Pulse oximetry as a means of assessing bowel viability

Utilizing a pulse oximeter, oxygen saturation was determined in the periphery (tongue) and compared to the intestinal wall in a canine model. Segmental intestinal ischemia was then produced and the last obtainable pulse oximetry reading was marked with a suture on either end of the ischemic segment. Reexploration was performed within 48 hr and full thickness biopsies were taken in normal intestine and at various distances into the ischemic segment. Blinded evaluation of the biopsies showed that all biopsies taken within 1 cm of a normal pulse oximetry reading were normal, whereas at 3 cm into the ischemic segment 7 of 15 biopsies showed partial necrosis and 5 of 15 showed full thickness necrosis. We conclude that pulse oximetry of the intestinal wall is a valuable method of assessing intestinal viability in this model.