Pyrexia in head-injured patients admitted to intensive care

Objectives: (a) To quantify the occurrence of pyrexia during the first week after head injury; (b) to elucidate the relationships between pyrexia and neurological severity, length of stay in the ICU, intracranial hypertension, and cerebral perfusion pressure (CPP); and (c) to describe the effects of antipyretic therapy on temperature, intracranial pressure (ICP) and CPP. Design and setting: Multicenter retrospective observational study in three ICUs in the Milan area. Patients: 110 patients with traumatic brain injury. Measurements and results: Eighty patients suffered pyrexia, defined as an external temperature higher than 38°C or internal temperature higher than 38.4°C. Occurrence and duration of pyrexia were associated with the degree of neurological impairment and with prolonged ICU stay. In patients with normal perimesencephalic cisterns the episodes of increased ICP were more frequent in febrile cases. Various antipyretic therapies were used in 66 patients. Pharmacological treatment was slightly effective (mean temperature reduction 0.58±0.7°C) but caused a significant drop in CPP (6.5±12.5 mmHg). Conclusions: Pyrexia is extremely frequent in the acute phase after head injury. Its incidence is higher in more severe cases and is correlated with a longer ICU stay. It may affect ICP, but its contribution is difficult to assess when other major causes of increased intracranial volume are present. Antipyretic therapy is poorly effective for controlling body temperature and may be deleterious for CPP.