Low intra-abdominal pressure and deep neuromuscular blockade laparoscopic surgery and surgical space conditions: A meta-analysis

BACKGROUND: Low intra-abdominal pressure (IAP) and deep neuromuscular blockade (NMB) are frequently used in laparoscopic abdominal surgery to improve surgical space conditions and decrease postoperative pain. The evidence supporting operations using low IAP and deep NMB is open to debate. METHODS: The feasibility of the routine use of low IAP +deep NMB during laparoscopic surgery was examined. A meta-analysis is conducted with randomized controlled trials (RCTs) to compare the influence of low IAP + deep NMB vs. low IAP + moderate NMB, standard IAP +deep NMB, and standard IAP + moderate NMB during laparoscopic procedures on surgical space conditions, the duration of surgery and postoperative pain. RCTs were identified using the Cochrane, Embase, PubMed, and Web of Science databases from initiation to June 2019. Our search identified 9 eligible studies on the use of low IAP + deep NMB and surgical space conditions. RESULTS: Low IAP + deep NMB during laparoscopic surgery did not improve the surgical space conditions when compared with the use of moderate NMB, with a mean difference (MD) of -0.09 (95% confidence interval (CI): -0.55-0.37). Subgroup analyses showed improved surgical space conditions with the use of low IAP + deep NMB compared with low IAP + moderate NMB, (MD = 0.63 [95% CI:0.06-1.19]), and slightly worse conditions compared with the use of standard IAP + deep NMB and standard IAP + moderate NMB, with MDs of -1.13(95% CI:-1.47 to 0.79) and -0.87(95% CI:-1.30 to 0.43), respectively. The duration of surgery did not improve with low IAP + deep NMB, (MD = 1.72 [95% CI: -1.69 to 5.14]), and no significant reduction in early postoperative pain was found in the deep-NMB group (MD = -0.14 [95% CI: -0.51 to 0.23]). CONCLUSION: Low IAP +deep NMB is not significantly more effective than other IAP +NMB combinations for optimizing surgical space conditions, duration of surgery, or postoperative pain in this meta-analysis. Whether the use of low IAP + deep NMB results in fewer intraoperative complications, enhanced quality of recovery or both after laparoscopic surgery should be studied in the future.