Abstract 177: Regional Cerebral Oxygen Saturation as a Novel Termination of Resuscitation Rule in Cases of Refractory Out-of-Hospital Cardiac Arrest
Background: To better utilize medical resources, basic life support (BLS) and advanced life support (ALS) pre-hospital termination-of-resuscitation (TOR) rules have been developed, validated, and implemented in North America. Recently, “regional cerebral oxygen saturation (rSO2) ≤15%”, as no detectable cortical oxygen value (N-value), has been considered to be a strong predictor of poor neurological outcome in patients with out-of-hospital cardiac arrest (OHCA).
Objective: To assess the impact of the N-value as a novel TOR rule.
Method: This study was a prospective cohort study. Of 418 OHCA patients, 186 consecutive non-traumatic, cardiac arrest on arrival (CAOA) patients were prospectively registered. The rSO2 were measured with sensors placed on either side of their forehead using a near-infrared spectroscopy (NIRS) device (INVOS, Covidien, US) immediately on hospital arrival. We monitored rSO2 values at least for more than one minute and used the lower of the 2 measured rSO2 values for analysis. Clinical staff performed ordinary post-cardiac-arrest interventions (PCAIs) regardless of rSO2 values. Primary outcome measure was good neurological outcome (CPC =<2) at hospital discharge according to the “Utstein-style”. We calculated the specificity and positive predictive value (PPV) of N-value TOR rule and BLS/ALS TOR rules for identifying CAOA patients without good neurological outcome.
Results: Among 186 CAOA patients in the PCAIs era, 18 patients (9.7%) had good neurological outcome at hospital discharge, and the specificity and PPV of N-value, BLS and ALS TOR rules were high. However, N-value TOR rule had relatively high specificity and PPV compared with BLS TOR rule and relatively high sensitivity compared with ALS TOR rule. In addition, NIRS provides non-invasive and objective rSO2 values immediately.
Conclusion: The N-value TOR rule may be of considerable help to make decisions to cease futile resuscitative efforts in CAOA patients after OHCA.
- © 2011 by American Heart Association, Inc.