Hypothermia in trauma patients arriving at an emergency department by ambulance in Johannesburg, South Africa: a prospective study

Introduction: Normal body temperature is considered to be between 36 and 38°C. Temperatures that are too low may negatively affect physiological functions. In trauma cases, factors that promote the development of hypothermia include concomitant hypoxia, hypotension, decreased levels of consciousness, contact with cold surfaces, exposure to low ambient temperatures and the administration of cold fluids. Studies on emergency department related hypothermia in Africa are sparse. This study investigated instances of hypothermia in a sample of trauma cases arriving by ambulance to an emergency department in Johannesburg, South Africa.

Methods: Core body temperatures of 140 trauma cases were measured upon arrival and 30 minutes later. Ambient temperatures outside the hospital, inside the ED and in the resuscitation areas were also recorded. Additional information was gathered describing the equipment available to the ambulance crews for temperature, control and rewarming.

Results: Seventy-two (51%) of the cases were found to have core body temperatures less than 36°C upon arrival. Twenty-nine (21%) the cases were considered clinically hypothermic (core temperatures of less than <35°C). After 30 minutes, 79 (56%) of the participants had core body temperatures of less than 36°C and 39 (28%) remained lower than 35°C. Patients were not warming up in the ED as expected. Rather, some had become colder. The study also found that the ambient temperature in the triage area fluctuated and was recorded as less than the recommended 21°C in 95 (68%) of the cases. In addition, the majority of ambulances that transported these cases lacked appropriate equipment on board to properly facilitate temperature control and rewarming.

Conclusion: Fifty-one percent of the trauma cases arriving by ambulance had core temperature <36°C. Many became even colder in the ED. Attention needs to be given to the early identification of hypothermia, the regulation of ambient temperatures inside the ED including the provision of appropriate heating and rewarming devices on ambulances.