Mild Hypothermia After Intravenous Thrombolysis in Patients With Acute Stroke A Randomized Controlled Trial

Background and Purpose Hypothermia improves outcome in resuscitated patients and newborns with hypoxic brain injury. We studied the safety and feasibility of mild hypothermia in awake patients with stroke after intravenous thrombolysis. Methods Patients were randomized 1:1 to mild hypothermia (35 degrees C) or to standard stroke unit care within 6 hours of symptom onset. Hypothermia was induced with a surface-cooling device and cold saline infusions. Active cooling was restrained gradually after 12 hours at <35.5 degrees C. The primary outcome measure was the number of patients with <36 degrees C body temperature for >80% of the 12-hour cooling period. Results We included 36 patients with a median of National Institutes of Health Stroke Scale score of 9 one hour after thrombolysis. Fifteen of 18 (83%) patients achieved the primary end point. Sixteen (89%) patients reached <35.5 degrees C in a median time of 10 hours (range, 7-16 hours) from symptom onset, spent 10.5 hours (1-17 hours) in hypothermia, and were back to normothermia in 23 hours (15-29 hours). Few serious adverse events were more common in the hypothermia group. At 3 months, 7 patients (39%) in both groups had good outcome (modified Ranking Scale, 0-2), whereas poor outcome (modified Ranking Scale, 4-6) was twice as common in the normothermia group (44% versus 22%). Conclusions Mild hypothermia with a surface-cooling device in an acute stroke unit is safe and feasible in thrombolyzed, spontaneously breathing patients with stroke, despite the adverse events.