Effect of Oxygen Saturation Targets on Neurologic Outcomes after Cardiac Arrest: A Secondary Analysis of the PILOT Trial.

Background: More than 600,000 adults in the United States experience a cardiac arrest each year. After resuscitation from cardiac arrest, most patients receive mechanical ventilation. The oxygenation target that optimizes neurologic outcomes after cardiac arrest is uncertain.

Research Question: After cardiac arrest, does a lower oxygen saturation (SpO ) target improve neurologic outcomes compared to a higher SpO target?

Study Design And Methods: We conducted a secondary analysis of patients who experienced a cardiac arrest before enrollment in the Pragmatic Investigation of optimal Oxygen Targets (PILOT) trial. The PILOT trial assigned critically ill adults receiving mechanical ventilation to a lower (88-92%), intermediate, (92-96%), or higher (96-100%) SpO target. This subgroup analysis compared patients randomized to a lower-or-intermediate SpO target (88-96%) versus a higher SpO target (96-100%) with regard to the primary outcome of survival with a favorable neurologic outcome at hospital discharge (Cerebral Performance Category 1 or 2). The secondary outcome was in-hospital death.

Results: Of 2,987 patients in the PILOT trial, 339 (11.3%) experienced a cardiac arrest before enrollment: 221 were assigned to a lower-or-intermediate SpO target, and 118 were assigned to a higher SpO target. Overall, the median age was 60 years, 43.5% were female, 58.7% experienced an in-hospital cardiac arrest, and 10.2% had an initial shockable rhythm. Survival with a favorable neurologic outcome occurred in 50 patients (22.6%) assigned to a lower-or-intermediate SpO target and 15 (12.7%) patients assigned to a higher SpO target (P=0.03). In-hospital death occurred in 146 patients (66.1%) assigned to a lower-or-intermediate SpO target and 89 (75.4%) assigned to a higher target (P=0.08).

Interpretation: Among patients receiving mechanical ventilation after a cardiac arrest, use of a lower-or-intermediate SpO target was associated with a higher incidence of a favorable neurologic outcome compared with a higher target. A randomized trial comparing these targets in the cardiac arrest population is needed to confirm these findings.