Chapter 56. Anesthesia for Gastrointestinal Surgery

1. Diseases of the gastrointestinal system frequently result in abnormal gastric function, with potentially increased anesthetic risk caused by increased intragastric pressure, delayed gastric emptying, gastric dilation, and increased gastric secretion.

2. Although volume, pH, and amount of particulate matter in the aspirate appear to be the 3 most important factors determining the severity of the pulmonary insult, overall the medical fragility of the patient is often the most important determinant influencing the clinical course and outcome of pulmonary aspiration.

3. Extensive bowel, pancreatic, or esophageal resections entail considerable morbidity, with potential serious postoperative complications such as hemorrhage, coagulopathy, and hepatic, renal, pulmonary, or cardiovascular failure.

4. Laparoscopy entails the installation of gas (usually CO2) into the peritoneal cavity with physiologic changes resulting from this gas under pressure and subsequent surgical positioning. Hemodynamic compromise can occur, which, although rare, can be catastrophic.

5. The systemic inflammatory response syndrome/multiorgan dysfunction syndrome continuum is often accompanied by gastrointestinal mucosal ischemia and the release of mediators that further compromise both splanchnic and systemic perfusion. Anesthetic care of these patients is especially challenging.

6. If the lower esophageal sphincter is not functioning properly, or if a hiatal hernia exists, stomach contents may reflux into the esophagus and pharynx during anesthesia and surgery, increasing the potential for serious aspiration pneumonia.

7. Narcotics have intestinal side effects that are well recognized. Lower esophageal sphincter tone is decreased. Gastric emptying is impaired because of decreased propulsive motility and increased tone in the antrum of the stomach.

8. During laparoscopy, the development of pneumothorax and/or pneumomediastinum is a serious and/or potentially life-threatening complication. When either is suspected, from hemodynamic deterioration or from the presence of subcutaneous emphysema, especially of the neck and face, aggressive investigation (auscultation, chest radiograph) and management (eg, chest tube for tension pneumothorax) should be undertaken. Procedures on the lower esophagus may be more likely to result in these complications. Conversion to an open procedure is usually required.

9. Approximately 40% of patients with gastroesophageal reflux have delayed gastric emptying, and in approximately one-third of these, the delay is clinically significant.

10. Maneuvers necessary for blunt esophagectomy are capable of causing serious hemodynamic and ventilatory compromise and require appropriate monitoring of blood pressure and respiration.

11. Bariatric surgery patients may have significant medical problems and their perioperative care can be quite challenging. Newer procedures continue to lessen morbidity and mortality.

Gastrointestinal (GI) surgical practice has evolved dramatically with experience and technology. Newer techniques result in less physiologic trespass and more rapid return to full activities, and the trend continues. Current robotics-assisted laparoscopic surgery will be augmented by remotely controlled natural orifice transluminal endoscopic surgery (NOTES).1

The GI system includes an amazingly complex neurochemical system with far-reaching implications on homeostasis and well-being.2 Furthermore, from routine appendectomies to advanced robotic-assisted natural orifice hepatic resections,3 GI surgery occupies a major percentage of the operative time in most hospitals. Therefore, providing anesthesia care for patients requiring these procedures represents a great portion of the anesthesiologist's time ...