Continuous intra-arterial versus noninvasive blood pressure monitoring for preventing hypotension during anesthesia induction in patients aged ≥ 75 years undergoing noncardiac surgery: a randomized controlled trial

Hypotension is common during the period after induction of general anesthesia and before surgical incision, particularly in older patients. The objective of this study was to compare the effectiveness of continuous intra-arterial pressure monitoring with that of noninvasive blood pressure monitoring in preventing hypotension during anesthesia induction in older patients (≥ 75 years) undergoing noncardiac surgery. In this single-center, randomized controlled trial, 82 older patients who were scheduled for elective noncardiac surgery under general anesthesia were randomly assigned to the continuous intra-arterial pressure monitoring group or the noninvasive blood pressure monitoring group. The primary outcome was the area under the curve for mean arterial pressure (MAP) < 65 mmHg during the first 15 min after induction, based on invasive blood pressure measurements. The area under the curve for mean arterial pressure < 65 mmHg was significantly lower in the continuous intra-arterial pressure monitoring group (median (interquartile range), 0 (0–6.09) mmHg∙min) than in the noninvasive group (3.67 (0–26.45) mmHg∙min; P = 0.008). The continuous intra-arterial pressure monitoring group also had a shorter duration of MAP < 65 mmHg (0 (0–1.42) vs. 0.87 (0–3.88) minutes; P = 0.010), received lower doses of propofol (16.67 (13.34–24.15) vs. 30 (24.17–40.83) mg; P = 0.011) and remifentanil (25.34 (16.67–40.00) vs. 34.18 (25.00–57.00) µg; P = 0.045), and received vasoactive drugs earlier (0.87 (0.67–1.00) vs. 2.33 (1.87–3.33) minutes; P < 0.001) and at higher doses in the continuous intra-arterial pressure monitoring group. Compared with noninvasive blood pressure monitoring, continuous intra‑arterial pressure monitoring initiated before induction was associated with reduced the incidence, severity, and duration of hypotension during anesthesia induction in older patients (≥ 75 years) undergoing noncardiac surgery. This trial was registered in the Chinese Clinical Trial Registry (ChiCTR2400088505) on August 20, 2024 ( https://www.chictr.org.cn/ ).