Lower Oxygenation Target Does Not Reduce Mortality in Acute Hypoxemic Respiratory Failure

A lower target for partial pressure of arterial oxygen (Pao₂) was not associated with lower 90-day mortality than a higher target in adult patients with acute hypoxemic respiratory failure admitted to the intensive care unit (ICU), according to study results published in the New England Journal of Medicine.

In the Handling Oxygenation Targets in the ICU (HOT-ICU; ClinicalTrials.gov Identifier: NCT03174002) trial, researchers randomly assigned adult patients admitted to the ICU for at least 12 hours to receive an oxygen therapy targeting a Pao₂ of 60 mg Hg (n=1441) or 90 mm Hg (n=1447) for up to 90 days. All patients were receiving at least 10 liters of oxygen per minute in an open system or had a fraction of inspired oxygen of at least 0.50 in a closed system. Researchers evaluated the mortality rate at 90 days.

The 90-day mortality rates were 42.9% in the 60 mg Hg group and 42.9% in the 90 mm Hg group (adjusted risk ratio, 1.02; 95% CI, 0.94-1.11; P =.64). There was no between-group difference at 90 days in regard to the percentage of days patients who were alive without life support (87.8% vs 84.4%; P =.10) or the percentage of days patients were alive following discharge (55.6% vs 50.0%; P =.67). Both groups experienced a similar number of serious adverse events, including shock, myocardial ischemia, ischemic stroke, or intestinal ischemia (P =.24).

Oxygenation targets in this trial may differ from standards of care across geographic regions, thereby limiting the generalizability of the findings.

The investigators added that their “findings lend weight to the utility of conservative oxygen therapy in patients with acute hypoxemic respiratory failure…”

Reference

Schjørring OL, Klitgaard TL, Perner A, et al; for the HOT-ICU Investigators. Lower or higher oxygenation targets for acute hypoxemic respiratory failure. Published online January 20, 2021. N Engl J Med. doi:10.1056/NEJMoa2032510