GASTRIC INTRAMUCOSAL ACIDOSIS IN PATIENTS WITH CHRONIC KIDNEY FAILURE

Background. Patients with chronic kidney failure have an increased inc idence of gastrointestinal complications, particularly bleeding from t he stomach. Diminished mucosal blood flow is thought to be an importan t etiologic factor for such bleeding. Methods. Eleven patients with ki dney failure on maintenance dialysis underwent placement of a gastric tonometer for the determination of gastric intramucosal pH (pH(i)) bef ore and during dialysis. The arterial pH (pH(a)), calculated pH(i), an d pH(a) - pH(i) differences were compared with the results in a contro l group of seven normal volunteers. Results. The patients with chronic kidney failure had a mean (+/- SD) pH(a) (7.36 +/- 0.04) similar ro t hat found in seven control subjects (7.3 7 +/- 0.04). However, the gas tric mucosal pH in the patients on dialysis (7.20 +/- 0.17) was lower than in the seven control subjects (7.38 +/- 0.06) (p < 0.01). A gastr ic mucosal pH thought to be predictive of either bleeding from stress ulceration (pH(i) < 7.32) or mucosal ischemia (pH(i) - pH(a) differenc e > 0.13) was found in nine (82%) of the patients with kidney failure and in only one (14%) of the control subjects (p < 0.001). Conclusions . This new preliminary finding suggests that the high incidence of gas tric bleeding in chronic kidney failure may be related to mucosal isch emia.