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

Background: Although spinal anesthesia is generally well tolerated, hypotension is a common adverse effectof subarachnoid block in some patients. In pregnant women, it was demonstrated that sympathetic activity isincreased 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 inobstetric 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 monitoredwith 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 ofbaseline HR was significantly higher in patients who developed post spinal hypotension than that in those whodidn’t. The cut point of baseline HR was 92 beats/mint., so baseline HR > 92 beats/mint. is predictive for postspinal hypotension. Requirement of ephedrine was significantly higher in hypotensive patients who had baselineHR > 92 than that in those who had baseline HR ≤ 92.Conclusion: Preoperative heart is a good predictor for post spinal hypotension in pregnant women underwentcesarean section under spinal c anesthesia.