Hypotension after spinal anaesthesia is not always the rule in parturients undergoing caesarean section

Abstract

Background General anaesthesia is a real challenge for the anaesthetist when anaesthetizing obstetric patients due its well-known complications of difficult intubation and thereby increasing morbidity and mortality of pregnant women. These risks can be easily avoided by regional anaesthesia. Spinal anaesthesia is frequently associated with hypotension which can have detrimental effects both on the mother and the neonate. Prophylactic phenylephrine administration had been widely practiced to prevent post-spinal hypotension during caesarean section. The goal of this study is to prove and determine that it is not always necessary to use a vasoconstrictor to avoid hypotension after spinal anesthesia for parturients undergoing caesarean section. Methods We enrolled 100 patients in this randomized controlled study who were having elective caesarean delivery. Spinal anaesthesia was performed under aseptic conditions. Immediately following spinal blockade, patients were randomly allocated to receive either a single bolus of phenylephrine 100μg in a volume of 10 ml, or equivalent volume of normal saline 0.9%. Incidence of post-spinal hypotension was used as the primary outcome. Maternal haemodynamic parameters, intraoperative nausea and vomiting, the need for phenylephrine or glycopyrrolate administration, neonatal Apgar score at 1, 5 minutes, and base excess (BE) value of the neonatal umbilical venous blood were all recorded and reflected the secondary outcome Results There was no significant difference regarding the incidence of post-spinal hypotension in phenylephrine and placebo group. There was no difference in neonatal Apgar score at 1, 5 minutes, and base excess in both groups. Conclusion The present study had demonstrated that it is not always necessary to provide a vasoconstrictor to avoid hypotension that results from spinal anaesthesia in caesarean sections.

Prevention of spinal hypotension during cesarean section: A systematic review and Bayesian network meta‐analysis based on ephedrine, phenylephrine, and norepinephrine

“…About 1397 duplicate literatures were deleted, 1656 literatures on subjects and interventions were deleted by reading title and abstract because they did not fit the inclusion criteria of this study, and 72 full texts that might meet the conditions were obtained. Subsequently, 5 research subjects did not conform to the criteria, and 50 intervention measures did not suit the criteria, 17 studies 8,10,15,16,[20][21][22][23][24][25][26][27][28][29][30][31][32] were finally included. Figure 1 was the flow chart for literature search and study selection.…”

“…Figure 1 was the flow chart for literature search and study selection. Of these 17 eligible studies, 10 were compared with the placebo (saline) 8,10,15,16,[25][26][27][28]30,31 ; 12 had two arms [20][21][22][23][24][25][26][27][29][30][31][32] ; 3 had three arms 8,10,15 ; 2 had four arms. 16,28 The characteristics of the selected included studies were displayed in Table 1, and the network plot and rank histogram were presented in Figure 2.…”

“…Our primary outcome was that 16 studies (1513 patients) reported the incidence of hypotension. 8,10,15,16,[20][21][22][23][24][25][26][27][28][29][30][31] The pairwise meta-analysis showed that compared with placebo (saline), prophylactic bolus injection of EP (high) (OR 14.66, 95% CI 4.22 to 50.91), EP (low) (OR 1.91, 95% CI 1.01 to 3.58), EP (middle) (OR 4.17, 95% CI 1.35…”

“…Data on maternal bradycardia were collected in 13 trials (1234 patients). 10,15,20,[22][23][24][25][26][27][28][29][30]32 The pair-wise meta-analysis indicated that no difference was detected between active intervention and placebo (saline) (Figure S3). The results of NMA showed in Table 4.…”

“…Fifteen studies (1394 patients) reported the incidence of intraoperative nausea or vomiting (IONV). 8,10,15,16,[20][21][22][24][25][26][27][28][29][30]32 The pair-wise metaanalysis indicated that no difference was detected between interventions (Figure S4). The results of NMA suggested that there was no different among interventions (Table 5).…”