Measurement Of Mucosal Capillary Hemoglobin Oxygen Saturation in the Colon By Reflectance Spectrophotometry

摘要

Advances in optical and computer technology have enabled the development of a device that utilizes white-light reflectance spectrophotometry to measure capillary hemoglobin saturation in intestinal mucosa during colonoscopy. Studies were performed using the colon oximeter in anesthetized animals and patients undergoing colonoscopy. Mucosal hemoglobin saturation in the normal colon (mean +/- S.D.) is 72% +/- 3.5%. In an animal model, ischemia via arterial ligation and hypoxemia via hypoxic ventilation each result in a decrease of over 40% in the mucosal saturation. In human patients with colon polyps, ischemia induced by epinephrine injection, stalk ligation using a loop, or clipping of the polyp stalk each result in a decrease of over 40% in the mucosal saturation (p<0.02). In contrast, saline injection does not decrease the mucosal saturation (p=N.S.). A patient who previously underwent partial colectomy with sacrifice of the inferior mesenteric artery had a saturation of 55% in the remaining sigmoid colon, with normal values in the superior mesenteric artery territory (p<0.05). A novel device for measuring capillary hemoglobin saturation in intestinal mucosa during colonoscopy is capable of providing reproducible measurements in normal patients and clearly detects dramatic decreases in saturation with ischemic and hypoxic insults.