Abstract P189: Method of Cold Saline Storage for Prehospital Induced Hypothermia

Abstract

Recent research supports the use of cold IV fluid as a method for initiating therapeutic hypothermia in post-cardiac arrest resuscitation. However, prehospital care programs employing this treatment have encountered various difficulties. Barriers to prehospital induced hypothermia protocols include the lack of effective or economically reasonable methods to maintain cold saline in the field. Objective. Determine the time that a standard commercial cooler can maintain two 1-liter normal saline solution (NSS) bags below 4°C in 3 different environments. Methods. Environments simulating an ambulance compartment were created for the experiment. NSS temperatures were continuously recorded inside a standard commercial cooler with or without ice packs (IPs) under one of three scenarios: ambient room temperature (25°C) without (IPs), ambient room temperature with IPs and 50°C ambient temperature with IPs. Four trials under each condition were performed. Time to warm to 4°C was compared using Kaplan-Meier log rank test. Results. In a room temperature environment with IPs, the NSS warmed to 4°C in a mean interval of 29 hrs 53 mins versus in ambient room temperature without IPs (1 hr 21 mins) versus in constant hot environment of 50°C with IPs (10 hrs 50 mins). A significant difference was found between the three environments (log-rank =17.90, dF =2, p =0.0001). Conclusions. Low technology methods in the form of a cooler and IPs can provide cold NSS storage for longer than a full 24 hour shift in a room temperature ambulance. In hot ambient conditions, 4°C NSS can be maintained for nearly 11 hours using this method. This model exhibits an economical, easily deployable cold saline storage unit.