The effects of moderate neuromuscular blockade combined with transverse abdominal plane block on surgical space conditions during laparoscopic colorectal surgery: a randomized clinical study

BACKGROUND: Deep neuromuscular blockade may be beneficial on surgical space conditions during laparoscopic surgery. The effects of moderate neuromuscular blockade combined with transverse abdominal plane block (TAPB) on surgical space conditions during laparoscopic surgery have not been described. This work investigated whether the above combination is associated with similar surgical space conditions to those of deep neuromuscular blockade. METHODS: Eighty patients undergoing elective laparoscopic surgery for colorectal cancer were randomly divided into two groups. The intervention group was treated with moderate neuromuscular blockade (train-of-four (TOF) count between 1 and 3) combined with TAPB (M group), while the control group was treated with deep neuromuscular blockade (D group), with a TOF count of 0 and a post-tetanic count (PTC) ≥1. Both groups received the same anesthesia management. The distance between the sacral promontory and the umbilical skin during the operation was compared between the two groups. The surgeon scored the surgical space conditions according to a five-point ordinal scale. Patients’ pain scores were evaluated 8 h after the operation. RESULTS: The distance from the sacral promontory to the umbilical skin after pneumoperitoneum was similar between the D group and M group (16.03 ± 2.17 cm versus 16.37 ± 2.78 cm; P = 0.544). The 95% confidence intervals of the difference in the distance from the sacral promontory to the umbilical skin between the two groups were − 1.45–0.77 cm. According to the preset non-inferior standard of 1.5 cm, (− 1.45, ∞) completely fell within (− 1.50, ∞), and the non-inferior effect test was qualified. No significant difference was found in the surgical rating score between the two groups. The dosage of rocuronium in the group D was significantly higher than that in the group M (P < 0.01). The M group had significantly lower pain scores than the D group 8 h after the operation (P < 0.05). CONCLUSIONS: Moderate neuromuscular blockade combined with TAPB applied to laparoscopic colorectal cancer surgery can provide surgical space conditions similar to those of deep neuromuscular blockade. In addition, it reduces the use of muscle relaxants, relieves postoperative pain within 4 h after operation, and shorten the extubation time and stay in PACU when neostigmine was used as muscle relaxant antagonist. TRIAL REGISTRATION: chictr.org.cn (ChiCTR2000034621), registered on July 12, 2020.