LAUSR

INTRODUCTION Intensive care management for TBI patients aims to prevent secondary cerebral damage. Targeted temperature management is one option to prevent cerebral damage, as hypothermia may have protective effects. By conducting a systematic literature review, we evaluated (1) the presence of a temperature difference (gradient) between brain temperature (Tb) and core temperature (Tc) in TBI patients and (2) clinical factors associated with reported differences. EVIDENCE ACQUISITION The PubMed database was systematically searched using MESH terms and keywords, and Web of Sciences was assessed for additional article citations. We included studies that continuously and simultaneously measured Tb and Tc in severe TBI patients. The National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies was modified to fit the purpose of our study. Statistical data were extracted for further meta-analyses. EVIDENCE SYNTHESIS We included 16 studies, with a total of 480 patients. Clinical heterogeneity consisted of Tb/Tc measurement site, measurement device, physiological changes, local protocols, and medical or surgical interventions. The studies have a high statistical heterogeneity (I2). The pooled mean temperature gradient between Tb and Tc was +0.14 °C (95% confidence interval: 0.03 to 0.24) and ranged from -1.29 to +1.1 °C. Patients who underwent a decompressive (hemi)craniectomy showed lower Tb values compared to Tc found in three studies. CONCLUSIONS Studies on Tb and Tc are heterogeneous and show that, on average, Tb and Tc are not clinically significant different in TBI patients (<0.2 C). Interpretations and interventions of the brain and central temperatures will benefit from standardisation of temperature measurements.