Effects of subanesthetic dose of esketamine on opioid consumption after thoracoscopic surgery

Abstract

Objective: To investigate the effect of continuous intravenous infusion of subanesthetic dose of esketamine intraoperatively on postoperative opioid consumption in patients undergoing thoracoscopic surgery. Methods: A total of 71 patients with elective thoracoscopic lung surgery in the First Affiliated Hospital of Zhengzhou University from December 2020 to December 2021 were selected. Patients who were classified as grade Ⅰ or Ⅱ by the American Society of Anesthesiologists (ASA) and aged 18-70 years were included, including 32 males and 39 females, with a body mass index (BMI) of 18.5-30.0 kg/m2. The patients were randomly divided into three groups: (1) Control group (group C, n=24): continuous intravenous infusion of normal saline at the same rate during surgery; (2) Subanesthetic dose of esketamine 0.125 mg·kg-1·h-1 group (group ES1, n=23): continuous intravenous infusion of esketamine at a rate of 0.125 mg·kg-1·h-1 during surgery; (3) Subanesthetic dose of esketamine 0.250 mg·kg-1·h-1 group (group ES2, n=24): continuous intravenous infusion of esketamine at a rate of 0.250 mg·kg-1·h-1 during surgery. The main outcome measures were the total consumptions of hydromorphone of 3 groups within 24 and 48 hours after surgery. The secondary outcome measures were the extubation time, length of postanesthesia care unit (PACU) stay, the time of first feeding, and the incidences of adverse effects within 24 h after surgery in 3 groups. Results: The 24 h postoperative consumption of hydromorphone in group C, ES1 and ES2 was (5.4±1.0) mg, (4.5±1.5) mg and (4.0±0.8) mg, respectively. Likewise, the 48 h postoperative consumption of hydromorphone was (9.7±2.2) mg, (9.0±3.0) mg and (7.7±1.8) mg, respectively. Compared with group C, the 24 h postoperative hydromorphone consumptions were significantly reduced in group ES1 and ES2 (both P<0.05). The extubation time, length of PACU stay and the time of first feeding after surgery in group C were (23±10) min,(70±12) min,(17±3) h,in group ES1 were (22±4) min,(69±11) min,(14±5) h,in group ES2 were (16±8) min,(58±12) min,(14±3) h, respectively. Compared with group C and group ES1, both of the extubation time and length of PACU stay were shortened in group ES2 (both P<0.05). Compared with group C, the first postoperative feeding time of group ES1 and ES2 was shortened (both P<0.05). There were no differences in the incidences of adverse effects at postoperative 24 h among 3 groups (all P>0.05). Conclusion: Continuously intravenous infusion of subanesthetic esketamine at a rate of 0.250 mg·kg-1·h-1 can significantly reduce the postoperative opioid consumption and improve the patient's outcomes.