Observation on the Analgesic Effect of Different Doses of a Combination of Esketamine and Dexmedetomidine Administered for Percutaneous Endoscopic Transforaminal Discectomy: A Randomized, Double-Blind Controlled Trial

Background: Percutaneous endoscopic transforaminal discectomy (PETD) is an effective method for treating lumbar disc herniation, and is typically performed under local anesthesia. However, inadequate analgesia during the procedure remains a concern, prompting the search for a medication that can provide optimal pain control with minimal impact on the respiratory and circulatory systems. Objectives: The aim of this study was to observe the effects of different doses of esketamine combined with dexmedetomidine on reducing visual analog scale (VAS) scores during surgical interventions. Methods: One hundred two patients who underwent PETD were randomly divided into a control group (group C: normal saline + dexmedetomidine), an E1 group (0.1 mg kg(-1) esketamine + dexmedetomidine), and an E2 group (0.2 mg kg(-1) esketamine + dexmedetomidine). The primary outcome was the maximum visual analogue scale (VAS) (score: 0 = no pain and 10 = worst pain) at six time points. The secondary outcomes included the Assessment of Alertness/Sedation Scale (OAA/S) score and mean arterial pressure (BP), heart rate (HR), respiratory rate (RR), and oxygen saturation (SpO(2)) at 11 time points. The incidence of adverse reactions during and 24 h after the operation and patient satisfaction with the anesthesia were also recorded. Results: Compared with those in group C, the VAS scores of patients in groups E1 and E2 were lower at T-6, T-7, and T-9 (P < 0.05). From T-4 to T-10, the OAA/S scores of the E1 and E2 groups were both lower than those of group C (P < 0.05), and at the T-4-T-6 time points, the OAA/S score of the E2 group was lower than that of group E1 (P < 0.05). At T-4 and T-5, the HR and BP of patients in groups E1 and E2 were greater than those in group C (P < 0.05). Compared with those in group C, the incidences of intraoperative illusion, floating sensation, postoperative dizziness, and hyperalgesia in groups E1 and E2 were significantly greater (P < 0.01). There was no significant difference in patient RR, SpO(2), or postoperative satisfaction with anesthesia among the three groups (P > 0.05). Conclusion: The combination of esketamine and dexmedetomidine can reduce VAS scores during certain stages of this type of surgery; it has minimal impact on respiration and circulation. However, this approach is associated with increased incidences of postoperative dizziness and psychiatric side effects, which may also affect patients' compliance with surgical instructions from medical staff. Patient satisfaction was not greater with dexmedetomidine combined with esketamine than with dexmedetomidine alone.