Regional cerebral oxygen saturation on hospital arrival is a potential novel predictor of neurological outcomes at hospital discharge in patients with out-of-hospital cardiac arrest.

Abstract

To investigate the association between regional brain oxygen saturation (rSO(2)) on hospital arrival and neurological outcomes at hospital discharge in patients with out-of-hospital cardiac arrest (OHCA). A prospective cohort study was conducted, registering 179 patients with OHCA who were referred to Senri Critical Care Medical Centre between April 2009 and June 2010. Of these patients, 92 met the inclusion criteria. The primary end point was "neurological outcomes" at hospital discharge according to the "Utstein style" guidelines. The overall rate of good neurological outcome at hospital discharge was 14% (n=13). Sixty-one patients with rSO(2) ≤25% showed poor neurological outcome in the receiver operating curve analysis (optimal cut-off point, 25%; sensitivity, 0.772; specificity, 1.000; positive predictive value, 1.000; area under the curve (AUC), 0.919; p<0.0001). The AUC for rSO(2) was greater than that for base excess (p=0.0461) or lactate (p=0.0128) measured on hospital arrival. Since rSO(2) >40% was previously collated with good neurological outcome after cardiovascular surgery, we categorised our patients into three groups in a post hoc analysis: patients with rSO(2) ≤25% (n=61); patients with rSO(2) 26-40% (n=9) and patients with rSO(2) >40% (n=22). Patients with good neurological outcome were as follows: 0 (0%)/61 with rSO(2) ≤25%; two (22.2%)/9 with rSO(2) 26-40% and 11 (50.0%)/22 with rSO(2) >40% (p<0.0001). rSO(2) on hospital arrival may help predict neurological outcomes at hospital discharge in patients with OHCA.