Study on changes of partial pressure of brain tissue oxygen and brain temperature in acute phase of severe head injury during mild hypothermia therapy

Objective: To study the changes of partial pressure of brain tissue oxygen (PbtO 2) and brain temperature in acute phase of severe head injury during mild hypothermia therapy and the clinical significance. Methods: One hundred and sixteen patients with severe head injury were selected and divided into a mild hypothermia group (n=58), and a control group (n=58) according to odd and even numbers of hospitalization. While mild hypothermia therapy was performed PbtO 2 and brain temperature were monitored for 1 7 days (mean=86 hours), simultaneously, the intracranial pressure, rectum temperature, cerebral perfusion pressure, PaO 2 and PaCO 2 were also monitored. The patients were followed up for 6 months and the prognosis was evaluated with GOS (Glasgow outcome scale). Results: The mean value of PbtO 2 within 24 hour monitoring in the 116 patients was 13.7 mm Hg ± 4.94 mm Hg , lower than the normal value (16 mm Hg ± 40 mm Hg ) The time of PbtO 2 recovering to the normal value in the mild hypothermia group was shortened by 10± 4.15 hours compared with the control group (P 0.05 ). The survival rate of the mild hypothermia group was 60.43 %, higher than that of the control group ( 46.55 %). After the recovery of the brain temperature, PbtO 2 increased with the rise of the brain temperature. Conclusions: Mild hypothermia can improve the survival rate of severe head injury. The technique of monitoring PbtO 2 and the brain temperature is safe and reliable, and has important clinical significance in judging disease condition and instructing clinical therapy.