Time to awakening tendency and withdrawal of life supporting treatment (WLST) in patients treated with therapeutic hypothermia after cardiac arrest

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction and objectives Treatment with therapeutic hypothermia after cardiac arrest remains controversial. It is still unclear how long it takes these patients to recover neurological responsiveness, and the time until awakening varies widely. The aim of our study was to identify the patients who had a later awakening and the factors related to late post-arrest awakening. Methods We performed a retrospective analysis of patients admitted in the Coronary Care Unit between 2006 and 2020 after a cardiac arrest. Patients were eligible if they remained comatose after return of spontaneous circulation (ROSC), with a Glasgow Coma Scale less than 10. We measured the time until awakening, defined as obedience to verbal commands. Results Amongst 271 cardiac arrest survivors, 182 remained comatose. Mean age was 65,8 ± 0,98 and there were 29% of females. 70 patients (38,5%) were treated with therapeutic hypothermia with a target temperature of 33ºC using an endovascular device. 60 patients (33%) awakened and median time of awakening was 4 days. The tendency of the awakening was similar if the patient was or not cooled before (Figure1: median: 4, p25: 3, p75: 6). 18 patients (30%) regained neurological responsiveness 5 days after cardiac arrest without differences between groups (p >0,001) (Figure 2: 28,2% cooling group versus 33,3% no control temperature group). We did not find variables associated with a later awakening in the multiple logistic regression analysis adjusted for age, sex, hospital admission year, initial rhythm and Glasgow Scale, and therapeutic hypothermia use. Conclusions The main cause of mortality after a cardiac arrest is the withdrawal of life support treatment. In our cohort, one third of the patients were late awakaners. Therefore, and in consistency with previous reports, we consider that the observation period to assess the neurological outcome should be extended to more than five days before WLST. Abstract Figure 1 and 2