RADOX' Reduced Abdominal Distension and Oxygen Delivery

The use of laparoscopic surgery is continuing to increase in colorectal resection and expected reach 80% in the next 10 years. Although laparoscopic (keyhole) or minimally invasive surgery can lead to faster recovery it can also put significant stresses on the patient's heart and cause fluctuations in blood pressure due to the extreme headdown positioning and abdominal insufflation of carbon dioxide gas. We have performed several surgical cases under deep neuromuscular block and this has allowed surgery to operate at lower abdominal pressures (from 14 down to 8 mmHg). This put less strain on the heart and allowed higher cardiac outputs. This study will look at whether deep neuromuscular block is beneficial for patients by 1. Increasing oxygen delivery, measured using oesophageal doppler monitoring of cardiovascular variables intraoperatively 2. Allowing surgery at lower abdominal insufflation pressures if they have a deep block 3. Reducing patient's analgesic requirements postoperatively in recovery and at 4 hours