Deep neuromuscular block reduces intra-abdominal pressure requirements during laparoscopic cholecystectomy: a prospective observational study.

Background: Laparoscopic surgery causes specific post-operative discomfort and intraoperative cardiovascular, pulmonary, and splanchnic changes. The CO2 pneumoperitoneum-related intra-abdominal pressure (IAP) remains one of the main drivers of these changes. We investigated the influence of deep neuromuscular blockade (NMB) on IAP and surgical conditions.

Methods: This is an open prospective single-subject design study in 20 patients (14 female/6 male) undergoing laparoscopic cholecystectomy. Inclusion criteria were 18 years or older, and American Society of Anesthesiologists classification 1 to 3. Under a standardised anaesthesia, lowest IAP providing adequate surgical conditions was assessed without NMB and with deep NMB [post-tetanic count (PTC)<2] with rocuronium. The differences between IAP allowing for an adequate surgical field before and after administration of rocuronium were determined, as were effects of patient gender, age, and body mass index.

Results: Mean IAP without NMB was 12.75 (standard deviation 4.49) mmHg. Immediately after achieving a deep NMB, this was 7.20 (2.51). This pressure difference of 5.55 mmHg (5.08, P<0.001) dropped to 3.00 mmHg (4.30, P<0.01) after 15 min. Higher IAP differences were found in women compared with men. A modest inverse relationship was found between pressure difference and age.

Conclusions: We found an almost 25% lower IAP after a deep NMB compared with no block in laparoscopic cholecystectomy. Younger and female patients appear to benefit more from deep neuromuscular blockade to reduce IAP.