title: Normal Values and Clinical Use of Bedside Sonographic Assessment of Postoperative Gastric Emptying: A Prospective Cohort Study.
abstract: BACKGROUND
  GI dysfunction is common after abdominal surgery. However, assessment and diagnosis currently lack objective measurement.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the feasibility and clinical use of bedside sonographic assessment of gastric emptying by measuring the time to complete emptying of a standard volume of ingested water in patients after colorectal surgery.
  
  
  METHODS
  This was a prospective cohort study.
  
  
  METHODS
  The study was conducted at a single tertiary institution in Sydney.
  
  
  METHODS
  Healthy volunteers (n = 30) were studied to establish a reference range. Gastric emptying was then measured in patients (n = 39) before and after colorectal surgery.
  
  
  METHODS
  Assessment of gastric emptying was performed on days 1 to 4 by measuring antral cross-sectional area every 10 minutes after ingestion of 250 mL of water.
  
  
  METHODS
  The time to complete emptying of water was used as a surrogate measure of gastric emptying. Information concerning postoperative outcomes, GI symptoms, and recovery was also recorded.
  
  
  RESULTS
  The median time to complete emptying of water for healthy volunteers was 20 minutes (range, 10-40 minutes). The study protocol was completed in 30 of 39 patients. The time to complete emptying of water on day 2 had the best discriminatory power to identify patients with ileus (sensitivity, 85.71%; specificity, 82.61%). Gastric emptying was normal in 20 of 30 (67%) patients, with only 1 case of ileus (false negative). These patients had less nausea (p = 0.0003), earlier intake of solid diet (p = 0.001), and shorter hospital stay (p = 0.040) compared with patients with abnormal gastric emptying.
  
  
  CONCLUSIONS
  Ultrasound is operator dependent with a learning curve.
  
  
  CONCLUSIONS
  Bedside sonographic assessment of gastric emptying is feasible and reliable. Assessment of antral contents with a single ultrasound 40 minutes after ingestion of water enables classification of patients into those with normal and abnormal gastric emptying. When performed on postoperative day 2, it has good sensitivity/specificity for discriminating patients with ileus.
authors.affiliation: 1 Academic Colorectal Unit, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia 2 Sydney Colorectal & Pelvic Floor Centre, Sydney, New South Wales, Australia 3 Department of Radiology, Concord Repatriation General Hospital, Concord, New South Wales, Australia 4 Concord Clinical School, Centre for Education and Research on Ageing, Concord, New South Wales, Australia.
authors.forename: Naseem
authors.initials: N
authors.lastname: Mirbagheri
authors.forename: Graham
authors.initials: G
authors.lastname: Dunn
authors.forename: Vasikaran
authors.initials: V
authors.lastname: Naganathan
authors.forename: Michael
authors.initials: M
authors.lastname: Suen
authors.forename: Marc A
authors.initials: MA
authors.lastname: Gladman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003082:Colectomy; D005240:Feasibility Studies; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D018589:Gastroparesis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D000067716:Point-of-Care Testing; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D012007:Rectum / Q000601:surgery*; D014463:Ultrasonography; D055815:Young Adult