Foundational Principles of ARDS
Objective
Equip the critical care pharmacist with a concise, high‐yield overview of ARDS epidemiology, predisposing factors, key pathophysiology, and clinical presentation to support exam prep and bedside decision making.
1. Epidemiology of ARDS
ARDS affects up to 10% of ICU admissions worldwide, yet is under‐recognized—especially in low-resource settings—leading to variable incidence and persistently high mortality.
- Global incidence: Approximately 10% of ICU admissions; approximately 23% of ventilated patients.
- Annual incidence: Approximately 79 cases per 100,000 population.
- Regional variation: Higher reported rates in high-income vs. low-middle-income countries; under‐reporting where diagnostics and registries are limited.
- Temporal trends: Awareness has improved since 2000 but ARDS remains a leading cause of acute hypoxemic respiratory failure.
2. Risk Factors and Predisposing Conditions
ARDS results from both direct lung insults (e.g., pneumonia, aspiration) and indirect systemic injuries (e.g., sepsis), with host factors and social determinants shaping individual risk and outcomes.
3. Pathophysiology of ARDS
4. Clinical Presentation and Differentiation
| Severity | PaO₂/FiO₂ Ratio (mmHg) |
|---|---|
| Mild | 201–300 |
| Moderate | 101–200 |
| Severe | ≤100 |
References
- Ashbaugh DG, Bigelow DB, Petty TL, Levine BE. Acute respiratory distress in adults. Lancet. 1967;2(7511):319–323.
- Rubenfeld GD, Caldwell E, Peabody E, et al. Incidence and outcomes of acute lung injury. N Engl J Med. 2005;353(16):1685–1693.
