title: Split-dose bowel preparation with polyethylene glycol for colonoscopy performed under propofol sedation. Is there an optimal timing?
abstract: OBJECTIVE
  Aspiration risk, especially with propofol sedation, remains a concern after split-dose bowel preparation of up to 1 L polyethylene glycol for the procedure. We aimed to identify the ideal timing of bowel preparation to achieve optimal colon cleansing with no increased risk of aspiration.
  
  
  METHODS
  A total of 892 consecutive patients undergoing simultaneous esophagogastroduodenoscopy (EGD) and colonoscopy were prospectively recruited. Residual gastric volume (RGV) and pH of gastric contents were measured at EGD, and patients' characteristics, runway time (duration between completion of the final liter of bowel preparation and colonoscopy commencement), and cleansing quality were recorded.
  
  
  RESULTS
  A shorter runway time resulted in better colon cleansing (r = -0.124, P < 0.001). No correlation between runway time and RGV or pH was found (r = -0.017, P = 0.62 and r = -0.030, P = 0.47, respectively). RGV and pH did not differ significantly with runway time of 4 or 5 h. RGV with runway time ≤3 h was 35.9 ± 11.8 mL and 17.4 ± 0.6 mL after runway time >3 h (P < 0.001). No aspiration pneumonia occurred. The only factors independently related to higher RGV were younger age and male sex.
  
  
  CONCLUSIONS
  The consumption of bowel preparation agent within 3-4 h before propofol sedation resulted in a similar RGV and pH as those achieved by more prolonged fasting, with no increased risk of aspiration even in patients perceived to be at high risk.
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.|School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Alaa
authors.identifier: http://orcid.org/0000-0002-9664-530X
authors.initials: A
authors.lastname: Alghamry
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Sureshkumar K
authors.initials: SK
authors.lastname: Ponnuswamy
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Aditya
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Hadi
authors.initials: H
authors.lastname: Moattar
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.|QLD Lung Transplant Service, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Stephanie T
authors.initials: ST
authors.lastname: Yerkovich
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.forename: Ann E
authors.initials: AE
authors.lastname: Vandeleur
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.|School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Thomas
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.|Division of Tropical Health and Medicine, College of Medicine and Dentistry, James Cook University, Cairns, Queensland, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Croese
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.|Division of Tropical Health and Medicine, College of Medicine and Dentistry, James Cook University, Cairns, Queensland, Australia.
authors.forename: Tony
authors.initials: T
authors.lastname: Rahman
authors.affiliation: Department of Gastroenterology and Hepatology, Centre for Service and Quality Improvement, The Prince Charles Hospital, Chermside, Queensland, Australia.|School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Ruth
authors.initials: R
authors.lastname: Hodgson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002400:Cathartics / Q000008:administration & dosage* / Q000009:adverse effects; D003113:Colonoscopy / Q000379:methods*; D016292:Procedural Sedation / Q000379:methods; D004334:Drug Administration Schedule; D016145:Endoscopy, Digestive System / Q000379:methods; D005260:Female; D005745:Gastric Acidity Determination; D005766:Gastrointestinal Contents; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006993:Hypnotics and Sedatives; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000209:etiology / Q000517:prevention & control; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000009:adverse effects; D015742:Propofol; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D002400:Cathartics; D006993:Hypnotics and Sedatives; D011092:Polyethylene Glycols; D015742:Propofol
keywords: aspiration pneumonia; colonoscopy; polyethylene glycols; residual gastric volume; split-dose bowel preparation