Anesthesiology
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Randomized Controlled Trial Clinical Trial
"Defasciculation" with metocurine prevents succinylcholine-induced increases in intracranial pressure.
In order to determine whether a small, "defasciculating" dose of metocurine could prevent increases in intracranial pressure (ICP) induced by succinylcholine (Sch), the authors studied 12 patients (ages 25-79 yr) undergoing craniotomy for excision of malignant supratentorial gliomas. After insertion of a subarachnoid bolt for ICP monitoring and a radial arterial cannula for determination of blood pressure and blood gas tensions, six patients (group I) were randomly allocated to receive MTC 0.03 mg/kg 3 min before induction of general anesthesia with thiopental 4 mg/kg and nitrous oxide 70% in O2. Six other patients (group II) received saline 0.015 ml/kg instead of MTC, followed by the same induction sequence. ⋯ In group I (MTC pretreatment), ICP did not change significantly from the mean value observed before Sch, 14 mmHg +/- 2 SE. In group II (saline pretreatment), ICP increased from 11 mmHg +/- 2 SE to 23 mmHg +/- 4 SE (P less than .05). This study not only confirms previous work showing that Sch may induce marked ICP increases in lightly anesthetized patients with intracranial mass lesions, but also indicates that pretreatment with a "defasciculating" dose of MTC can prevent these potentially deleterious ICP increases in patients known to be at risk.
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Randomized Controlled Trial Clinical Trial
Anesthesia and hypertension: the effect of clonidine on perioperative hemodynamics and isoflurane requirements.
Thirty patients (ASA physical status II-III) with a history of arterial hypertension, whose blood pressure (BP) control varied from normotension to moderate hypertension (diastolic BP less than 110 mmHg), scheduled for elective surgery under general anesthesia, were randomly assigned to two groups. Group 1 was premedicated 90-120 min prior to induction with diazepam 0.15 mg X kg-1 po; group 2, in addition, received clonidine 5 micrograms X kg-1 po. Anesthetic depth was assessed by on-line aperiodic analysis of the electroencephalogram. ⋯ In group 2, clonidine produced a rapid preoperative control of systolic and diastolic BP from 166 +/- 32/95 +/- 14 to 136 +/- 80 +/- 11 (P less than 0.01), was more effective in blunting the reflex tachycardia associated with laryngoscopy and endotracheal intubation than lidocaine-fentanyl pretreatment. It significantly reduced the intraoperative lability (coefficient of variation) of systolic (P less than 0.01) and diastolic BP and heart rate (HR) (P less than 0.05), and resulted in significantly slower HR during recovery (P less than 0.01). Anesthetic requirements for isoflurane were reduced 40% (P less than 0.01) in group 2; narcotic supplementation was also significantly reduced (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
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The authors examined the effect of clonidine, a preferential alpha 2-adrenergic agonist, upon narcotic requirements, hemodynamics, and adrenergic responses during the perioperative period in patients undergoing CABG surgery. Anesthesia was provided by sufentanil supplemented with isoflurane; sodium nitroprusside was given as needed for hemodynamic control. Ten patients received oral clonidine preoperatively at the time of premedication, and again intraoperatively by nasogastric tube. ⋯ After cardiopulmonary bypass and postoperatively, cardiac outputs were significantly higher in the treated group. Patients who had received clonidine were extubated significantly earlier, and fewer of them shivered postoperatively. We conclude that perioperative treatment with clonidine reduced narcotic and anesthetic requirements, improved hemodynamics, reduced plasma catecholamines, and shortened the period of postoperative ventilation in patients undergoing coronary artery surgery.