Subanesthetic Esketamine for Hemodynamic Stability and Recovery in Elderly Thoracic Surgery Patients

Intravenous administration of a subanesthetic dose of esketamine (0.25 mg/kg) during induction of general anesthesia. The drug was administered slowly over approximately 30 seconds after midazolam (2 mg) and sufentanil (50 µg), and prior to propofol (2 mg/kg) and rocuronium (0.6 mg/kg). The goal was to evaluate its effect on intraoperative hemodynamic stability and postoperative recovery in elderly patients undergoing thoracic surgery.

Intravenous administration of an equivalent volume of 0.9% normal saline during anesthesia induction, matching the timing and method of the esketamine group. Used as a placebo comparator.

Intravenous administration of 2 mg midazolam during anesthesia induction for sedation. Administered prior to study drug.

Intravenous administration of 50 µg sufentanil for analgesia during anesthesia induction. Administered prior to study drug.

Intravenous administration of 2 mg/kg propofol for loss of consciousness during anesthesia induction. Administered after study drug.

Intravenous administration of 0.6 mg/kg rocuronium to facilitate neuromuscular blockade and endotracheal intubation.