Gastric tonometer monitoring in infants undergoing repair of coarctation of the aorta

Objective: To evaluate gastric tonometer monitoring for splanchnic hypoperf usion in infants during surgical intervention for aortic coarctation, espec ially within aortic crossclamp periods. Design: A prospective study. Setting: Cardiovascular intensive care unit in a university hospital. Participants: Fourteen infant patients after elective, uncomplicated repair of coarctation of the aorta. Interventions: After the anesthesia induction, a 7F tonometry catheter was inserted into the stomach oropharyngeally. Gastric carbon dioxide, arterial blood gases, blood pressure of upper extremities, and hematocrit values we re measured in 5 different time intervals. Time periods were as follows: T1 (after the anesthesia induction), T2 (before aortic cross-clamp), T3 (imme diately after aortic cross-clamp removal), T4 (40 minutes after aortic cros s-clamp removal), and T5 (as the patient reached the intensive care unit). Intramucosal pH was measured by means of the Henderson-Hasselbach equation. The mean values of all parameters were calculated. According to T1 time, T 2, T3, T4, and T5 times were compared with Student's t-test. Measurements and Main Results: Mean aortic cross-clamp time was 19.4 +/- 6. 6 minutes. Intramucosal pH values of T3 (p < 0.001) and 14 (p < 0.01) were found to be lower than values of T1. The gastric carbon dioxide values of T 3 were significantly higher than T1 (p < 0.01), and bicarbonate and arteria l pH values of T3 were significantly lower (p < 0.01). There were no signif icant differences in other parameters over time intervals. Conclusion: Splanchnic hypoperfusion exists during aortic cross-clamping in infant aortic coarctation surgery, and the tonometric catheter is consider ed to be a safe method for monitoring this hypoperfusion. Copyright (C) 200 0 by W.B, Saunders Company.