Introduction: The objective of this study was to test the hypothesis that hemoglobin levels after return of spontaneous circulation (ROSC) are associated with neurologic outcome after cardiac arrest treated with therapeutic hypothermia (TH).
Methods: We studied consecutive adult patients with out-of-hospital cardiac arrest treated with TH between January 2009 and December 2015. We quantified the association between post ROSC hemoglobin level and poor neurologic outcome (defined as Cerebral Performance Category of 3 to 5) at 6 months after CA using multivariate logistic regression analysis.
Results: A total of 246 subjects were finally included in this study. The mean age was 54 years (SD 17), and 168 (68%) subjects were male. Eighty seven (35%) subjects had a good neurologic outcome. Hemoglobin levels were higher in good outcome group than in poor outcome group (14.4 ± 2.0 vs. 12.8 ± 2.5, p < 0.001). Multivariate logistic analysis showed that hemoglobin levels were associated with poor neurologic outcome at 6 months after CA after adjusting for other confounding factors (adjusted OR 0.843, 95% C.I. 0.717-0.992).
Conclusions: These results show that hemoglobin levels after ROSC are associated with neurologic outcome at 6 months after CA. It is unclear whether this effect is due to impaired oxygen delivery or hemoglobin is a surrogate marker for illness severity.