Study of usage does of granisetron on hypotension in puerperants undergoing caesarean section under spinal anesthesia

Abstract

Objective To explore the minimum effect dose of granisetron required based on the puerperants′ weight to improve hypotension following spinal anesthesia for cesarean section. Methods A total of 146 puerperants who underwent elective cesarean section from January 1 to December 31 in 2018 in West China Second University Hospital, Sichuan University, were included in this study. They were randomly allocated into three groups by random digits table method to receive either granisetron 40 μg/kg (group A, n=49) or granisetron 20 μg/kg (group B, n=49) or normal saline (group C, n=48, as blank) intravenous injection slowly 5 min before induction of spinal anesthesia. The general clinical data, operation related data and the newborn Apgar scores were compared among three groups by using one-way analysis of variance, Kruskal-Wallis H rank sum test and chi-square test. Changes of mean arterial blood pressure (MABP) and heart rates at different time points after spinal anesthesia were compared statistically among three groups by using analysis of variance of repeated measurement data. The adverse drug reaction and outcomes of maternal and newborns were also evaluated. This study was in line with World Medical Association Declaration of Helsinki revised in 2013, and written consents from all patients were obtained. Results ①There were no significant differences among three groups of puerperants in general clinical data including age, body height and weight, and operation related data including time of sensory block to T6, operating time, incidence rates and times of hypotension, the phenylephrine and atropine requirements, and 1 and 5 min Apgar scores of newborns (P>0.05). ②There were significant differences in MABP and heart rates of puerperants at different time points including 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45 min after spinal anesthesia, respectively (Ftime=15.606, P<0.001; Ftime=4.297, P<0.001). There were no significant differences among three groups of puerperants in MABP and heart rates, respectively (Fintervention=1.103, P=0.335; Fintervention=0.706, P=0.496). ③There were no reports of drug-related adverse reactions and adverse outcomes including QT prolongation or serious cardiovascular events in puerperants, and bradycardia or hypothermia or central nervous system lesion in newborns in among three groups. Conclusions Granisetron 20 μg/kg or 40 μg/kg administered by intravenous injection slowly before spinal anesthesia could not effectively improve the puerperants′ hypotension in elective cesarean section. Key words: Granisetron; Hypotension; Anesthesia, spinal; Serotonin; Cesarean section; Puerperents