Baseline heart rate as a predictor of post-spinal hypotension in patients undergoing a caesarean section: An observational study

Abstract

>Background: Hypotension is a well-known side effect of spinal anaesthesia in obstetrics patients undergoing caesarean section. This is likely to affect both mother and fetal well-being. Systemic haemodynamics are modulated by autonomic nervous system (ANS). Evaluation of ANS may be helpful in predicting hypotension. The present study is designed to identify the subset of pregnant patients at higher risk of developing post-spinal hypotension based on baseline heart rate (HR) prior to administration of anaesthesia.Materials and Methods: This was a prospective study conducted on 100 patients aged 20–30 years, of American Society of Anaesthesiologists (ASA) grade I or II, scheduled for elective caesarean section under spinal anaesthesia. Patients were divided into two groups based on their baseline HR. Incidence of hypotension and ephedrine requirement following spinal anaesthesia were noted.Results: Thirty nine patients out of 100 developed hypotension (39%), of whom 27 were in the group with HR >91 beats per minute (bpm) (50.9%) and 12 patients were in the group with HR 91 bpm than group with HR <90 bpm (mean 3.9 ± 0.45 vs 4.34 ± 0.45, P = 0.0148) and it was statistically significant.Conclusion: Pre-operative baseline HR may be used to predict risk of post-spinal hypotension in obstetric patients undergoing caesarean section.

Keywords

• Caesarean section
• hypotension
• pre-operative heart rate
• spinal anaesthesia