Effect of neuromuscular block on surgical conditions during short-duration paediatric laparoscopic surgery involving a supraglottic airway.
Study Type and Method
This was a single centre randomised control trial conducted at Hunan Children’s Hospital in China. It compared surgical conditions of paediatric patients (<12 years of age) undergoing unilateral laparoscopic inguinal hernia repair with Proseal LMAs either receiving neuromuscular blockade (intervention) or not (control).
The primary outcome measure was the Leiden-surgical rating scale (L-SRS), assessed by the surgeon. This evaluated surgical operating conditions from extremely poor (score 1) to excellent (score 5).
Secondary outcomes included physiological parameters, surgical and anaesthetic time, time to removal of LMA, PACU discharge time and perioperative adverse events.
Findings:
68 patients were randomised. The mean L-SRS score was 3.5 vs 4.1 in the control vs the intervention group, P<0.0001. A subgroup analysis of children aged 0-3 years showed no difference between the groups with overall lower L-SRS scores.
Adverse events occurred more commonly in the control group (45.5%) vs intervention group (12.1%) during anaesthesia and surgery.
Peak pressures during insufflation were greater in the control group with a value of 17.9 (1.8) vs 16.2 (1.9) cmH2O for the intervention group (P=0.0004).
Other secondary outcomes were similar between groups.
Commentary:
A 0.5 difference in L-SRS scores was deemed clinically significant based on a previous study. This has resulted in the study demonstrating significance when the control group had a score half-way between acceptable and good versus the intervention group just having slightly better than a good score. This was not translated into faster surgical times in the intervention group. However, the study was not powered sufficiently for secondary outcomes. Interestingly the differences in surgical conditions were not demonstrated in younger children. The authors have suggested this maybe a reflection of reduced muscle strength.
Although the study was not powered for secondary outcomes, the adverse events are more than tripled in the control group. This is something that cannot be ignored, however, as usual, a larger study would be helpful to truly delineate this.
All patients received total intravenous anaesthesia (TIVA) with propofol. Sevoflurane may improve muscle relaxation and is the maintenance of choice for some anaesthetists. Therefore, a study using a sevoflurane-based anaesthetic would be useful. Additionally, the intervention group had a bolus of rocuronium followed by an infusion to maintain neuromuscular blockade at target depth. This would not be normal practice for laparoscopic surgery, at least in my institution, and thus extrapolation of results from this study would be with caution.
Take home message:
Neuromuscular blockade for laparoscopic surgery when using TIVA may improve surgical conditions and reduce adverse events without affecting duration of anaesthetic time especially in children older than 3 years of age.
Reviewed by Dr Sorcha Evans
