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.