Oxygen Saturation Targets and Neurologic Outcomes Following Cardiac Arrest: A Secondary Analysis of the Pragmatic Investigation of Optimal Oxygen Targets Trial.

Abstract

More than 600,000 adults in the United States experience an out-of-hospital or in-hospital cardiac arrest each year. Following resuscitation from cardiac arrest, most patients receive mechanical ventilation. The oxygenation target that optimizes neurologic outcomes following cardiac arrest is uncertain. Following cardiac arrest, does a lower oxygen saturation (Spo₂) target improve neurologic outcomes compared with a higher Spo₂ target? This study was a secondary analysis of patients who experienced a cardiac arrest prior to 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%) Spo₂ target. This subgroup analysis compared patients randomized to a lower or intermediate Spo₂ target (88-96%) vs a higher Spo₂ target (96%-100%) regarding the primary outcome of survival with a favorable neurologic outcome at hospital discharge (Cerebral Performance Category 1 or 2). Of 2,987 patients in the PILOT trial, 339 (11.3%) experienced a cardiac arrest prior to enrollment: 221 were assigned to a lower or intermediate Spo₂ target, and 118 were assigned to a higher Spo₂ 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 Spo₂ target and 15 (12.7%) patients assigned to a higher Spo₂ target (absolute risk difference, 9.9 percentage points; 95% CI, 1.8-18.1; P = .03). Among patients receiving mechanical ventilation following a cardiac arrest, use of a lower or intermediate Spo₂ 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.