Surgery of any kind represents a traumatic insult to the body and is accompanied by a verifiable stress response dependent on the magnitude of the insult. While the general principles of broad-based anaesthesia have been covered in Section 1, Chapters 2, 3 and 4, the purpose of this chapter is to alert the reader to operative procedures that have specific problems or caveats associated with them. For reasons of space, only the more frequently encountered operations have been included.
The majority of patients requiring laparotomy will present an aspiration risk, and therefore require rapid sequence induction and subsequent muscular relaxation with controlled ventilation. In the case of a perforated viscus (duodenal ulcer, for example) electrolyte imbalance, dehydration and cardiovascular instability make for a high-risk procedure. The presence of faecal soiling of the peritoneum is a particularly bad prognostic indicator. Anastomosis of the bowel requires special consideration. Survival of anastomoses is maximised if the blood supply to the joined section is not compromised in any way. In practice, this requires the avoidance of reversal drugs (and therefore a careful choice of relaxant and its dose) and the use of epidural anaesthesia, usually combined with general anaesthesia if there are no contraindicating factors to the technique (such as poor haemodynamic resuscitation). Epidural anaesthesia provides better postoperative pain relief than patient-controlled analgesia (PCA), which is important in the avoidance of pneumonia after upper abdominal incisions.