The association between post resuscitation hemoglobin level and survival with good neurological outcome following Out Of Hospital cardiac arrest

Aims: to explore the association between post return of spontaneous circulation (ROSC) hemoglobin level and survival with good neurological outcome following out-of-hospital cardiac arrest. Methods: We studied adults with non-traumatic out-of-hospital cardiac arrest who achieved ROSC within 50 min of collapse. We quantified the association between post ROSC hemoglobin level and good neurological outcome (defined as Cerebral Performance Category score of 1or 2), using multivariate logistic regression analyses. The impact of Post ROSC hemoglobin level ≥ 10 g dl^-1 and time varying hemoglobin level ≥ 10 g dl^-1 on time to Survival with good outcome was assessed using Cox proportional hazard models. Results: Of 931 cardiac arrest patients, 146 (16%) achieved ROSC and 30 survived to discharge with a good neurological outcome. Of those with post ROSC hemoglobin level ≥ 10g dl^-1, 28% (27/98) had good outcome, whereas of those with level < 10 mg dl^-1 only 6% (3/48) had good outcome (CPC < 3, P = 0.003). The use of blood transfusions and therapeutic hypothermia were comparable in both good and bad outcome groups. An immediate post ROSC hemoglobin level ≥ 10 g dl^-1 was significantly associated with good neurological outcome (AOR 8.31 95% CI 1.89-36.52 P = 0.005). Patients with post ROSC hemoglobin ≥ 10 g dl^-1 were more likely to achieve good outcome earlier (HR 6.02 95% CI 1.75-20.72 P = 0.004). Conclusions: Post ROSC hemoglobin level ≥ 10 g dl^-1 is associated with survival with good neurological outcome. The importance of time to achieve such level and the role of blood transfusion warrants further investigation.