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

Elderly patients are at increased risk for anesthesia-related complications due to reduced physiological reserves and comorbidities. Thoracic surgery further increases this risk by inducing significant cardiovascular and sympathetic stress. Esketamine, the S-enantiomer of ketamine, possesses sympathomimetic and analgesic properties that may help stabilize circulation and reduce postoperative complications when used at subanesthetic doses.

In this single-center, randomized controlled trial, patients aged 65-75 scheduled for elective thoracic surgery were administered either 0.25 mg/kg esketamine or normal saline during anesthesia induction. Hemodynamic parameters (mean arterial pressure, heart rate), plasma catecholamine concentrations (norepinephrine, epinephrine), and adverse cardiovascular responses were recorded. Postoperative outcomes included emergence time, PACU stay, incidence of delirium, hallucinations, nausea and vomiting, and opioid consumption.

Inclusion criteria

• Age 65-75 years
• Scheduled for elective thoracic surgery (e.g., lobectomy, bullectomy)
• ASA physical status I-III
• Adequate cardiopulmonary function
• Able to provide informed consent
• Preoperative systolic blood pressure <160 mmHg with stable control
• No cognitive impairment

Exclusion criteria

• Severe cardiovascular disease (e.g., unstable angina, heart failure ≥ NYHA class III)
• History of cerebrovascular disease
• Uncontrolled hypertension (SBP >180 mmHg)
• Severe hepatic or renal dysfunction
• Chronic psychiatric illness or long-term CNS-active drug use
• Allergy to ketamine or its derivatives
• Elevated intracranial or intraocular pressure
• Use of monoamine oxidase inhibitors within 24 hours before surgery
• History of substance abuse