Prophylactic bolus dose of Nor-Epinephrine versus Phenylephrine bolus for Management of post- spinal Hypotension among patients undergoing Elective Caesarean Section. A Prospective Cohort Study

Background: Cesarean section (CS) is the preferable procedure to preserve life when spontaneous vaginal delivery poses a risk to the mother and child. Since spinal anesthesia for CS offers superior neonatal and mother outcomes than general anaesthesia, its acceptability has grown significantly. However, there are drawbacks to spinal anaesthesia for Cs. Hypotension (a decrease in systolic blood pressure below 20% of baseline) is the most frequent complication, with an incidence ranging from 7.4% to 74.4%. The most frequent mechanism underlying the hypotension linked to spinal anesthesia is the predominance of vasodilation over vasoconstriction. After spinal anaesthesia, the mechanism for vasodilation is caused by the preganglionic level blocking of sympathetic nerve fibers. Method: An institutional-based prospective cohort study was conducted on 60 pregnant women undergoing elective caesarean section. Based on the responsible anaesthetist’s post spinal hypotension management plan, patients were divided into two groups. patients who received Phenylephrine are grouped into PE, n= 30) group, and patients who received nor-epinephrine are grouped under the nor-epinephrine group (NE, n=30) by data collectors. After the aseptic technique, spinal anaesthesia was administered with 0.5% (3 ml) bupivacaine using a 23G spinal needle. During spinal anaesthesia, a prophylactic bolus dose of 100 µg (4 ml) Phenylephrine and 32 gµ (4 ml) NE was given based on the management plan of the shift anaesthetist. Mean arterial pressure (MAP), the heart rate (HR), number of boluses of vasopressor used, incidence of nausea and vomiting, and the Apgar score of babies at 1 and 5 min between the groups were recorded. Results: The nor-epinephrine group had a statistically significant higher MAP compared to the Phenylephrine group in the first 10 and 15 min (p>0.05) of the study period. thereafter, there was no statistically significant difference in heart rate between the groups until the end of the study period (p > 0.05). The nor-epinephrine group required a lower bolus number of vasopressors compared to the Phenylephrine group to maintain blood pressure(p<0.05). Apgar scores of all babies at 1 and 5 min were greater than seven. Significant differences regarding maternal complications nausea and vomiting) between the groups were not detected (nausea, and vomiting, p=0.092). Conclusion. Intraoperative hypotension is common after spinal anaesthesia for Caesarean section. Inadequate treatment may lead to significant maternal, fetal, or both adverse outcomes. Consensus guidelines for the management of hypotension during Caesarean section has recommended a standard approach and includes detailed guidance on how to introduce phenylephrine in-fusions into practice. Other agents with a preferable adrenergic profile may be the focus of further. For a pregnant woman who underwent an elective caesarean section under spinal anaesthesia, nor-epinephrine can be administered in place of phenylephrine to maintain the mother's blood pressure without having a side effect on the mother and fetus.