ABG Analysis Study Guide PDF - Respiratory Failure

ABG Analysis Normal Values: ​ pH: ​ 7.35 – 7.45 ​ PaCO2: ​ 45 – 35 ​ HCO3: ​ 22 – 26 ​ PaO2: ​ 80 – 100 ​ O2%: ​ 95 – 100% pH: A measure of the hydrogen ion concentration of the blood. PaCO2: A measure of the partial pressure...

ABG Analysis Normal Values: ​ pH: ​ 7.35 – 7.45 ​ PaCO2: ​ 45 – 35 ​ HCO3: ​ 22 – 26 ​ PaO2: ​ 80 – 100 ​ O2%: ​ 95 – 100% pH: A measure of the hydrogen ion concentration of the blood. PaCO2: A measure of the partial pressure of CO2 in arterial blood; indicates the effectiveness of ventilation in the lungs. PaCO2 moves in the opposite direction of the pH. HCO3: Part of the body’s acid-base balance buffer; it moves in the same direction as the pH. PaO2: A measurement of the partial pressure exerted by O2 dissolved in arterial blood. O2%: Represents the percentage of hemoglobin actually carrying O2 as opposed to the percentage that could carry O2 (100%) Acute Respiratory Failure (ARF) What is it? Failure to ventilate and/or oxygenate which causes failure of gas exchange (O2, CO2, both) ​ Criteria for acute respiratory failure are based on ABG values. More information: ​ Ventilatory failure is due to a mechanical abnormality of the lungs or chest wall, impaired muscle function (especially the diaphragm), or malfunction in the respiratory control center in the brain. ​ Oxygenation failure can result from a lack of perfusion to the pulmonary capillary bed (pulmonary embolism) or a condition that alters gas exchange medium (pulmonary edema, pneumonia) ​ Both inadequate ventilation and oxygenation can occur in clients who have diseased lungs (asthma, emphysema, or cystic fibrosis). Combined failure leads to more profound hypoxemia than either ventilatory failure or oxygenation failure alone. Two types of ARFs: ​ Type 1: Hypoxemic: when not enough O2 in blood to perfuse to tissue ○​ ABG analysis: ​ PaO2 < 60 mmHg ​ Type 2: Hypercapnic: : when there is too much CO2 and body can’t get rid of it, altering pH as a result ○​ ABG analysis: ​ PaCO2 > 50 mmHg ​ pH < 7.35 What can ARF lead to? Multi organ failure & Death from failure of gas exchange Causes of ARF ​ Impaired ventilation/hypoventilation (extrapulmonary): due to impaired muscle function or neurological depression ○​ Neurological depression ​ Medications or drug overdose ​ Narcotics analgesia ​ Sedatives ​ Anesthesia ​ Increased ICP (head injury, stroke) ○​ Nerve impairment ​ Spinal cord injury (C4 and up): nerve impairment ​ Inflammation/diseases (myasthenia gravis) ○​ Fatigue of respiratory muscles ​ Chest wall injury (flail chest) ​ Impaired gas exchange/oxygenation (pulmonary): due to pulmonary damage or fluid (alveoli cannot exchange gas & lack of perfusion to capillary beds) ○​ Inhalation of toxic gasses ○​ Pneumonia (infection) ○​ Sepsis ○​ Pulmonary edema (fluid in lungs) ○​ Pneumothorax (air leaks in lungs, collapsed lung) ○​ Pleural effusion (fluid in pleural cavity) ○​ Atelectasis (lung collapsed) ○​ Emphysema (damaged alveoli, impaired gas exchanged) ​ Airway obstruction: prevent flow into lungs (thickening of airway wall, blockage, compression) ○​ Pulmonary edema ○​ Cystic fibrosis ○​ Asthma ○​ COPD ○​ Blockage of foreign body Oxyhaemoglobin Dissociation Curve: describes the relation between the partial pressure of oxygen (x axis) and the oxygen saturation (y axis) Diagnostics: ​ ABGs (gold standard) ○​ PaO2 < 60 ○​ PaCO2 > 50 ○​ pH < 7.30 ○​ SaO2 < 90 ​ Chest x-ray (determine underlying cause)  ○​ Ex. Pulmonary edema ​ Labs ​ Cultures (Blood and sputum prior to antibiotic therapy) ​ CT scan ​ ETCO2 (the level of CO2 that is released at the end of an exhaled breath, 35-45) Clinical manifestations: depends on type of resp. failure ​ Altered mental status (first sign cause of hypoxia) ○​ Agitation ○​ Restlessness ○​ Confusion ​ Tachycardia ​ Tachypnea (rapid, shallow breathing) ​ Pallor ​ Mild increased work of breathing- paradoxical breathing (opposite movement of breathing, chest wall goes in during taking a breath) ​ Use of accessory muscles ​ SOB Nursing management: Support oxygenation & ventilation!! Many causes of resp failure are treatable, and may require aggressive support of oxygenation and ventilation to allow time for underlying problems to resolve. ​ Goal: ○​ Proper oxygenation (correct hypoxemia) ​ PaO2 > 60 ​ SaO2 > 90% ○​ Improve ventilation (correct resp. acidosis) ​ PaCO2 < 50 ​ pH > 7.30 ○​ Rest ventilator muscles ​ Maintain a patent airway and monitor respiratory status every hour and more often as needed ​ Non-invasive support (pt condition will dictate if able) ○​ Non-rebreather mask ○​ High-flow O2 (after non-rebreather) ○​ BiPAP/CPAP ​ Invasive support (when is this indicated??) ○​ Intubate & mechanically ventilate (for better airway & proper ventilation) ​ Hemodynamic monitoring if needed (PEEP) ​ Assess lung sounds ​ Assess and document sputum color, amount, and consistency ​ Pulmonary hygiene ○​ Augmented coughing: pressure of base of lungs when coughing  ○​ Huff coughing: say the word ○​ Staged coughing: press on diaphragm when coughing ​ Suctioning ​ Humidification when giving oxygen (to prevent dryness) ​ Hydration ​ Monitor vital signs and assess pain level Treatment: ​ Medications ○​ Steroids for airway inflammation ○​ Albuterol for bronchospasms ○​ Expectorant and mucolytics for pulmonary congestion ○​ Benzodiazepines (lorazepam) ​ Reduces anxiety and resistance to ventilation ○​ Antibiotics (vancomycin) ​ Treats infection Acute respiratory distress syndrome (ARDS) What is it? Sudden progressive form of acute respiratory failure ​ Acute diffuse alveolar inflammation & Subsequent damage (Life threatening!!) ​ Patho​ ​ ○​ Direct damage or systemically inflammatory response like sepsis (common) injures/weaken the alveolar capillary membrane and become permeable to intravascular fluid (gets filled with fluid) ​ A reduction is surfactant weakens the alveoli, which causes collapse or filling of fluid, leading to worsening edema ○​ Decrease gas exchange in alveoli due to less surface area and collapse from fluid entering, which leads to hypoxia ○​ Intrapulmonary shunt (V/Q mismatch) ​ Good perfusion without good gas exchange ​ Patient won’t really respond to O2 administration alone ○​ Can lead to pulmonary fibrosis (scarred lungs) Causes: Not just one disease! ARDs is a expected response to many etiologies) ​ Primary/direct: direct damage to alveolar membrane (damage & inflammation) ○​ Aspiration ○​ Pneumonia ○​ Drowning ○​ Toxic inhalation ○​ Blunt trauma (pulmonary contusion) ​ Secondary/Indirect: Damage to capillary membranes (systemic inflammation) ○​ Sepsis (most common cause) ○​ Shock  ○​ Fat embolism ○​ Trauma ○​ Blood transfusion Diagnostics: ​ Chest x-ray (test to diagnose) ○​ Diffuse infiltrates or “white-out” because of consolidation and widespread infiltrates throughout the lungs ○​ Indicates diffuse alveolar damage Clinical manifestations: ​ Dyspnea, tachypnea, cough ​ Restlessness ​ Crackles (fluid collection) ​ Dense patchy bilateral pulmonary infiltrates (shown in chest x-ray) ​ Severe hypoxemia despite administration of 100% oxygen Late manifestations: ​ Increased WOB ​ Tachypnea, cyanosis, pallor ​ Diffuse crackles ​ ABGs- refractory hypoxemia & hypercapnia (more severe) ​ P/F ratio poor (PaO2:FiO2: the worse it is = more severe respiratory failure) ​ Chest x-ray: white-out (diffuse- extensive bilateral) Nursing management: Support oxygenation & ventilation!! Many causes of ARDs are treatable, and may require aggressive support of oxygenation and ventilation to allow time for underlying problems to resolve. ​ Supporting oxygenation: ○​ Bi-PAP (start with least invasive) ○​ Intubation with mechanical ventilation (If hypoxemia worsens) ​ Lung protective Mechanical ventilation/volume settings to reduce risk of lung damage (high risk of barotrauma & volutrauma from resistance of ARDs lungs) ​ Low tidal volume ​ Low pressure ​ Permissive hypercapnia (maintain pH) ​ PEEP! (positive end expiratory pressure) ○​ High PEEP = high mean airway pressure ○​ To prevent alveolar collapse during expiration ○​ Increase intrathoracic pressure which decreases cardiac output and can lead to hypotension ​ Hemodynamic monitoring  ○​ Paralytic therapy ​ Neuromuscular blocking agents (NMBAs) ​ Ensure deep sedation before paralytics started ​ to help compliance on ventilator & prevent fighting against vent ○​ Proning: last strategy effort- used when not responding to other therapies ​ Positioning patient lying face down in prone positioner to improve oxygenation ​ Used during covid ○​ ECMO (for severe ARDS, life threatening) P:F ratio low ​ Machine that oxygenate blood without need for functional lungs ​ Allows minimally ventilate lungs (prevent barotrauma) ​ Continuous lateral rotation (kinetic therapy) ○​ Bed that rotates laterally alters client positioning to reduce atelectasis and improve ventilation ○​ Begin slowly and gradually increase degree of rotation as tolerated ○​ Stop if client becomes distressed ○​ Skin care to prevent breakdown ○​ Sedate as needed ARDS complications ​ Ventilator associated pneumonia (VAP) ○​ Ventilation protocol bundle ​ Elevate HOB 30-45 degrees ​ Daily “sedation holidays” (waking up patient to assess neuro & readiness to extubate) ​ VTE prophylaxis (decrease risk of DVT and PE) ​ Oral care every 4 hours with chlorhexidine ​ Barotrauma: damage to the lungs by positive pressure (PEEP) ○​ Monitor oxygenation status & chest x-ray ○​ Assess for crackles ○​ Monitor high-pressure ventilator alarm (indicate pneumothorax) ​ Volutrauma: damage to lungs by volume delivered from one lung to the other (lung overdistention) ​ High risk for stress ulcers ​ VTE ​ AKI (acute kidney injury) from dialysis/CRRT ○​ Continuous renal replacement therapy (CRRT) when treating underlying cause of shock for ARDs Respiratory Management & Mechanical Ventilation Oxygen masks ​ Nasal cannula ○​ O2: 24-44%  ○​ Flow rate: 1-6 L/min ​ Venturi mask ○​ O2: 24-60% ○​ Flow rate: 4-12 L/min ​ Non-rebreather mask ○​ O2: 60-90% ○​ Flow rate: 10-15 L/min ​ High-flow Nasal Cannula ○​ O2: up to 100% ○​ Flow rate: up to 60 L/min ○​ Can use humidification Nursing care for oxygen masks: ​ Assess frequently to ensure accurate flow rate ​ Make sure tubing is free of kinks ​ Assess for skin breakdown (especially under mask & on the nares) Noninvasive Positive-Pressure Ventilation -(usually used post extubation) ​ CPAP (continuous positive airway pressure) ○​ Delivers same amount of pressure at all times ○​ No set rate or tidal volume ○​ Pt breathes at their own spontaneous tidal volumes ○​ Useful for hypoxemic resp failure ​ BIPAP (bilevel positive airway pressure) ○​ 2 levels of pressure support ​ Inspiratory (IPAP): high pressure during inspiration ​ Helps remove CO2 ​ Expiratory (EPAP): lower pressure during expiration ​ Keeps alveoli open ○​ Useful for hypercapnic resp failure or combination ○​ Good option to prevent intubation ○​ Think support for patient taking breath which helps with ventilation Nursing care for CPAP & BIPAP: ​ Assess pt LOC, hemodynamic stability, and WOB (work of breathing) ​ Assess mask size and fit ​ Assess skin for breakdown due to tight seal (leak proof mask) ​ Raise HOB 30-45 degrees (risk for aspiration) ​ Provide mouth, nares, and eye care ​ Check oxygen percentage for inspiratory pressure and expiratory pressure when client is receiving BIPAP What to do when CPAP & BIPAP don't work? ​ Intubate and put on a mechanical ventilator Endotracheal Intubation Intubation: Insertion of an ETT (endotracheal tube) into the trachea through the mouth (easier) or nose Goals: ○​ Establish the airway ○​ Assist in secretion removal ○​ Protection from aspiration ○​ Provide mechanical ventilation ​ Placement ○​ Usually done by nurse anesthetist, anesthesiologist, or physician ○​ Chest x-ray verifies correct placement ○​ End of ET tube (cuff) is inflated to ensure placement and seal ○​ Patient cannot talk once cuff is inflated Nurse’s role during Intubation? ​ Know proper equipment and its use ​ Have resuscitation equipment to include manual resuscitation bag with a face mask at bedside at all times ​ Anticipate rapid sequence intubation (intubation equipment on standby) ​ Position the patient (supine with neck flexion) ​ Ensure intubation attempts last no longer than 30 seconds and then reoxygenate before another attempt ​ Auscultate for breath sounds bilaterally after intubation ​ Provide suction as necessary ​ Monitor vital signs and verify ET tube placement by checking carbon dioxide levels with detector & chest x-ray ​ Stabilize ET tube with tube-holding device or tape ​ Provide information and reassurance ​ Monitor for hypoxia, dysrhythmias, & aspiration Equipment needed for endotracheal intubation: A.​ stylet (disposable) B.​ endotracheal tube with 10-mL syringe for cuff inflation C.​ laryngoscope handle with attached curved blade (left) and straight blade (right) D.​ water-soluble lubricant E.​ colorimetric carbon dioxide detector to check tube placement F.​ tape or G.​ commercial device to secure tube H.​ Yankauer disposable pharyngeal suction device I.​ Magill forceps (optional) J.​ Additional equipment, not shown, includes suction source and stethoscope. Types of ETT ​ Cuffed endotracheal tube ​ Uncuffed endotracheal tube ​ Laryngospasm airway (LMA) ​ ETT with Subglottic suction How do you check correct placement of the ETT in the trachea vs incorrect placement in the esophagus? ​ Auscultate the epigastric and lung fields for bilateral breath sounds and expansion (rise and fall) ​ Make sure a portable CXR (chest x-ray) is ordered to confirm tube placement (should be at least 4 cm (5-7 cm) above carina in neutral position of the neck) ​ CO2 detector ​ Secure tube (tape or commercial device) Post-intubation Nursing management: ​ Confirm placement ​ Secure and maintain ETT placement ​ Document tube placement in cm at client’s lip line (cm line on ETT) ​ Maintain & monitor cuff pressure (indicates proper seal) ○​ Always at 15 - 20 H20 ​ Monitor oxygenation and ventilation ○​ ABGs 15-30 min post intubation ​ Maintain tube patency ○​ Assess and confirm placement ○​ Apply soft wrist restraints according to hospital Protocol to prevent extubation ○​ Use caution when moving patient ○​ Suction oral secretions (always get vitals and hyperoxygenate before suctioning) ○​ Support ventilator tubing to prevent mucosal erosion ○​ Have resuscitation bag with face mask available at bedside at all times incase of ventilator malfunction or accidental extubation (BMV)200 ​ Provide oral care ​ Foster comfort and communication ○​ SEDATE!! (used to prevent hyperventilation, pt fighting the machine) ​ Analgesics: morphine ​ Sedatives: propofol, diazepam ○​ Ulcer preventing meds: PPIs (omeprazole) ○​ Antibiotics for infection ​ Assess skin integrity ○​ Reposition ETT every 24 hours or according to protocol ​ Assess respiratory status every 1-2 hours  ○​ Monitor RR, rhythm and effort, lung sounds, and O2 to determine client’s need for O2 ○​ Manifestations of hypoxemia (SOB, tachypnea, tachycardia, pallor) ​ Monitor and document ventilator settings every hour ○​ Rate, fiO2, tidal volume ○​ Mode of ventilation’ ○​ Use of adjuncts (PEEP, CPAP) ○​ Monitor ventilator alarm sounds ​ Low pressure alarm (indicates low exhaled volume due to disconnection, leak or tube displacement) ​ If persists, ventilate patient with bag valve attached ETT ​ High pressure alarms (indicates excess secretions, tubing kinks, coughing, pulmonary edema, water trapped in lines) ​ Apnea alarms (indicates respirations undetected) ​ Start at the lowest flow to correct hypoxemia and gradually discontinue oxygen (weaning) ​ Monitor the client during the weaning process for signs of weaning intolerance ○​ RR greater than 30/min or less than 8/min ○​ BP or HR changes more than 20% of baseline ○​ O2 30 and < 8 (maintains this RR) ​ Vital capacity 30 or < 8 ​ Tidal volume < 5 mL/kg ​ Labored respirations ​ Use of accessory muscles ​ O2 < 90% ​ HR or BP changes more than 20% from baseline ​ Dysrhythmias (PVCs, elevated ST) ​ Decreased LOC ​ Anxiety What to do if SBT Fails? ​ Sedation resumes at 50% ​ Placed back on full ventilatory support  ​ Reattempt the next day ​ Goal is to allow patient to rest and decrease work of breathing aiming for success the next day Extubation management ​ Prepare equipment ○​ Oral suction ○​ 100% non-rebreather ​ Hyperoxygenate ​ Loosen ETT securement ​ Oral and ETT suction ​ Instruct patient to take deep breaths ​ At peak inspiration deflate ETT cuff and pull ETT ​ Closely monitor patient status for 1 hour post extubation ○​ Monitor for signs of respiratory distress (ineffective cough, dyspnea, stridor) ○​ Assess O2 and vital signs every 5 min ○​ Encourage coughing, deep breathing, and incentive spirometer ○​ Reposition client to promote mobility of secretions (more position changes for older clients) Chest Trauma Causes: ​ Blunt trauma ​ Penetrating open wound through pleural space Flail chest: 3+ consecutive rib fractures caused by blunt trauma ​ Expected findings ○​ Unequal chest expansion (affected side can appear diminish in size or remain stationary and not expand) ○​ Paradoxical chest wall movement (inward movement during inspiration, and outward moving during expiration) ○​ Tachycardia ○​ Hypotension ○​ Dyspnea ○​ Cyanosis ○​ Anxiety ○​ Chest pain ​ Management ○​ Maintain adequate airway and ventilation ○​ Administer humidified oxygen ○​ Review findings of x-ray and ABGs ○​ Monitor vital signs and O2 ○​ Assess lung sounds, color, and cap refill ○​ Promote lung expansion by deep breathing and proper position ○​ Administer analgesia for pain  ​ Patient-controlled analgesia ​ Epidural block ○​ Surgical fixation (offer support and explain procedures) Pneumothorax: air in pleural space that causes lung collapse ​ Hemothorax: blood in pleural space ​ Tension Pneumothorax: life threatening emergency when large collection of air compromises respiratory and cardiac function (compress lungs and decrease venous return to heart) ○​ Emergent intervention: Needle decompression ​ Needle inserted into pleural space to decompression tension pneumothorax (lets air out through catheter) ​ Expected findings: ○​ Anxiety ○​ Pleuritic pain ○​ Respiratory distress ​ Tachypnea ​ Tachycardia ​ Hypoxia ​ Use of accessory muscles ○​ Absent breath sounds on affected side ○​ Asymmetrical chest movement (less on affected side) ​ Diagnostics: ○​ Chest x-ray ○​ Thoracentesis: surgical perforation of pleural space with a large bore needle ​ To confirm hemothorax ​ Patient remain still (no moving, coughing, or deep breathing) ​ Local anesthetic is used ​ Management ○​ Chest tube placement ○​ Needle decompression ○​ Administer O2 ○​ Auscultate heart and lung sounds every 4 hours and monitor vital signs ○​ Document ventilator setting hourly if used ○​ Check x-ray and ABGs ○​ Monitor chest tube drainage Chest tubes: inserted in pleural space or mediastinal to drain fluid, blood, or air ​ Reestablishes negative pressure ○​ Lungs re-expands ○​ Air or fluid is removed from pleural space  ​ Suction control chamber ○​ Want to see gentle continuous bubbling which indicates suctioning ○​ Amount of water in chamber controls suction (usually at 20 cm) ○​ Adjust suction until gentle bubbling in third chamber ​ Water-seal chamber: allows air to exit from pleural space on exhalation and stops air from entering the lungs with inhalation ○​ Want to see steady and rise with breathing (rise with inspiration and fall with expiration) which indicates tidaling (GOOD) ○​ Tidaling: movement of fluid level with respirations and well reduce when lungs re-expand ○​ Bubbling in air leak monitor indicates air leak (BAD) ​ Collection chamber: collection of fluid from lungs ​ Nursing management of chest tubes ○​ Keep drainage below the client’s chest level ○​ Monitor chest tube placement and function ​ Check water seal every 2 hours, and add fluid if needed ​ Document amount and color of drainage hourly for the first 24 hours, then at least every 8 hours ​ Mark the date, hour, drainage level at the end of every shift and report excess drainage (> 70 ml) ​ Monitor fluid in suction control chamber and maintain prescribed level ​ Check for expected findings of tidaling and only bubbling in suction chamber ​ Monitor tubing for any kinks ○​ Monitor chest tube insertion site for signs of infection ○​ Position client in semi-fowler's to promote lung expansion and drainage ○​ Monitor vital signs, breath sounds, O2, and respiratory effort every 4 hours ○​ Encourage deep breathing and coughing Management after thoracic surgery Lung Cancer Risk factors ​ Smoking (#1 risk factor) ​ Pollution ​ Radiation ​ Asbestos (building minerals that are resistant to heat) Prevention: ​ Smoking cessation ​ Wearing masks in high risk environments ​ Screening (annual CT) for high risk people Expected findings: ​ Early manifestations ○​ Persistent cough with sputum (most common) ○​ Pneumonitis (inflammation of lung tissue) ○​ Hemoptysis (coughing blood) ○​ Dyspnea ○​ Wheezing ○​ Chest pain ​ Late manifestations ○​ Anorexia, fatigue, weight loss ○​ Nausea & vomiting ○​ Hoarseness ○​ Unilateral paralysis of diaphragm ○​ Superior vena cava obstruction ○​ Palpable lymph nodes Diagnostics: ​ Chest x-ray (initial test for suspected) ○​ Lung mass (tumor) or infiltration ○​ Evidence of metastasis ​ CT scan (used to further evaluate) ○​ Can identify location and extent of masses in chest ​ Lung biopsy for definitive diagnosis ○​ Obtained by CT-guided needle aspiration ​ Bronchoscopy ​ Thoracoscopy ​ mediastinoscopy ​ Sputum cytology ○​ Cancer cells in sputum ○​ Rarely used cause cancer cells are not always present in sputum ​ Thoracentesis with pleural biopsy ○​ If thoracentesis is performed to relieve pleural effusion, the fluid is also analyzed for cancer cells Nursing management: ​ Monitor nutritional status, weight loss, and anorexia ○​ Promote adequate nutrition ​ Maintain patent airway and suction as needed ○​ Supporting oxygenation  ○​ Position in fowler's to maximize ventilation ​ Emotional support ​ Patient and family education ​ If patient illness progressing, suggest palliative care or hospice depending on staging and prognosis Chest tube drainage system: Steps for intubation: 1.​ Gather supplies 2.​ Sedation 3.​ Attached O2 to wall 4.​ Hyperoxygenate 5.​ Position Head 6.​ Secure tubing 7.​ Listen to breath sounds to check for placement 8.​ Attach ETT to mechanical ventilation