Respiratory Compromise & Acute ARDS
Arterial blood gas (ABG) interpretation, acute respiratory distress syndrome (ARDS) refractory hypoxemia, and mechanical ventilation safety rules.
High-Yield Clinical Takeaways & NCLEX Priorities
- Refractory hypoxemia (PaO2 remains low despite 100% FiO2) is the hallmark indicator of ARDS.
- Prone positioning significantly improves ventilation-perfusion matching by recruiting dorsal lung regions.
- Uncompensated respiratory acidosis presents with low pH (< 7.35) and high PaCO2 (> 45 mmHg) commonly seen in opioid overdose or COPD exacerbations.
1. Acute Respiratory Failure vs. ARDS
Type I (hypoxemic) respiratory failure involves PaO2 < 60 mmHg on room air, while Type II (hypercapnic) involves PaCO2 > 50 mmHg with pH < 7.35. ARDS develops following direct (aspiration, pneumonia) or indirect (sepsis, pancreatitis) pulmonary insult, causing diffuse alveolar-capillary membrane permeability.
Essential Nursing Action Items:
- •Hallmark triad of ARDS: Bilateral alveolar infiltrates ('white out' on CXR), refractory hypoxemia, and normal pulmonary capillary wedge pressure (< 18 mmHg).
- •Ventilator bundle: Head of bed elevated 30–45 degrees, daily sedation vacation, peptic ulcer prophylaxis, and DVT prophylaxis.
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