Further Study Of Mild Hypothermia In The Treatment Of Patients With Severe Head Injuries

[Objective] To monitor the changes of multiple factors in patients with severe head injury treated with mild hypothermia, and investigate the effect of mild hypothermia on patients with severe head injury.[Methods] Forty-tow patients ( average age 41.7 years old ) with severe head injury admitted to the clinical college of chongqing university of medical sciences from October 2000 to February 2002 were selected for this study. Mild hypothermia group received cooling C32~34℃, for 3~5 days within 12 hours after head injury. Control group received normothermia treatment. Brain tissue PO2 was continuously monitored. Serum electrolytes, arterial O2, CSF pH and CSF lactic acid were examined before cooling, 24 hours/48 hours/72 hours after cooling.[Results] there was no difference for brain tissue PO2 between both group patients with GCS 6~8 before cooling, 4 hours after cooling or after rewarming ( P>0.05 ); brain tissue PO2 was lower in cooling group than that in control group 24 hours/48 hours/72 hours after cooling ( P<0.05 ). There was no difference between both group patients with GCS 3~5 at different periods ( P>0.05 ). Brain tissue PO2 from 48 hours to 72 hours after cooling was lower than that before or after this time interval and P_aO2 was higher during cooling than that before cooling or after rewarming in patients with GCS 6~8. PbO2 and PaO2 decreased gradually during the whole observation period in patients with GCS 3~5. there was no difference for CSF lactic acid for both groups before cooling ( P>0.05 ); CSF lactic acid was lower in cooling group than that in control group 24 hours/48 hours/72 hours after cooling ( P<0.05 ). Serum K~+, Ca~2+ showed no differences between both groups before cooling or after rewarming ( P>0.05 ); serum K~+, Ca~2+ were lower in cooling group than that in control group 4 hours/24 hours/48 hours/72 hours after cooling ( P<0.05 ). Serum Na~+ showed no difference between both groups ( P>0.05 ). Two patients in cooling group suffered from arrhythmia.[Conclusions] mild hypothermia may decrease CSF lactic acid and brain tissue PO2, but can not improve brain acidosis. Cooling treatment can not improve conditions in patients with GCS 3~5. mild hypothermia may lead to decreased serum K~+, Ca~2+ and arrhythmia.