The effect of active warming in prehospital trauma care during road and air ambulance transportation - a clinical randomized trial

Scand J Trauma Resusc Emerg Med. 2011 Oct 21;19:59. doi: 10.1186/1757-7241-19-59.

Abstract

Background: Prevention and treatment of hypothermia by active warming in prehospital trauma care is recommended but scientific 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.

Methods: 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.

Results: 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).

Conclusions: 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 might also reduce the cold induced stress response.

Trial registration: ClinicalTrials.gov: NCT01400152.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Ambulances
  • Ambulances*
  • Bedding and Linens*
  • Body Temperature / physiology
  • Chi-Square Distribution
  • Emergency Medical Services / methods*
  • Female
  • Humans
  • Hypothermia / etiology
  • Hypothermia / prevention & control*
  • Male
  • Middle Aged
  • Rewarming / methods*
  • Statistics, Nonparametric
  • Treatment Outcome
  • Wounds and Injuries / complications*

Associated data

  • ClinicalTrials.gov/NCT01400152