Esketamine attenuates hemodynamic oscillations during anesthesia induction in elderly gastrointestinal surgical patients: a randomized trial.

Background: Patients undergoing gastrointestinal tumor surgery face heightened susceptibility to hemodynamic instability during anesthesia induction, a risk further exacerbated by preoperative fasting. Oscillatory blood pressure fluctuations increase perioperative risks. Esketamine's sympathomimetic properties may counteract propofol-induced hypotension. This study aimed to evaluate the impact of adjunctive esketamine on hemodynamic instability incidence during induction.

Methods: This prospective, double-blind RCT (ChiCTR2200060641, registered on June 6, 2022) enrolled ASA I-III patients (18-75 years) scheduled for gastrointestinal tumor surgery at Foshan First People's Hospital (Jun 2022-May 2023). Patients were randomized 1:1 to receive IV esketamine (0.2 mg/kg) or saline placebo during induction. Anesthesia was induced with propofol (1.5-2.0 mg/kg), sufentanil (0.2 µg/kg), and cisatracurium (0.3 mg/kg). The primary outcome was the incidence of hemodynamic instability (defined as hypertension [MAP > 20% baseline], hypotension [MAP < 65 mmHg or > 20% decrease], tachycardia [HR > 100 bpm], bradycardia [HR < 50 bpm], or vasopressor use) from induction to 5 min post-intubation. The secondary outcomes included intraoperative ephedrine consumption, postoperative recovery time, extubation time, duration of post-anaesthesia care unit (PACU) stay, emergence agitation, cough during intubation, and other adverse effects.

Results: The incidence of hemodynamic instability was significantly lower in the esketamine group than in the control group during induction (29.3% vs. 55.9%; OR = 0.33, 95% CI: 0.18-0.60; P < 0.001). Specifically, esketamine reduced hypotension (27.2% vs. 44.1%; P = 0.016) and hypertension (3.3% vs. 12.9%; P = 0.016). Ephedrine use was lower (12.0% vs. 24.7%; P = 0.025). CO was preserved in the esketamine group but declined significantly in the control group post-induction (P < 0.05). Cough incidence was reduced with esketamine (8.7% vs. 32.3%; P < 0.001). No differences existed in recovery times, emergence agitation, or PONV.

Conclusions: Adjunctive low-dose esketamine (0.2 mg/kg) during propofol-based induction significantly attenuates hemodynamic instability and preserves cardiac output in gastrointestinal surgery patients, without delaying recovery. This approach enhances cardiovascular safety during high-risk induction.

Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR2200060641) on June 6, 2022.