Hypothermia prevention in burn patients

Overview

Hypothermia is a common, modifiable, and underappreciated risk factor in burn patients. A nationwide analysis of 116,796 burn encounters demonstrated that 20.6% of patients arrive hypothermic (below 36.0 degrees C) and that each degree Celsius below 36.0 independently increases mortality by 5%, even after controlling for burn size, inhalation injury, age, and comorbidities ^[1]. This dose-response relationship persists across burn severities, establishing hypothermia prevention as a clinical priority equal to fluid resuscitation from the point of first contact.

Pathophysiology

Burn patients lose heat through multiple mechanisms: evaporative losses from disrupted skin barrier, convective losses from exposed wounds, and conductive losses from cold intravenous fluids and cold operating surfaces. Large wound surface areas amplify all of these mechanisms. The thermal challenge is most acute during wound care, dressing changes, and operative procedures when wounds are exposed ^[3]. Burn resuscitation itself contributes to heat loss when large volumes of room-temperature crystalloid are administered.

Assessment

In the nationwide NTDB analysis (2007-2018), 20.6% of burn patients were hypothermic (<36.0 degrees C) on admission, 77.9% were euthermic, and 1.45% were hyperthermic ^[1]. For every 1.0 degrees C drop below 36.0 degrees C, mortality increased by 5% ^[1]. Both hypothermia and hyperthermia were independently associated with increased odds of death after controlling for all measured confounders (p < .001) ^[1]. Patients with admission temperatures between 32.5 and 33.5 degrees C had the highest adjusted odds of mortality at 22.0 (95% CI 15.6-31.0, p < .001) ^[1]. The critical threshold is preventing core temperature from dropping below 36.0 degrees C.

Management

Maintaining ambient operating room temperatures at 28-33 degrees C is the single most effective intraoperative intervention, though compliance is limited by staff thermal discomfort ^[2]. Forced-air warming of unburned surfaces and warming all intravenous fluids to 37-40 degrees C provide additional measurable benefit during operative cases ^[2]. Minimizing exposed wound surface area during procedures reduces evaporative and convective heat losses ^[2][3].

Prehospital and emergency department warming deserve the same systematic attention as fluid resuscitation. Stanton et al. propose that emergency department admission temperature could serve as a quality metric for benchmarking burn center performance ^[1].

Controversies and Evidence Gaps

The NTDB analysis is retrospective and cannot establish causation; hypothermic patients may have had unmeasured confounders such as prolonged extrication or prehospital delays ^[1]. Burn-specific randomized trials comparing warming strategies are lacking. Most perioperative warming recommendations are extrapolated from non-burn surgical literature or based on institutional protocols rather than controlled evidence ^[2]. The optimal OR ambient temperature remains a practical controversy, balancing patient safety with staff thermal comfort.

References

[1] Stanton E, Gillenwater J, Pham TN, Sheckter CC (2023). Temperature Derangement on Admission is Associated With Mortality in Burn Patients. PMID: 36335477 [2] Rizzo JA et al. (2017). Perioperative Temperature Management During Burn Care. PMID: 27294857 [3] Zurcher C et al. (2022). Temperature management of adult burn patients in intensive care. PMID: 36189905 [4] Gomez M et al. (2017). Impact of Early Inpatient Rehabilitation on Adult Burn Survivors. PMID: 27380119