Intraoperative variables and early outcome after aneurysm surgery.

BACKGROUND: The purpose of this study was to investigate the effects of blood pressure, temperature, and anesthetic agents on outcome in patients undergoing craniotomy for cerebral aneurysms.

METHODS: All ruptured and unruptured intracranial aneurysms operated on from 1992 to 1998 were reviewed retrospectively. The data included 297 aneurysms (190 ruptured and 107 unruptured). Data were collected on variables known to influence outcome after aneurysmal subarachnoid hemorrhage as well as on intraoperative factors that might influence outcome (intraoperative blood pressure, temperature, temporary clipping, anesthetic agents). Outcome was assessed at discharge using the Glasgow Outcome Scale.

RESULTS: In univariate analysis of patients with ruptured aneurysms, younger age, better clinical grade, lower Fisher grade, lower intraoperative blood pressure (maximum systolic and mean blood pressure), smaller decrease in intraoperative compared to preoperative systolic blood pressure, shorter duration of surgery, and use of propofol, pancuronium, or N(2)O were associated with significantly better outcome. In patients with unruptured aneurysms, increased intraoperative minimum diastolic and mean blood pressure, a decrease in the difference between multiple measures of preoperative and intraoperative blood pressure, and a shorter duration of surgery were associated with significantly better outcome. Intraoperative temperature did not affect outcome in either group. In multivariate analysis of patients with ruptured aneurysms, younger age, better clinical grade, lower maximum systolic intraoperative blood pressure, shorter duration of surgery, and use of propofol were independently associated with better outcome.

CONCLUSIONS: Multivariate analysis of intraoperative factors affecting outcome in patients undergoing craniotomy for ruptured aneurysms shows that decreased intraoperative blood pressure and use of propofol are associated with improved outcome. Univariate analysis suggests that decreasing the magnitude of drop in blood pressure intraoperatively from preoperative values in patients with ruptured or unruptured aneurysms is associated with better outcome. Intraoperative hypothermia did not affect outcome.