Most Common Causes of Acute Hypoxemic Respiratory Failure
The most common causes of acute hypoxemic respiratory failure are pneumonia/sepsis (approximately 46-50%), followed by aspiration (23%), multiple trauma (26%), surgery (33%), and pulmonary contusion (18%), with ARDS developing in approximately 33% of cases. 1, 2
Primary Etiologies with Approximate Percentages
In Adult Populations
Pneumonia and sepsis represent the leading cause, accounting for approximately 46-50% of acute hypoxemic respiratory failure cases requiring mechanical ventilation 1, 2
Aspiration accounts for approximately 23% of cases in adult populations with ARDS 1
Multiple trauma contributes to approximately 26% of cases 1
Post-surgical complications account for approximately 33% of cases 1
Pulmonary contusion represents approximately 18% of cases 1
In Neonatal Populations
The distribution differs significantly in neonates, where:
- Meconium aspiration syndrome (MAS) accounts for 49% of hypoxic respiratory failure cases 3
- Pneumonia/sepsis represents 21-24% 3
- Idiopathic primary pulmonary hypertension of the newborn (PPHN) accounts for 17-30% 3
- Respiratory distress syndrome (RDS) represents 8-11% 3
Clinical Context and ARDS Development
Approximately 33% of patients with acute hypoxemic respiratory failure meet Berlin criteria for ARDS, with these patients demonstrating higher mortality and more severe pulmonary dysfunction compared to non-ARDS hypoxemic respiratory failure 2
Polymicrobial infections are common, particularly in patients with ARDS, where infection rates are especially elevated 1
Aerobic gram-negative bacilli (P. aeruginosa, K. pneumoniae, Acinetobacter species) and gram-positive cocci (S. aureus, including MRSA) are the predominant bacterial pathogens in hospital-acquired cases 1
Mortality and Outcomes by Cause
Sepsis remains the most common primary cause of death in patients with acute hypoxemic respiratory failure, accounting for 26% of deaths, followed by pulmonary dysfunction at 22% and neurologic dysfunction at 19% 2
Multi-organ failure is present in 70% of patients at the time of death, most commonly driven by sepsis (50% of all patients) 2
Refractory hypoxemia directly causes only 10-16% of deaths in ARDS patients, with most deaths occurring from sepsis or multi-organ failure rather than insupportable oxygenation 2, 4, 5
Important Clinical Distinctions
Patients with ARDS are more likely to have pulmonary dysfunction as the primary cause of death (28% vs 19% in non-ARDS hypoxemic failure) and die while requiring significant respiratory support (82% vs 64%) 2
Approximately 85% of deaths occur following withdrawal of life support rather than from refractory hypoxemia, highlighting that prognosis and goals of care discussions are critical 2
Only 2% of patients have truly insupportable oxygenation or ventilation at the time of death in contemporary cohorts 2