Regional cerebral oxygen saturation monitoring for predicting interventional outcomes in patients following out-of-hospital cardiac arrest of presumed cardiac cause: A prospective, observational, multicentre study.

Aim: This study investigated the value of regional cerebral oxygen saturation (rSO2) monitoring upon arrival at the hospital for predicting post-cardiac arrest intervention outcomes.

Methods: We enrolled 1195 patients with out-of-hospital cardiac arrest of presumed cardiac cause from the Japan-Prediction of Neurological Outcomes in Patients Post-cardiac Arrest Registry. The primary endpoint was a good neurologic outcome (cerebral performance categories 1 or 2 [CPC1/2]) 90 days post-event.

Results: A total of 68 patients (6%) had good neurologic outcomes. We found a mean rSO2 of 21%±13%. A receiver operating characteristic curve analysis indicated an optimal rSO2 cut-off of ≥40% for good neurologic outcomes (area under the curve 0.92, sensitivity 0.81, specificity 0.96). Good neurologic outcomes were observed in 53% (55/103) and 1% (13/1092) of patients with high (≥40%) and low (<40%) rSO2, respectively. Even without return of spontaneous circulation (ROSC) upon arrival at the hospital, 30% (9/30) of patients with high rSO2 had good neurologic outcomes. Furthermore, 16 patients demonstrating ROSC upon arrival at the hospital and low rSO2 had poor neurologic outcomes. Multivariate analyses indicated that high rSO2 was independently associated with good neurologic outcomes (odds ratio=14.07, P<0.001). Patients with high rSO2 showed favourable neurologic prognoses if they had undergone therapeutic hypothermia or coronary angiography (CPC1/2, 69% [54/78]). However, 24% (25/103) of those with high rSO2 did not undergo these procedures and exhibited unfavourable neurologic prognoses (CPC1/2, 4% [1/25]).

Conclusion: rSO2 is a good indicator of 90-day neurologic outcomes for post-cardiac arrest intervention patients.