Residual Gastric Volume After Bowel Preparation With Polyethylene Glycol for Elective Colonoscopy: A Prospective Observational Study.

Abstract

To examine the residual gastric volume (RGV) in colonoscopy after bowel preparations with 3-L polyethylene glycol (PEG). Obstacles to high-volume bowel preparation by anesthesia providers resulting from concerns over aspiration risk are common during colonoscopy. Prospective measurements of RGV were performed in patients undergoing esophagogastroduodenoscopy (EGD) and morning colonoscopy with split-dose PEG preparation, patients undergoing EGD and afternoon colonoscopy with same-day PEG preparation, and patients undergoing EGD alone under moderate conscious sedation. Colonoscopy patients were allowed to ingest clear liquids until 2 hours before the procedure. Patients undergoing EGD alone were instructed to eat/drink nothing after midnight. There were 860 evaluated patients, including 330 in the split-dose preparation group, 100 in the same-day preparation group, and 430 in the EGD-only group. Baseline demographics and disease/medication factors were similar. The mean RGV in patients receiving the same-day preparation (35.4 mL or 0.56 mL/kg) was significantly higher than that in patients receiving the split-dose preparation (28.5 mL or 0.45 mL/kg) and in patients undergoing EGD alone (22.8 mL or 0.36 mL/kg) (P=0.023 and P<0.0001, respectively). Within the bowel-preparation groups, patients with fasting times of 2 to 3 hours had similar RGV compared with patients who had fasting times >3 hours. The shape of the distribution and the range of RGV among the 3 study groups were similar. No aspiration occurred in any group. PEG bowel preparations increase RGV mildly, but seem to have no clinical significance. These results support the current fasting guidelines for colonoscopy.