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

Abstract

BackgroundPrevention 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.MethodsPatients 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.ResultsMean 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).ConclusionsIn 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 RegistrationClinicalTrials.gov: NCT01400152

The opinions of ambulance personnel regarding using a heated mattress for patients being cared for in a cold climate – An intervention study in ambulance care

“…In one study into surgery, those who were not pre-warmed needed a 20% longer hospital stay [38]. Use of polyester blankets alone without an active heat source means patients take longer to warm up again [21]. With the support of Aléx’s [5] PhD thesis, which describes the development of the knowledge surrounding heated mattresses, this constitutes an innovative care development that is both cheap and simple to implement in the care system.…”

“…Chemical heating pads placed on top of patients have been shown to be effective in reducing shivering and improving pre-hospital thermal comfort [21]. Patients given active warming in ambulances and in air ambulances and those given warm chemical heating pads during transport had a higher body temperature compared with patients given a heated drip or blankets [22].…”

Systematic Review of Evidence-Based in Beneficial Preventing Hypothermia for Adult Trauma Patients in Accident.

“…One of the studies (39) recruited patients who suffer burn accidents with total burn surface area greater than 20% (ranged from 20% to 87%). The other article was patients with blunt trauma who were under cold stress (40) . The age of the subjects were from 20 to 78 with mean age of 38-58 in the four articles except one of them failed to provide the age of subjects (36) .…”

“…We identified five (36,37,38,39,40) clinical randomized trials,the sample size of two studies were 100 participants (37) and 298patients (36) . The other two studies had sample sizes of 30 patients (38) and 48 paitents (40) .…”

“…The other two studies had sample sizes of 30 patients (38) and 48 paitents (40) . One study was within subject design and had sample sizes of 10 (39) .three out of thosestudies included patients which were all minor to medium level trauma with abdominal trauma, fractures, contusion, hematoma and injury severity scored (36,37,38) .…”