Objective To investigate the effect of esketamine on perioperative pain and depression in patients with thoracoscopic pulmonary nodule resection.

Methods A total of 120 patients with selective thoracoscopic pulmonary nodule resection were randomly divided into low-dose esketamine group (group L), high-dose esketamine group (group H) and saline control group (group C), with 40 cases in each group. Before skin incisionafter anesthetic induction, 0.25 mg/kgesketamine, 0.50 mg/kg esketamine and the equivalent amount of saline were separately administered for patients in the three groups. Visual Analogue Scale (VAS) score for pain and the Self-rating Depression Scale (SDS) score were compared among the three groups at the time points of one day before surgery (T₀), one day after surgery (T₁), three days after surgery (T₂), and the day of discharge (T₃), and postoperative analgesia within 24 h and perioperative adverse reactions were also recorded.

Results The VAS scores for rest and coughing at T₁ were significantly lower in group L and group H than group C (P < 0.05); compared with group C, the total press number of analgesic pump with in 24 h and effective press number were significantly decreased in group L and group H, and the dosage of sufentanil was also significantly decreased(P < 0.05). There were no significant differences in depression scores at different time points among the three groups (P>0.05). There were no significant differences in the incidence rates of nausea, vomiting, dizziness, hallucinations, and nightmares among the three groups (P>0.05).

Conclusion Esketamine can effectively alleviate pain on the first day after operation and reduce the dosage of opioid analgesics without increasing the incidence of adverse reactions in patients with thoracoscopic pulmonary nodule resection; compared with 0.25 mg/kg esketamine, 0.50 mg/kg esketamine doesn't demonstrate better postoperative analgesia or improvement in perioperative depression.