Granisetron Reduces Shivering after General Anesthesia
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- Category: Vol. 81, December 2013
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Granisetron Reduces Shivering after General Anesthesia, MOHAMED A. MAHMOUD and AHMED M. ZAKI
Abstract
Background: The neurotransmitter pathways involved in the mechanism of postanesthetic shivering (PAS) are poorly understood. Meperidine, clonidine, and physostigmine are all effective treatments, indicating that opioid, a2-adrenergic, and anticholinergic systems are probably involved. We inves-tigated the effect of Granisetron, a [5-hydroxytryptamine (5- HT3)] antagonist used to treat postoperative nausea and vomiting, on intraoperative core and peripheral temperatures and PAS.
Methods: Forty five patients (age, 18-60yr) undergoing orthopedic, general, or urological surgery were randomly assigned to receive an intravenous bolus of Granisetron 15mg/kg, isotonic saline, or 0.5mg/kg meperidine, immediately before the anesthetic induction. Core (tympanic) and fingertip temperature (dorsum of middle finger) were recorded. Anes-thesia was induced with IV fentanyl 1mg/kg and propofol 2.0- 2.5mg/kg and maintained with 1 minimum alveolar anesthetic concentration isoflurane in oxygen. Heart rate, mean arterial blood pressure, oxygen saturation, visual analog pain score, temperature, and postanesthetic shivering were measured during recovery by anesthesiologist, who was unaware of the group assignment.
Results: Postanesthetic shivering occurred in 6 of 15 (40%) patients given saline. In contrast, postanesthetic shiv-ering was significantly reduced in Granisetron treated patients (1 of 15, or 6%) and peripheral temperature increased signif-icantly, but there were no significant differences among the groups at any time interval. Granisetron 15mg/kg IV given during the induction of anesthesia prevents PAS without affecting the core-to-peripheral redistribution of heat during general anesthesia.
Conclusions: Granisetron inhibited shivering as well as did established treatment, meperidine. These data suggest that serotonergic pathways have a role in the regulation of PAS.
Implications: In a randomized, double-blinded, placebo-controlled, clinical study, Granisetron 15mg/kg IV, given just before the induction, reduced the incidence of postanesthetic shivering compared with saline. The anticipated core-to-peripheral redistribution of body temperature during general anesthesia was not affected. This implies that Granisetron probably acts by a central inhibitory mechanism, and that 5- hydroxytryptaminergic pathways have a role in regulating postanesthetic shivering.