What level of neuromuscular block is recommended for a laparoscopic sigmoid resection for colon cancer?

Neuromuscular Block Level for Laparoscopic Sigmoid Resection for Colon Cancer

While there is insufficient evidence to make a definitive recommendation on the required intensity of neuromuscular blockade for laparoscopic sigmoid resection, deep neuromuscular blockade appears to provide better surgical conditions with lower intra-abdominal pressures compared to moderate blockade, which may benefit postoperative outcomes. 1

Evidence for Deep vs. Moderate Neuromuscular Blockade

Surgical Conditions and Intra-abdominal Pressure

• Deep neuromuscular blockade (1-2 post-tetanic count responses at the adductor pollicis) allows for significantly lower intra-abdominal pressures (9 mmHg) compared to moderate blockade (12 mmHg) while maintaining satisfactory surgical conditions during colorectal surgery 1, 2
• In laparoscopic cholecystectomy, insufflation pressure needed to be increased from 8 mmHg to 12 mmHg in 34% of cases with moderate blockade versus only 12% with deep blockade 1
• Deep blockade provides a 25% absolute difference in obtaining good or excellent operating conditions compared to moderate blockade 1

Postoperative Outcomes

• Deep neuromuscular blockade is associated with lower postoperative pain scores, reduced incidence of shoulder tip pain, and faster bowel function recovery (earlier gas passing time and oral intake) 2
• These benefits may contribute to enhanced recovery after surgery, which is a priority in colorectal cancer management 1

Important Considerations

Monitoring Requirements

• Regardless of blockade depth chosen, intraoperative monitoring of neuromuscular blockade is strongly recommended (GRADE 1+) 1
• Quantitative adductor pollicis monitoring is recommended for accurate assessment of blockade depth and recovery 1
• For moderate blockade: maintain 1-2 TOF responses at the adductor pollicis 1
• For deep blockade: maintain 1-2 post-tetanic count (PTC) responses at the adductor pollicis 1

Reversal Strategies

• After using deep blockade, appropriate reversal is critical to prevent residual neuromuscular blockade 1
• For neostigmine reversal, await spontaneous recovery to four muscle responses at the adductor pollicis following TOF stimulation before administration 1
• Sugammadex may be preferred for reversal of deep blockade as it allows for more rapid and complete reversal 1

Limitations of Current Evidence

• Most studies have small sample sizes (n = 24 to 102) 1
• No trials have shown significant differences between deep and moderate blockade in terms of intraoperative adverse surgical events or specific morbidity 1
• The 2020 guidelines state it is "impossible to make a recommendation on the depth of neuromuscular blockade required to achieve a reduction in intraoperative and postoperative surgical morbidity" 1

Clinical Approach

• Use deep neuromuscular blockade during laparoscopic sigmoid resection for colon cancer when:
  • Lower intra-abdominal pressures are desired (9 mmHg vs 12 mmHg) 2
  • Optimal surgical field visualization is critical 1
  • Enhanced recovery is a priority 1, 2
• Ensure proper monitoring and reversal strategies are in place to prevent residual neuromuscular blockade and its associated complications 1

Pitfalls to Avoid

• Failing to monitor neuromuscular blockade quantitatively can lead to residual blockade 1
• Residual neuromuscular blockade is associated with higher morbidity and mortality, critical respiratory events, postoperative pneumonia, and delayed discharge 1
• Inadequate reversal of deep blockade may lead to prolonged recovery and respiratory complications 1