Conservative Oxygen Strategy Didn't Benefit Critically Ill Patients

Hyperoxia, or supranormal partial pressures of oxygen, has been associated with longer ventilation times and excess mortality in critically ill patients. But whether lower blood oxygen targets confer benefit remains unclear.

Investigators from Australia and New Zealand randomized 965 critically ill patients who were receiving mechanical ventilation (for ≤2 hours at enrollment) to conservative (fraction of inspired oxygen [FiO₂] goal, 0.21; supplemental oxygen turned down at saturation >96%) or liberal oxygen therapy (FiO₂ goal, ≥0.30; no guidance on oxygen titration). During a median ICU stay of 5 days, patients in the conservative arm spent less time with oxygen saturation >96% than did patients in the liberal arm (mean, 27 vs. 49 hours).

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