Workplace violence and psychosocial risks exposures: a multicenter cross-sectional study.

Complex spinal surgery, such as thoracolumbar spinal fusion for idiopathic scoliosis or ankylosing spondylitis, is associated with significant surgical trauma due to extensive dissection, retraction, resection, and implantation of internal fixation devices. Patients recovering from complex spinal surgery usually experience moderate-to-severe pain [, ] which may last from 4 to 7 days [, ]. Persistent severe pain increases the risk of excessive opioid consumption and related adverse events, including nausea, vomiting, pruritus, urine retention, and constipation [–]. Additionally, the potential development of acute opioid tolerance and opioid-induced hyperalgesia represent a critical challenge in pain management [–]. As recommended by guidelines [, ], multimodal analgesia has become a cornerstone of pain management after complex spinal surgery [–]. Ketamine is a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor and plays a key role in inhibiting central sensitization and opioid-induced hyperalgesia [–]. Esketamine is the S-enantiomer of racemic ketamine and is approximately twice as potent as racemate in analgesia. Moreover, esketamine produces fewer psychiatric disturbances at clinically equivalent doses compared to its racemic counterpart [, ]. Perioperative use of both ketamine and esketamine is reported effective in improving analgesia after spinal surgery, as manifested by attenuated pain intensity, reduced moderate-to-severe pain, delayed requirement of rescue analgesia, and reduced opioid consumption [–]. Esketamine has been used in combination with opioids for patient-controlled intravenous analgesia (PCIA) [, ]. A clinical trial of Brink and colleagues investigated the effect of increasing doses of esketamine in PCIA (0.0, 0.25, 0.5, and 0.75 mg/mL; mean 0.0, 6.6, 11.8, and 14.8 µg/kg/h, respectively) after major lumber fusion surgery and found that only the highest dose esketamine reduced opioid consumption []. In another clinical trial, Zhang and colleagues added higher doses of esketamine to PCIA (0.0, 0.5, 1.0, and 2 mg/kg/48 h; mean 0.0, 10.4, 20.8, and 41.7 µg/kg/h, respectively) in thoracoscopic surgery patients; they also found a dose-dependent analgesia promoting effect; however, the highest dose esketamine produced sedation []. The optimal dosing regimen of esketamine for PCIA after complex spinal surgery remains poorly defined.