Liberal or Conservative Oxygen Therapy for Acute Respiratory Distress Syndrome

Area of Science:

• Critical Care Medicine
• Pulmonology
• Clinical Trials

Background:

• Current guidelines recommend a partial pressure of arterial oxygen (Pao2) of 55-80 mm Hg for acute respiratory distress syndrome (ARDS).
• Prospective validation of this recommended oxygenation range in ARDS patients is limited.
• This study investigated the hypothesis that targeting the lower end of the recommended Pao2 range could enhance patient outcomes.

Purpose of the Study:

• To evaluate the efficacy and safety of a conservative oxygen therapy strategy compared to liberal oxygen therapy in patients with ARDS.
• To determine if targeting a lower Pao2 range (55-70 mm Hg) improves 28-day survival in ARDS patients.

Main Methods:

• A multicenter, randomized trial involving patients with ARDS.
• Two groups were assigned: conservative oxygen therapy (Pao2: 55-70 mm Hg; Spo2: 88-92%) and liberal oxygen therapy (Pao2: 90-105 mm Hg; Spo2: ≥96%).
• Mechanical ventilation strategies were standardized across both groups; the primary outcome was 28-day all-cause mortality.

Main Results:

• The trial was stopped early due to safety concerns and a low probability of detecting a significant difference.
• At 28 days, mortality was 34.3% in the conservative group versus 26.5% in the liberal group.
• At 90 days, mortality was 44.4% in the conservative group versus 30.4% in the liberal group, with five mesenteric ischemic events in the conservative group.

Conclusions:

• Early conservative oxygenation targeting a Pao2 of 55-70 mm Hg did not improve 28-day survival in patients with ARDS.
• The findings suggest that a conservative oxygen strategy may not be beneficial and could potentially be associated with harm in ARDS patients.
• Further research may be needed to establish optimal oxygenation targets in ARDS, considering both efficacy and safety.