Unterschiede zwischen der zerebralen, transurethralen und tympanischen Temperatur in Patienten nach Subarachnoidalblutung

Fever is a common phenonmenon (~72%) in patients suffering from subarachnoid hemorrhage during the first 48h after bleeding or as a result of a nosocomial infection. Strict critical care management of raised core temperature is crucial since it is associated with an increased mortality. The core temperature, which is used as the target parameter can be measured at various measuring points in the body (e.g. bladder or tympanon). The goal of this study was to analyze the temperature differences between the different measuring points and the influence on the cerebral metabolism.

We included patients suffering from subarachnoid hemorrhage, who were treated at our instiution between 2016 and 2019, and received multimodal neuromonitoring including temperature measuring in the brain, as well as microdialyses for analyses of the cerebral metabolism. The core temperature was measured via a transurethral and tympanic measurement. We distingushed three phases of temperatures: hyperthermia >37.5°C, normothermia 36,0°C - 37,5°C and hypthermia <36,0°C.

Alltogether, we were able to include 20 consecutive patients after subarachnoid hemorrhage. The differences between brain and core temperature were 0.38°C [CI:0.27-0.48; p<0.001]. The temperature differences between the brain and tympanon were 0,70°C [CI:0.48-0.92; p<0.001]. During hyperthermia we observed a decrease of intracerebral glucose concentration, as well as an increase in lactate-pyruvate-ratio and simultaneously a decrease in pyruvate concentration as compared to normo- and hypothermia (p<0.001).

The temperature in the brain was higher than the core temperature and the temperate measured at the tympanon, respectively. Especially during phases of hyperthermia the glucose demand and the lactate-pyruvate-ratio was increased. This might be the result of an disrupted cerebral metabolism which further on can have a major impact on the morbidity of the patients.