Prediction of Intracranial Temperature Through Invasive and Noninvasive Measurements on Patients with Severe Traumatic Brain Injury

Abstract

The brain's temperature measurements (T_B) in patients with severe brain damage are important, in order to offer the optimal treatment. The purpose of this research is the creation of mathematical models for the T_B's prediction, based on the temperatures in the bladder (T_BL), femoral artery (T_FA), ear canal (T_ΕC), and axilla (T_A), without the need for placement of intracranial catheter, contributing significantly to the research of the human thermoregulatory system.The research involved 18 patients (13 men and 5 women), who were hospitalized in the adult intensive care units (ICU) of Larissa's two hospitals, with severe brain injury. An intracranial catheter with a thermistor was used to continuously measure T_B and other parameters. The T_B's measurements, and simultaneously one or more of T_BL, T_FA, T_EC, and T_A, were recorded every 1 h.To create T_B predicting models, the data of each measurement was separated into (a) model sample (measurements' 80%) and (b) validation sample (measurements' 20%). Multivariate linear regression analysis demonstrated that it is possible to predict brain's temperature (PrT_B), using independent variables (R₂ was T_BL = 0.73, T_FA = 0.80, T_EC = 0.27, and T_A = 0.17, p < 0.05). Significant linear associations were found, statistically, and no difference in means between T_B and PrT_B of each prediction model. Also, the 95% limits of agreement and the percent coefficient of variation showed sufficient agreement between the T_B and PrT_B in each prediction model.In conclusion, brain's temperature prediction models based on T_BL, T_FA, T_EC, and T_A were successful. Its determination contributes to the improvement of clinical decision-making.

Keywords: Brain temperature; Intracranial catheter; Neuroparametry; Temperature prediction model.