The purpose of our study was to measure surface body temperatures (SBT) and to determine rewarming patterns after surface cooling in adult comatose survivors of cardiac arrest. We performed a prospective study in two phases from April to May 2016 and from December 2017 to March 2018. In the first phase we measured SBT as soon as possible after admission (t0) and 10 minutes later (t10). In the second phase we measured SBT and changes of SBT after local cooling of different regions in the maintenance phase of targeted temperature management. We included six patients to each phase of the study. In the first phase, we observed lower SBT compared with core body temperature (CBT) at t0 and t10, with nonsignificant differences in head and axillary region at t0 (35.2°C ± 1.3°C vs. 36°C ± 0.6°C, p = 0.11, and 35.7°C ± 1.4°C vs. 36°C ± 0.6°C, p = 0.41, respectively) and head at t10 (34.8°C ± 1.6°C vs. 35.9°C ± 0.6°C, p = 0.13). SBT in all other body regions at t0 and t10 was significantly lower compared with CBT (all p values <0.05). In the second phase, SBT was significantly lower compared with CBT in all regions (all p values <0.05). After local cooling we observed no significant differences in rewarming rate between head (2.1 ± 0.3°C/min), thorax (1.6 ± 0.4°C/min), and abdomen (1.7 ± 0.2°C/min), and a significantly faster rewarming rate when comparing other body regions with legs (0.8 ± 0.4°C/min, all p values <0.03). To conclude, in comatose survivors of cardiac arrest we discovered lower SBT compared with CBT, necessitating CBT measurements as soon as possible, and higher SBT and rewarming rates after local cooling in central (head, thorax, and abdomen) compared with peripheral (upper and lower extremities) regions of the body.
Keywords: body temperature regulation; cardiac arrest; surface body temperature.