Usefulness of cerebral rSO₂ monitoring during CPR to predict the probability of return of spontaneous circulation.

Abstract

Cerebral oximetry (rSO₂) may be useful in assessing the probability of return of spontaneous circulation (ROSC). However, the potential of assessing the trend in the rSO₂ value has not been discussed when determining the probability of ROSC. This was a retrospective study of out-of-hospital cardiac arrest (OHCA) patients with continuous rSO₂ values recorded during cardiopulmonary arrest. We used logistic regression analysis at each time point to investigate the best subsets of rSO₂-related variables for ROSC, which included rSO₂ (baseline), the baseline value of rSO₂; amount of maximum rise, the maximum difference of rSO₂ from rSO₂ (baseline) over t minutes; ΔrSO₂ (t):(amount of maximum rise)/rSO₂ (baseline) over t minutes after hospital arrival. Among the 90 included patients, 35 achieved ROSC. Area under the curve (AUC) analysis revealed that ΔrSO₂ over a 16-min measurement period was significantly higher than ΔrSO₂ measured over 4-, 8-, 12-, and 20-min periods. During this 16-min period, the subset showing the best AUC value was interaction of the amount of maximum rise and rSO₂ (baseline) rather than the amount of maximum rise or ΔrSO₂ alone (AUC = 0.91). The combination of rSO₂ (baseline) with the amount of maximum rise in rSO₂ value over time might be a new index for the prediction of ROSC that could be useful in guiding cardiopulmonary resuscitation. Further studies are needed to validate these findings.