Abstract
Background: Hypothalamic thermoregulation allows humans to adjust and maintain core body temperature, facilitating essential biochemical reactions for metabolic processes. When heat energy loss exceeds endothermic capacity of the body, core body temperature decreases, slowing critical reactions. Without patient warming solutions, patients with injuries resulting in thermoregulatory disturbances are at risk of multiple organ failure and/or death.
Aim: Illustrate thermoregulatory stabilization capacity of heated, humidified high velocity therapy (HVT), a refined form of high flow nasal canula (HFNC), and its utilization in a range of clinical scenarios which traditionally require active temperature management.
Scope: Many clinicians are unaware that the lungs can provide as much as 140m 2 surface area for heat exchange, compared with approximately 2m 2 of skin. With HVT there is an opportunity for clinicians to offer efficient additional thermoregulatory support via non-invasive methods with an established safety profile, whilst simultaneously meeting oxygen and ventilation requirements of the patient.
Case 1: A 67-year-old female presented with accidental hypothermia due to environmental exposure, with hyperextension injury at C4-C5. The patient"™s core body temperature was 30°C [86°F] upon discovery. Within 4 hours the patient"™s temperature increased to 35°C [95° F] with the use of heated blanket and HVT. The underlying injury and pattern of recovery was consistent with central cord syndrome.
Case 2: A 5-month-old female experienced severe burns and was weaned from intubation using HVT for respiratory and thermoregulatory support. This patient was at high risk for mucosal airway dysfunction, temperature instability, and other poor outcomes, but remained stable and recovered.
Discussion: The utility of HVT as a respiratory device with thermoregulatory capacity was explored using case studies and available literature. HVT delivers warmed humidified gas that oxygenates and ventilates simultaneously, reduces work of breathing, preserves mucociliary clearance, and reduces metabolic cost associated with humidifying and heating inspired air. HVT performed within its accepted safety profile with no identified side effects.
Conclusion: HVT can offer an adjunctive warming benefit for patients with reduced temperature control capacity. This may be especially valuable for patients requiring respiratory support or those who may benefit from optimized humidification of inspired gas.