Mini-dose Esketamine-dexmedetomidine Supplemented Analgesia and Long-term Outcomes

Chronic postsurgical pain (CPSP) refers to pain that occurs or increases after surgery and lasts longer than 3 months. Severe postoperative acute pain is one of the major risk factors of CPSP. Spine surgery brings severe postoperative pain due to large trauma and long duration. Ketamine and esketamine are N-methyl-D-aspartate receptor antagonists; they have anti-hyperalgesic effects and may reduce CPSP. Dexmedetomidine is an alpha 2-adrenoceptor agonist with sedative, anxiolytic, and analgesic effect; it is frequently used as an adjuvant to postoperative analgesia. In a previous trial of the investigators, 200 patients following scoliosis correction surgery were randomzied to receive opioid analgsia supplemented with either mini-dose esketamine-dexmedetomidine combination or placebo. The results showed that esketamine-dexmedetomidine supplement analgesia significantly improved analgesia and sleep quality after surgery. This study is designed to test the hypothesis that mini-dose esketamine-dexmedetomidine supplemented analgesia may reduce CPSP at 2 years after scoliosis correction surgery.

Inclusion Criteria:Patients aged ≥18 years;Scheduled for scoliosis correction surgery;Required patient-controlled intravenous analgesia (PCIA) after surgery.Exclusion Criteria:Preoperative sick sinus syndrome, severe sinus bradycardia (heart rate <50 beats per minute), atrioventricular block grade II or above without pacemaker, congenital heart disease, arrhythmia, or other serious cardiovascular diseases with a New York Heart Association class ≥III;Obstructive sleep apnea syndrome, or a STOP-Bang score ≥3 in combination with a serum bicarbonate level ≥28 mmol/L;Comorbid hyperthyroidism or pheochromocytoma;History of schizophrenia, epilepsy, myasthenia gravis;Preoperative delirium or communication barrier;Severe liver dysfunction (Child-Pugh grade C), severe renal dysfunction (preoperative dialysis), or American Society of Anaesthesiologists grade ≥IV;Body weight <40 kg;Enrolled in other clinical studies;Loss to follow-up;Other conditions that were considered unsuitable for study participation.