Baseline Heart Rate as a Predictor of Post-Spinal Hypotension in Patients Undergoing a Caesarean Section

Abstract

Background: Although spinal anesthesia is generally well tolerated, hypotension is a common adverse effect
of subarachnoid block in some patients. In pregnant women, it was demonstrated that sympathetic activity is
increased as compared with that of not pregnant women.
Aim of study: To determine whether preoperative heart rate is a predictor for post spinal hypotension or not in
obstetric patients.
Methods: A prospective trial study that was conducted in the Obstetrics operating room at Al-Imamain Al-
Kadhmain and Baghdad Teaching Hospitals, Baghdad, Iraq for a period of 12 months from Nov. 2019 to Nov.
2020. It involved 100 healthy full term pregnant women scheduled for elective C/S under spinal anesthesia.
Baseline systolic, diastolic, mean arterial pressure, and heart rate were recorded. Blood pressure was monitored
with an automated cuff blood pressure monitor at three-minute intervals until 30 minutes then every five minutes.
Results: In this study, 55% of study patients complained from hypotension after spinal anesthesia. mean of
baseline HR was significantly higher in patients who developed post spinal hypotension than that in those who
didn’t. The cut point of baseline HR was 92 beats/mint., so baseline HR > 92 beats/mint. is predictive for post
spinal hypotension. Requirement of ephedrine was significantly higher in hypotensive patients who had baseline
HR > 92 than that in those who had baseline HR ≤ 92.
Conclusion: Preoperative heart is a good predictor for post spinal hypotension in pregnant women underwent
cesarean section under spinal c anesthesia.