Safety and therapeutical benefit of hemicraniectomy combined with mild hypothermia in comparison with hemicraniectomy alone in patients with malignant ischemic stroke. Effects of therapeutic mild hypothermia on patients with severe traumatic brain injury after craniotomy. Mild hypothermia as a protective therapy during intracranial aneurysm surgery: a randomized prospective pilot trial. Mild intraoperative hypothermia during surgery for intracranial aneurysm.
Both for hemicraniectomy and for hypothermia, several reports describe a beneficial effect in patients with malignant supratentorial cerebral ischemia. We compared the safety and the clinical outcome in patients with a malignant supratentorial infarction who were treated with hemicraniectomy alone (HA) or received a combination therapy with hemicraniectomy and hypothermia of 35 degrees C (HH), respectively.
                In a prospective and randomized study, 25 consecutive patients were treated after an ischemic infarction of more than two thirds of one hemisphere by HA (n=13 patients) or the HH combination therapy (n=12 patients). Safety parameters were compared between both treatment groups, the clinical outcome was assessed during treatment and after 6 months.
                Age, cranial CT or MRI findings, initial National institutes of Health Stroke Scale Score (NIHSSS) and level of consciousness were not significantly different between both groups. Hemicraniectomy was performed within 15+/- 6 h after the ischemic event. Hypothermia was induced immediately after surgery. Overall mortality was 12% (2/13 vs. 1/12 in the two groups), but none of these 3 patients died due to treatment-related complications. There were no severe side effects of hypothermia. Duration of need for intensive care or for mechanical ventilation and infectious status did not differ significantly between both groups, but the need for catecholamine application was increased in the HH group. The clinical outcome showed a tendency for a better outcome in the HH compared with the HA group with respect to status after 6 months, as assessed by the NIHSSS (10+/-1 vs. 11+/-3, p<0.08).
                The present study suggests that a combined therapy of mild hypothermia and hemicraniectomy in malignant brain infarction does not imply additional risks by side effects and improves functional outcome as compared with hemicraniectomy alone.
                Copyright (c) 2006 S. Karger AG, Basel. We investigated the effects of therapeutic mild hypothermia on patients with severe traumatic brain injury after craniotomy (TBI).
                Eighty patients with severe TBI after unilateral craniotomy were randomized into a therapeutic hypothermia group with the brain temperature maintained at 33 degrees C to 35 degrees C for 4 days, and a normothermia control group in the intensive care unit. Vital signs, intracranial pressure, serum superoxide dismutase level, Glasgow Outcome Scale scores, and complications were prospectively analyzed.
                The mean intracranial pressure values of the therapeutic hypothermia group at 24, 48, and 72 hours after injury were much lower than those of the control group (23.49 +/- 2.38, 24.68 +/- 1.71, and 22.51 +/- 2.44 vs 25.87 +/- 2.18, 25.90 +/- 1.86, and 24.57 +/- 3.95 mm Hg; P = .000, .000, and .003, respectively). The mean serum superoxide dismutase levels of the therapeutic hypothermia group at days 3 and 7 were much higher than those of the control group at the same time point (533.0 +/- 103.4 and 600.5 +/- 82.9 vs 458.7 +/- 68.1 and 497.0 +/- 57.3 mug/L, respectively; P = .000). The percentage of favorable neurologic outcome 1 year after injury was 70.0% and 47.5%, respectively (P = .041). Complications, including pulmonary infections (57.5% in the therapeutic hypothermia group vs 32.5% in the control group; P = .025) were managed without severe sequelae.
                Therapeutic mild hypothermia provides a promising way in the intensive care unit for patients with severe TBI after craniotomy. To conduct a pilot trial of mild intraoperative hypothermia during cerebral aneurysm surgery.
                One hundred fourteen patients undergoing cerebral aneurysm clipping with (n = 52) (World Federation of Neurological Surgeons score < or =III) and without (n = 62) acute aneurysmal subarachnoid hemorrhage (SAH) were randomized to normothermic (target esophageal temperature at clip application of 36.5 degrees C) and hypothermic (target temperature of 33.5 degrees C) groups. Neurological status was prospectively evaluated before surgery, 24 and 72 hours postoperatively (National Institutes of Health Stroke Scale), and 3 to 6 months after surgery (Glasgow Outcome Scale). Secondary outcomes included postoperative critical care requirements, respiratory and cardiovascular complications, duration of hospitalization, and discharge disposition.
                Seven hypothermic patients (12%) could not be cooled to within 1 degrees C of target temperature; three of the seven were obese. Patients randomized to the hypothermic group more frequently required intubation and rewarming for the first 2 hours after surgery. Although not achieving statistical significance, patients with SAH randomized to the hypothermic group, when compared with patients in the normothermic group, had the following: 1) a lower frequency of neurological deterioration at 24 and 72 hours after surgery (21 versus 37-41%), 2) a greater frequency of discharge to home (75 versus 57%), and 3) a greater incidence of good long-term outcomes (71 versus 57%). For patients without acute SAH, there were no outcome differences between the temperature groups. There was no suggestion that hypothermia was associated with excess morbidity or mortality.
                Mild hypothermia during cerebral aneurysm surgery is feasible in nonobese patients and is well tolerated. Our results indicate that a multicenter trial enrolling 300 to 900 patients with acute aneurysmal SAH will be required to demonstrate a statistically significant benefit with mild intraoperative hypothermia. Surgery for intracranial aneurysm often results in postoperative neurologic deficits. We conducted a randomized trial at 30 centers to determine whether intraoperative cooling during open craniotomy would improve the outcome among patients with acute aneurysmal subarachnoid hemorrhage.
                A total of 1001 patients with a preoperative World Federation of Neurological Surgeons score of I, II, or III ("good-grade patients"), who had had a subarachnoid hemorrhage no more than 14 days before planned surgical aneurysm clipping, were randomly assigned to intraoperative hypothermia (target temperature, 33 degrees C, with the use of surface cooling techniques) or normothermia (target temperature, 36.5 degrees C). Patients were followed closely postoperatively and examined approximately 90 days after surgery, at which time a Glasgow Outcome Score was assigned.
                There were no significant differences between the group assigned to intraoperative hypothermia and the group assigned to normothermia in the duration of stay in the intensive care unit, the total length of hospitalization, the rates of death at follow-up (6 percent in both groups), or the destination at discharge (home or another hospital, among surviving patients). At the final follow-up, 329 of 499 patients in the hypothermia group had a Glasgow Outcome Score of 1 (good outcome), as compared with 314 of 501 patients in the normothermia group (66 percent vs. 63 percent; odds ratio, 1.14; 95 percent confidence interval, 0.88 to 1.48; P=0.32). Postoperative bacteremia was more common in the hypothermia group than in the normothermia group (5 percent vs. 3 percent, P=0.05).
                Intraoperative hypothermia did not improve the neurologic outcome after craniotomy among good-grade patients with aneurysmal subarachnoid hemorrhage.
                Copyright 2005 Massachusetts Medical Society.
Although there is some evidence that mild hypothermia is safe, its effectiveness is not clear when compared with normothermia. We need to perform more clinical trials in order to establish the benefit, if any, of hypothermia for cerebral protection during brain surgery before making firm recommendations for the routine use of this intervention.