Influence of Deep Neuromuscular Blockade on Perioperative Stress Response in Patients Undergoing Robot-Assisted Gastrectomy: A Prospective Double-Blinded Randomized-Controlled Trial

Attenuating the intraoperative stress response is crucial; however, the effect of neuromuscular blockade (NMB) on surgical stress is not completely understood. We aimed to investigate the effects of NMB on the perioperative stress response during robot-assisted gastrectomy. Patients were assigned to the deep or moderate NMB group. Serum cortisol, prolactin, and interleukin-6 (IL-6) levels and natural killer (NK) cell percentage were measured before anesthesia induction, 90 min after pneumoperitoneum, operation end (OP(End)), and postoperative day 1. Additionally, C-reactive protein (CRP) and albumin levels were estimated. Additionally, intraoperative heart rate variability was evaluated. The deep NMB group showed significantly lower levels of low-frequency/high-frequency (HF) ratio at OP(End) compared to the moderate NMB group (1.4 ± 0.2 vs. 2.2 ± 0.3, respectively; Bonferroni corrected p = 0.039). Furthermore, HF power in the deep NMB group was significantly higher at OP(End) than that in the moderate NMB group (45.2 ± 3.6 vs. 33.8 ± 4.0, respectively; Bonferroni corrected p = 0.044). However, no significant differences in cortisol, prolactin, IL-6, CRP, and albumin levels and NK cell percentage were found between the two groups. The degree of NMB may have similar effects on stress-related biological markers in patients undergoing robot-assisted gastrectomy.