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).

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.

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).

Therapeutic hypothermia increases the incidence of thrombocytopenia in severe TBI, and patients with thrombocytopenia after therapeutic hypothermia are associated with unfavorable neurological prognosis.