1*Department of Physiology, Geetanjali Medical College and Hospital, Udaipur, Rajasthan, India.
2Geetanjali Medical College and Hospital, Udaipur, Rajasthan, India.
3Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru, Karnataka, India.
Objective: Hypotension is a common complication of neuraxial anaesthesia and is difficult to predict. This study evaluated whether preoperative heart rate variability (HRV) can predict neuraxial anaesthesia–induced hypotension in non-diabetic, normotensive patients undergoing lower limb orthopaedic surgery.
Materials and Methods: This was a cross-sectional observational study of 107 adults aged 18–60 years who underwent lower limb orthopaedic surgery under neuraxial anaesthesia. Before surgery, HRV was measured using a five-minute artefact-free electrocardiogram recording. Time-domain, frequency-domain, and nonlinear HRV parameters were analysed. Intraoperative hypotension was defined based on institutional criteria and recorded. The ability of HRV to predict hypotension was assessed using sensitivity, specificity, predictive values, and receiver operating characteristic (ROC) analysis.
Results: Hypotension occurred in 71 patients (66.36%). Root mean square of successive differences (RMSSD) demonstrated high sensitivity (83.33%) with moderate specificity (71.43%) for predicting hypotension at a threshold of 30 ms. The low-frequency to high-frequency (LF/HF) ratio showed a sensitivity of 74.65% and high specificity (91.67%) at a threshold of 3.5, with an overall diagnostic accuracy of 80.37%. ROC analysis confirmed good discriminatory ability for both RMSSD and LF/HF ratio. Patients who remained stable during surgery had higher parasympathetic activity and a more balanced sympathovagal tone before surgery.
Conclusion: Preoperative HRV, especially RMSSD and LF/HF ratio, is a reliable and non-invasive method to predict hypotension after neuraxial anaesthesia in healthy patients. Adding HRV to routine preoperative assessment may help identify high-risk patients and improve perioperative blood pressure management.
Keywords: Heart rate variability, Neuraxial anaesthesia, Hypotension, Autonomic nervous system, Orthopaedic surgery.
How to cite this article: Kaur M, Gupta S, Udupa K. Preoperative Heart Rate Variability As A Predictor Of Hypotension Following Neuraxial Anaesthesia: A Cross-Sectional Study Of Non-Diabetic Normotensive Patients Undergoing Lower Limb Orthopaedic Surgery. Int J Drug Deliv Technol. 2026;16(15s): 462-469. DOI: 10.25258/ijddt.16.15s.55
Source of support: Nil.
Conflict of interest: None