Pre-op. I try to fast the patients for as short a time as possible and also include pre-operative carbohydrate loading. This is in line with Enhanced Recovery After Surgery (ERAS) Guidelines for major bowel surgery and has been shown to reduce the negative nitrogen balance that occurs following major surgery. I use 200ml cartons of Polycal, which is clear and non-particulate, prescribed 12 and 3 hours pre-operatively. Clear fluids are encouraged up to 2 hours pre-op as this improves gastric emptying and minimises pre-operative dehydration.
Intra-op. I use a mixed technique of both general and regional anaesthesia. The general consists of a fairly standard technique with a Propofol induction and maintenance with Desflurane and a Remifentanil infusion. To reduce post-operative nausea and vomiting I use ondansetron, cyclizine and dexamethasone. The regional part is a spinal anaesthetic using 0.5% Hyperbaric Bupivacaine with additional intrathecal Diamorphine. Regional anaesthesia has been shown to reduce peri-operative DVT formation, probably by blocking sympathetic activity and improving blood flow through the legs, it also produces profound muscular relaxation enabling better pelvic vision and easier insufflation. In addition there is some evidence that appears to suggest regional anaesthesia may reduce the recurrence rate of prostate cancer. As the patients are positioned in a steep trendelenberg they are all intubated and ventilated with a small amount of additional PEEP to reduce pulmonary atelectasis.
Post-op. Intrathecal diamorphine usually provides 12-14 hours of good quality post operative analgesia. Intrathecal opiates act locally producing segmental analgesia and therefore do not produce the systemic side effects to the same degree as intravenous opiates. The ondansetron given peri-operatively may reduce the incidence of opiate induced pruritus as well as acting as an excellent antiemetic. Additional analgesia will be required but usually paracetamol and ibuprofen are sufficient. It is unusual for patients to require any additional stronger opioid medications and this is helpful in ensuring that gastric stasis and reduced gut motility do not occur. This enables the patients to be rapidly progressed on to a light solid diet that in turn further reduces the occurrence of a post-operative ileus.
Fluid Management. Using this starvation policy, patients should commence their surgery with only a minimum degree of dehydration. Remifentanil produces an extremely cardio-stable anaesthetic and with the patients being head down peri-operative hypotension is unusual. Should this however occur blood pressure should be maintained with the judicial use of vasopressors and fluid if necessary. Post-operative urine output can be maintained if required with plasma expanders and diuretics.
Richard Morey qualified from MHMS in 1987 and has been a Consultant Anaesthetist in SE London since 1997. His particular interests are ERAS/ Laparoscopic Surgery along with ENT and Difficult Airways.