Active Warming in Prehospital Trauma Care
Prevention and treatment of hypothermia by active warming in prehospital trauma care is recommended but scientifical evidence of its effectiveness in a clinical setting is scarce. The objective of this study was to evaluate the effect of additional active warming during road or air ambulance transportation of trauma patients.
Patients were assigned to either passive warming with blankets or passive warming with blankets with the addition of an active warming intervention using a large chemical heat pad applied to the upper torso. Ear canal temperature, subjective sensation of cold discomfort and vital signs were monitored.
Mean core temperatures increased from 35.1°C (95% CI; 34.7-35.5 °C) to 36.0°C (95% CI; 35.7-36.3 °C) (p<0.05) in patients assigned to passive warming only (n=22) and from 35.6°C (95% CI; 35.2-36.0 °C) to 36.4°C (95% CI; 36.1-36.7°C) (p<0.05) in patients assigned to additional active warming (n=26) with no significant differences between the groups. Cold discomfort decreased in 2/3 of patients assigned to passive warming only and in all patients assigned to additional active warming, the difference in cold discomfort change being statistically significant (p<0.05). Patients assigned to additional active warming also presented a statistically significant decrease in heart rate and respiratory frequency (p<0.05).
In mildly hypothermic trauma patients, with preserved shivering capacity, adequate passive warming is an effective treatment to establish a slow rewarming rate and to reduce cold discomfort during prehospital transportation. However, the addition of active warming using a chemical heat pad applied to the torso will significantly improve thermal comfort even further and reduce the cold induced stress response.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
|Official Title:||The Effect of Active Warming in Prehospital Trauma Care During Road and Air Ambulance Transportation - a Clinical Randomized Trial|
- Body core temperature [ Time Frame: From initial assessment upon arrival of EMS crew until second assessment about 30 minutes later. ] [ Designated as safety issue: No ]
- Cold discomfort [ Time Frame: From initial assessment upon arrival of EMS crew until second assessment about 30 minutes later. ] [ Designated as safety issue: No ]
|Study Start Date:||December 2007|
|Study Completion Date:||May 2010|
|Primary Completion Date:||May 2010 (Final data collection date for primary outcome measure)|
|Active Comparator: Passive warming with additional active warming||
Device: Additional active warming
Chemical heat pad applied to the upper torso
|No Intervention: Passive warming|
|Department of Surgery and Perioperative Sciences, Umeå University|
|Umeå, Sweden, 901 85|
|Principal Investigator:||Ulf Björnstig, MD, PhD||Umeå University|