Brain-systemic temperature gradient is temperature-dependent in children with severe traumatic brain injury

Area of Science:

• Pediatric critical care medicine
• Neuroscience
• Biomedical engineering

Background:

• Accurate temperature monitoring is crucial in managing severe traumatic brain injury (TBI) in children.
• Understanding the gradient between core (brain) and peripheral (rectal) temperatures is essential for effective therapeutic interventions.

Purpose of the Study:

• To investigate the relationship between rectal and brain temperatures in pediatric patients with severe TBI.
• To determine if body surface area influences the temperature gradient.
• To examine how this gradient changes across different physiological temperature ranges.

Main Methods:

• Retrospective review of a prospectively collected pediatric neurotrauma registry.
• Analysis of hourly paired brain and rectal temperature measurements from 40 children with severe TBI.
• Stratification of patients by body surface area and brain temperature.

Main Results:

• Brain and rectal temperatures showed a strong overall correlation (r = .86, p < .001).
• The gradient reversed during brain hypothermia (brain temp-rectal temp = -1.87 ± 0.8) and hyperthermia (brain temp-rectal temp = 1.75 ± 0.4).
• Correlation weakened significantly when stratified by brain temperature, particularly during moderate brain hypothermia (≤34°C).

Conclusions:

• Brain and rectal temperatures are generally correlated in pediatric TBI, but the gradient varies significantly at temperature extremes.
• The reversed gradient during hypothermia suggests that targeting brain temperature for neuroprotection may allow for slightly higher systemic (rectal) temperatures, potentially reducing side effects.
• Findings may inform future clinical trials for neuroprotection using therapeutic hypothermia.