Comparison of the effects of deep and moderate neuromuscular block on respiratory system compliance and surgical space conditions during robot-assisted laparoscopic radical prostatectomy: a randomized clinical study

Abstract

Robot-assisted radical prostatectomy (RARP) requires pneumoperitoneum (Pnp) and a steep head-down position that may disturb respiratory system compliance (Crs) during surgery. Our aim was to compare the effects of different degrees of neuromuscular block (NMB) on Crs with the same Pnp pressure during RARP. One hundred patients who underwent RARP were enrolled and randomly allocated to a deep or moderate NMB group with 50 patients in each group. Rocuronium was administered to both groups: in the moderate NMB group to maintain 1-2 responses to train-of-four (TOF) stimulation; and in the deep NMB group to maintain no response to TOF stimulation and 1-2 responses in the post-tetanic count. Pnp pressure in both groups was 10 mmHg (1 mmHg=133.3 Pa). Peak inspiratory pressure (Ppeak), mean pressure (Pmean), Crs, and airway resistance (Raw) were recorded after anesthesia induction and at 0, 30, 60, and 90 min of Pnp and post-Pnp. Surgical space conditions were evaluated after the procedure on a 4-point scale. Immediately after the Pnp, Ppeak, Pmean, and Raw significantly increased, while Crs decreased and persisted during Pnp in both groups. The results did not significantly differ between the two groups at any of the time points. There was no difference in surgical space conditions between groups. Body movements occurred in 14 cases in the moderate NMB group and in one case in the deep NMB group, and all occurred during obturator lymphadenectomy. A significant difference between the two groups was observed. Under the same Pnp pressure in RARP, deep and moderate NMBs resulted in similar changes in Crs, and in other respiratory mechanics and surgical space conditions. However, deep NMB significantly reduced body movements during surgery.