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

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.

Method

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 100 μg 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 outcomes.

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 demonstrated that it is not necessary to provide a vasoconstrictor to avoid hypotension that results from spinal anaesthesia in caesarean sections.