Epidural Plus General Anesthesia Vs General Anesthesia Alone for Elective Aortic Surgery: Effects on Gastric Electrical Activity and Serum Gastrin Secretion

Background: The aim of this study was to evaluate differences in electrogastrographic activity and serum gastrin secretion in patients subjected to general anesthesia (GA) vs blended anesthesia (BA = GA plus epidural analgesia) for abdominal aortic surgery.

Methods: Thirty-four patients (all males: 28 with abdominal aorta aneurysm, 6 with obstructive aorto-iliac disease; mean age: 68+/-7 years) were randomly assigned either to GA (N.=17) or to BA (N.=17) for abdominal aortic surgery. Each patient was evaluated for serum gastrin secretion at the time of electrogastrography (EGG) 24 h before and after surgery, using ambulatory equipment. Gastrin levels were tested under fasting conditions and after a standard meal. EGG shows gastric electrical activity that parallels gastric motor activity.

Results: Before surgery, no significant difference was found for any of the EGG parameters or the serum gastrin integrated value (area under the curve [AUC]) between the two groups of patients. After surgery, an increased frequency of electrical waves (tachygastria) was observed in 22% of those undergoing GA and in 5% of patients undergoing BA. The power ratio (postprandial/fasting total power) was exceedingly high (>4) in 53% of the GA patients and in 11% of the BA patients (P<0.05). The gastrin AUC was 263+/-58 pg/mL in the GA group and 179+/-92 pg/mL in the BA group (P<0.01).

Conclusions: An excess of EGG activity and serum gastrin secretion was observed in patients undergoing GA vs those submitted to BA. Thus, the latter procedure seems to affect gastric function less than GA alone.