A systematic review of clinical outcomes, perioperative data and selective adverse events related to mild hypothermia in intracranial aneurysm surgery.

BACKGROUND

In the last two decades, mild intraoperative hypothermia has become widely accepted as a protective therapy in neurosurgery. However, its effect in intracranial aneurysm surgery remains unclear.

OBJECTIVE

The purpose of this study was to assess the perioperative effects and selected adverse events associated with intraoperative mild hypothermia in aneurysm surgery and to compare those with events in normothermic surgery.

METHODS

Three literature databases, namely the Cochrane Library, PubMed and EMBASE, were searched for randomised controlled trials (RCTs) of aneurysm surgery that compared intraoperative mild hypothermia and normothermia from January 1965 to August 2010. Three RCTs were identified. We extracted the following information: author names and publication year; clinical outcome (number of deaths and Glasgow outcome scales); perioperative data (number of moderate or severe intraoperative brain swelling occurrences, hypertensive episodes, ruptured or leaking aneurysms, volume of blood loss during surgery, duration of temporary clipping, and number of patients who received protective drugs, who required rewarming and who were intubated); number of adverse events (cerebral infarctions, brain swelling, myocardial ischaemia or infarction, congestive heart failure, meningitis or ventriculitis and pneumonia). Except for author names and publication year, the data were pooled to perform a mean effect size estimate. The effects of intraoperative mild hypothermia were then analysed.

RESULTS

The number of patients requiring rewarming in the mild hypothermia group was significantly greater than in the normothermia group (odds ratio, 33.89; 95% confidence intervals, 3.61-318.36). There were no other statistically significant differences.

CONCLUSION

Based on available RCTs, especially involving surgery of low-grade aneurysms, intraoperative mild hypothermia showed no advantages compared with normothermia.