Deep Neuromuscular Block Attenuates Chronic Postsurgical Pain and Enhances Long-Term Postoperative Recovery After Spinal Surgery: A Randomized Controlled Trial

INTRODUCTION: The effects of deep neuromuscular block (DNMB) on chronic postsurgical pain (CPSP) have not been conclusively determined. Moreover, a limited number of studies have examined the impact of DNMB on long-term recovery quality after spinal surgery. We investigated the impact of DNMB on CPSP and the quality of long-term recovery in patients who had been subjected to spinal surgery. METHODS: This was a randomized, controlled, double-blind, single-center study performed from May 2022 to November 2022. A total of 220 patients who underwent spinal surgery under general anesthesia were randomly assigned to receive either DNMB (post-tetanic count at 1–2) (the D group) or moderate NMB (MNMB) (train-of-four at 1–3) (the M group). The primary endpoint was the incidence of CPSP. The secondary endpoints included the visual analogue scale (VAS) score in the post-anesthesia recovery unit (PACU), at 12, 24, 48 h and 3 months after surgery; postoperative opioid consumption; quality of recovery-15 (QoR-15) scores on the second postoperative day, before discharge, and 3 months after surgery. RESULTS: The incidence of CPSP was significantly lower in the D group (30/104, 28.85%) than in the M group (45/105, 42.86%) (p = 0.035). Besides, VAS scores were significantly reduced at the third month in the D group (p = 0.016). In the PACU and 12 h after surgery, VAS scores were also significantly lower in the D group than in the M group (p < 0.001, p = 0.004, respectively). The total amount of postoperative opioid consumption (expressed in total oral morphine equivalents) was significantly less in D group than M group (p = 0.027). At 3 months after surgery, QoR-15 scores were significantly higher in D group than M group (p = 0.003). CONCLUSIONS: Compared with MNMB, DNMB significantly reduced CPSP and postoperative opioid consumption in spinal surgery patients. Moreover, DNMB improved the long-term recovery of patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2200058454).