must be placed on pressure control ventilation to control the PIP level at 35 cm H2O. This reduces alveolar ventilation, which increases the PaCO2. To counteract hypercapnia, the respiratory rate should be increased. To increase the PaO2, PEEP should be increased because the FIO2 is already 0.75. If FIO2 levels are 0.60 or higher with hypoxemia, the PEEP must be increased. 31) The respiratory therapist is called to a patient's room to check the oxygen setup. The flow to the patient's mask is supplied by an air flow meter running at 15 L/min and an O2 flow meter running at 15 L/min. The delivered oxygen percentage from this device is which of the following? A. 24% B. 35% C. 40% D. 60% Correct Answer is D Rationale: A liter flow of 15 L/min of oxygen and 15 L/min of air represents an air-to-O2 ratio of 1:1, which results in an oxygen percentage of 60%. 32) A 34-year-old patient with pneumonia who is on a 2-L/min nasal cannula becomes slightly cyanotic when in the Trendelenburg position during chest physical therapy. Which of the following is the most appropriate recommendation in this situation? A. Discontinue the treatment and administer IPPB. B. Continue the treatment as ordered, with no modifications. C. Increase the O2 flow on the patient's cannula to 5 L/min during the treatment. D. Place the patient on CPAP for the remainder of the treatment. Correct Answer is C Rationale: It is not unusual for the patient with pulmonary problems to become cyanotic while in a head-down position. To help alleviate the hypoxia, increase the O2 liter flow for the duration of the treatment. The flow should be returned to the original flow after the treatment if the patient is no longer cyanotic or in any respiratory distress. 33) A chest radiograph film of a spontaneously breathing neonate in a 60% O2 hood reveals right upper and middle lobe atelectasis. Arterial blood gases are as follows: pH 7.36 PaCO2 39 mm Hg PaO2 38 mm Hg HCO3- 22 mEq/L BE -2 mEq/L To increase this infant's PaO2, the respiratory therapist should recommend a change to which of the following devices? A. O2 tent B. High-frequency oscillation C. Nasal CPAP D. Mechanical ventilator Correct Answer is C Rationale: This neonate is ventilating well (no need for mechanical ventilation or high-frequency oscillation) but is hypoxemic on 60% O2. Never increase the FIO2 over 60% in a case such as this. CPAP is indicated to decrease atelectasis and improve the PaO2. This can be accomplished using nasal CPAP or more commonly, a nasal cannula. 34) These data were obtained from a 70-kg (154-lb) patient on volume-controlled ventilation in the assist-control mode: Mode Assist-control FIO2 0.70 Rate 12 breaths/min VT 550 mL PEEP 8 cm H2O ABGs pH 7.42 PaCO2 43 mm Hg PaO2 172 mm Hg HCO3- 23 mEq/L BE -2 mEq/L On the basis of this information, the respiratory therapist should recommend which of the following? A. Decrease FIO2 to 0.60. B. Increase VT to 700 mL. C. Decrease rate to 8 breaths/min. D. Decrease PEEP to 4 cm H2O. Correct Answer is A Rationale: The patient's PaO2 needs to be reduced; this is best accomplished by decreasing the FIO2 (because it is above 0.60) first. Once the FIO2 is decreased to 0.60, the PEEP level can be reduced, unless the patient has ARDS, then reducing the FIO2 would be more appropriate because maintaining PEEP is advantageous for patients with ARDS. 35) A 40% aerosol mask being analyzed with a polarographic O2 analyzer reads 75%. Which of the following is the appropriate action? A. Decrease the flow to the nebulizer. B. Replace the O2 flowmeter. C. Add H2O to the nebulizer. D. Drain the H2O out of the aerosol tubing. Correct Answer is D Rationale: When H2O builds up in the aerosol tubing, resistance to gas flow occurs and results in back pressure into the nebulizer reservoir. This higher pressure in the nebulizer causes less room air to be entrained; therefore, the concentration of delivered O2 is higher. 36) A patient on a 60% aerosol mask has the following ABG values: pH 7.47 PaCO2 34 mm Hg PaO2 58 mm Hg HCO3- 24 mEq/L BE +1 mEq/L Which of the following is the most appropriate recommendation at this time? A. Change to a nonrebreathing mask. B. Place the patient on CPAP. C. Increase O2 to 70%. D. Decrease the liter flow to the mask. Correct Answer is B Rationale: With the patient already on 60% O2 and still hypoxemic, the most appropriate choice is to place the patient on CPAP, not increase the O2 to 70%. The patient has refractory hypoxemia and intrapulmonary shunting, whereby the PaO2 will only increase marginally with increases in FIO2. Positive pressure is necessary to increase mean airway pressure to increase the PaO2. An FIO2 of more than 0.50 to 0.60 mL should be avoided because exceeding these levels increases the possibility of oxygen toxicity. 37) The following ventilatory parameters have been measured on a 65-kg (143-lb) patient who is receiving O2 on a 2-L/min nasal cannula: VT 550 mL Respiratory rate 15 breaths/min This patient's alveolar minute volume is which of the following? A. 4.3 L B. 6.1 L C. 7.3 L D. 8.3 L Correct Answer is B Rationale: Alveolar ventilation is calculated as follows: Alveolar ventilation = (VT-VD) × RR In which VD is dead space and RR is respiratory rate. Note: VD = 1 mL/lb of body weight. Change the VT from milliliters to liters by dividing by 1000. (0.550 -0.143) × 15 = 0.407 × 15 = 6.1 L 38) The respiratory therapist has been asked to recommend an O2 delivery device that has the capability of delivering 40% O2 at a flow rate high enough to meet the patient's 40-L/min inspiratory flow demand. Which of the following devices would meet this demand? 1. Air entrainment mask 2. Nasal cannula 3. Simple O2 mask 4. Aerosol mask A. 1 and 3 only B. 1 and 4 only C. 1, 2, and 3 only D. 2, 3, and 4 only Correct Answer is B Rationale: No low-flow device can deliver 40 L/min of flow, so the choice to meet this high flow rate must be a high-flow device. The air entrainment mask and aerosol mask are both considered high-flow masks. 39) During a routine ventilator check, the high-pressure alarm begins to sound. The respiratory therapist should do which of the following to determine why the alarm is sounding? A. Check to see whether the patient has become disconnected from the ventilator. B. Ensure that the expiratory drive line is properly connected. C. Listen to the patient's breath sounds to determine whether the patient needs to be suctioned. D. Increase the high-pressure limit. Correct Answer is C Rationale: Secretions in the airway increase airway resistance, resulting in higher peak inspiratory pressures. Increasing the pressure limit does not correct the increased airway resistance. The first two choices would result in the low-pressure and low-volume alarms being triggered. 40) The respiratory therapist is assessing a ventilator-dependent patient's ability to be weaned. The weaning protocol states that the patient can be weaned when the patient's spontaneous tidal volume is at least 3 mL/lb of the patient's ideal body weight, which is 60 kg (132 lb). The therapist measures the patient's spontaneous minute ventilation (VE) to be 8 L/min and the respiratory rate to be 20 breaths/min. What is the most appropriate recommendation? A. Proceed with weaning. B. Consult with the physician. C. Notify the supervisor. D. Maintain the current ventilator settings. Correct Answer is A Rationale: For weaning to be initiated, the patient's VT needs to be at least 3 mL/lb of the ideal body weight. In other words, the VT must be at least three times his weight. The patient weighs 132 lb; therefore, his spontaneous VT must be at least 396 mL for weaning to be appropriate. His measured minute ventilation (VE) is 8 L/min with a respiratory rate of 20 breaths/min. To determine his VT, VE must be divided by rate: 8/20 = 0.4 L (400 mL) This indicates that initiating weaning is appropriate. 41) While manually ventilating an intubated apneic patient with a manual resuscitator, very little resistance is found when the bag is compressed, and the patient's chest rises only minimally. Which of the following may be the cause of this problem? A. Excessive ET tube cuff pressure B. Exhalation valve jammed in the closed position C. Patient's lungs are noncompliant D. Leak through the bag intake valve Correct Answer is D Rationale: Three possible causes are a leak through the exhalation valve, bag intake valve, or around the ET tube or tracheostomy tube cuff. 42) The following PFT values have been obtained on a 55-year-old male patient: Parameter Actual Predicted %Predicted FEV1 1.4 L 3.0 L 47% FEV1/FVC 48% 70% — VC 2.1 L 3.8 L 55% TLC 6.4 L 4.8 L 133% FRC 3.4 L 2.5 L 136% Which of the following pulmonary disorders is consistent with these findings? A. Pulmonary fibrosis B. Pneumonia C. Atelectasis D. Emphysema Correct Answer is D Rationale: Patients with emphysema have significant air trapping in the severe stages of the disease. Air trapping results in more air left in the lungs after exhalation, as evidenced by elevated FRC, RV, and TLC pulmonary function values. Because of the premature collapse of the upper airways, expiratory flows will be decreased, such as the FEV1 and FEV1/FVC. An examination tip: Note that of the four choices given, three are restrictive conditions and one is an obstructive condition. A pulmonary function test can determine whether a restrictive or obstructive condition is present, but of the tests given in this question, even if a restrictive condition were present, you would not be able to determine which one was causing the restriction. Therefore, the answer has to be the single obstructive choice, emphysema. 43) The respiratory therapist has been administering PEP therapy at 10 cm H2O to a patient with cystic fibrosis. Secretion clearance has not improved. Which of the following should the therapist recommend at this time? A. Discontinue the therapy. B. Decrease the PEP level to 5 cm H2O. C. Increase the PEP level to 15 cm H2O. D. Increase the PEP level to 25 cm H2O. Correct Answer is C Rationale: Normal PEP levels for treatment of retained secretions are 10 to 20 cm H2O. If secretion removal is not improving, the PEP level should be increased, generally in 5-cm H2O increments. 44) The purpose of adding PEEP to a patient on a ventilator is to increase which of the following? 1. FRC 2. P (A-a) o2 3. Lung compliance A. 1 only B. 3 only C. 1 and 3 only D. 1, 2, and 3 Correct Answer is C Rationale: PEEP increases FRC by opening up alveoli, which in turn increases CL. By recruiting more alveoli for gas exchange to occur, the PaO2 will increase, which decreases the P (a- a) o2. 45) Which of the following are common findings for patients with acute respiratory distress syndrome (ARDS) ? 1. Decreased V/Q mismatch 2. Decreased lung compliance 3. PaO2/FIO2< 150 4. Normal PCWP A. 1 and 2 only B. 2 and 3 only C. 1, 2, and 4 only D. 2, 3, and 4 only Correct Answer is D Rationale: Characteristic features of ARDS are stiff noncompliant lungs and severe hypoxemia (decreased PaO2/FIO2 ratio). Heart function is generally normal, although pulmonary edema may be present. The edema results from damage to the alveolar capillary membrane, resulting in leakage of fluid into the lungs and an increased V/Q mismatch. This is referred to as noncardiogenic pulmonary edema or pulmonary edema that results from some condition other than left heart failure. Therefore, the pulmonary capillary wedge pressure (PCWP) is normal. 46) A ventilator patient's cardiac index decreases from 3.5 to 2.2 L/min/m2. This may occur in which of the following situations? A. Decreased vascular resistance B. Hypervolemia C. Excessive level of PEEP D. Dopamine administration Correct Answer is C Rationale: Cardiac index is determined by dividing the patient's cardiac output by body surface area. It is simply a reflection of the patient's cardiac output. A decreasing cardiac index indicates that the cardiac output has decreased. Applying an excessive amount of PEEP to the airway results in compression of the superior and inferior venae cavae, restricting venous blood return back to the heart. With less blood flow returning to the right side of the heart, less blood is pumped to the left side of the heart and out to the body, resulting in decreased cardiac output. 47) A patient on volume-controlled ventilation has the following ABG results: pH 7.24 PaCO2 23 mm Hg PaO2 80 mm Hg HCO3- 10 mEq/L BE -13 mEq/L Which of the following ventilator changes do you recommend? A. Decrease the VT. B. Increase the ventilator rate. C. Decrease the ventilator rate. D. No ventilator changes are necessary. Correct Answer is D Rationale: These ABG levels indicate metabolic acidosis, which may be corrected with administration of NaHCO3-. The patient's PaCO2 is low because the lungs compensate for the metabolic problem. Once the HCO3- level is increased, the pH will increase, and the patient's hyperventilation will subside. 48) A “damped” pressure tracing on an arterial line may be caused by which of the following? 1. The catheter tip resting against the wall of the vessel 2. A clot occluding the catheter 3. A clot in the transducer 4. Air bubbles in the line A. 1 and 2 only B. 2 and 3 only C. 1, 2, and 4 only D. 1, 2, 3, and 4 Correct Answer is D Rationale: A damped waveform renders inaccurate arterial pressure readings. The catheter must be completely patent for it to read accurately. 49) A 4-year-old child with croup and inspiratory stridor is admitted to the pediatric department. The respiratory therapist recommends cool mist to be delivered to the airway to do which of the following? A. Reduce the potential of bronchospasm. B. Aid in the mobilization of thick tenacious secretions. C. Prevent laryngospasm. D. Reduce upper airway swelling. Correct Answer is D Rationale: Inspiratory stridor is caused by swelling of the subglottic area, which is common in croup. Cool mist to the upper airway causes vasoconstriction and results in a decrease in swelling. 50) The respiratory therapist should recommend a lateral neck radiograph film to help diagnose which of the following conditions? A. Epiglottitis B. Pneumothorax C. Pleural effusion D. Bronchiectasis Correct Answer is A Rationale: Epiglottitis may be confirmed with a lateral neck radiograph film that shows a broadening and flattened epiglottis (thumb sign) , thickening of the arytenoepiglottic folds, and ballooning of the hypopharynx. 51) A pulse oximeter may not read accurately in which of the following situations? 1. Increased perfusion 2. Presence of HbCO 3. Hypotension A. 1 only B. 1 and 2 only C. 2 and 3 only D. 1, 2, and 3 Correct Answer is C Rationale: If blood pressure is low, causing reduced perfusion to the site of the pulse oximeter probe, the reading may not be accurate, which is why oximeters should not be used during resuscitation efforts. The oximeter cannot distinguish which element is bound to hemoglobin (Hb) ; it only indicates that some substance is occupying the binding site. A patient may have a high HbCO level, indicating that a high percentage of the CO is bound to Hb, when the oximeter is reading 100%. For this reason, a pulse oximeter should never be used on a patient who may have been exposed to smoke inhalation or CO. 52) Which of the following devices is most likely to deliver contaminated particles to the patient's airway? A. Bubble humidifier B. Heated jet nebulizer C. Heated cascade humidifier D. Passover humidifier Correct Answer is B Rationale: Although both the heated humidifier and nebulizer are more prone to grow bacteria than unheated devices, a nebulizer has a greater potential for delivery of the organisms to the patient. This is because the aerosolized particles are approximately the same size as the bacteria and can carry the bacteria more easily than the microscopic particles produced by a humidifier. 53) The following data are obtained from a patient on a ventilator: PEEP Level (cm Peak Inspiratory Pressure (cm Plateau Pressure (cm VT H2O) H2O) H2O) (mL) 6 35 18 700 8 38 20 700 10 42 23 700 12 45 26 700 The optimal PEEP level is which of the following? A. 6 cm H2O B. 8 cm H2O C. 10 cm H2O D. 12 cm H2O Correct Answer is B Rationale: Optimal PEEP is the level of PEEP that gives the best static compliance (CL) without decreasing cardiac output (QT). QT is not an issue in this question, so you must decide the best static compliance. Calculation of the compliance at all four PEEP levels is not necessary. Simply subtract the PEEP level for its corresponding plateau pressure; the lowest number obtained results in the highest compliance when divided into the 700-mL VT. Choices a and b have a difference of 12 cm H2O. The difference for choice c is 13 cm H2O, which indicates that compliance has decreased. Return to the PEEP level right before the compliance decreases; this is the optimal PEEP level. In this problem, that is choice b, 8 cm H2O. 54) A patient's PaCO2 decreases from 42 to 31 mm Hg. All the following could have increased except which of the following? A. Physiologic VD B. VT C. Minute ventilation D. Respiratory rate Correct Answer is A Rationale: Increasing VT, respiratory rate, or minute ventilation results in improved ventilation and therefore, decreasing PaCO2 levels. When physiologic VD increases, PaCO2 increases, indicating that less of the patient's VT is reaching the alveoli and taking part in gas exchange. 55) Pulmozyme is most commonly used to treat patients with which of the following lung disorders? 1. Emphysema 2. Bronchiectasis 3. Cystic fibrosis A. 2 only B. 3 only C. 1 and 2 only D. 2 and 3 only Correct Answer is D Rationale: Pulmozyme is a mucoactive agent that works by breaking down the DNA of sputum, thereby reducing its viscosity. It is indicated for patients who produce thick tenacious secretions, which are commonly seen with patients who have bronchiectasis and cystic fibrosis. 56) After increasing a patient's PEEP level from 8 to 12 cm H2O, the partial oxygen pressure in mixed venous blood (Pvo2) drops 6 mm Hg. The respiratory therapist should suspect that which of the following has occurred? A. Lung compliance has increased. B. Cardiac output has decreased. C. Arterial-venous content difference has decreased. D. Venous return to the heart has increased. Correct Answer is B Rationale: A decrease in Pvo2 after an increase in the PEEP level is an indication of decreased cardiac output. As PEEP levels increase, intrathoracic pressure increases, which places pressure on the blood vessels returning blood to the heart (superior and inferior venae cavae). This decreases venous return, which decreases cardiac output, causing a drop in mixed venous partial pressure of oxygen (PO2). Pvo2 is a measure of the partial pressure of O2 in the pulmonary artery using a pulmonary artery catheter. As cardiac output decreases, less blood is made available to the tissues, but the tissues continue to extract O2 from the blood at the same rate. By the time the blood reaches the pulmonary artery (the end of the venous circuit) , less O2 is present, which results in a decreased Pvo2. 57) A 34-year-old patient with Guillain-Barré syndrome has had progressive respiratory distress for the past 6 hours. He is presently on a 2-L/min nasal cannula. The MIP has changed from -45 to -23 cm H2O. The following data have been recorded: Respiratory rate 36 breaths/min Pulse 104 beats/min pH 7.35 PaCO2 44 mm Hg PaO2 72 mm Hg HCO3- 26 mEq/L BE +1 mEq/L On the basis of these data, the respiratory therapist should recommend which of the following? A. Place the patient on a nonrebreathing mask at 12 L/min. B. Intubate the patient and institute mechanical ventilation. C. Place the patient on a CPAP mask. D. Increase O2 flow to 6 L/min. Correct Answer is B Rationale: Although this action may seem to be a drastic measure, especially with “normal” ABG levels, it is appropriate at this time. This patient's PaCO2 may be normal, but he has doubled or tripled his normal respiratory rate to maintain a normal PaCO2. This is an example of impending ventilatory failure. The patient's respiratory muscle strength has diminished over the past 6 hours and, with this condition (Guillain-Barré syndrome) , his ventilatory status will also continue to worsen, in addition to not being able to protect the airway. Intubation and ventilation now are better than waiting until the patient goes into full respiratory failure or arrest. 58) The inspiratory-to-expiratory (I:E) ratio alarm is sounding on a patient being ventilated in volume-controlled ventilation. Which of the following ventilator adjustments can correct this problem? A. Increase the flow. B. Increase the VT. C. Decrease the flow. D. Add an inspiratory pause. Correct Answer is A Rationale: The I:E ratio alarm signifies that the inspiratory time is longer than expiratory time. Inverse ratios are used to improve oxygenation on neonates and adults with acute respiratory distress syndrome (ARDS). In many cases, however, the ratio is not advantageous and should be corrected. Increasing flow gets the VT to the patient faster and, in volume-controlled ventilation, inspiration ends once the volume is delivered. Thus, the inspiratory time is shorter, correcting the inverse I:E ratio. 59) A patient with a suspected drug overdose is receiving volume-controlled ventilation on the following settings: Rate 15 breaths/min Mode Assist-control Tidal volume 700 mL Inspiratory flow 30 L/min Pressure limit 40 cm H2O The I:E ratio alarm is triggered. Which ventilator adjustment should the respiratory therapist make at this time? A. Increase the pressure limit. B. Increase the tidal volume. C. Increase the inspiratory flow. D. Increase the rate. Correct Answer is C Rationale: When inspiratory time exceeds expiratory time, an inverse I:E exists. Sometimes use of this ratio is indicated, such as with patients with ARDS, when high FIO2 levels and PEEP levels are not correcting hypoxemia. In this question, an alarm is sounding to alert the therapist about a problem with the ventilator settings. Inspiration is longer than expiration. This can be corrected to a 1:2 or 1:3 ratio during volume-controlled ventilation by decreasing the tidal volume or decreasing the respiratory rate. Decreasing the tidal volume decreases the inspiratory time, and decreasing the respiratory rate provides a longer expiratory time. However, both these parameters decrease the minute ventilation, which may result in an increased PaCO2 level. The most appropriate parameter change is to increase the inspiratory flowrate. Note that in this question, the ventilator flow is set at only 30 L/min, which is too low. It should be set at a minimum of 40 to 60 L/min. A flow setting that is too low increases the inspiratory time and may result in a longer inspiratory time than expiratory time. 60) The respiratory therapist notes the following data while reviewing the patient's chart: Dynamic compliance 48 mL/cm H2O Static compliance 30 mL/cm H2O The therapist should conclude which of the following? A. Airway resistance is 18 cm H2O/L/s. B. A pneumothorax has likely developed. C. The data are erroneous. D. The patient has severe restrictive disease. Correct Answer is C Rationale: Dynamic compliance can never be higher than static compliance, based on the calculations. In the calculation of static compliance, plateau pressure is divided into the tidal volume, as opposed to the use of peak pressure in the calculation of dynamic compliance. Because static or plateau pressure is always lower than peak pressure, dividing it into the tidal volume always results in a higher number. 61) A drug overdose patient is being transferred to the ICU. The patient weighs 60 kg (132 lb) and is being manually ventilated with 100% O2. Which of the following represents the most appropriate ventilator settings? A. Mode = assist-control; tidal volume = 600 mL; rate = 6 breaths/min; FIO2 = 1.0 B. Mode = control; tidal volume = 500 mL; rate = 12 breaths/min; FIO2 = 0.60 C. Mode = assist-control; tidal volume = 650 mL; rate = 16 breaths/min; FIO2 = 0.8 D. Mode = SIMV; tidal volume = 400 mL; rate = 12 breaths/min; FIO 2 = 1.0 Correct Answer is D Rationale: First, set the patient on the FIO2 setting that was used before placement on the ventilator. In this question, rule out any choice that isn't 100% oxygen. Then select a VT of 6 to 8 mL/kg of ideal body weight and a ventilator rate of 10 to 16 breaths/min. These guidelines for initial ventilator settings are most consistent for the NBRC examinations. 62) The following data are from an infant with hyaline membrane disease on pressure control ventilation: Mode SIMV Ventilator rate 45 breaths/min PIP 25 cm H2O PEEP 6 cm H2O FIO2 0.50 ABGs pH 7.27 PaCO2 56 mm Hg PaO2 53 mm Hg HCO3- 22 mEq/L BE – 2 mEq/L On the basis of these data, which of the following ventilator setting changes do you recommend? A. Increase the FIO2 to 0.60. B. Increase the PIP to 30 cm H2O. C. Decrease the PEEP to 5 cm H2O. D. Decrease the ventilator rate to 40 breaths/min. Correct Answer is B Rationale: A PaCO2 of 56 mm Hg indicates that the infant is not ventilating adequately. By increasing the PIP, alveolar ventilation should increase, resulting in a decrease in the PaCO2 level. 63) Shortly after PEEP is increased from 8 to 12 cm H2O, the patient becomes restless and agitated. Auscultation of breath sounds reveals diminished breath sounds on the right side, and chest inspection reveals the trachea shifted to the left of midline. These abnormal findings are most likely the result of which of the following? A. Atelectasis of the right lung B. Left-sided pneumothorax C. Right-sided tension pneumothorax D. Consolidation of the right lung Correct Answer is C Rationale: Pneumothorax is a potential complication of PEEP. Because the patient's condition changed after PEEP was increased, note which symptoms are consistent. Diminished breath sounds on the right, with tracheal deviation to the left, along with restlessness and agitation, all point to a tension pneumothorax. 64) During O2 rounds, the respiratory therapist notices that the bed sheet is pulled over the entrainment port of a patient's air entrainment mask. Which of the following are true statements regarding this situation? 1. The FIO2 will decrease. 2. The total flow will decrease. 3. The FIO2 will increase. 4. The O2 flow will increase. A. 1 and 2 only B. 2 and 3 only C. 2 and 4 only D. 3 and 4 only Correct Answer is B Rationale: If the entrainment port is occluded, less room air can be entrained to mix with the O 2; therefore, FIO2 increases. Because room air entrainment decreases, the total overall flow also decreases. 65) After a patient is intubated, the CO2 detector on the proximal end of the ET tube reads 2%. Which of the following should the respiratory therapist do at this time? A. Leave the tube at this position. B. Withdraw the tube completely and attempt intubation again. C. Withdraw the tube 2 cm. D. Advance the tube 2 cm. Correct Answer is B Rationale: Exhaled air contains approximately 5% to 6% CO2. If the ET tube is in the trachea or anywhere in the airway, CO2 is in the exhaled air passing through the detector, which shows a reading of 5% to 6%. If the tube is in the esophagus, the reading is less than 5%. One exception to this is when a patient is in full cardiac arrest and the exchange of gases is greatly diminished. In this case, even if the ET tube is in the trachea, the CO2 detector may read zero. 66) To decrease the incidence of damage to the tracheal wall by the ET tube cuff, which of the following should be recommended? A. Never instill more than 5 mL of air into the cuff. B. Use a low-volume, high-pressure cuff. C. Deflate the cuff every 2 hours for 5 minutes. D. Use the minimal leak technique. Correct Answer is D Rationale: The minimal leak technique is performed by instilling air into the ET tube cuff while listening with a stethoscope over the larynx. The cuff is filled during inspiration until no leak is heard (minimal occlusive volume) and then air is withdrawn until a slight leak is heard (minimal leak). This ensures that adequate pressure is in the cuff to seal the airway from major leaks but that minimal pressure is on the trachea during exhalation. 67) A patient is on a 30% air entrainment mask running at 5 L/min. What is the total flow that the patient is receiving from this device? A. 40 L/min B. 45 L/min C. 55 L/min D. 64 L/min Correct Answer is B Rationale: With the tic-tac-toe box or the equation, you should be subtracting 21 from 30 (to get 9) and 30 from 100 (to get 70) and dividing 70 by 9. This gives an air-to-O2 ratio of about 8:1. To calculate total flow, add the two ratio parts together (8 + 1 = 9) and multiply by the flow rate (9 × 5 = 45 L/min). 68) A patient has just arrived in the emergency department after being pulled from a burning house. Which of the following values best determine this patient's oxygenation status? A. Sao2 B. PaO2 C. Hb D. CaO2 Correct Answer is D Rationale: Arterial O2 content (CaO2) takes into account both O2 dissolved in the plasma and that which is bound to Hb. This value gives us a much better picture of the oxygenation status than observing only one value. Arterial O2 content is the total amount of O2 bound to Hbplus the amount of O2 dissolved in the plasma: O2 bound to Hb = 1.34 × Hb × Sao2 O2 dissolved in plasma = 0.003 × PaO2 Note: Use the fractional concentration of the Sao2. Example: For Sao2 of 97%, use 0.97 in the equation. 69) A 57-year-old patient with severe COPD enters the emergency department with shortness of breath. Room air ABG levels are as follows: pH 7.44 PaCO2 49 mm Hg PaO2 47 mm Hg HCO3- 37 mEq/L BE +12 mEq/L On the basis of this information, which of the following is the most appropriate O2 therapy? A. Nonrebreathing mask at 15 L/min B. 40% air entrainment mask C. Nasal cannula at 2 L/min D. 28% air entrainment mask Correct Answer is D Rationale: A high-flow O2 device such as an air entrainment mask should be used if the patient's RR is above 25 breaths/min because it will deliver more consistent O2 concentrations to the patient than a low-flow device (e. g., cannula). Although the RR is not given in this question, you should assume it is high because ABG levels reveal that this patient is hyperventilating. A patient with severe COPD normally has a PaCO2 in the range of 50 to 60 mm Hg, or even much higher in some cases, with a pH range of 7.30 to 7.40. We know that this patient's PaCO2 must be quite high because the HCO3– is so high (37 mEq/L) , compensating for the respiratory acidosis. It may seem strange to see a PaCO 2 above the normal range (35 to 45 mm Hg) and yet call it hyperventilation. Normally, we would interpret this PaCO2 as hypoventilation, but this patient has a different set of “normal” ABG levels. Because the patient has a high PaCO2 whenever he hyperventilates, the PaCO2 is higher than normal for patients without severe COPD. This patient is hyperventilating in response to a lower level of hypoxemia than he normally has, which generally is in the range of 50 to 65 mm Hg. 70) Which of the following equipment cleaning techniques or chemicals have the ability to kill spores? 1. Pasteurization 2. Glutaraldehyde 3. Ethylene oxide 4. Acetic acid A. 1 and 2 only B. 2 and 3 only C. 3 and 4 only D. 2, 3, and 4 only Correct Answer is B Rationale: Both glutaraldehyde solutions and ethylene oxide are sporicidal. However, the glutaraldehydes (e. g., Cidex) are generally used as disinfectants. Disinfection takes only 10 to 15 minutes; the agents are sporicidal in 3 to 10 hours. 71) A 24-year-old woman with diabetes has the following ABG results: pH 7.18 PaCO2 18 mm Hg PaO2 78 mm Hg HCO3- 10 mEq/L BE – 15 mEq/L You interpret these ABG values which of the following? A. Partially compensated metabolic acidosis B. Compensated respiratory alkalosis C. Partially compensated respiratory acidosis D. Uncompensated metabolic acidosis Correct Answer is A Rationale: This ABG result is commonly observed in patients with diabetic ketoacidosis (DKA). The values show an acidic pH, which is caused by an elevated PaCO2 or decreased HCO3- level. In this case, the PaCO2 is low, so the HCO3- has to be causing the acidosis. As you observe the HCO3-, you note that it is low. This level indicates metabolic acidosis, which is considered partially compensated because the patient is hyperventilating, as evidenced by the decreased PaCO2. Hyperventilation is increasing the pH, but because the pH is not back to the normal range (7.35 to 7.45) , it is considered partially compensated. Once the pH returns to normal through compensation, it is referred to as being fully compensated. 72) The exhaled VT monitor in volume ventilation reads 550 mL. The VT control is set at 800 mL. To determine whether the problem is caused by an inaccurate VT control, the respiratory therapist should measure the volume at which of the following? A. Patient connection B. Ventilator outlet C. Exhalation valve D. Humidifier outlet Correct Answer is B Rationale: To determine how much volume is being delivered by the ventilator most accurately, place the respirometer as close to the ventilator as possible, which is at the ventilator outlet. Placement downstream is not as accurate because if a leak is present anywhere in the circuit, an inaccurate volume reading is given. 73) Which of the following is measured when incentive spirometry is administered properly? A. ERV B. Sustained IC C. Sustained VT D. FVC Correct Answer is B Rationale: The patient should be instructed to take the deepest breath possible from a resting expiratory level. Inspiration should be slow, with a 2- to 3-second breath hold at peak inspiration, followed by a normal exhalation. 74) The following data are collected from a patient on volume-controlled ventilation: Time PIP Plateau Pressure VT 0800 29 cm H2O 13 cm H2O 800 mL 0900 36 cm H2O 13 cm H2O 800 mL 1000 40 cm H2O 13 cm H2O 800 mL 1100 42 cm H2O 13 cm H2O 800 mL On the basis of these data, you conclude that: A. Static lung compliance is decreasing. B. Airway resistance is decreasing. C. Dynamic lung compliance is increasing. D. Airway resistance is increasing. Correct Answer is D Rationale: The data in this question show a stable plateau pressure with increasing peak pressures over 3 hours on a ventilator VT of 800 mL. Because plateau pressure is used to determine static compliance, and it is unchanged, then static compliance is unchanged. Peak pressure is used to calculate dynamic compliance, which is a measurement of airway resistance. As peak pressures increase, dynamic compliance decreases, which means airway resistance (Raw) is increased. Raw increases as a result of H2O in the ventilator tubing, secretions in the airway, bronchospasm, or mucosal edema. To help decrease Raw, determine the cause and treat it. For example, you can drain H2O from tubing, suction the patient, or recommend administration of a bronchodilator or a corticosteroid (for mucosal edema). 75) A transcutaneous PO2 (TcPO2) probe is attached to a neonate's left leg and reads 41 mm Hg; another TcPO2 probe is attached to the right arm and reads 62 mm Hg. Which of the following is most likely causing this discrepancy? A. A loose probe on the leg B. Presence of a pneumothorax C. Presence of a patent ductus arteriosus (PDA) D. Inadequate perfusion to the upper extremities Correct Answer is C Rationale: The PDA is a communication between the pulmonary artery and descending aorta. Blood that passes through the ductus totally bypasses the lungs and enters the descending aorta, which directs blood to the lower part of the body. By placing a TcPO2 monitor on the right arm (preductal blood) and one on the lower extremities or abdomen (postductal) , the difference between the two can be monitored. If there is a significant right-to-left shunt through the PDA, there is a difference between preductal and postductal PaO2 of more than 10 mm Hg. An ultrasound scan can positively confirm the condition because the ductus is visible between the aorta and pulmonary artery. 76) The following ABG results have been collected on a 52-year-old man with a pulmonary embolism. The patient was not receiving O2 when the sample was drawn. pH 7.55 PaCO2 28 mm Hg PaO2 142 mm Hg Which of the following should the respiratory therapist recommend at this time? A. Intubate the patient and institute mechanical ventilation. B. Place the patient on a 40% CPAP mask at 5 cm H2O. C. Redraw the ABG sample because this result suggests air in the sample. D. Place the patient on a nonrebreathing mask. Correct Answer is C Rationale: A general rule of thumb is that when on room air, the sum total of the PaO 2 and PaCO2 cannot exceed 140 mm Hg. In this question, the total of the values is 170 mm Hg and therefore must not be accurate. We expect a patient with suspected pulmonary embolism to be hyperventilating in response to hypoxemia, but we do not expect a PaO 2 at this level on room air. It fact, it would be impossible. 77) These data pertain to a sedated, paralyzed patient on volume-controlled ventilation in the assist- control mode: Mode Assist-control VT 750 mL Rate 12 breaths/min Flow 50 L/min FIO2 0.50 ABGs pH 7.52 PaCO2 27 mm Hg PaO2 98 mm Hg HCO3- 26 mEq/L BE +2 mEq/L On the basis of this information, which of the following changes could be made to correct this alkalosis? 1. Decrease the VT. 2. Increase the flow rate. 3. Decrease the ventilator rate. 4. Increase the FIO2. A. 1 and 2 only B. 1 and 3 only C. 3 and 4 only D. 1, 3, and 4 only Correct Answer is B Rationale: These ABG values indicate respiratory alkalosis (hyperventilation) , with adequate oxygenation. To increase the PaCO2 toward normal levels, minute ventilation needs to be decreased. This is accomplished by decreasing the ventilator rate or VT. 78) A premature infant on pressure control ventilation has a PaCO2 of 28 mm Hg. Which of the following ventilator settings should be decreased to correct the hypocapnia? A. FIO2 B. Tidal volume C. PEEP D. Inspiratory pressure Correct Answer is D Rationale: To increase the PaCO2 level with pressure control ventilation, the ventilator rate or PIP can be decreased. Decreasing the rate or PIP reduces minute ventilation, raising the PaCO 2. 79) A patient with asthma is being discharged from the hospital. Which of the following medications should be recommended to help prevent further attacks? A. Theophylline (Aminophylline) B. Albuterol (Ventolin) C. Ipratroprium bromide (Atrovent) D. Montelukast (Singulair) Correct Answer is D Rationale: Leukotrienes occur naturally in leukocytes and produce allergic and inflammatory responses, such as bronchoconstriction and mucosal swelling. Montelukast is a leukotriene modifier that blocks the response and controls asthma attacks. 80) A patient has shortness of breath on a 60% aerosol mask. The following data are obtained: Pulse 112 beats/min Respiratory rate 34 breaths/min ABGs pH 7.27 PaCO2 53 mm Hg PaO2 68 mm Hg On the basis of this information, which of the following should be recommended at this time? A. Place the patient on CPAP and 60% O2. B. Intubate the patient and institute mechanical ventilation. C. Increase levels to 70% O2. D. Place the patient on a nonrebreathing mask. Correct Answer is B Rationale: These ABG levels reveal acute respiratory acidosis, also referred to as acute ventilatory failure, which is evidenced by the elevated PaCO2 value. It must be treated by increasing alveolar ventilation with mechanical ventilation. 81) The following data are collected from a patient on volume-controlled ventilation: Mode Assist-control Ventilator rate 10 breaths/min VT 800 mL Peak inspiratory pressure 45 cm H2O Plateau pressure 25 cm H2O PEEP 5 cm H2O On the basis of these data, this patient's static lung compliance is which of the following? A. 18 mL/cm H2O B. 20 mL/cm H2O C. 32 mL/cm H2O D. 40 mL/cm H2O Correct Answer is D Rationale: Static compliance is calculated with the following formula: VT/ (plateau pressure -PEEP) = 800 mL/20 cm H2O = 40 mL/cm H2O You may notice that the three wrong choices have answers that you get when the problem is worked incorrectly. The NBRC uses answers that fit the most frequent mistakes on problems such as this one. If you forget to subtract PEEP, an answer correlates with it. If you use peak pressure instead of plateau pressure, one of the choices fits. Be sure to check your work before moving to the next question. You may think that you answered the question correctly because a choice matched the answer you just calculated, but that does not always mean that you chose the correct answer. 82) An order is received to set up a 60% aerosol mask on a patient. The respiratory therapist sets the flow meter at 8 L/min. One hour later, the therapist monitors the patient's response to the therapy, and the data are as follows: Respiratory rate (RR) 26 breaths/min Heart rate 122 beats/min SpO2 88% On the basis of these data, what is the most appropriate action for the therapist to take? A. Place the patient on CPAP. B. Begin bronchodilator therapy. C. Increase flow to the nebulizer. D. Intubate the patient and institute mechanical ventilation. Correct Answer is C Rationale: The air-to-O2 ratio for 60% is 1:1. If the flow meter is set at 8 L/min, then the total flow to the patient is only 16 L/min. The flow rate is inadequate to meet the patient's inspiratory flow demands. (Normal inspiratory flow rate is 25 to 30 L/min.) As the patient inhales, he receives all the flow available from the nebulizer but, because it is inadequate, he gets the rest of the inspired air through the exhalation ports from the room. This dilutes the O2 percentage to less than 60%; therefore, the patient is receiving less O2 than prescribed with the hypoxemia not being corrected, which has resulted in tachycardia, tachypnea, and a decreased SpO2 level. 83) A patient on 50% oxygen has a PaO2 of 252 mm Hg. Which of the following should the respiratory therapist recommend? A. Decrease the oxygen to 40%. B. Decrease the oxygen to 30%. C. Discontinue oxygen therapy. D. Repeat the blood gases because the PaO2 value is not possible with this FIO2. Correct Answer is C Rationale: The patient has a PaO2 of 252 mm Hg on 50% oxygen, which represents a normal PaO2 on this oxygen percentage. If the PaO2 is at least five times the percentage of O2, the patient's ability to oxygenate is normal, so supplemental O2 is not necessary and should be discontinued. 84) The respiratory therapist is having difficulty suctioning secretions from an adult patient's tracheostomy tube. The suction regulator is set at -70 mm Hg. Which of the following is the most appropriate action? A. Increase the suction level to-120 mm Hg. B. Use a larger suction catheter. C. Increase the suction level to-150 mm Hg. D. Use a coude-tip suction catheter. The Correct Answer is A Rationale: Normal suction levels for adults are between -80 – and -120 mm Hg, with a maximum pressure of -150 mm Hg. Suctioning at a pressure of -70 mm Hg is inadequate for the removal of secretions. 85) The physician has ordered a 75-kg (165-lb) male patient with pneumonia to be placed on volume- controlled ventilation. Which of the following VT levels and respiratory rates is most appropriate for the initial ventilator settings? A. VT = 600 mL, RR = 10 breaths/min B. VT = 750 mL, RR = 18 breaths/min C. VT = 700 mL, RR = 16 breaths/min D. VT = 950 mL, RR = 6 breaths/min The Correct Answer is A Rationale: The initial ventilator rate should be set at 8 to 12 breaths/min, with a VT of approximately 6 to 8 mL/kg of ideal body weight. 86) Which of the following statements regarding the technique of intubation is false? A. The laryngoscope should be inserted into the right side of the mouth and the tongue pushed to the left. B. One minute is the maximal time allowed for any given intubation attempt. C. The patient should be placed in the “sniff” position. D. The Miller blade directly lifts the epiglottis so that the vocal cords may be visualized. The Correct Answer is B Rationale: The maximal time to perform intubation should be no longer than 15 to 20 seconds. The patient's color, pulse oximetry (SpO2) , and cardiac rhythm should be monitored during the procedure. If any of these worsen, the procedure should be stopped and the patient manually ventilated until he or she is stabilized before intubation is reattempted. 87) The most effective method for determination of ET tube location after intubation is which of the following? A. Auscultation of breath sounds B. Direct visualization during intubation C. Observance on chest radiograph film D. Listening for air flow at the tube outlet The Correct Answer is C Rationale: Be sure to read the question carefully. The most effective method is always to see the tube and not simply hear air flow. If the question states that you have just intubated the patient when it is indicated to determine tube placement immediately, the correct answer is to auscultate breath sounds. 88) While monitoring a patient's chest tube, you notice it is obstructed with a blood clot. The first action that should be taken is to do the following: A. “Milk” the chest tube. B. Clamp off the drainage tube. C. Remove the chest tube. D. Increase the suction pressure. The Correct Answer is A Rationale: By milking the tubing, you are compressing the tubing and releasing it quickly. This produces a pressure buildup, which rapidly decreases, pushing the blood clot on through the tubing. 89) Which of the following indicates that a patient is not ready to be weaned from the ventilator? A. P/F ratio of 275 B. Spontaneous VT of 175 mL C. VD/VT ratio of 0.35 D. VC of 1.75 L The Correct Answer is B Rationale: An adult's spontaneous VT should be at least 250 to 300 mL before weaning is considered. 90) The following data have been collected from a patient on a 50% air entrainment mask: pH 7.41 PaCO2 40 mm Hg PaO2 90 mm Hg HCO3- 25 mEq/L BE +2 mEq/L A. 210 mm Hg B. 300 mm Hg C. 370 mm Hg D. 450 mm Hg The Correct Answer is A Rationale: To calculate P (A-a) o2, alveolar PO2 (PaO2) must first be determined and then arterial PO2 (PaO2) subtracted from it to get the A-a gradient: PaO2 = FIO2 (BP - 47) – PaCO2 + 10 = (0.50 × 700) -50 = 350 -50 = 300 mm Hg PaO2 = 300 mm Hg Note that choice b is 300 mm Hg, but we are not finished with this problem yet. We must still subtract the PaO2 (i. e., 300 -90 = 210 mm Hg). 91) The physician orders 30% O2 to be administered to a patient who has a VT that fluctuates between 300 and 600 mL. The respiratory therapist should recommend which O 2 delivery device? A. Partial rebreathing mask at 10 L/min B. Nasal cannula at 3 L/min C. Air entrainment mask D. Simple O2 mask at 6 L/min The Correct Answer is C Rationale: An air entrainment mask is indicated because of the fluctuating VT. With this type of breathing pattern, the O2 percentage fluctuates with any low-flow device but remains fairly consistent with a high-flow device such as an air entrainment mask. Also, with a cannula or other low-flow device, the O2 percentage that the patient is receiving cannot be determined. 92) The respiratory therapist is administering IPPB to a patient with COPD who is receiving 28% O 2 via an air entrainment mask. With the air dilution mode being used, the therapist notes that the patient's respiratory rate has decreased from 18 breaths/min at the start of the treatment to 6 breaths/min after 5 minutes. The most appropriate recommendation is to: A. Decrease the inspiratory pressure. B. Use a nasal cannula at 2 L/min and administer the treatment on room air. C. Increase the flow. D. Administer the treatment on 100% O2. The Correct Answer is B Rationale: Most IPPB machines used on air mix or air dilution deliver a minimum of 40% O2. In this case, the patient's drive to breathe has been diminished. The patient still needs O 2 during the treatment, but give the treatment on room air. Use of 2 L/min closely approximates the 28% air entrainment mask. 93) A patient being mechanically ventilated in the assist-control mode at a rate of 12 breaths/min is triggering the ventilator at a rate of 34 breaths/min. The patient is anxious and agitated and has the following ABG results: pH 7.55 PaCO2 25 mm Hg PaO2 96 mm Hg HCO3- 25 mEq/L BE +1 Which of the following medications should the respiratory therapist recommend at this time? A. Albuterol (Proventil) B. Nitroprusside (Nipride) C. Vecuronium (Norcuron) D. Midazolam (Versed) The Correct Answer is D Rationale: The patient is hyperventilating because of anxiousness and agitation. This can best be corrected with sedation. A commonly used sedative is midazolam (Versed). 94) A patient on volume-controlled ventilation is placed on PEEP of 5 cm H2O. You expect which of the following to increase? A. FRC B. Raw C. PaCO2 D. Cardiac output (QT) The Correct Answer is A Rationale: FRC, the amount of air in the lungs after a normal exhalation, should increase after the administration of PEEP. PEEP opens up collapsed alveoli, which in turn increases FRC. 95) These data pertain to an 80-kg (176-lb) patient on volume-controlled ventilation in the assist- control mode: Mode Assist-control VT 700 mL Rate 10 breaths/min Flow 50 L/min FIO2 0.60 ABGs pH 7.41 PaCO2 37 mm Hg PaO2 53 mm Hg HCO3- 25 mEq/L BE 0 mEq/L On the basis of this information, the respiratory therapist should recommend which of the following ventilator changes? A. Increase VT to 800 mL. B. Increase FIO2 to 0.75. C. Increase flow to 60 L/min. D. Add 5 cm H2O PEEP. The Correct Answer is D Rationale: The patient is ventilating adequately but is hypoxemic on 60% O2. To increase the PaO2 most effectively, PEEP should be instituted. 96) An increased PCWP may be the result of which of the following conditions? 1. Pulmonary hypertension 2. Cor pulmonale 3. Left ventricular failure 4. Mitral valve stenosis A. 1 and 2 only B. 2 and 3 only C. 3 and 4 only D. 1, 2, and 3 only The Correct Answer is C Rationale: Pulmonary (capillary) wedge pressure (PCWP) is a measurement of left atrial pressure and left ventricular end-diastolic pressure; therefore, it is elevated as a result of left heart abnormalities. If the left ventricle is failing or blood is flowing through a stenotic or narrowed mitral valve (between the left atrium and left ventricle) , left heart pressures begin to rise. 97) The following data have been collected from a patient in the ICU: CVP 14 mm Hg PAP 38/20 mm Hg PVR 9 mm Hg/L/min PCWP 5 mm Hg These data indicate that the patient has which of the following? A. Left ventricular failure B. Aortic stenosis C. Pulmonary hypertension D. Mitral regurgitation The Correct Answer is C Rationale: Remember that capillary wedge pressure is a measurement of left heart pressure, and CVP and PAP reflect right heart pressure. CVP and PAP are both elevated in the case of an increased pulmonary vascular resistance (PVR; normal value = 1.5 to 3.0 mm Hg). Wedge pressure is normal; therefore, it is not a left heart problem. That rules out any problem associated with the left side of the heart (e. g., left ventricular failure, aortic stenosis, mitral valve regurgitation). A classic sign of pulmonary hypertension is increased PVR, with a resultant increase in PAP and CVP. As the pulmonary vasculature constricts, the right side of the heart must work harder to pump the blood through the pulmonary vessels. This results in increased pressures on the right side of the heart. 98) A 10-day-old, 900-g neonate on pressure control ventilation at an FIO2 of 0.90 remains hypoxemic, with gradually increasing mean airway pressure. The chest radiograph reveals a ground glass appearance. Which of the following should the respiratory therapist recommend at this time? A. Administer artificial surfactant. B. Increase the FIO2 to 1.0. C. Begin extracorporeal membrane oxygenation (ECMO). D. Change to a volume ventilator. The Correct Answer is A Rationale: Artificial surfactant is indicated for neonates who have RDS and inadequate oxygenation, even though they are on high levels of O2. Artificial surfactant should be administered no longer than 12 to 24 hours after the onset of symptoms. Surfactant should improve PaO2 as the atelectasis is reversed. 99) The respiratory therapist is assessing a patient with emphysema and observes pedal edema and jugular venous distention. The therapist should note in the patient's chart that these signs are most likely the result of which of the following? A. Systemic hypertension B. Hypercapnia C. Pulmonary infection D. Right ventricular hypertrophy The Correct Answer is D Rationale: The chronic hypoxemia observed in patients with COPD results in constriction of the pulmonary blood vessels, referred to as pulmonary hypertension. The right ventricle must work harder to pump the blood through the narrowed pulmonary vessels and, as a result, right heart pressure increases. The increased workload on the right heart causes the right ventricle to enlarge or hypertrophy. Venous blood returning to the heart begins to back up because of the higher pressure in the right atrium. This results in blood pooling in the jugular veins and lower extremities. 100) Laboratory results indicate that a patient's sputum sample has an elevated eosinophil count. This is indicative of which of the following? A. Pulmonary edema B. Pneumonia C. Emphysema D. Asthma The Correct Answer is D Rationale: Most asthma is related to an allergic response to inhaled antigens. When mast cells are stimulated, several chemical mediators are released, resulting in bronchoconstriction. One of those mediators is eosinophil chemotactic factor of anaphylaxis (ECF-A). Thus, a high eosinophil count can be found in both sputum and blood. 101) A 37-year-old patient receiving volume-controlled ventilation is recovering from gallbladder surgery and is receiving continuous IV infusions. Blood chemistry results reveal decreased BUN and Hb levels. The patient's urine output has remained at 50 mL/h for the past 4 hours. Assessment of this patient most likely reveals which of the following? A. Inspiratory stridor B. Hypotension C. Auscultation of fine crackles D. Increased CL The Correct Answer is C Rationale: The decreased Hb level may be the result of overhydration via the continuous IV fluids. Note that the urine output has not increased over the past 4 hours, even with continuous infusion of fluids, and the BUN level has decreased. These findings are consistent with overhydration, which can result in fine crackles being auscultated in the lungs. 102) A 65-kg (143-lb) patient has a respiratory rate of 18 breaths/min and a VT of 450 mL. The VE is: A. 5.5 L. B. 6.9 L. C. 8.1 L. D. 9.8 L. The Correct Answer is C Rationale: See the equation: VE = VT × RR = 0.45 L × 18 = 8.1 L Remember, you do not subtract VD when calculating VE. You do this only when calculating alveolar minute volume. 103) Which of the following are potential side effects of PEEP therapy? 1. Decreased QT 2. Decreased antidiuretic hormone (ADH) 3. Pneumothorax 4. Decreased FRC A. 1 and 2 only B. 1 and 3 only C. 1, 2, and 4 only D. 2, 3, and 4 only The Correct Answer is B Rationale: Increased pressure in the lungs from PEEP increases the possibility of barotrauma and cardiac compromise because the pressure is transferred to the vessels returning blood to the heart. This reduces venous return, which results in a decreased cardiac output. Cardiac effects are less likely in patients with stiff noncompliant lungs because the pressure from the lungs to the blood vessels is not transferred as easily. 104) The following arterial blood gas results are obtained from a patient on volume-controlled ventilation in the SIMV mode: Mode SIMV pH 7.54 PaCO2 28 mm Hg PaO2 124 mm Hg HCO3- 24 mEq/L BE 0 Which of the following ventilator changes should the respiratory therapist make first? A. Decrease the FIO2. B. Decrease the inspiratory flow. C. Increase the pressure support. D. Decrease the tidal volume. The Correct Answer is D Rationale: These ABG results should be interpreted as respiratory alkalosis with hyperoxemia. Which is more detrimental to the patient and must be corrected first, the alkalosis or hyperoxemia? Alkalosis is more detrimental and should be corrected first. Therefore, decrease the tidal volume. This will increase the PaCO2, resulting in a decreased pH. Alkalosis may lead to electrolyte imbalances, cardiac arrhythmias, and decreased tissue oxygenation as the oxyhemoglobin curve shifts to the left. 105) These data pertain to a 60-kg (132-lb) patient on volume-controlled ventilation in the assist- control mode: Mode Assist-control VT 500 mL Rate 10 breaths/min Flow 50 L/min FIO2 0.60 PEEP 4 cm H2O ABGs pH 7.51 PaCO2 27 mm Hg PaO2 59 mm Hg HCO3- 25 mEq/L BE +1 mEq/L On the basis of this information, the respiratory therapist should recommend which of the following ventilator changes? A. Decrease VT to 450 mL. B. Increase FIO2 to 0.70. C. Add 100 mL of dead space. D. Increase PEEP to 8 cm H2O. The Correct Answer is D Rationale: The blood gas results indicate acute respiratory alkalosis (hyperventilation). The hyperventilation, however, is not the result of excessive tidal volume but because the patient is hypoxemic. Reducing the VT or adding dead space increases the PaCO2 but does not correct the patient's hypoxemia and, in fact, worsens it. Because the patient is on an FIO2 of 0.60, the most appropriate choice to reverse the hypoxemia is to increase the PEEP level. 106) A chest radiograph shows infiltrates in the posterior basal segment of the patient's right lower lobe. The most appropriate postural drainage position is which of the following? A. Trendelenburg position, with patient lying on her or his right side B. Prone position, with bed in a Trendelenburg position C. Fowler's position D. Trendelenburg position, with patient lying supine The Correct Answer is B Rationale: Because the infiltrates are in the back (posterior) segments of the lung, the patient must be placed on the stomach (prone) with the head of the bed down (Trendelenburg) to drain the secretions anteriorly into the larger airways for removal. 107) Which of the values below represents the normal value for CVP? A. 2 to 8 mm Hg B. 8 to 10 mm Hg C. 10 to 15 mm Hg D. 15 to 18 mm Hg The Correct Answer is A Rationale: CVP is the measurement of right atrial pressure, with a normal value of 2 to 8 mm Hg. 108) A premature infant is being ventilated with pressure control ventilation. The infant's lung compliance begins to decrease. Which of the following statements is true regarding this situation? A. The infant's delivered volume will decrease. B. Peak inspiratory pressure will increase. C. The infant's lungs will be easier to ventilate. D. The infant's PaCO2 should begin to decrease. The Correct Answer is A Rationale: When CL decreases or the lungs become stiffer and harder to ventilate, peak inspiratory pressure must increase to maintain the same VT. But on pressure control ventilation, inspiratory pressure is limited so that it cannot increase; therefore, VT must decrease. 109) The following data are collected on a 70-kg (154-lb) patient on volume-controlled ventilation: Mode SIMV Ventilator rate 12 breaths/min VT 450 mL FIO2 0.50 PEE 5 cm H2O Pressure support 5 cm H2O pH 7.27 PaCO2 52 mm Hg PaO2 68 mm Hg HCO3- 25 mEq/L BE +1 mEq/L On the basis of these findings, the respiratory therapist should recommend which of the following? A. Increase the FIO2 to 0.60. B. Increase the ventilator rate to 18 breaths/min. C. Increase PEEP to 10 cm H2O breaths/min. D. Increase the VT to 550 mL. The Correct Answer is D Rationale: The patient is hypercapnic on the current ventilator settings. To decrease the PaCO2, the rate or volume must be increased. Increasing the rate by 6 breaths/min is not as appropriate as increasing the VT by 100 mL because the current VT setting is less than 10 mL/kg of body weight. Although the patient is hypoxemic, increasing the FIO2 or PEEP is not indicated. The patient is hypoxemic as a result of inadequate ventilation. When the VT is increased, ventilation should improve, causing the PaO2 to increase. 110) The respiratory therapist has completed an IPPB treatment on a patient. The most appropriate charting notation is which of the following? A. IPPB treatment given with 0.5 mL of albuterol in 2.5 mL of normal saline solution; tolerated well; vital signs stable B. Treatment given as ordered C. IPPB treatment given at 20 cm H2O; pulse stable at 80 beats/min during therapy; blood pressure (BP) stable at 115/75 mm Hg during therapy; patient had strong productive cough with small amount of thin white secretions; tolerated well D. IPPB treatment given at 20 cm H2O without difficulty; small amount of thin white secretions coughed up The Correct Answer is C Rationale: This choice gives the most concise and pertinent information when compared with the other choices. 111) The following data are obtained from a 70-kg (154-lb) male patient with pneumonia on volume- controlled ventilation: Mode SIMV Ventilator rate 4 breaths/min Pressure support 10 cm H2O VT 600 mL FIO2 0.40 PEEP 5 cm H2O pH 7.28 PaCO2 51 mm Hg PaO2 70 mm Hg HCO3- 25 mEq/L BE +1 mEq/L On the basis of these data, the respiratory therapist should recommend which of the following? A. Increase the VT to 700 mL. B. Increase the FIO2 to 0.50. C. Increase the SIMV rate to 8 breaths/min. D. Increase PEEP to 10 cm H2O. The Correct Answer is C Rationale: Because the patient's PaCO2 is elevated, minute ventilation (VE) must be increased. This can be accomplished by increasing the VT or the ventilator rate. Because this patient is only on a rate of 4 breaths/min and SIMV, it is obvious that this patient is being weaned but was not able to tolerate this low ventilator rate. Thus, the SIMV rate should be increased, not the VT. Although the PaO 2 is slightly low, that is the result of inadequate ventilation. Therefore, increasing the FIO2 or PEEP is not indicated. 112) Which set of ABG results indicates a partially compensated respiratory acidosis? A. pH = 7.23; PCO2 = 58 mm Hg; PO2 = 67 mm Hg; HCO3- = 24 mEq/L B. pH = 7.38; PCO2 = 54 mm Hg; PO2 = 74 mm Hg; HCO3- = 36 mEq/L C. pH = 7.31; PCO2 = 53 mm Hg; PO2 = 70 mm Hg; HCO3- = 30 mEq/L D. pH = 7.29; PCO2 = 24 mm Hg; PO2 = 72 mm Hg; HCO3- = 14 mEq/L The Correct Answer is C Rationale: Initially, the pH decreased as a result of an increased PaCO2. The HCO3- level is increasing in an effort to return the pH back to normal. Because the pH is increasing, but not yet back to normal, it is considered partially compensated. 113) To prevent pulmonary infarction from occurring during the measurement of PCWP, the cuff on the tip of the pulmonary artery catheter should remain inflated for no longer than which of the following? A. 5 seconds B. 10 to 15 seconds C. 15 to 20 seconds D. 20 to 30 seconds The Correct Answer is C Rationale: If the catheter balloon is inflated for longer than 15 to 20 seconds, pulmonary infarction may occur because no blood flows past the inflated balloon. 114) The following values were obtained from a patient on a 28% air entrainment mask in the cardiac care unit: PCWP 22 mm Hg PAP 34/24 mm Hg CVP 6 mm Hg These data are consistent with which of the following? 1. Left ventricular failure 2. Decreased PVR 3. Right ventricular failure A. 1 only B. 2 only C. 1 and 3 only D. 2 and 3 only The Correct Answer is A Rationale: These values indicate an elevated PCWP and PAP, with a normal or slightly elevated CVP. An elevated PCWP indicates that the left atrial pressure has increased because of the inability of the left ventricle to pump the blood adequately through the aorta and out to the body. Because pressure on the left side of the heart has increased, blood begins to “dam up” upstream in the pulmonary arteries and capillaries, resulting in an increased PAP. CVP, which is the pressure in the right atrium, is only slightly elevated. If it continues to increase, right heart failure is indicated. An increased pressure in the right atrium causes blood in the venous system trying to return to the heart to back up, leading to jugular venous distention (JVD) and pedal edema. 115) A 26-year-old patient with pneumonia has a PaO2 of 54 mm Hg and a PaCO2 of 31 mm Hg while on a 50% air entrainment mask. Which statement is false regarding this patient? A. The patient is hypocarbic. B. The patient has a decreased (A-a) gradient. C. The patient is hyperventilating in response to hypoxemia. D. This patient's pH is most likely alkaline. The Correct Answer is B Rationale: The normal PaO2 on 50% O2 is approximately 250 mm Hg (calculated by multiplying the O2 percentage by 5). This patient's PaO2 is only 54 mm Hg. To determine the A-a gradient, use this formula: PaO2 = PaO2 PaO2 = (BP – 47 mm Hg) × FIO2-PaCO2+ 10 (assume a Pb of 747) (700 × 0.5) – (31 + 10) 350 -41 = 309 mm Hg 309 -54 (PaO2) = 255 mm Hg This represents an increased A-a gradient. 116) A 5-ft 4-in, 150-kg (330-lb) female patient is placed on a ventilator in the recovery room after abdominal surgery. Which of the following ventilator settings is most appropriate? A. VT = 450 mL; rate = 12 breaths/min B. VT = 600 mL; rate = 12 breaths/min C. VT = 850 mL; rate = 12 breaths/min D. VT = 1000 mL; rate = 10 breaths/min The Correct Answer is A Rationale: The patient's ideal body weight must be calculated and converted from pounds to kilograms. These calculations are for a female: Ideal weight = 105 + 5 (height in inches -60) = 105 + 20 = 125 lb = 125/2.2 = 57 kg The patient's ideal body weight is 57 kg; therefore, using 6 to 8 mL/kg, the most appropriate VT is 450 mL. 117) Which bedside assessment best determines whether a patient with Guillain-Barré syndrome is in need of ventilatory assistance? A. VC B. TLC C. FRC D. Maximal voluntary ventilation (MVV) The Correct Answer is A Rationale: Performing a VC maneuver determines the patient's respiratory muscle strength and therefore helps determine the need for ventilatory assistance. The patient should be able to obtain a minimum VC of 10 to 15 mL/kg of body weight. A VC of less than 10-15 mL/kg indicates inadequate respiratory muscle strength to cough and clear secretions. 118) Room air will not be entrained through the exhalation ports of an aerosol mask if: A. The total gas flow exceeds the patient's inspiratory flow demands. B. The mist totally disappears, exiting the mask as the patient inhales. C. The patient's inspiratory flow exceeds the total flow from the nebulizer. D. The total gas flow is 40 L/min, and the patient's inspiratory flow demand is 50 L/min. Select option of choice, then click Submit. The Correct Answer is A Rationale: The total flow from a high-flow device, such as an aerosol mask, must be higher than the patient's inspiratory flow demands, or room air will enter through the exhalation ports as the patient continues to inspire. This decreases the delivered O2 percentage. This situation is observed clinically when the mist totally disappears as the patient inspires. Mist should always be visible exiting the exhalation ports of the mask, even at peak inspiration, or the flow is too low. 119) A 3-month-old infant with respiratory syncytial virus (RSV) has the following capillary blood gas results on a 60% O2 hood: pH 7.37 Pcco2 43 mm Hg PCO2 60 mm Hg On the basis of this information, the most appropriate action is which of the following? A. Increase FIO2 to 0.70. B. Place on nasal CPAP of 4 cm H2O and FIO2 of 0.50. C. Decrease FIO2 to 0.50. D. Intubate the patient and institute mechanical ventilation. The Correct Answer is C Rationale: Normal capillary PO2 is 40 to 50 mm Hg; therefore, the FIO2 should be decreased. 120) The respiratory therapist is administering IPPB to a patient with a tracheostomy tube who is having difficulty cycling the machine into the expiratory phase. Which of the following could be done to correct this problem? A. Increase the sensitivity. B. Decrease the flow. C. Check for air in the tracheostomy tube cuff. D. Increase the inspiratory pressure. The Correct Answer is C Rationale: Because the cuff of a tracheostomy tube should be left deflated, except during eating and breathing treatments, it is not unusual to forget to inflate the cuff before the treatment. If the cuff is not inflated, air leaks around the cuff into the mouth, and the patient can not cycle the unit into expiration. 121) These data were collected on a patient on volume-controlled ventilation in the assist-control mode: Time PEEP (cm H2O) PaO2 (mm Hg) Pvo2 (mm Hg) 4:00 pm 6 68 39 6:00 pm 8 74 43 8:00 pm 10 78 41 9:00 pm 12 83 38 On the basis of this information, which of the following PEEP levels is best for this patient? A. 6 cm H2O B. 8 cm H2O C. 10 cm H2O D. 12 cm H2O The Correct Answer is B Rationale: Optimal PEEP is determined by the PEEP level that results in the highest static CL or the highest Pvo2. In this question, note that as the PEEP is increased, the Pvo2 increases, until a PEEP level of 10 cm H2O is reached. At this level, the Pvo2 drops. This indicates that when the PEEP was increased from 8 to 10 cm H2O, cardiac output decreased, resulting in a drop in the Pvo2. Therefore, the optimal PEEP level is 8 cm H2O. Note also in this question how the PaO2 increases with each increase in the PEEP level. This commonly occurs but does not indicate an increased oxygenation state because the PaO2 has increased at the expense of a decreased cardiac 122) During ventilator checks on a patient being ventilated on volume-controlled ventilation, the respiratory therapist notices that the peak inspiratory pressure has been gradually increasing over the past 5 hours, with no change in the plateau pressure. This indicates which of the following? A. Static compliance is decreasing. B. The patient may need to be suctioned. C. Raw is decreasing. D. The patient's VT should be increased. The Correct Answer is B Rationale: The data in this question show a stable plateau pressure, with increasing peak pressures over 3 hours on a ventilator VT of 800 mL. Because plateau pressure is used to determine static compliance, and it is unchanged, then static compliance is unchanged. Peak pressure is used to calculate dynamic compliance, which is a measurement of airway resistance. As peak pressures increase, dynamic compliance decreases, which means that airway resistance (Raw) is increased. Raw increases as a result of H2O in the ventilator tubing, secretions in the airway, bronchospasm, or mucosal edema. To help decrease Raw, determine the cause and treat it. For example, you can drain H2O from tubing, suction the patient, or recommend administration of a bronchodilator or a corticosteroid (for mucosal edema). 123) A patient's cardiac monitor indicates the patient is experiencing PVCs. Which of the following should the respiratory therapist recommend? A. Administer an antiarrhythmic drug. B. Get a pulse oximetry reading. C. Get serum electrolyte levels. D. Administer oxygen. The Correct Answer is C Rationale: Because changes in electrolytes, particularly potassium, can result in arrhythmia, it is advantageous to check the electrolyte levels rather than recommending an antiarrhythmic drug. If the potassium level is low, resulting in the PVCs, potassium can be added to the IV. Although hypoxemia can also cause PVCs, there is no mention in the question of any signs that the patient is hypoxemic. 124) The following data are collected on a 75-kg (165-lb) patient receiving volume-controlled ventilation: Mode Assist-control Ventilator rate 15/min Tidal volume 600 mL FIO2 0.70 PEEP 10 cm H2O ABGs pH 7.36 PaCO2 41 mm Hg PaO2 139 mm Hg HCO3- 25 mEq/L BE +2 Which of the following ventilator changes should the respiratory therapist recommend? A. Decrease the PEEP to 8 cm H2O. B. Decrease the FIO2 to 0.60. C. Increase the rate to 20 breaths/min. D. Increase the tidal volume to 650 mL. The Correct Answer is B Rationale: The patient is hyperoxemic (PaO2- 139 mm Hg) on an FIO2 of 0.70 and a PEEP of 10 cm H2O. To reduce the PaO2, the FIO2 or PEEP should be reduced. Because the FIO2 is above 0.60, it should be reduced first. Then PEEP may be decreased. Increasing the VT or rate will decrease PaCO 2 and cause an increase in PaO2. 125) During a pulmonary assessment, the patient tells the respiratory therapist that he has been coughing up green, foul-smelling secretions. This suggests to the therapist that the patient most likely has which of the following? A. Pleural effusion B. Pulmonary edema C. Viral infection D. Pseudomonas infection The Correct Answer is D Rationale: Pseudomonas species infections characteristically result in the production of green, foul- smelling sputum. 126) The following data were collected from a 70-kg (154-lb) patient on volume-controlled ventilation: Mode Assist-control Ventilator rate 12 breaths/min Total rate 22 breaths/min VT 650 mL FIO2 0.60 ABGs pH 7.51 PaCO2 30 mm Hg PaO2 54 mm Hg HCO3-