Heart rate variability as a predictor of hypotension following spinal for elective caesarean section: a prospective observational study

Summary Post‐spinal hypotension remains a common and clinically‐important problem during caesarean section, and accurate pre‐operative prediction of this complication might enhance clinical management. We conducted a prospective, single‐centre, observational study of heart rate variability in 102 patients undergoing elective caesarean section in a South African regional hospital. We performed Holter recording for ≥ 5 min in the hour preceding spinal anaesthesia. The low‐frequency/high‐frequency ratio component of heart rate variability was compared, using a logistic regression model, with baseline heart rate and body mass index (BMI) as a predictor of hypotension (defined as systolic arterial pressure < 90 mmHg) occurring from the time of spinal insertion until 15 min after delivery of the baby. We also assessed clinically relevant cut‐point estimations for low‐frequency/high‐frequency ratio. Low‐frequency/high‐frequency ratio predicted hypotension (p = 0.046; OR 1.478, 95% CI 1.008‐1.014), with an optimal cut‐point estimation of 2.0; this threshold predicted hypotension better than previously determined thresholds (p = 0.003; c‐statistic 0.645). Baseline heart rate (p = 0.20; OR 1.022, 05% CI 0.988‐1.057) and BMI (p = 0.60; OR 1.017, 95% CI 0.954‐1.085) did not predict hypotension. Heart rate variability analysis is a potentially useful clinical tool for the prediction of hypotension. Future studies should consider a low‐frequency/high...
Source: Anaesthesia - Category: Anesthesiology Authors: Tags: Original Article Source Type: research