Mild hypothermia after intravenous thrombolysis in patients with acute stroke: a randomized controlled trial

Abstract

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°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°C. The primary outcome measure was the number of patients with <36°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°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.

Clinical trial registration url: http://www.clinicaltrials.gov. Unique identifier: NCT00987922.

Keywords: hypothermia; ischemic stroke; thrombolytic therapy.