The utility of traditional prehospital interventions in maintaining thermostasis

Objective. Hypothermia can have a negative effect on the metabolic and hemostatic functions of patients with traumatic injuries. Multiple methods of rewarming are currently used in the prehospital arena, but little objective evidence for their effectiveness in this setting exists. The purpose of this study was to assess the relative effectiveness of traditional prehospital measures in maintaining thermostasis in trauma patients. Methods. Participating helicopter and ground ambulance ALS units were prospectively randomized to provide either routine care only (passive or no warming) or routine care (passive warming) in conjunction with active warming (either reflective blankets, hot pack rewarming, or warmed IV fluids). A total of 174 trauma code patients, aged >14 years, who met inclusion criteria were prospectively enrolled by prehospital providers. Patients who received a non-assigned intervention or who had incomplete temperature data were dropped from the analysis. A total of 134 patients were included in the final analysis. Results. Patients who received hot pack rewarming showed a mean increase in body temperature during transport (+1.36°F/0.74°C), while all other groups (no intervention, passive rewarming, reflective blankets, warmed IV fluids, warmed IV fluid plus reflective blanket) showed a mean decrease in temperature during transport [-0.34 to -0.61°F (-0.2 to -0.4°C); p < 0.01]. In addition, the hot pack group was consistent, with every patient who received hot pack warming showing an increase in body temperature during transport, while in all other groups there were patients who had both increases and decreases in temperature. The intervention groups did not differ significantly on exposure to precipitation, transport unit temperature, total prehospital time, initial vital signs, amount of fluid administered, Injury Severity Score, or Glasgow Coma Score. Conclusions. Most traditional methods of maintaining trauma patient temperature during prehospital transport appear to be inadequate. Aggressive use of hot packs, a simple, inexpensive intervention to maintain thermostasis, deserves further study as a potential basic intervention for trauma patients.