PRE-OPERATIVE HEART RATE MONITORING AS A PREDICTOR OF POST SPINAL HYPOTENSION IN PATIENTS UNDERGOING LOWER SEGMENT CAESAREAN SECTION: AN OBSERVATIONAL STUDY

Abstract

Background and Aims: Subarachnoid block (SAB) is widely used regional anaesthesia technique for the patients undergoing lower segment caesarean section (LSCS). It is associated with sympathetic autonomic nervous system blockade, as it blocks lumbosacral segment of the spinal cord. Haemodynamics is mainly controlled by autonomic nervous system, so this study was conducted to assess correlation between baseline heart rate and incidence of hypotension following subarachnoid block in parturients. Materials and Methods: After obtaining written and informed consent, 150 parturients aged >18 years, with gestational age >32 weeks were included in this prospective observational study. Parturients were randomly divided in two groups according to their baseline heart rate. Group I (n=75): parturients with HR ≥ 91 bpm and Group II (n=75): parturients with HR ≤ 90 bpm. All parturients were given inj. bupivacaine 0.5% Heavy 2 ml (10 mg) in SAB. Incidence of hypotension and other parameters, requirement of rescue drug were recorded. Results : In Group I (HR ≥ 91 bpm) incidence of hypotension (34 vs 21, P=0.0279), duration of hypotensive episode per parturient (2.15± 3.16 vs 1.02 ± 2.01, P=0.009) and requirement of rescue drug (mephentermine) per parturient (4.24±5.47 mg vs 2.56±4.54 mg, p=0.042) were signicantly higher as compared to Group II (HR ≤ 90 bpm). (p<0.05) Conclusion: Parturients with HR ≥91 are at higher risk of developing hypotension after subarachnoid block and requirement of vasopressors is more as compared to those parturients with HR ≤90.