Mechanical Ventilation Review PDF

Mechanical ventilation RODERICK M. TUMANGUIL, RTRP  RESPIRATORY FAILURE Inability of the lungs to provide O2 and excrete CO2 Patient in Acute Respiratory Distress Failure of CO2...

Mechanical ventilation RODERICK M. TUMANGUIL, RTRP  RESPIRATORY FAILURE Inability of the lungs to provide O2 and excrete CO2 Patient in Acute Respiratory Distress Failure of CO2 Failure of Homoeostasis/ Oxygenation (LUNG ventilation (PUMP FAILURE) FAILURE) HYPERCAPNEIC HYPOXEMIC RESP. RESP FAILURE FAILURE  ventilatory Failure - > failure of the lungs to excrete CO2 -> PaCO2 > 45 – 50 mmHg - > often accompanied by hypoxemia corrected by supplemental oxygen -> decrease alveolar minute ventilation -> increase deadspace ventilation  Oxygenation Failure - > a severe hypoxemia that does not respond to moderate to high level of supplemental oxygen (PaO2 of < 40 mmHg with FiO2 of > 60%) - > CAUSES: Hypoventilation Ventilation/Perfusion Mismatch Intrapulmonary Shunting Intrapulmonary shunting (low v/q) - > Refers to perfusion in excess of ventilation - > shunted blood is not useful in gas exchange because it does not come in contact with ventilated and oxygenated alveoli - > causes refractory hypoxemia - low oxygen in the blood that responds poorly with oxygen therapy alone INTERPRETATION of SHUNT < 10% Normal 10 – 20% Mild shunt 20 – 30% Significant Shunt > 30% Critical and Severe Shunt INTERPRETATION of Oxygenation Status HYPOXEMIA STATUS PaO2 Normal 80 – 100 mm Hg Mild 60 – 79 mm Hg Moderate 40 – 59 mm Hg Severe 45 mmHg, 50 mmHg ( higher in COPD) pH: < 7.30 2. Impending Ventilatory Tidal Volume: < 5 ml / kg Failure Frequency: > 35 / min Minute Volume: > 10 L / min Vital Capacity: < 10 ml / kg MIP: < - 20 cmH20 Rising PaCO2 > 50 mmHg VD/Vt > 60%  Indications of Mechanical Ventilation INDICATION PARAMETERS 3. Severe hypoxemia or PaO2: < 60 mmHg at FiO2 > 50 % or Oxygenation failure PaO2: < 40 mmHg at any FiO2 PaO2/FiO2 (P/F ratio): < 300 mmHg for ALI PaO2/FiO2 (P/F ratio): < 200 mmHg for ARDS P (A-a) O2 > 450 mmHg at 100 % 4. Prophylactic vent. Reduce Pulmonary Complications support Reduce hypoxia of major body organs Reduce cardiopulmonary stress example  The purpose of mechanical ventilation is to: A. Protect the airway B. Support gas exchange while other management strategies address the cause of respiratory failure. C. Prevent barotrauma and pulmonary oxygen toxicity. D. Heal the lungs  Which of the following is NOT an indication for continuous mechanical ventilation? A. MIP -20 cmH2O B. acute ventilatory failure C. Vt < 5 mL/kg D. VC < 10 mL/kg  A need for some form of ventilatory support is usually indicated when an adult’s rate of breathing rises above what level? a. 35/min b. 30/min c. 25/min d. 20/min  Which of the following measures taken on adult patients indicate unacceptably high ventilatory demands or work of breathing? a. VE of 17 L/min b. breathing rate of 22/min c. VD/VT of 0.45 d. MIP of –40 cm H2O  Which of the following measures taken on adult patients indicative of mechanical ventilation? a. PaO2 of 65 mmHg at FiO2 of 50 % b. P (A-a) O2 of 257 mmHg at FiO2 of 100 % c. P / F ratio of 150 mmHg d. Respiratory Rate of 12 bpm  Ventilatory support may be indicated when the VC falls below what level? a. 45 ml/kg b. 65 ml/kg c. 10 ml/kg d. 30 ml/kg  Which of the following MIP measures taken on an adult patient indicates inadequate respiratory muscle strength? a. –90 cm H2O b. –70 cm H2O c. –40 cm H2O d. –15 cm H2O  Complications of mechanical ventilation  complications 1. Barotrauma -> hyperinflation of alveoli past rupture point. a. pneumothorax : characterized by subcutaneous emphysema b. Pneumomediastinum c. Pneumopericardium -> Airway pressures that could lead to barotrauma: a. PEEP > 10 mmHg b. PAP > 50mmHg c. Pplat > 35mmHm d. mPaw > 30mmHg complications 2. Pulmonary infection 3. Atelectasis 4. Pulmonary Oxygen toxicity 5. Tracheal damage 6. Decrease cardiac output 7. Decrease urine output 8. Lack of nutrition example  5. Prolonged ventilation has been associated with the following except: a. increased incidence of ventilator associated pneumonia b. increased multi organ failure c. decreased used of hospital resources d. increased mortality  A 42 y/o male with severe bronchial asthma in acute exacerbation is intubated and ventilated for respiratory failure. High Peak pressures are noted (55mmHg) and the plateau pressures are within normal limits. This high pressure will: A. Will be transmitted to the alveoli and is likely to cause barotrauma. B. Is not transmitted to the alveoli and is unlikely to cause barotrauma. C. Reflects alveolar over distension D. Could be the result of pneumothorax. A mechanically ventilated patient has a pH 7.48, Paco2 22 mm Hg, Pao2 84 mm Hg. Tidal volume is set at 700 mL (12 mL/kg) and the respiratory rate is set at 15 breaths/min. PEEP is 8 cm H2O and Fio2 is 0.4. The plateau pressure is 36 cm H2O. Which of the following would you recommend? a. Decrease the tidal volume b. increase the respiratory rate c. Decrease the PEEP d. Increase the Fio2  MECHANICAL VENTILATION NEGATIVE PRESSURE VENTILATION POSITIVE PRESSURE VENTILATION NON INVASIVE ADVANCE VOLUM PRESSURE MODES (COMBINATION OF P AND V) E INVASIVE VENTILATIONNON - INVASIVE STRATEGY IN MECHANICAL VENTILATION NON - INVASIVE INVASIVE VOLUME VENTILATION PRESSURE VENTILATION PRESSURE CONTROL – INVERSE RATIO VENTILATION ADVANCE MODES Classification of ventilators  Classification I. Negative Pressure Ventilation II. Positive Pressure Ventilation Negative pressure ventilation Uses negative pressure to bring air into the lungs It is a non - invasive type of ventilation Ex ample of which is the chest cultrass also called the “iron lung” Positive pressure ventilation Uses positive pressure to bring air into the lungs Can be used for both invasive and non invasive ventilation Also has 3 types: 1. Volume type 2. Pressure Type 3. Pressure and Volume (Advance modes) Characteristics of mechanical ventilators 1. Limits: a. Pressure limited b. volume limited 2. Breath delivered: a. mandatory breath b. assisted breath c. spontaneous breath Characteristics of mechanical ventilators 3. Triggering: to inspiration a. Pressure triggered b. Flow triggered c. Time triggered Characteristics of mechanical ventilators 4. Cycling: to expiration a. volume cycled b. pressure cycled c. flow cycled d. time cycled Characteristics of mechanical ventilators 5. Variability: a. Pressure variable b. Volume variable Volume ventilation Volume ventilation CHARACTERISTICS: > Volume limited or volume pre – set > volume cycled or time cycled > pressure variable Volume ventilation SET PARAMETERS: MODE: Full or Partial ventilator support Vt: 8 – 10 kg/PBW RR: 1o - 16 bpm FiO2: 21% - 100 % PFR: 40 - 60 lpm PEEP: 5 cmH2O FLOW PATTERN: Square wave SENSITIVITY: - 2 cmH2O or 1 L Modes of volume ventilation  Different Modes ON VOLUME VENTILATION FULL VENTILATORY PARTIAL VENTILATORY SUPPORT SUPPORT 1. Controlled Mandatory 1. Intermittent Mandatory Ventilation (CMV) Ventilation (IMV) 2. Assist Ventilation 2. Synchronized 3. Assist/Control Intermitent Mandatory Ventilation (SIMV)  Controlled mandatory ventilation CHARACTERISTICS: > volume limited, Time cycled > pressure variable > machine, time triggered > purely mechanical breath > correction of PaCO2 level can be done through changing Tidal Volume and RR settings CONTROLLED MANDATORY VENTILATION(CMV)  assisted ventilation CHARACTERISTICS: > Volume limited, volume cycled > pressure variable > patient triggered > purely mechanical breath > correction of PaCO2 level can be done through changing Tidal Volume , sensitivity settings  Assist/control ventilation CHARACTERISTICS: > Volume limited, volume cycled and or Time cycled > pressure variable > patient or machine triggered > purely machine breath > correction of PaCO2 level can be done through changing Tidal Volume , RR settings and sensitivity settings Control and assist control mode  Intermittent mandatory ventilation CHARACTERISTICS: > volume limited and volume cycled for mechanical breaths > pressure variable > patient and machine triggered > machine breath and spontaneous breaths > correction of PaCO2 level can be done through changing Tidal Volume and RR settings > NO LONGER USE due to breath stacking  Synchronized Intermittent mandatory ventilation CHARACTERISTICS: > volume limited and volume cycled for mechanical breaths > pressure variable > patient and machine triggered > machine breath and spontaneous breaths > correction of PaCO2 level can be done through changing Tidal Volume and RR settings > Use as a weaning method IMV and SIMV mode example. Which of the following modes of ventilation delivers a set pressure or volume and a set rate? a. controlled mandatory ventilation b. continuous positive airway pressure c. assist control ventilation d. SIMV  A 52 y/o male with COPD exacerbation is placed on A/C mode:, Vt: 400 ml, RR: 12bpm. Patient is obviously awake and is triggering at a rate of 20/minute. No alarms on the ventilator are being triggered. The approximate minute volume for this patient is: A. 8000 cc B. 4800 cc C. 4800 cc + an additional volume that depends on lung compliance and muscle strenght D. > 8000 cc E. cannot be calculated based on the given information.  A 52 y/o male with COPD exacerbation is placed on A/C mode:, Vt: 400 ml, RR: 12bpm, PS: 5 cmH20. Patient is obviously awake and is breathing at a rate of 20/minute. No alarms on the ventilator are being triggered. The approximate minute volume for this patient is: A. 8000 cc B. 4800 cc C. 4800 cc + an additional volume that depends on lung compliance and muscle strenght D. > 8000 cc E. cannot be calculated based on the given information.  Which of the following modes delivers a controlled breaths and allows the patient to breath spontaneously between controlled breaths preventing breath stacking: a. assist b. Assist/Control c. control d. SIMV  Which of the following modes can prevent respiratory muscle atrophy: a. assist b. Assist/Control c. control d. SIMV  In an A/C mode with a back up rate of 12 bpm, if the patient has a total of 16 triggered breaths, how many breaths did the patient receive from the ventilator? a. 12 b. 28 c. 16 d. 4  In SIMV mode, if the back up rate is 12 bpm and the patient had a total of 8 spontaneous breaths, how many breaths did the patient receive in all? a. 12 b. 8 c. 20 d. 4  Other settings of volume ventilation Respiratory rate > set at 10 – 16 bpm > usual parameter that is manipulated to correct PaCO2 level > affects the I:E ratio > ↑ RR leads to ↓ I:E ratio or shorter E time > ↓ RR leads to ↑ I:E ratio or longer E time Tidal volume > set parameter under volume ventilation, 8 – 10 ml/kg of PBW > also manipulated to correct PaCO2 level > affects I:E ratio > ↑ Vt leads to ↑ I time or ↓ E time or ↓ I:E ratio > ↓ Vt leads to decrease ↓ I time or ↑ E time or ↑ I:E ratio > computed by obtaining Predicted Body Weight 1. Male PBW in kg = 106 + [6 x (Height in inches – 60)] ÷ 2.2 2. Female PBW in kg = 105 + [5 x (Height in inches – 60)] ÷ 2.2 Volume time waveform > can be use to assess for air trapping or leak Volume/ Air-Trapping or Leak Loss of volume If the exhalation side of the waveform doesn’t return to baseline, it could be from air-trapping or there could be a leak (ETT, vent circuit, chest tube, etc.) Peak flow rate > initially set from 40 – 60 lpm > determines how fast the set Vt is delivered > affects I:E ratio > ↑ PFR leads to ↓ I time or ↑ E time or ↑ I:E ratio > ↓ PFR leads to ↑ I time or ↓ E time ↓ I:E ratio > can cause dyssynchrony example  A 44 year old male patient is being mechanically ventilated with a volume cycled ventilator. You observe that there is insufficient time for the patient to exhale completely. You would now do which of the following to correct the problem? A. increase the flow B. decrease the minute volume C. add PEEP D. none of the above Using flow rates to change I:E ratio A patient in a volume limited ventilator has minute volume of 12 L/min. What should be your minimum PFR if you want an I:E ratio of 1:4? Solution: Flow = minute volume × sum of I:E = 12 L/min × (1+4) = 12L/min × 5 = 60 L/min a. 40 LPM b. 60 LPM c. 50 LPM d. 70 LPM  A patient in a volume limited ventilator has minute volume of 10 L/min. What should be your minimum PFR if you want an I:E ratio of 1:3? a. 40 LPM b. 60 LPM c. 50 LPM d. 70 LPM Peak flow pattern > determines the manner of delivery of set Vt > use to assess or monitor : 1. dyssynchrony 2. auto PEEP 3. changes in expiratory flow Peak flow pattern > has 5 available waveforms: 1. square wave – maximum flow is throughout inspiration 2. decelerating – maximum flow at start and diminishes as inspiration ends 3. sine wave – maximum flow at mid inspiration, resembles spontaneous breath 4. accelerating – maximum flow at end inspiration 5. decay – has some similarity with decelerating Flow patterns most commonly use flow patterns Volume Pressure examples Flow/Tim Auto-Peep (air trapping) Expiratory flow doesn’t return to baseline Start of next breath If expiratory flow doesn’t return to baseline before the next breath starts, there’s auto-PEEP (air trapping) present , e.g. emphysema. Recognizing prolonged expiration (air trapping) Recognize airway obstruction when Expiratory flow quickly tapers off and then enters a prolonged low-flow state without returning to baseline (auto- PEEP) This is classic for the flow limitation and decreased lung elastance characteristic of COPD or status asthmaticus Flow/Time Scalar Bronchodilator Response Pre-Bronchodilator Post-Bronchodilator Longer Shorter E-time E-time Peak Exp. Flow Improved Peak Exp. Flow To assess response to bronchodilator therapy, you should see an increase in peak expiratory flow rate. The expiratory curve should return to baseline sooner. Recognizing ineffective/wasted patient effort Patient inspiratory effort fails to trigger vent resulting in a wasted effort fio2 > set from.21 to 1.0 or 21% to 100% > the usual parameter manipulated to correct oxygenation > causes oxygen toxicity example  Mode: control ABG: Rate: 12 bpm pH 7.44 Vt: 700 ml PaCO2 36 mmHg FiO2: 35 % PaO2 55 mmHg The following data are obtained from a patient receiving mechanical ventilation with a volume ventilator. To increase the PaO2 to 80 mmHg, what must be your FiO2? a. 35 % b. 40 % c. 45 % d. 50% Solution: Desired FiO2 = PaO2 (desired) x FiO2 current PaO2 current = 80 x.35 ÷ 55 =.50 or 50 %  Mode: control ABG: Rate: 12 bpm pH 7.44 Vt: 700 ml PaCO2 36 mmHg FiO2: 30 % PaO2 53 mmHg The following data are obtained from a patient receiving mechanical ventilation with a volume ventilator. To increase the PaO2 to 80 mmHg, what must be your FiO2? a. 35 % b. 40 % c. 45 % d. 50% Mode: A/C pH 7.52 Vt: 750 ml PaCO2 27 mmHg BUR: 12 bpm PaO2 57 mmHg FiO2: 40% HCO3 23 mEq PEEP: 5 cmH2O The following data’s are collected from a patient receiving mechanical ventilation with a volume ventilator. Based on the following data’s, which of the following changes would you recommend? a. increased PEEP to 7 cmH2O b. decreased Vt to 650 ml c. decreased BUR to 8 bpm d. increased FiO2 to 50 %  A 68 y/o male who was admitted for pneumonia is currently on mechanical ventilation (mode: A/C, Vt: 360 ml, RR: 12 bpm, PEEP: 5 cmH20, FiO2: 55%). You are concerned about the significant respiratory alkalosis that this patient has. You will address this by making the following changes: A. Increase the FiO2 to decrease respiratory drive B. decrease RR C. decrease PEEP D. increase sensitivity for triggering the ventilator E. none of the above sensitivity > senses patient breathing effort > has two types: 1. Pressure sensitivity - set from – 0.5 to – 5.0 cm H20 2. Flow sensitivity - more sensitive to patient breathing effort compared to pressure - set from 1 to 5 liters Positive end expiratory pressure > use in lung recruitment > prevents collapse of alveoli > prevents alveolar injury due to shearing effect of opening and closing of alveoli > used to correct refractory hypoxemia caused by intrapulmonary shunting > a PEEP of 5 cmH2O is used as a physiologic PEEP Indications of peep 1. Intrapulmonary shunt and refractory hypoxemia - a. PaO2 < 60mmHg with FiO2 of 50% and above b. PaO2/FiO2 (P/F) ratio < 200mmHg 2. Decrease FRC and lung compliance 3. auto PEEP not responsive to adjustments in ventilator settings 4. Pulmonary edema Complications/hazards of peep 1. Barotrauma 2. Decrease venous return 3. Decrease cardiac output 4. Decrease urinary output Complications/Hazards of PEEP ↑PEEP ↑mPaw, ↑PIP Increase pleural pressures ↓ venous return Decrease cardiac output Decrease O2 delivery example. For a patient on mechanical ventilation, total collapse of the alveoli can be prevented by: a. low tidal volumes b. PEEP c. High FiO2 d. low peak flow rates Pressure ventilation  Characteristics PRESSURE VENTILATION > Pressure pre – set > Pressure limited > Time cycled, Flow cycled or Pressure cycled > Volume variable > use for invasive and non invasive ventilation PRESSURE VENTILATION SETTINGS: Mode: FVS, PVS PIP: 20 cmH2O RR: 12 - 16 bpm FiO2: 21 - 100 % PEEP: 5 cmH2O I time: 1 sec to 1.5 sec I:E ratio: 1:3  Modes ON pressure VENTILATION FULL VENTILATORY PARTIAL VENTILATORY SUPPORT SUPPORT 1. PCV 1. PSV 2. Assist/Control 2. CPAP 3. PC - IRV 3. BiPAP Modes of pressure ventilation  PRESSURE CONTROLLED VENTILATION CHARACTERISTICS: > Pressure limited > Time cycled > Time Triggered > Volume variable  Assist/Control CHARACTERISTICS: > Pressure limited > Time cycled and or Pressure cycled > Time Triggered or Patient triggered > Volume variable  PRESSURE CONTROLLED – inverse ratio VENTILATION CHARACTERISTICS: > Pressure limited > Time cycled > Time Triggered > Volume variable  PRESSURE support VENTILATION CHARACTERISTICS: > Pressure limited > Flow cycled > Patient Triggered > Volume variable > use as a weaning method Continuous positive airway pressure ventilation CHARACTERISTICS: > Pressure limited > use as a weaning method especially in infants > use during non invasive ventilation (NIPPV)  Bi level positive airway pressure CHARACTERISTICS: > Pressure limited > Time or flow cycled > Time or patient Triggered > Volume variable > use for non invasive ventilation  Other settings of pressure ventilation Respiratory rate > set at 10 – 16 bpm > usual parameter that is manipulated to correct PaCO2 level > affects the I:E ratio ` > affects mean airway pressure > ↑ RR leads to ↓ I:E ratio or shorter E time > ↓ RR leads to ↑ I:E ratio or longer E time Peak Inspiratory pressure (PIP) > set parameter under pressure ventilation > manipulated to correct PaCO2 level, can also affect PaO2 level > affects mean airway pressure (mPaw) fio2 > set from.21 to 1.0 or 21% to 100% > the usual parameter manipulated to correct oxygenation > can cause oxygen toxicity sensitivity > senses patient breathing effort > has two types: 1. Pressure sensitivity - set from – 0.5 to – 5.0 cm H20 2. Flow sensitivity - more sensitive to patient breathing effort compared to pressure - set from 1 to 5 liters I time > set from 1 sec to 1.5 seconds > affects mean airway pressure  i:e ratio > ratio of inspiration to expiration > normally set at 1:2 to 1: 4 > affects mean airway pressure > use inversely in conjunction with pressure ventilation (PCV-IRV) during: severe hypoxemia not responsive to conventional ventilation Positive end expiratory pressure > use in lung recruitment > prevents collapse of alveoli > prevents alveolar injury due to shearing effect of opening and closing of alveoli > used to correct refractory hypoxemia caused by intrapulmonary shunting > a PEEP of 5 cmH2O is used as a physiologic PEEP > affects mean airway pressure Points to remember in pressure ventilation Increase in: pCO2 pO2 MAP FiO2 no change increase no change usually no Rate decrease increase change PIP decrease increase increase Inspiratory usually no increase increase time change usually no PEEP increase increase change terminologies Peak Inspiratory Pressure (PIP) or Peak Airway Pressure -> pressure used to deliver the tidal volume to the lung Plateau Pressure (Pplat) ->pressure that maintains lung inflation in the absence of airflow Mean airway Pressure (mPaw) - > average pressure within the airway during one complete respiratory cycle Mean airway Pressure (mPaw) Normal value: < 30 cmH20 in adult Equation: mPaw = (f x I time) x (PiP – PEEP) + PEEP 60 Where: mPaw – mean airway pressure (cmH20) f – respiratory in 1 minute I time – inspiratory time in 1 sec PIP – Peak inspiratory Pressure (cmH20) PEEP – Positive end expiratory Pressure Example A patient is currently ventilated in pressure type ventilator under a control mode. The ventilator settings are: RR: 45/min I time: 0.5 sec PIP: 35 cmH20 PEEP: 5 cmH2O FiO2:100 % Compute for the mPaw: Solution mPaw = (45 x 0.5) x (35 – 5) + 5 60 = 16.25 cmH2O  Pressure control Inverse ratio ventilation - Improves oxygenation by: 1. Reduction of intrapulmonary shunting 2. Improvement of V/Q matching 3. Decrease of deadspace ventilation 4. Increase of mean airway pressure 5. Presence of Auto PEEP - According to shansholtz, these mechanism are also achievable by conventional ventilation with PEEP except number 4 and 5. example  Which ventilator mode delivers gas at a preset rate and tidal volume or pressure regardless of inspiratory effort? a. assist-control ventilation b. control ventilation c. CPAP d. SIMV  Mean airway pressure may be increased by all of the following adjustments, except increasing the: a. inspiratory time b. frequency c. positive end-expiratory pressure level d. FIO2  Which of the following set parameters under pressure limited ventilation can affect both ventilation and oxygenation: a. inspiratory time b. frequency c. positive end-expiratory pressure level d. Peak Inspiratory Pressure  During pressure-targeted modes of ventilatory support, the volume delivered depends on which of the following? 1. set pressure limit 2. patient lung mechanics 3. patient effort a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1, 2, and 3  The doctor wants to increase the mean airway of the pressure limited ventilator currently use by the patient. Which of the following could be increased to accomplish this? 1. PEEP 2. PIP 3. Inspiratory Time a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1, 2, and 3  A patient is currently mechanically ventilated on a pressure pre-set ventilation with the following settings: Mode: PCV, PIP: 20cmH2O, I time:.5 seconds, RR – 15 BPM, Fi02 – 50 %. If the I time is increased to 1 second, which of the following responses will most likely occur? A. mPaw will increase B. peak inspiratory will increase C. Vt will decrease D. FiO2 will increase Non invasive ventilation  nippv > intended to avoid complications of invasive ventilation. > first type of ventilation to consider to a patient in acute respiratory failure MODES UNDER nippv  CPAP > may be set initially at 5 cmH2O > may be achieved with the use : a. nasal prongs b. CPAP mask > Indications: 1. Treatment of postoperative atelectasis 2. obstructive sleep apnea 3. cardiogenic pulmonary edema 4. weaning  Bipap > is a bi - level positive airway pressure ventilation > settings are: IPAP: 10 cmH2O EPAP: 4 cmH2O > Indications : 1. acute respiratory failure 2. obstructive sleep apnea 3. other conditions that result in hypoventilation  Common Interfaces for CPAP and BiPAP 1. nasal mask 2. oronasal mask 3. Full face mask 4. nasal pillows ( nasal prongs) Adjustments of Bipap to improve ventilation 1. Increasing IPAP level 2. decreasing EPAP level 3. improving compliance 4. reducing air flow resistance Adjustments Of bipap to improve oxygenation 1. increasing EPAP level  contraindications 1. hemodynamically unstable 2. hypoventilation 3. nausea 4. facial trauma 5. untreated pneumothorax 6. elevated intracranial pressure (ICP). example  Which statement is correct about NIMV? a. It can't be used with PEEP. b. Available modes include bilevel positive airway pressure and CPAP. c. Inspiration is initiated only by the ventilator. d. It's contraindicated in patients with obstructive sleep apnea.  Which of the following would the respiratory therapist select to treat a patient who has obstructive sleep apnea? A. BiPAP® B. Nasal cannula C. Chest cuirass ventilator D. simple oxygen mask  A patient with COPD is extubated after receiving mechanical ventilation for 2 weeks. Several hours after extubation, the patient complains of progressively worsening while on 2lpm cannula. His RR increase from 16 to 26 bpm. Which of the following is the appropriate recommendation? A. initiate noninvasive positive pressure ventilation B. reintubate and begin mechanical ventilation C. give the patient a non rebreathing mask D. begin postural drainage and percussion every 4 hours  Difference between pressure and volume  Assuming that the right and left lung are the same in size, shape and patency, and we are to ventilate them separately. One with volume and the other with pressure. What changes would take place if there is an increase in airway resistance or bronchospasm? VOLUME VENTILATION PRESSURE VENTILATION Settings before Settings before bronchospasm bronchospasm 1. Tidal Volume: 500ml 1. PIP: 25 cmH2O 2. Observed PIP: 25 2. Observed Tidal Volume: cmH2O 500 ml CHANGES CHANGES A. constant Vt A. constant PIP B. increase PIP B. decrease Vt  What changes would take place if there is a decrease in compliance or ARDS? VOLUME VENTILATION PRESSURE VENTILATION Settings before ARDS Settings before ARDS 1. Tidal Volume: 500ml 1. PIP: 25 cmH2O 2. Observed PIP: 25 2. Observed Tidal Volume: cmH2O 500 ml CHANGES CHANGES A. constant Vt A. constant PIP B. increased PIP B. decrease Vt  Lung Compliance Changes and the P-V Loop…. (Volume mode) ↑C C ↓C Preset VT Volume Pressure PIP levels Constant VT………. Variable Pressure  Lung Compliance Changing in P-V Loop (pressure mode)…………. 1.With surfactant 2. Emphysematous L VT levels RDS…lung Volume Pressure Preset PIP Constant PIP……… variable VT  What changes would take place if there is an increase in compliance or resolve pulmonary edema? VOLUME VENTILATION PRESSURE VENTILATION Settings during presence Settings during presence of pulmonary edema of pulmonary edema 1. Tidal Volume: 500ml 1. PIP: 40 cmH2O 2. Observed PIP: 40 2. observed Tidal Volume: cmH2O 500 ml CHANGES CHANGES A. constant Vt A. constant PIP B. decreased PIP B. increase Vt  Lung Compliance Changes and the P-V Loop…. (Volume mode) ↑C C ↓C Preset VT Volume Pressure PIP levels Constant VT………. Variable Pressure  Lung Compliance Changing in P-V Loop (pressure mode)…………. 1.With surfactant 2. Emphysematous L VT levels RDS…lung Volume Pressure Preset PIP Constant PIP……… variable VT example. Which of the following types of ventilation would deliver a constant tidal volume during an increase in airway resistance? a. Pressure controlled ventilation b. Volume controlled ventilation c. both d. None of the above. Which of these airway changes will affect the delivered tidal volume on a pressure limited ventilator? 1. decrease lung compliance 2. increase lung compliance 3. increase airway resistance a. 1 only b. 1 and 2 only c. 2 and 3 only d. 1, 2 and 3. Which of these airway changes will affect the delivered tidal volume on a volume limited ventilator? 1. decrease lung compliance 2. increase lung compliance 3. increase airway resistance a. 1 only b. 1 and 2 only c. 1, 2 and 3 d. none of the above Monitoring and management of mechanically ventilated patient What do we monitor? 1.Ventilation 2.Oxygenation 3.Airway Pressures : a. Peak Airway Pressure b. Plateau Pressure c. Mean Airway Pressure d. PEEP 4.Lung compliance and Airway resistance 5.Vital signs Monitoring ventilation > the most reliable monitoring tool to check for ventilation is ABG analysis > check for level of PaCO2: 35 – 45 mmHg and pH: 7.35 – 7.45 > OTHER MONITORING TOOLS: A. CAPNOGRAPHY – for continuous monitoring in adult B. TRANCUTANEOUS PCO2 – for continuous monitoring in infants Strategy to improve ventilation on volume limited ventilators > Respiratory Rate and tidal Volume are the 2 parameters that can improve ventilation > Respiratory Rate is the first parameter to consider in improving ventilation > adjusting RR to improve ventilation is more beneficial in control and SIMV modes > Adjusting tidal volumes to improve ventilation can be done in situations where a patient has atelectasis or the set tidal volume is beyond Predicted Body Weight example  To most effectively increase a patients alveolar minute ventilation while the patient is using a volume ventilator in a control mode, you would recommend increasing which of the following? a. FiO2 b. Vt c. RR d. Peak flow rate When a patient is receiving ventilation in a control mode, how may the PaCO2 best be raised? a. increase Vt b. increase FiO2 c. decrease RR d. increase Peak flow rate Other strategies  > If Airway pressures are indicative of barotrauma: a. PEEP > 10 mmHg b. PAP > 50mmHg c. Pplat > 35mmHg > you can use: a. Permissive hypercapnia b. shift to Pressure Control Ventilation Permissive Hypercapnia -> strategy to minimize barotrauma - > Vt of 4-7 ml / kg to keep plateau pressure lower than 35 cmH20  LOW TIDAL VOLUME PEAK ATELECTA RESPIRATORY AIRWAY SIS ACIDOSIS HYPOXEMIA PaCO2 PRESSURE MEAN MAY BE AIRWAY MAY BE CORRECTE NORMALIZED PRESSURE WITH D BICARBONATE BY USING A LIKELIHOOD ON HIGHER OF THROMETHAMI FIO2 BAROTHRAU NE MA Mechanism and physiological changes of permissive hypercapnia example  A 50 kg (110 lb) patient is being mechanically ventilated with the following settings: Mode - Assist/control, FI02 - 1.0, Rate - 12bpm, PEEP - 10 cm H20 , VT - 650 mL, Peak airway pressure - 80 cm H20 Sp02 - 85% : A current chest x-ray shows diffuse bilateral infiltrates. To reduce peak airway pressure which of the following is the most appropriate action? A. Increase the frequency. B. Change to PCV C. increase the FI02. D. Increase PEEP to 15 cm H20.  A 50 kg (110 lb) patient is being mechanically ventilated with the following settings: Mode - Assist/control, FI02 - 1.0, Rate - 12bpm, PEEP - 10 cm H20 , VT - 650 mL, Peak airway pressure - 80 cm H20 Sp02 - 85% : A current chest x-ray shows diffuse bilateral infiltrates. To reduce peak airway pressure which of the following is the most appropriate action? A. Increase the frequency. B. decrease Vt C. increase the FI02. D. Increase PEEP to 15 cm H20.  A 50 kg (110 lb) patient is being mechanically ventilated with the following settings: Mode - Assist/control, FI02 - 1.0, Rate - 12bpm, PEEP - 10 cm H20 , VT - 650 mL, Peak airway pressure - 80 cm H20 Sp02 - 85% : A current chest x-ray shows diffuse bilateral infiltrates. To reduce peak airway pressure which of the following is the most appropriate action? A. Increase the frequency. B. use permissive hypercapnia C. increase the FI02. D. Increase PEEP to 15 cm H20.  Mode: control ABG: Rate: 16 bpm pH 7.21 Vt: 600 ml PaCO2 55 mmHg FiO2: 90% PaO2 74 mmHg PEEP 15 HCO3 24 mEQ/L cmH20 FLOW RATE 60 LPM BE +2 PAP 38 cmH20 The following data are collected from an 80 kg (176-lb) patient with ARDS receiving volume- controlled ventilation and under low tidal volume or permissive hypercapnia strategy. Which of the following is the most appropriate recommendation? a. administer sodium bicarbonate b. increase Flow Rate c. Increase the FiO2 to 1.0 d. Increase the tidal volume to 800 ml  Which of the following conditions does not require high mechanical respiratory rates? a. metabolic alkalosis b. ARDS c. increased intracranial pressure d. metabolic acidosis  Mode: A/C ABG: Rate: 18 bpm pH 7.35 Vt: 800 ml PaCO2 47 mmHg FiO2: 90% PaO2 53 mmHg PEEP 15 HCO3 26 mEQ/L cmH20 PAP 53 cm BE +2 H20 The following data are collected from an 80 kg (176-lb) patient with ARDS receiving volume- controlled ventilation; Which of the following is the most appropriate recommendation? a. Increase PEEP to 20 cm H2O b. Switch to pressure-control ventilation c. Increase the FiO2 to 1.0 d. Increase the tidal volume to 900 ml Strategy to improve ventilation on pressure limited ventilators > Respiratory Rate and PIP are the 2 parameters that can improve Ventilation > Respiratory Rate is the first parameter to consider in improving ventilation > as long as the set rate is not below normal spontaneous rate, the PIP level is adjusted to improve ventilation The most effective way to improve ventilation is to increase tidal volume not Ventilator Rate computation  Mode: Control ABG: Rate: 15 bpm pH: 7.50 Vt: 800 ml PaCO2: 30 mmHg PaO2: 98 mmHg These data have been collected from a patient in a mechanical ventilator. To increase this patients PaCO2 to 40 mmHg, the ventilator rate should be adjusted to what level? a. 10/min b. 11/min c. 12/min d. 13/min Solution: Desired Rate = Rate (current) x PaCO2 (current) ÷ PaCO2 (desired) = 15 x 30 ÷ 40 = 11 bpm  Mode: Control ABG: Rate: 10 bpm pH: 7.30 Vt: 800 ml PaCO2: 50 mmHg PaO2: 98 mmHg These data have been collected from a patient in a mechanical ventilator. To increase this patients PaCO2 to 40 mmHg, the ventilator rate should be adjusted to what level? a. 10/min b. 11/min c. 12/min d. 13/min Monitoring Oxygenation > the most reliable monitoring tool to check for oxygenation is ABG analysis > check for level of PaO2: 80 – 100 mmHg > OTHER MONITORING TOOLS: A. Pulse Oximetry – for continuous monitoring in adult B. TRANCUTANEOUS PO2 – for continuous monitoring in infants Strategy to improve Oxygenation on volume limited ventilators > adjust FiO2 level which is from 21% to 100% > In moderate to severe hypoxemia due to refractory hypoxemia brought about by intrapulmonary shunting, PEEP level is titrated a. PaO2 < 60mmHg with FiO2 of 50% and above b. PaO2/FiO2 (P/F) ratio < 200mmHg > Titrate PEEP to attain OPTIMAL PEEP > Shift to PC-IRV EXAMPLE  A 50 kg (110 lb) patient is being mechanically ventilated with the following settings: Mode - Assist/control, FI02 - 1.0, Rate - 12bpm, PEEP - 10 cm H20 , VT - 650 mL, Peak airway pressure - 80 cm H20 Sp02 - 85% : A current chest x-ray shows diffuse bilateral infiltrates. To reduce peak airway pressure and improve oxygenation, which of the following is the most appropriate action? A. Increase the frequency. B. Change to PC-IRV C. Decrease the FI02. D. Increase PEEP to 15 cm H20. Optimal peep  OPTIMAL PEEP > a PEEP level that improves oxygenation and compliance without decreasing cardiac output. > can be determined by: 1. PaO2 2. PvO2 3. compliance 4. Oxygen Saturation example Which of the following is the optimum peep using compliance PEEP(cmH2O) PAP(cmH2O) PPLAT(cmH2 Vt (ml) O) 4 36 20 500 6 39 22 500 8 42 23 500 10 45 27 500 Which of the following is the optimum peep using compliance PEEP(cmH2O) PAP(cmH2O) PPLAT(cmH2 Vt (ml) O) 5 35 23 500 7 38 25 500 9 40 27 500 11 43 28 500 13 46 33 500 WHICH OF THE FOLLOWING IS THE OPTIMUM PEEP USING PaO2 AND COMPLIANCE AS INDICATOR? Titration of Optimal PEEP using PaO2 and Compliance as Indicator PEEP (cmH20) PaO2 (mmHg) Compliance (ml/cmH20) 0 43 26 5 67 33 8 77 37 10 83 43 12 79 41 WHICH OF THE FOLLOWING IS THE OPTIMUM PEEP USING PaO2 AND COMPLIANCE AS INDICATOR? Titration of Optimal PEEP using PaO2 and Compliance as Indicator PEEP (cmH20) PaO2 (mmHg) compliance 0 45 35 5 63 37 8 76 45 10 81 32 12 79 30 WHICH OF THE FOLLOWING IS THE OPTIMUM PEEP? Titration of Optimal PEEP using PaO2 and Compliance as Indicator PEEP FiO2 % PaO2 Compliance (cmH20) (mmHg) (ml/cmH20) 5 100 47 21 7 100 60 23 9 100 67 27 11 100 78 29 13 100 87 32 15 100 78 28 PvO2 : > partial pressure of venous oxygen tension > normal range is 35 – 45 mmHg > obtained from Pul. Art. Catheter > reflects Titration cardiac of Optimal PEEP output using PaO2 and PvO2 as Indicator PEEP (cmH20) PaO2 (mmHg) PvO2 4 68 34 6 74 37 8 78 33 10 82 32 Weaning from PEEP and high Fi02 Maintain PEEP and Keep Pa02 >60mmHg or Sa02 decrease Fi02 to 40%. > 90% Monitor V/S for acute changes Maintain Fi02 and decrease PEEP to about Keep Pa02 >60mmHg or Sa02 5cmH20 (2-3 cmH20 > 90% increments) Monitor V/S for acute changes Maintain or Discontinue Monitor V/S for hypoxia and PEEP of 5 cmH2O increased WOB  Weaning of FiO2 using O2Sat, PaO2 and vital signs as Indicator PEEP FiO2 O2Sa PaO2 Vital Signs (cmH20) % t (mmHg) 15 100 99 110 normal 15 90 98 98 normal 15 80 98 92 normal 15 70 98 85 normal 15 60 96 82 normal 15 40 95 80 normal  Weaning of PEEP using PaO2 and vital signs as Indicator PEEP FiO2 % O2Sat PaO2 (mmHg) Vital Signs (cmH20) 15 40 99 110 normal 13 40 95 95 normal 11 40 97 88 normal 9 40 96 85 normal 7 40 95 83 normal 5 40 95 78 normal EXAMPLE  To manage a mechanically ventilated patient with ARDS, which of the following would best decrease intrapulmonary shunting? A. increasing the PEEP B. increasing the tidal volume C. increasing the expiratory time D. increasing the respiratory rate  A 6 year old child who weighs 20 kg (44 lbs) is intubated and being mechanically ventilated on the following settings: Mode: A/C , FIO2: 0.80, Set rate: 12 br/min., Total rate: 15 br/min. Tidal volume: 200 ml Arterial blood gas results: pH: 7.48 PaCO2: 31 torr PaO2: 54 torr HCO3: 22 mEq/L  The respiratory care practitioner should recommend which of the following? A. initiate 6 cmH2O PEEP B. decrease the rate to 10 C. increase the tidal volume to 300 ml D. increase the FIO2 to 0.85  Which of the following indicate severely impaired oxygenation requiring high FIO2s and positive end- expiratory pressure? 1. PaO2–PaO2 greater than 350 mm Hg on 100% O2 2. VC less than 10 ml/kg 3. PaO2/FIO2 less than 200 a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1,2, and 3  Which of the following conditions is associated with a lack of response to increased FIO2 in patients receiving positive-pressure ventilation? a. dead space b. shunt c. hypoxemia d. hypoventilation  A patient with ARDS is receiving mechanical ventilation with PEEP. The PEEP level is increased from 5 cmH2O to 10 cmH2O. Which of the following should be monitored by the respiratory therapist to evaluate the patient response. 1. blood pressure 2. heart rate 3. body temperature 4. fluid intake and output a. 1 and 2 b. 1, 2 and 3 c. 1, 2 and 4 d. 2, 3 and 4 e. 1, 2, 3 and 4  After a ventilator patient’s PEEP level is increased from 8 cmH2O to 12 cmH2O, the PvO2 drops from 37 mmHg to 33 mmHg. This indicates which of the following? a. venous return has increased b. tissue oxygenation has increased c. static compliance has increased d. cardiac output has decreased  A mechanically ventilated patient needs to be titrated with PEEP to improve oxygenation: All of the following are used to assess optimal PEEP except: a. PaO2 b. static compliance c. PvO2 d. FiO2 Airway pressures Pressure level that would most likely lead to barotrauma 1. Peak Airway Pressure: > 50 cmH2O 2. PEEP: > 1o cmH2O 3. Plateau Pressure: > 35 cmH2O 4. Mean Airway Pressure: > 30 cmH2O Airway resistance, Dynamic compliance and static compliance  Airway resistance > airflow obstruction in the airway > Normal Value (intubated patient): 5 cmH2O/L/sec > can be monitored on the pressure wave form and P-V loop > can be computed by: Raw = (PIP – Plateau P) PFR  example The following data have been collected from a patient using a volume ventilator: Compute for the Raw: Peak Inspiratory pressure: 35 cmH2O Plateau pressure: 20 cmH2O Peak Flow rate:60 L/min or 1 L/sec Raw = 35 cmH2O – 20 cmH2Op 1 L/sec = 15 cmH2O/L/sec  example The following data have been collected from a patient using a volume ventilator: Compute for the Raw: Peak Inspiratory pressure: 12 cmH2O Plateau pressure: 10 cmH2O Peak Flow rate: 50 L/min  PRESSURE TIME CURVE pressure Paw(peak) Pres Pplat Pres time flow This is a normal pressure-time waveform time With normal peak pressures ( Ppeak) ; plateau pressures (Pplat )and ‘Square wave’ airway resistance pressures (Pres) flow pattern  HIGH AIRWAY RESISTANCE pressure Ppeak Normal Pres e.g. ET tube blockage Pplat Pres time flow The increase in the peak airway pressure is driven time entirely This isby anan increasepressure-time abnormal in the airwayswaveform resistance pressure. Note the normal plateau pressure. ‘Square wave’ flow pattern  Clinical Conditions that increases Airway Resistance Type Clinical Conditions  1. COPD  Emphysema, Asthma  Chronic bronchitis  Bronchitis  2. Mechanical Obstruction  Post intubation obstruction  Foreign body aspiration  ET tube  Condensation in the circuit  3. Infection  Croup  Epiglottitis  Bronchiolitis compliance  Why the need for Compliance Measurement -> because abnormally high or low compliance impairs patients ability to maintain efficient gas exchange. LUNG COMPLIANCE > defined as the ease with which the lung expands > normal value is 80 – 100 ml/cmH2O > can be computed by: Compliance = Volume/pressure  Dynamic Compliance -> is a measurement of airway resistance and lung compliance - > not an accurate measurement of lung compliance - > can be computed: Dynamic Compliance = Corrected Vt______ Peak Pressure – PEEP  Clinical Ranges For critically ill patients: DYNAMIC COMPLIANCE: 30 -40 ml/cmH2O Note: much lower in intubated patients example  Given the following data, calculate the patients dynamic compliance. Vt: 600 ml PIP: 35 cmH2O PEEP: 5 cmH2O Dynamic Compliance = Corrected Vt______ Peak Pressure – PEEP Dynamic CL = 600 ml 30 cmH2O = 20 ml/cmH2O  Given the following data, calculate the patients dynamic compliance. Vt: 500 ml PIP: 25 cmH2O PEEP: 5 cmH2O  HIGH AIRWAY RESISTANCE pressure Ppeak Normal Pres e.g. ET tube blockage Pplat Pres time The increase in the peak airway pressure is driven entirely This isby anan increasepressure-time abnormal in the airwayswaveform resistance pressure. Note the normal plateau pressure.  Static Compliance > more accurate measurement of lung compliance > measured with no air flowing through airways > use in determining optimal PEEP > can be computed by: Static CL = Corrected Vt Plateau Pressure – PEEP  Clinical Ranges For critically ill patients: STATIC COMPLIANCE: 40 – 60 ml/cmH2O Note: much lower in intubated patients example  example Given the following data, calculate the patients static compliance. Vt: 800 ml PPlat: 25 cmH2O PEEP: 5 cmH2O Peak P: 45 cmH2O Static CL = Corrected Vt Plateau Pressure – PEEP Static CL = 800 ml 20 cmH2O = 40 ml/cmH2O  example Given the following data, calculate the patients static compliance. Vt: 700 ml PPlat: 20 cmH2O PEEP: 5 cmH2O Peak P: 35 cmH2O Tubing compression Factor (TCF): 3 ml/cmH2O Corrected Vt = Vt – (Peak P X TCF) = 700 ml – (35 cmH2O x 3 ml/cmH2O) = 700 ml – 105 ml = 595 ml  example SOLUTION: Static CL = 595 ml 15 cmH2O = 39.6 ml/cmH2O  example Given the following data, calculate the patients static compliance. Vt: 500 ml PPlat: 15 cmH2O PEEP: 5 cmH2O Peak P: 25 cmH2O Tubing compression Factor (TCF): 3 ml/cmH2O  DECREASE COMPLIANCE Paw(peak) pressure Normal Pres e.g. ARDS Pplat Pres time flow The increase in the peak airway pressure is driven by the decrease in the lung compliance. time This is an abnormal Increased pressure-time airways resistance waveform is often also a part of this scenario. ‘Square wave’ flow pattern Clinical conditions that decrease Compliance Type of Compliance Clinical Condition  Static Compliance  ARDS  Atelectasis  Tension Pneumothorax  Obesity  Retained Secretions in the lungs  Bronchospasm  Dynamic  Kinking of ET tube Compliance  Airway Obstruction  Retained secretions in the airways  Points to remember - conditions causing changes in plateau pressure and static compliance invoke similar changes in peak inspiratory pressure and dynamic compliance - conditions where airflow resistance is increased, the peak inspiratory pressure is increased, while the plateau pressure stays unchanged. examples  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 28 cmH2O 10 cmH20 700 am 34 cmH2O 10 cmH2O 8:00 am 42 cmH2O 10 cmH20 What does it indicate: a. an increasing in airway resistance b. a decreasing in dynamic compliance  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 28 cmH2O 10 cmH20 700 am 34 cmH2O 10 cmH2O 8:00 am 42 cmH2O 10 cmH20 Which of the following conditions could manifest these changes: a. kink ET tube b. patient biting the ET tube c. bronchospasm d. airway obstruction  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 42 cmH2O 10 cmH20 700 am 34 cmH2O 10 cmH2O 8:00 am 28 cmH2O 10 cmH20 What does it indicate: a. a decreasing in airway resistance b. an increasing in dynamic compliance  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 28 cmH2O 10 cmH20 700 am 34 cmH2O 20 cmH2O 8:00 am 42 cmH2O 30 cmH20 What does it indicate: a. a decreasing static compliance b. a decreasing dynamic compliance  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 28 cmH2O 10 cmH20 700 am 34 cmH2O 20 cmH2O 8:00 am 42 cmH2O 30 cmH20 Which of the following conditions could manifest these changes: 1. obesity 2. retained secretions in the lungs 3. ARDS 4. atelectasis  TIME PEAK PRESSURE PLATEAU PRESSURE 6: 00 am 42 cmH2O 30 cmH20 700 am 34 cmH2O 20 cmH2O 8:00 am 28 cmH2O 10 cmH20 What does it indicate: a. an increasing or improving static compliance  A 58-year-old man is being mechanically ventilated. During a routine ventilator check, the respiratory therapist notices that the static lung compliance has remained constant, while the dynamic lung compliance has decreased over 2 hours. The most likely reason for this change is: A. Increased airway resistance. B. Noncardiogenic pulmonary edema. C. Decreased tidal volume. D. Development of atelectasis.  It is important to monitor airway pressure in a patient receiving mechanical ventilation because it best reflects: A. lung compliance B. PaO2 C. PaCO2 D. ICP  A respiratory care practitioner reviews a ventilator parameter sheet and finds that the peak inspiratory pressure has been gradually rising for the past several hours. Which of the following could be the cause for this change? I. Bronchospasm II. Increasing pulmonary compliance III. Accumulation of secretions IV. Increasing airway resistance A. III only B. I & III only C. I, III & IV D. I, II, III &IV Calculation of compliance is also important in the determination of optimal peep level PEEP(cmH2O) PAP(cmH2O) PPLAT(cmH2 Vt (ml) O) 5 36 21 500 7 40 23 500 11 43 26 500 12 48 29 500 Which of the following is the best PEEP?  WHICH OF THE FOLLOWING IS THE BEST PEEP PEEP (cmH20) PaO2 (mmHg) Compliance (ml/cmH20) 0 43 26 5 67 33 8 77 37 10 83 43 12 79 41  Which of the following could cause an increase in Peak Inspiratory Pressure on a volume ventilator? 1. decrease compliance 2. decrease Raw 3. Partially occluded ET 4. High Inspiratory Flow setting a. 1 and 2 b. 2 and 3 c. 1, 3 and 4 d. 1, 2, 3 and 4 weaning  > is the process of abruptly or gradually widrawing ventilator support when the cause of respiratory failure is under resolution. Weaning Success -> is able to maintain normal spontaneous breathing 48 hours following extubation Weaning Failure - means failure of the patient to sustain normal spontaneous breathing 48 hours after extubation. Weaning in Progress -> patients who are extubated but continue to receive ventilatory support by Non Invasive Ventilation. -> purposely to prevent complications of long term mechanical ventilation signs of Weaning Failure CLINICAL SIGNS 1. tachypnea 2. Tachycardia 3. Hypertension 4. Hypotension 5. Hypoxemia 6. acidosis 7. arrhytmias signs of Weaning Failure PHYSICAL SIGNS 1. agitation 2. distress 3. diminished mental status 4. diaphoresis 5. increased work of breathing Patient Condition Prior to Weaning Two (2) important points pertaining to the patients clinical condition: 1. Recovery from the acute phase of the disease or injury that prompted the need for MV. 2. Absence of clinical conditions that may interfere with the patients ability to maintain work of breathing. Weaning Criteria -> evaluate readiness for weaning trial and the likelihood of weaning success.  Common Weaning Criteria CATEGORY EXAMPLE Note Clinical Criteria Resolution of acute phase of disease Adequate cough Absence of excessive secretions Cardiovascular and hemodynamic stability no anemia, fever or electrolytes imbalance Ventilatory Spontaneous breathing Trial Tolerates 20 – 30 Criteria minutes PaCO2 < 50 mmHg w/ normal ph Vital Capacity > 10 ml/kg Spontaneous Vt > 5 ml/kg Spontaneous f (RR) < 25 / min f / Vt (RSBI) < 105 breaths / min / L Minute Ventilation < 10 L with satisfactory ABG Occlusion Pressure in 0.1 sec < 6 cmH2O  Common Weaning Criteria CATEGORY EXAMPLE Note Oxygenation PaO2 without PEEP > 60 mmHg @ Fio2 up to Criteria 0.40 PaO2 with PEEP (< 8 cm > 100 mmHg @ Fi02 up H2O) to 0.40 SaO2 > 90% @ Fi02 up to 0.40 Qs/Qt < 20% P(A-a)O2 < 350 mmHg @ Fi02 of 1.0 PaO2/FiO2 (P/F) > 200 mmHg Pulmonary Reserve Vital Capacity > 10 ml / kg MIP > – 20 cmH20 in 20 sec Pulmonary Static Compliance > 30 ml/cmH20 Measurements Airway Resistance Stable or improving VD/Vt < 60% while intubated Respiratory to Tidal Volume Ratio (RSBi) -> Evaluates the presence and severity of a spontaneous breathing that is rapid (High RR) and shallow (low Vt) - > most reliable among all other weaning criterias Equation: RSBi = f/Vt example Respiratory to Tidal Volume Ratio (RSBi) Example: Calculate the RSBi given the spontaneous respiratory rate of 14 bpm and Vt of 0.5 L (500ml). Does this index indicate a successful weaning? Solution: RSBi = f/Vt = 14 bpm/0.5 L = 28 breaths/min/L Calculate the RSBi of a patient whose spontaneous respiratory rate is 20 bpm and Vt of 500 ml. Does this index indicate a successful weaning? Weaning modes T – piece weaning - an abrupt discontinuation of MV and resumption of spontaneous breathing through a T – tube system. - > SIMPLEST weaning method - > single trial lasting up to 2 hours if tolerated SIMV -> A pre set number of volume controlled breaths are set while allowing spontaneous breaths without assistance -> Gradual decrease in mandatory breaths until such time that the back up rate of 4 or less is achieved. - > When used in conjunction with Pressure Support Ventilation, decrease Pressure Support level first at 5 – 10 cmH2O before decreasing back up rate. Pressure Support Ventilation - > Gradual reduction of PSV level until a minimum of 5 cmH2O is reached - > prevents activation of accessory muscles - > Has the highest weaning outcome in weaning trials Signs of Weaning Failure - tachypnea - use of accessory muscles - paradoxical abdominal movements - dyspnea - chest pain - diaphoresis - delirium Terminal Weaning - Withdrawal of MV that results in the death of the patient - Due to the following Reasons: 1. patients informed request 2. medical futility 3. reduction of pain and suffering 4. Fear and distress examples  1. A 60 y/o COPD patient who was confined due to acute myocardial infarction is on mechanical ventilator, if weaning is to consider, which of the following would be your first consideration? a. Primary medical problem b. COPD issues c. Fluid status of the patient d. oxygenation  2. Which of the following indicates that weaning should not be attempted? a. cessation of use of sedatives and neuromuscular blocking agents b. continuous use of dopamine and dobutamine drip c. normal potassium level d. PaO2 of >60 mmHg at FiO2 of <.40  3. A method of weaning that imposes abrupt discontinuation of respiratory support. a. Pressure support weaning b. SIMV weaning c. Non Invasive Ventilation d. T piece weaning  5. A patient is currently ventilated on volume ventilator on an A/C mode with the following settings. RR: 12 , FiO2: 40%, PEEP of 5 cmH2O. His vital signs are normal and all other lab results are within normal limits: His ABG are as follows: pH: 7.37, PaCO2: 45 mmHg, PaO2: 78 mmHg, HCO3: 23 mEq Which of the following would you recommend? a. Decrease FiO2 to 30% b. Decrease PEEP to 3 cmH2O c. recommend for weaning trial d. Extubate the patient  Mode: SIMV ABG: Rate: 6 bpm pH 7.35 Vt: 700 ml PaCO2 43 mmHg FiO2: 40% PaO2 98 mmHg Pressure 25 Support cmH20 A postoperative patient is to be weaned from mechanical ventilation. The following ventilator settings are being used Which of the following should the respiratory therapist recommend to begin weaning this patient? a. Decrease the FiO2 b. Decrease pressure support c. Decrease VT d. Increase inspiratory flow  Mode: SIMV ABG: Rate: 10 bpm pH 7.24 Vt: 700 ml PaCO2 57 mmHg Total rate 28 bpm PaO2 66 mmHg FiO2 35 % HCO3 23 mEq/l Peak Flow Rate 25 LPM Pressure Support 10 cmH2O The patient is tachypneic and agitated and the high pressure alarm is triggering with each breath. On the basis of these information: Which of the following should the respiratory therapist recommend? a. increase peak flow rate b. increase FiO2 c. increase pressure support d. Increase tidal volume  For successful weaning, a patient generally needs a vital capacity of at least a. 5 ml/kg. b. 7 ml/kg. c. 10 ml/kg. d. 15 ml/kg.  Which of the following values are not indicative of weaning? a. PaO2 of 83 mmHg b. PEEP of 5 cmH2O c. FiO2 of 40% d. none of the above  For successful weaning, your patient's negative inspiratory pressure should be at least a. -10 cm H2O. b. -15 cm H2O. c. -20 cm H2O. d. -30 cm H2O.  Which weaning method provides a gradual transition from ventilatory support to spontaneous breathing while maintaining a patent airway with an ET tube? a. T-piece b. PSV c. CPAP d. SIMV  A mechanically ventilated patient is recovering from a drug overdose has a PaO2 of 76 mmHg on 30% oxygen. What is the PaO2/FiO2 (P/F) index: a. 350 b. 253 c. 479 d. 135  A physician wants to wean a patient from a ventilator. Which of the following measurements obtained by an RT indicative of a successful weaning? 1. MIP of – 41 cmH2O 2. P (A-a) O2 190 mmHg at 1oo% FiO2 3. Vital capacity of 14 ml/kg A. 1 only B. 1 & 3 only C. 2 and 3 only D. 1, 2 and 3  Which of the following weaning parameters is the most reliable indicator of a successful weaning: a. MIP b. RSBi c. P/F ratio d. PaCO2  Which is most likely a sign of weaning intolerance in your patient? a. heart rate of 90 beats/minute b. BP of 185/104 c. respiratory rate of 24 breaths/minute d. Spo2 of 92%  Which of the following indicates that the patient should not be extubated? a. VC: 18 ml/kg, MIP: - 40 cmH2O, VD/Vt: 30 % b. VC: 16 ml/kg, MIP: - 80 cmH2O, VD/Vt: 40% c. VC: 14 ml/kg, MIP: - 16 cmH2O, VD/Vt: 50% d. VC: 16 ml/kg, MIP: - 80 cmH2O, VD/Vt: 55%  Mode: SIMV ABG: Rate: 6 bpm pH 7.44 Vt: 700 ml PaCO2 34 mmHg FiO2: 35 % PaO2 89 mmHg HCO3 24 mEq/l Based on the following data, the therapists should recommend which of the following? a. administer NaHCO3 b. extubate the patient c. Decrease VT to 600ml d. decrease Rate to 4/min Ventilator alarms and trouble shooting Alarms that signal leak in the system 1. Low Pressure alarm : set at 5 to 10 cmH2O below PIP 2. Low PEEP alarm: set 2 to 4 cmh2O below baseline level 3. Low Tidal volume alarm: set approximately 10% below the set Tidal volume Apnea alarm -> set between 10 to 15 seconds -> signals that no breath is being taken or delivered to the patient High pressure alarm -> should be set 5 to 10 cmH2O above PIP -> signals the presence of increasing airway resistance or decrease in compliance. -> activation in volume ventilator will lead to premature cycling to expiration delivering a decrease Vt. EXAMPLE  A patients low pressure alarm is triggered persistently. The likely causes of this condition include all of the following except: a. Disconnection of the ventilator circuit b. Kinking of the endotracheal tube c. leak in the humidifier d. Leakage of the ET cuff tub  A patients high pressure alarm is triggered persistently. The likely causes of this condition include all of the following except: a. bronchospasm b. coughing c. high pressure alarm set too high d. mucus plug  A patient was given a paralyzing drug and is receiving mechanical ventilation. Which of the following ventilator alarms would be the most important? A. low pressure B. high pressure C. High RR D. High minute ventilation examples  Venous return is least impaired by which of the following ventilator settings? A. SIMV mode, rate of 12bpm B. Control mode, rate of 10bpm C. A/C mode, rate of 10 bpm D. SIMV mode, rate 8 bpm A 70 kg male patient suffering from ckd is using a volume ventilator in an a/c mode. Appropriate data from his chart are as follows: ABG: Vt: 700ml PFR: 60LPM pH: 7.21 Rate: 12/min PCO2: 28 mmHg FiO2: 50%PaO2: 98 mmHg PEEP: 5 cmH2O HCO3: 10.0 mEq What changes would you recommend base on ABG? 1. Increase PEEP 2. increase rate 3. increase FiO2 to 70% 4. None of the above  Mode: control ABG: Rate: 16 bpm pH 7.55 Vt: 600 ml PaCO2 45 mmHg FiO2: 60 PaO2 81 mmHg PEEP 5 cmH20 HCO3 35 mEQ/L FLOW RATE 50 LPM BE +11 PAP 22 cmH20 The following data are collected from a 60 kg patient receiving volume-controlled ventilation. Which of the following is the most appropriate recommendation? a. administer sodium bicarbonate b. decrease Flow Rate c. decrease the tidal volume to 800 ml d. none of the above A 70 kg male patient suffering from ckd is using a volume ventilator in an a/c mode. Appropriate data from his chart are as follows: ABG: Vt: 700ml PFR: 60LPM pH: 7.21 Rate: 12/min PCO2: 28 mmHg FiO2: 50%PaO2: 98 mmHg PEEP: 5 cmH2O HCO3: 10.0 mEq What changes would you recommend base on ABG? 1. Increase PEEP 2. increase rate 3. increase FiO2 to 70% 4. Administer sodium bicarbonate A 75 kg male patient is using a volume ventilator in the control mode. Appropriate data from his chart are as follows: ABG: Vt: 700ml PFR: 60LPM pH: 7.28 Rate: 12/min PCO2: 54 mmHg FiO2: 50%PaO2: 74 mmHg PEEP: 5 cmH2O HCO3: 25 mEq What changes would you recommend base on ABG? 1. Increase PEEP 2. increase rate 3. increase FiO2 to 70% 4. Increase Vt to 750 ml A patient weighing 80kg is using a volume ventilator in the control mode. Pertinent data as follows: ABG: Vt: 800ml PFR: 60LPM pH: 7.41 Rate: 12/min PaCO2: 37 mmHg FiO2: 60% PaO2: 137 mmHg PEEP: 8 cmH2O HCO3: 26 mEq What changes would you recommend base on ABG? 1. Decrease FiO2 to 50% 2. decrease Vt to 700ml 3. decrease rate to 10 4. Decrease PEEP to 6 cmH2O A 46 y/o 50 kg male is mechanically ventilated with a volume ventilator in A/C mode with data as follows: ABG: Vt: 500ml pH: 7.48 Rate: 12/min PaCO2: 27 mmHg FiO2: 30% PaO2: 53 mmHg What changes would you recommend base on ABG? 1. Decrease rate to 8 2. Decrease Vt to 450 ml 3. Increase FiO2 to 50% 4. Begin PEEP at 8 cmH2O A patient is using a Pressure ventilator in control mode with the following settings: ABG: PIP: 30 cmH2O pH: 7.50 Rate: 10/min PaCO2: 29 mmHg FiO2: 35% PaO2: 97 mmHg I:E Ratio: 1:3 HCO3: 25 mEq What changes would you recommend base on ABG? 1. Change I:E ratio 2. Decrease FiO2 3. Decrease PIP 4. Decrease RR A 60 kg (132lbs) female patient is using a volume ventilator in a control mode with the following settings: ABG: Vt: 800ml pH: 7.52 Rate: 12/min PaCO2: 28 mmHg FiO2: 40% PaO2: 92 mmHg What changes would you recommend base on ABG? 1. decrease FIO2 to 50% 2. Add PEEP of 5 cmH2O 3. decrease rate to 6/min 4. Decrease Vt to 600 ml A patient is currently hook on a volume ventilator in assist control mode with the following settings. What would be your recommendation based on the abg? ABG: Vt: 750ml pH: 7.52 Rate: 12/min PaCO2: 28 mmHg FiO2: 40% PaO2: 92 mmHg What changes would you recommend base on ABG? 1. decrease FIO2 2. Add PEEP 3. decrease rate 4. Decrease Vt  THANK YOU AND GOD BLESS!!!