Abstract: Objective To study the protective mechanism of mild hypothermia from severe traumatic brain injury (sTBI). Methods 160 cases with sTBI were treated under normothermia (NT group, n=80) and mild hypothermia (HT group, n=80) respectively. Their serum level of anti-brain antibody (ABAb) was measured with ELISA, cerebral haemodynamics with transcranial Doppler, and intracranial pressure (ICP) with ICP monitor 1 d, 3 d, 5 d, 7 d and 14 d after injury, while they were assessed with Glasgow coma scale (GCS) and Glasgow outcome scale (GOS). Results The level of ABAb was lower in HT group than in NT group (P<0.05) at every point. The scores of GCS increased (P<0.05), and the volume of systole, mean and pulse index improved more in HT group 5 d after injury (P<0.01). The ICP was lower in HT group 3 d after injury (P<0.01). The score of GOS was better in HT group than in NT group when discharged (P<0.05). Conclusion Mild hypothermia can reduce the level of serum anti-brain antibody, improve cerebral haemodynamics, decrease ICP and improve the prognosis in patients with sTBl.

Key words: severe traumatic brain injury, mild hypothermia, anti-brain antibody, haemodynamics, intracranial pressure