PERIOPERATIVE GASTROINTESTINAL ACIDOTIC EPISODES DURING REPAIR OF ABDOMINAL AORTIC-ANEURYSMS

Questions under study: Surgery of abdominal aortic aneurysms involves a high risk of postoperative complications. It has been suggested that the incidence of postoperative complications is related to the develo pment of gastrointestinal acidotic episodes of the mucosa. The goal of this study was, therefore, to determine the incidence of gastrointest inal acidotic episodes during repair of abdominal aortic aneurysms, an d to test the hypothesis that these episodes predict an adverse postop erative course. Methods: In 49 consecutive patients undergoing electiv e surgery for repair of an abdominal aneurysm, intramucosal gastric pH (pHi) was measured perioperatively. The length of the surgical proced ure, perioperative intravenous fluid intake, use of vasoactive drugs, APACHE-II scores, days with an endotracheal tube in place, days of int ensive care and major postoperative complications were prospectively a ssessed. The patients were assigned to either a group with a pHi great er than or equal to 7.35 or a group with pHi <7.35 measured towards th e end of the surgical procedure, and then compared. Results: The pHi d ecreased from 7.42+/-0.03 after induction of anesthesia to 7.37+/-0.07 (p <0.05) during clamping of the aorta, and continued to decrease to 7.34+/-0.08 (p <0.001) towards the end of surgery and on admission to the surgical intensive care unit (mean+/-standard deviation). The perc entage of patients with pHi <7.35 increased from 10% at the beginning of the operation to 55% on admission to the intensive care unit (p <0. 0001). There was no difference in the postoperative course between pat ients with pi-Ii greater than or equal to 7.35 and those with pHi <7.3 5 measured after declamping of the aorta. Patients who had a mai or co mplication during their stay in the intensive care unit had lower peri operative pHi values than patients without complications (p <0.001). C onclusions: Perioperative gastrointestinal acidotic episodes of the mu cosa are common during repair of abdominal aortic aneurysms. The perio perative course, however, is not influenced by these acidotic episodes , despite the fact that patients with complications during their stay in the intensive care unit had lower perioperative pHi values. The rou tine use of pHi measurements during elective surgery of abdominal aort ic aneurysms, therefore, is not justified.