RNSG 2432: Exam 2, Mod.2 - ARDS/Vents|Advanced Critical Care Nursing Examination: Acute Respiratory Failure Pathophysiology Hypoxemia and Hypercapnia Gas Exchange Failure, Ventilation Perfusion Mismatch Diffusion Limitation and Pulmonary Shunt Mechanisms,

RNSG 2432: Exam 2, Mod.2 - ARDS/Vents|Advanced Critical Care Nursing Examination: Acute Respiratory Failure Pathophysiology Hypoxemia and Hypercapnia Gas Exchange Failure, Ventilation Perfusion Mismatch Diffusion Limitation and Pulmonary Shunt Mechanisms, Acute Respiratory Distress Syndrome ARDS Stages Exudative Proliferative and Fibrotic Lung Injury, Refractory Hypoxemia and Noncardiogenic Pulmonary Edema, Mechanical Ventilation Management Low Tidal Volume Strategy and Positive End Expiratory Pressure Hemodynamics, Synchronized Intermittent Mandatory Ventilation Weaning Strategies, Ventilator Associated Pneumonia Prevention and Airway Secretion Management, Ventilator Alarm Troubleshooting High Pressure Low Pressure and Apnea Alerts, Pulmonary Artery Wedge Pressure Interpretation in ARDS, Prone Positioning and Extracorporeal Membrane Oxygenation ECMO Therapy Exam Questions Verified and Provided with Complete A+ Graded Rationales Latest Updated 2026 learning guide 1. What is respiratory failure? Respiratory failure is the inability of the cardiac and pulmonary systems to maintain an adequate exchange of oxygen and carbon dioxide in the lungs. It results in hypoxemia (pO₂ 60 mmHg) and/or hypercapnia (pCO₂ 45 mmHg). 2. Patients at risk for acute respiratory failure (predisposing factors) and why? Patients with: Lung diseases (COPD, pneumonia, ARDS) → Impaired gas exchange. Neuromuscular disorders (ALS, Guillain-Barré, myasthenia gravis) → Weak respiratory muscles. CNS depression (opioid overdose, brain injury) → Reduced respiratory drive. Cardiovascular issues (heart failure, shock) → Poor oxygen delivery. Severe trauma or sepsis → Increased metabolic demands and potential ARDS. 3. Signs and symptoms of respiratory failure? Early: Tachycardia, hypertension, tachypnea, restlessness, confusion. Later: Dysrhythmias, metabolic acidosis, decreased CO and BP, cyanosis. Hypercapnia signs: Dyspnea, headache, drowsiness, coma, respiratory acidosis. 4. Physiologic mechanisms leading to hypoxemia V/Q Mismatch: Disproportion between ventilation (V) and perfusion (Q). Examples: Pulmonary embolism, asthma, pneumonia, COPD. Shunt: Blood bypasses ventilated alveoli, leading to severe hypoxemia. Examples: ARDS, pneumonia, congenital heart defects (VSD). Diffusion Limitation: Thickened alveolar membrane hinders O₂ transport. Examples: Pulmonary fibrosis, ARDS. 5. Medications and supportive treatments for respiratory failure Bronchodilators (e.g., Albuterol, Alupent): Open airways. Corticosteroids: Reduce inflammation. Diuretics (e.g., Furosemide): Reduce pulmonary congestion. Antibiotics: Treat infections. Sedatives (e.g., Ativan, Propofol): Reduce anxiety and work of breathing. Neuromuscular blockers (e.g., Norcuron, Nimbex): Used in ventilated patients. Supportive treatments: O₂ therapy, mechanical ventilation, hydration, secretion management. 6. ARDS: Basic premise and hallmark sign ARDS is a sudden, progressive respiratory failure due to increased alveolar-capillary membrane permeability, leading to fluid-filled alveoli.Hallmark sign: Refractory hypoxemia (hypoxemia unresponsive to oxygen therapy). 7. Pathophysiology of ARDS stages Exudative (1-7 days): Edema, atelectasis, and refractory hypoxemia. Proliferative (1-2 weeks): Fibrosis and pulmonary hypertension. Fibrotic (2-3 weeks): Diffuse scarring, severe lung stiffness. 8. Nursing assessment for ARDS Early signs: Dyspnea, tachypnea, restlessness, fine crackles. At-risk patients: Pneumonia, sepsis, trauma, aspiration. Assessment tools: ABGs, chest X-ray, lung sounds. 9. Pulmonary artery wedge pressure (PAWP) in ARDS Normal or low PAWP (≤18 mmHg) because ARDS is non-cardiogenic pulmonary edema, unlike heart failure. 10. Complications of ARDS Ventilator-induced lung injury Barotrauma Oxygen toxicity Multi-organ dysfunction syndrome (MODS) 11. Medical supportive therapies for ARDS Mechanical ventilation with low tidal volumes and PEEP.