The hemoglobin (Hb) level is an essential determinant of oxygen delivery. The restoration of blood perfusion to vital organs and the capacity for oxygen delivery may be associated with ischemia and reperfusion injuries during cardiac arrest and after cardiac arrest. However, whether the Hb level is associated with neurologic outcome in post–cardiac arrest patients remains unclear.

Emergency medical service information and clinical demographics were compiled for witnessed out-of-hospital cardiac arrest patients with coma after the restoration of spontaneous circulation. The study end point was defined as a favorable neurologic outcome at 28 days. We evaluated the relationship between the Hb level at the time of hospital arrival and the neurologic outcome using univariate analyses and a multivariate logistic regression analysis.

There were 137 witnessed cardiac arrest patients: 49 (35.7%) survived and 34 (24.8%) achieved a favorable neurologic outcome. Univariate analyses showed that the favorable outcome group was characterized as having a higher Hb level, a younger age, a higher percentage of male patients, and ventricular fibrillation as the initial cardiac rhythm. In a multivariate analysis adjusting for potential confounding factors, the Hb level at the time of hospital arrival (odds ratio, 1.26; 95% confidence interval, 1.00-1.58) was an independent predictor of a favorable neurologic outcome.

A higher Hb level at the time of hospital arrival was associated with a favorable short-term neurologic outcome among post–cardiac arrest patients with a presumed cardiac etiology.