Thrombocytopenia after therapeutic hypothermia in severe traumatic brain injury

To investigate the clinical characteristics and significance of thrombocytopenia after therapeutic hypothermia in severe traumatic brain injury （TBI）. Methods： Ninety-six .inpatients with severe brain injury were randomized into three groups： SBC （ selective brain cooling ） group （ n =24）, MSH （ mild systemic hypothermia ） group （ n = 30）, and control （normothermia） group （n=42）. The platelet counts and prognosis were retrospectively analyzed. Results： Thrombocytopenia was present in 18 （75 % ）, 23 （ 77 % ） and 15 （36 % ） patients in SBC group, MSH group and control group, respectively （P 〈0.01 ）. Thrombocytopenia, in which the minimum platelet count was seen 3 days after hypothermia, showed no significant difference between SBC and MSH group （P 〉 0.05 ）. Most platelet counts （37 cases, 90% ） in hypothermia group were returned to normal level after 1 to 2 days of natural rewarming. The platelet count in SBC group reduced by 16%, 27% and 29% at day 1, 3 and 5 respectively compared with the baseline value. Good recovery （ GOS score 4-5 ） rate of thrombocytopenia 1 year after injury for hypothermia group （ 17 cases, 37 % ） was significantly lower than that of control group （ P 〈 0. 01 ）. Conclnsions： Therapeutic hypothermia increases the incidence of thrombocytopenia in severe TBI, and patients with thrombocytopenia after therapeutic hypothermia are associated with unfavorable neurological prognosis.