Limiting oxygen after cardiac arrest shows no benefit. The LOGICAL trial found that a conservative oxygen strategy offered no survival or functional advantage over a liberal approach in post-cardiac arrest patients with suspected brain injury. At 180 days, outcomes were nearly identical between the two groups, reinforcing findings from prior trials.
For years, clinicians hoped that dialing back oxygen after cardiac arrest could protect the brain from reperfusion injury — but a major new trial says otherwise. The LOGICAL trial, published in the New England Journal of Medicine, enrolled 1,840 adults across 53 ICUs in New Zealand, Australia, and Ireland, all of whom were unresponsive after cardiac arrest with suspected hypoxic ischemic encephalopathy. Patients were randomized to either a conservative or liberal oxygen strategy and followed for 180 days.
The results? Essentially a wash. Favorable functional outcomes were seen in 38.2% of the conservative group vs. 39.7% in the liberal group — a difference that was not statistically significant. Survival, quality of life, and cognitive scores were also nearly identical between groups, regardless of when patients were enrolled after resuscitation.
By the Numbers:
Why it matters: These findings, consistent with prior trials like EXACT and BOX, strongly suggest that conservative oxygen therapy after cardiac arrest offers no meaningful benefit — regardless of timing. With the larger Mega-ROX HIE trial still ongoing, the full picture is coming, but the evidence is already pointing in one clear direction.
