Abstract 259: Outcomes of Targeted Temperature Management in Patients with Out-of-hospital Refractory Ventricular Fibrillation/ventricular Tachycardia Cardiac Arrest

Abstract

Background: Current guidelines recommend use of targeted temperature management (TTM) with goal between 32 and 36°C for all comatose adult patients with ROSC after cardiac arrest. However, refractory cardiac arrest with prolonged hypoperfusion, may cause passive cooling below goal temperature. The impact of this passive cooling and subsequent cooling strategies remains unknown. This study aims to describe the association between passive intra-arrest cooling and survival in patients suffering refractory VF/VT cardiac arrest treated with the University of Minnesota extracorporeal cardiopulmonary resuscitation (ECPR) protocol. Methods: Between December 2015 and October 2019, consecutive adult patients with refractory VF/VT arrest requiring ongoing CPR were transported by EMS to the CCL where ECPR, coronary angiography, and PCI were performed, as appropriate. TTM was initiated with goal temperature of 34°C unless clinically significant bleeding occurred, where a goal of 36°C was used. Patient and arrest characteristics, temperature data, and survival were collected retrospectively. Results: Data was gathered for 153 consecutive patients transferred for ECPR; 12 were excluded due to death in CCL prior to TTM. Of the remaining patients, 63 (41%) survived to discharge, where 55 (36%) had CPC scores of 1-2. Among deceased patients, 25 died from acute brain death while 47 died from other causes. Patients with CPC 1-2 had an initial temperature of 34.1°C versus 32.7°C in patients developing acute brain death (p=0.002). Survivors had shorter (p=0.0001) CPR time (52 minutes) versus deceased patients (65 minutes). If the initial temperature was below goal, patients were actively warmed to goal due to bleeding risk with ECPR. Survival to hospital discharge with CPC 1-2 was associated with lower peak warming rate compared with acute brain death (0.37°C/hr vs 0.69°C/hr; p=0.014) Conclusions: Survivors with CPC 1-2 after refractory VF/VT cardiac arrest and ECPR have preserved initial temperatures compared to more severe passive cooling in patients with acute brain death. This may be due to shorter duration of CPR. However, patients with acute brain death were noted to have higher peak rate of rewarming during TTM.