Comparison of clinical prediction rules for termination of resuscitation of out-of-hospital cardiac arrests on arrival to emergency department

Objective: To compare the discriminative capacities of various termination of resuscitation (TOR) rules in the prediction of futile resuscitation in the emergency department (ED). Design: Prospective cohort study. Setting: 2 public hospitals in a cluster in Hong Kong. Methods: The data were obtained from a Cardiac Arrest Registry of the EDs of two hospitals, including consecutive adult patients suffering from non-traumatic out-of-hospital cardiac arrest from 1st August 2010 to 30th June 2012. Those with return of spontaneous circulation before ED arrival and cases without resuscitation in the EDs were excluded. The modified basic life support (BLS), modified advanced life support (ALS) and neurologic TOR rules were applied to the cohort. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value were calculated. The outcome measures were survival to hospital admission (STA) and survival to discharge (STD). Results: Totally 1125 cases were included. The mean age was 72.4. Return of spontaneous circulation and STA occurred in 302 patients and 9 had STD. Regarding the outcome of STD, the modified ALS and neurologic TOR rules had outperformed the modified BLS rule. The specificity and PPV were 100% for both rules in predicting death when the rules suggested TOR. Regarding the outcome of STA, the neurologic TOR rule had the highest specificity [84.4%; 95% confident interval (CI): 79.7-88.2%] and PPV (84.5%; 95% CI: 79.8-88.3%). Conclusions: The modified ALS and neurologic TOR rules have similar discriminative capacities to predict STD. The neurologic TOR rule has the highest ability to predict STA in the ED.