No association between intraoperative hypothermia or supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: findings from the Intraoperative Hypothermia for Aneurysm Surgery Trial.
BACKGROUND
Although hypothermia and barbiturates improve neurologic outcomes in animal temporary focal ischemia models, the clinical efficacy of these interventions during temporary occlusion of the cerebral vasculature during intracranial aneurysm surgery (temporary clipping) is not established.


METHODS
A post hoc analysis of patients from the Intraoperative Hypothermia for Aneurysm Surgery Trial who underwent temporary clipping was performed. Univariate and multivariate logistic regression methods were used to test for associations between hypothermia, supplemental protective drug, and short- (24-h) and long-term (3-month) neurologic outcomes. An odds ratio more than 1 denotes better outcome.


RESULTS
Patients undergoing temporary clipping (n = 441) were assigned to intraoperative hypothermia (33.3 degrees +/- 0.8 degrees C, n = 208) or normothermia (36.7 degrees +/- 0.5 degrees C, n = 233), with 178 patients also receiving supplemental protective drug (thiopental or etomidate) during temporary clipping. Three months after surgery, 278 patients (63%) had good outcome (Glasgow Outcome Score = 1). Neither hypothermia (P = 0.847; odds ratio = 1.043, 95% CI = 0.678-1.606) nor supplemental protective drug (P = 0.835; odds ratio = 1.048, 95% CI = 0.674-1.631) were associated with 3-month Glasgow Outcome Score. The effect of supplemental protective drug did not significantly vary with temperature. The effects of hypothermia and protective drug did not significantly vary with temporary clip duration. Similar findings were made for 24-h neurologic status and 3-month Neuropsychological Composite Score.


CONCLUSIONS
In the Intraoperative Hypothermia for Aneurysm Surgery Trial, neither systemic hypothermia nor supplemental protective drug affected short- or long-term neurologic outcomes of patients undergoing temporary clipping.
Hindman
Bradley J
BJ
Department of Anesthesia, University of Iowa, Iowa City, Iowa, USA. brad-hindman@uiowa.edu
Bayman
Emine O
EO
Pfisterer
Wolfgang K
WK
Torner
James C
JC
Todd
Michael M
MM
D000368:Aged; D000768:Anesthesia, General; D017542:Aneurysm, Ruptured / Q000601:surgery; D001831:Body Temperature / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D023261:Glasgow Outcome Scale; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D007036:Hypothermia, Induced; D002532:Intracranial Aneurysm / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology*; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D011446:Prospective Studies; D020011:Protective Agents / Q000494:pharmacology*; D013874:Thiopental / Q000627:therapeutic use; D016896:Treatment Outcome
D006993:Hypnotics and Sedatives; D020011:Protective Agents; D013874:Thiopental