A multicomponent titrated slow induction strategy in adults aged 75 years or older undergoing lower-limb orthopedic surgery: a randomized controlled trial

Background Older adults have limited physiological reserve and altered responses to anesthetic drugs. This trial compared a multicomponent titrated slow induction strategy with conventional rapid induction for peri-airway hemodynamics and early postoperative recovery. Methods In this single-center, parallel-group randomized trial, 160 patients aged 75–99 years with American Society of Anesthesiologists physical status III–IV undergoing lower-limb orthopedic surgery were assigned 1:1 to a multicomponent strategy (Group M) or conventional rapid induction (Group C). Group M combined bispectral index (BIS)-guided titration, a different induction-drug regimen, airway topical anesthesia, preserved spontaneous ventilation, and neuromuscular blockade after intubation. The primary hemodynamic outcome analyzed was the peri-intubation invasive mean arterial pressure (MAP, mmHg) profile at six protocol-defined time points (T0–T5), with T0 as the pre-induction reference for descriptive mean changes. Repeated-measures analysis compared MAP trajectories; time-point between-group absolute-MAP differences with 95% confidence intervals were reported as supplementary clinical contrasts. Recovery scores, recovery times, exploratory biomarkers, and reported adverse events were also assessed. Results Of 167 patients screened, 160 were randomized and analyzed (80 per group). The reported analysis showed a MAP group × time interaction (F = 83.305, P < 0.001). Mean MAP changes from baseline immediately after intubation were − 4.46 mmHg in Group M and + 9.64 mmHg in Group C. The T2 between-group absolute-MAP difference was − 13.75 mmHg (95% CI − 16.25 to − 11.25; Table 3B). A renewed review of all 160 intraoperative anesthesia records confirmed that no MAP < 65 mmHg values were documented in either group. Group M had shorter reported awakening, extubation, and post-anesthesia care unit stay times, higher postoperative Quality of Recovery-15 scores, and lower CAM-S scores. Continuous arterial-pressure waveforms, detailed vasoactive-drug data and postoperative organ-injury outcomes were unavailable for analysis. Conclusions The reported results suggest different peri-airway MAP profiles and favorable early recovery measures with the multicomponent strategy. Individual component effects, delirium incidence, and net clinical safety cannot be determined. Retrospective registration and incomplete safety data warrant cautious interpretation. Trial registration Chinese Clinical Trial Registry, ChiCTR2600125496. Registered on 27 May 2026 retrospectively registered.