Using end tidal CO2 levels in predicting the termination of resuscitative efforts at emergency department

Kudu E, Using End Tidal CO2 Levels in Predicting the Termination of Resuscitative Efforts at Emergency Department, Hacettepe University Faculty of Medicine, Emergency Medicine Thesis. Ankara, 2020. American Heart Association and European Resuscitation Council have each reported their own criteria for terminating resuscitative efforts. In this study, we aimed to integrate end tidal CO2 levels (EtCO2) with other parameters to improve these criteria for resuscitation termination to prevent unnecessary use of resources at the emergency department. This observational, prospective study included non-traumatic adult patients who were admitted to Hacettepe University Emergency Medicine Department due to a cardiac arrest from August 2018 to July 2019. Along with Utstein parameters, we record EtCO2 levels at baseline, 5th, 10th, 20th, 30th, 40th minutes and after cardiopulmonary resuscitation (CPR). We also monitored neurological outcomes at the end of one month. We included 86 patients. We created different models to predict the outcome after CPR. The most sensitive model that predicted the termination of resuscitation efforts included the following criteria: arrest was not witnessed; no by stander CPR was provided; no return of spontaneous circulation after full advanced life support care in the field, and no automatic external defibrillator shocks were delivered, EtCO2 at 20 min less than 20.5 mmHg. This model had a specificity and a positive predictive value of 100%. This study also showed a high specificity (%87,5) and positive predictive value (95%) for prediciting the course of EtCO2 levels during CPR. We conclude that physicians should use EtCO2 levels along with other parameters to better predict the return of spontaneous circulation during CPR.