Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jul 2001
Randomized Controlled Trial Comparative Study Clinical TrialEffect of a subanesthetic dose of intravenous ketamine and/or local anesthetic infiltration on hemodynamic responses to skull-pin placement: a prospective, placebo-controlled, randomized, double-blind study.
Insertion of cranial pins for stabilization of the head can result in a marked hypertensive response, which may adversely affect cerebral hemodynamics. The efficacy of a subanesthetic dose of intravenous ketamine (0.5 mg/kg) and/or lidocaine infiltration (1%) at pin fixation sites before pinning was studied in a prospective, double-blind, placebo-controlled, randomized trial of 40 patients. The subjects were divided into four groups of 10. ⋯ Significant attenuation of MBP and HR was observed in the lidocaine and ketamine-lidocaine groups (P < .05). A minimal increase in HR was observed in the lidocaine-ketamine group. The current study demonstrates maximum attenuation of hemodynamic responses when a subanesthetic dose of intravenous ketamine (0.5 mg/kg) is administered with 1% lidocaine infiltration.
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J Neurosurg Anesthesiol · Jul 2001
Randomized Controlled Trial Comparative Study Clinical TrialEffect of prophylactic ondansetron on postoperative nausea and vomiting after elective craniotomy.
This prospective, randomized, placebo-controlled, double-blind study was designed to evaluate the efficacy of ondansetron, a 5-HT3 antagonist, in preventing postoperative nausea and vomiting (PONV) after elective craniotomy in adult patients. The authors also tried to discover certain predictors for postcraniotomy nausea and vomiting. We studied 170 ASA physical status I and II patients, aged 15 to 70 years, undergoing elective craniotomy for resecting various intracranial tumors and vascular lesions. ⋯ Prophylactic ondansetron had a favorable influence on PONV outcome measures such as patient satisfaction and number needed to prevent emesis (3.5). Side effects were similar in both groups. We conclude that ondansetron 4 mg given at the time of dural closure is safe and effective in preventing emetic episodes after elective craniotomy in adult patients.
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J Neurosurg Anesthesiol · Jul 2001
Randomized Controlled Trial Comparative Study Clinical TrialEffects of dihydroergotamine on intracranial pressure, cerebral blood flow, and cerebral metabolism in patients undergoing craniotomy for brain tumors.
In a search for a nonsurgical intervention to control intracranial hypertension during craniotomy, the authors studied the effects of dihydroergotamine on mean arterial blood pressure (MABP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and cerebral metabolism in patients who underwent craniotomy for supratentorial brain tumors. Twenty patients were randomized to receive either dihydroergotamine 0.25 mg intravenously or placebo as a bolus dose during craniotomy. Anesthesia was induced with thiopental/fentanyl/atracurium, and maintained with isoflurane/N2O/fentanyl at normocapnia. ⋯ Intracranial pressure was significantly higher after dihydroergotamine than after placebo. In conclusion, no ICP decreasing effect of a bolus dose of dihydroergotamine was found when administered to patients with brain tumors during isoflurane/N2O anesthesia. Corresponding increases in MABP and ICP suggest that abolished cerebral autoregulation might explain why dihydroergotamine was associated with an ICP increase.
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J Neurosurg Anesthesiol · Jul 2001
Effects of alterations in arterial CO2 tension on cerebral blood flow during acute intracranial hypertension in rats.
Cerebrovascular reactivity to CO2 in clinical and experimental studies has been found to be impaired during increased intracranial pressure (ICP). However, from previous study results it has not been possible to estimate whether the impairment was caused by elevated ICP, or caused by decreased cerebral perfusion pressure (CPP). The current study was carried out in a group of unmanipulated control rats and in six investigation groups of six rats each: two groups with elevated ICP (30 and 50 mm Hg) and spontaneous arterial blood pressure (MABP), two groups with spontaneous ICP and arterial hypotension (77 and 64 mm Hg), and two groups with elevated ICP (30 and 50 mm Hg) and arterial hypertension (124 mm Hg). ⋯ By plotting each individual value of CO2 reactivity against the corresponding CPP value from the seven investigation groups, CPP was significantly and directly related to CO2 reactivity of CBF (P < .001). No correlation was found by plotting CO2 reactivity values against the corresponding MABP values or the corresponding ICP values. Thus, the results show that CO2 reactivity is at least partially determined by CPP and that the impaired CO2 reactivity observed at intracranial hypertension and arterial hypotension may be caused by reduced CPP.
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J Neurosurg Anesthesiol · Jul 2001
Clinical TrialMonitored anesthesia care using remifentanil and propofol for awake craniotomy.
Adequate analgesia and sedation with adequate respiratory and hemodynamic control are needed during brain surgery in awake patients. In this study, a protocol using clonidine premedication, intraoperative propofol, remifentanil, and labetalol was evaluated prospectively in 25 patients (aged 50 +/- 16). In all but one patient, no significant problems regarding cooperation, brain swelling, or loss of control were noticed, and it was not necessary to prematurely discontinue any of the procedures. ⋯ Nausea and vomiting were not recorded in any of the patients. Although these findings attest to the safety of awake craniotomy, they demonstrate the difficulty of achieving adequate sedation without compromising ventilation and oxygenation. The learning curve of using a new protocol and a new potent anesthetic drug is emphasized.