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BACKGROUND: Opioid-based anesthetic techniques are commonly used during neurosurgical procedures. In the present randomized prospective study, we studied emergence after 4 anesthetic regimens combining intermediate duration opioids with isoflurane and nitrous oxide (N(2)O), in patients undergoing craniotomy for large (> 30 mm diameter with intracranial mass effect) intracranial tumors. METHODS: One hundred seven patients were randomized into 4 groups: Group A: fentanyl (≤ 5 µg/kg) + isoflurane (≤ 1 minimum alveolar concentration [MAC]), Group B: sufentanil (1-2 µg/kg plus infusion) + isoflurane (≤ 0.5 MAC), Group C: sufentanil (2 µg/kg bolus only) + isoflurane (≤ 1 MAC), and Group D: alfentanil (100 µg/kg plus infusion) + isoflurane (≤ 0.5 MAC). Boluses were administered as divided doses during induction, laryngoscopy, head pinning, and incision. Blood pressure was controlled at ±25% of baseline levels. All infusions were discontinued at the start of dural closure. Emergence was assessed using a mini-neurologic examination consisting of 7 questions. Groups were compared on time to emergence using survival analysis methods. RESULTS: The groups did not differ regarding extubation time, which occurred at a median of 4 to 6 minutes across groups after discontinuing N(2)O. The median emergence time ranged from 15 to 22.5 minutes and did not differ among groups. However, across all groups more women had emerged by 30 minutes compared with men (83% vs 57%, P â=â .002). The median emergence time in women was found to be significantly shorter (0-15 minutes) than in men (15-30 minutes) (P â=â .012). CONCLUSIONS: No between-group differences in emergence time were observed; the study was stopped early because of evidence that no differences were likely to be found if the study were continued. However, in a post hoc analysis, female gender was associated with faster emergence.
RESUMO
α(2)-Agonists are a novel class of drugs with mechanisms of action that differ from other commonly used anesthetic drugs. They have neuroprotective, cardioprotective, and sedative effects. These unique characteristics make them potentially useful during neuroanesthesia and intensive care. We review the effects of dexmedetomidine on cerebral blood flow and cerebral metabolism, along with recent advances in using α(2)-agonists in neuroanesthesia and neurointensive care.
RESUMO
PURPOSE: At least one retrospective study has suggested that the need for postoperative control of pain and nausea depends on the location of the cranial surgery. This prospective study was performed to examine the hypothesis that patients who have had infratentorial craniotomy experience more severe pain and more frequent nausea than those with supratentorial procedures. METHODS: We compared postoperative outcomes in 28 patients with infratentorial craniotomy, 53 with supratentorial craniotomy, and 47 with complex spinal cord surgery (the control group). Anesthesia was standardized for all three groups and the concentration of isoflurane was titrated to keep mean arterial pressure within 30% of preoperative values. Severity of pain and frequency of nausea and vomiting were recorded for 24 h after surgery. Pain was assessed with a verbal pain score scale of 0-10, with 10 being the worst pain imaginable. Data were collected for 24 h postoperatively. RESULTS: Because nausea and pain diminish drastically 2 h after surgery, pairwise differences were assessed at each point within the first 2 h. Within 30 min of extubation, median pain scores in the supratentorial and spine groups rose to 2 and in the infratentorial group to 5. The statistical differences between groups were not significant ( P > 0.06) by logistic regression. Also, the incidence of nausea was not significantly different (57% supratentorial, 57% spine, 67% infratentorial; P = 0.62) by Dunn's procedure. CONCLUSION: There were no significant differences in the severity of pain or the frequency of nausea based on the craniotomy site.