Spinal hypotension is a common and concerning side effect of spinal anesthesia during cesarean sections, affecting both the mother and the fetus. Accurate prediction of spinal hypotension is crucial for proactive management and improved patient outcomes. The occurrence of hypotension is influenced by preoperative sympathetic tone, which, in turn, is dependent on baseline heart rate (HR) and postural changes in blood pressure (BP) and HR. This observational study aims to predict the incidence of spinal hypotension during cesarean sections based on baseline HR and the positional changes in BP and HR from supine to sitting positions.
Fifty-six parturients of ASA grade II were selected for this prospective observational study. Preoperative haemodynamic parameters, including baseline HR and changes in systolic, diastolic, and mean blood pressure and heart rate in supine and sitting positions, were recorded. The incidence of hypotension was noted during the cesarean section procedure. Statistical analysis was performed using Microsoft Excel and SPSS version 20.
The study found a significant correlation between baseline heart rate and the occurrence of spinal hypotension during cesarean sections (p-value = 0.015). Parturients with a baseline HR of more than 90 bpm exhibited increased sympathetic tone, which was associated with a higher likelihood of experiencing spinal hypotension. However, the postural changes in blood pressure and heart rate failed to demonstrate a significant correlation with the incidence of spinal hypotension in this study.
This study highlights the importance of pre-operative sympathetic activity, as reflected by the baseline heart rate, in predicting the occurrence of spinal hypotension during cesarean sections. A baseline heart rate of more than 90 bpm was found to be indicative of heightened sympathetic tone and associated with a higher risk of spinal hypotension. However, the postural changes in blood pressure and heart rate did not prove to be reliable predictors of spinal hypotension in this specific patient population. This knowledge may aid anesthesiologists in better identifying patients at risk for spinal hypotension and implementing targeted interventions to mitigate this adverse effect.