Deep Neuromuscular Block with Low Pressure Pneumoperitoneum in Laparoscopic Abdominal Surgeries: A Randomized Controlled Trial

Abstract

Background: Postoperative pain management remains a challenge in laparoscopic abdominal surgeries.

Objectives: The purpose of this research was to determine the effects of deep neuromuscular blockade (NMB) in conjunction with low-pressure pneumoperitoneum )PP) on postoperative pain, surgical parameters, and recovery outcomes.

Methods: This randomized controlled double-blind study included 44 participants undergoing laparoscopic abdominal surgery. Patients were randomized equally into two groups (22 each): Group D received deep NMB, while group M received moderate NMB using cis-atracurium, through the utilization of computer-generated random numbers enclosed within sealed, opaque envelopes, following a parallel approach. Regarding deep NMB, following an initial dose of 0.15 mg/kg, a continuous infusion of 0.06 - 0.12 mg/kg/hr was administered to maintain a post-tetanic count between 1 and 2, with low PP pressure of 10 - 12 mmHg. Conversely, for moderate NMB, after the same initial dose of 0.15 mg/kg, the continuous infusion commenced upon the train-of-four count returning to 2, with the rate adjusted to sustain a count between 1 and 3, and standard PP pressure of 15 mmHg. The primary outcome was postoperative pain intensity as measured by Numerical Rating Scale (NRS) scores in the post-anesthesia care unit (PACU). The secondary outcomes included postoperative pain intensity measured by NRS scores from 2 hours to 48 hours post-surgery, time to first analgesic administration, cumulative opioid consumption within the initial 48-hour postoperative period, and patient-reported satisfaction with postoperative pain management. Statistical analysis using SPSS v26 included tests for normality (Shapiro-Wilks), with parametric data analyzed by t-test, non-parametric data by Mann-Whitney, and qualitative data by chi-square/Fisher's test.

Results: Group D experienced a considerably longer time until the first analgesic rescue compared to group M (9.82 ± 1.5 hours vs. 7.23 ± 1.19 hours, P < 0.001). Morphine consumption in the first 24 hours was lower in Group D (10.77 ± 1.51 mg vs. 13.09 ± 1.74 mg, P < 0.001). At 6, 8, and 12 hours postoperatively, group D exhibited significantly lower pain scores (P < 0.05). Surgical duration, surgical field quality, complication rates, and patient satisfaction were comparable between groups.

Conclusions: Deep NMB combined with low-pressure PP provided superior postoperative analgesia without compromising surgical field quality or increasing complications in laparoscopic abdominal surgeries.

Keywords: Laparoscopic; Low Pressure; Neuromuscular Block; Pneumoperitoneum; Postoperative Pain.

Figure 1.. CONSORT flowchart of the enrolled patients

Figure 2.. A, heart rate; and B, mean blood pressure of the studied groups