Preoperative Antihypertensive Use and Risk of Post- Spinal Hypotension in Elderly Patients Undergoing Hip Fracture Surgery: A Retrospective Secondary Analysis

Objective: To examine the association between preoperative antihypertensive medication use and the risk of postspinal hypotension in patients aged ≥80 years undergoing hip fracture surgery. Materials and Methods: This retrospective cohort study was a secondary analysis of patients aged ≥80 years who underwent hip fracture surgery under spinal anesthesia at a tertiary-care hospital between October 2016 and September 2023. Patients were categorized according to whether antihypertensive medications were taken on the day of surgery. The primary outcome was post-spinal hypotension. Univariable and multivariable risk ratio regression analyses were performed. Results: Overall, 63% of patients developed post-spinal hypotension. Preoperative antihypertensive use was not significantly associated with hypotension in the multivariable analysis. However, use of renin–angiotensin–aldosterone system (RAAS) antagonists was independently associated with an increased risk (RR 1.38; 95% CI 1.13–1.68; p = 0.002). A significant dose–response relationship was observed between the number of antihypertensive agents and the incidence of hypotension (p for trend = 0.036). Patients receiving ≥3 antihypertensive agents had the highest adjusted risk ratio, although this was not statistically significant. Conclusion: Preoperative antihypertensive use was not associated with an increased risk of post-spinal hypotension in patients aged 80 years and older with hip fractures. However, RAAS antagonists and multiple-antihypertensive regimens may increase susceptibility to hemodynamic instability. Careful preoperative assessment of antihypertensive therapy is recommended.