title: Ultrasound-Assessed Gastric Antral Area Correlates With Aspirated Tube Feed Volume in Enterally Fed Critically Ill Patients.
abstract: BACKGROUND
  Enteral tube feed (ETF) intolerance occurs frequently in hospitalized patients and more so in critically ill patients. Most critical care nurses continue to assess gastric residual volume (GRV), especially among those with a history of ETF intolerance. We hypothesized that ultrasound assessment of GRV correlates directly with aspirated tube feed volume.
  
  
  METHODS
  This was a prospective cohort study of a convenience sample of critically ill mechanically ventilated patients admitted to an intensive care unit receiving ETF. The gastric antrum was imaged using the aorta and inferior vena cava (IVC) as landmarks concurrently and simultaneously using a curvilinear probe in the midline. All ultrasound measurements were performed at 30 degrees head up, in the supine position, and prior to the assessment of GRV by nursing staff blinding the ultrasonographer to gastric volume aspirated. Gastric antral area was determined by assessing anteroposterior (AP) and craniocaudal (CC) diameters of the gastric antrum.
  
  
  RESULTS
  Gastric cross-sectional area (CSA) using IVC as a landmark ( R2= 0.92, P < .0001) and aorta as a landmark ( R2= 0.86, P < .0001) correlated with aspirated volume. CC diameter of the stomach measured using the aorta as a landmark correlated with aspirated volume and increased linearly with increasing GRV ( R2= 0.78, P < .0001). A CC diameter of <10 cm using the aorta as a landmark predicted a gastric volume of <500 mL.
  
  
  CONCLUSIONS
  Ultrasound assessment provides accurate assessment of gastric volume in real-life settings, and the CC diameter of the gastric antrum provides a simple surrogate of GRV.
authors.affiliation: 1 John H. Stroger Hospital of Cook County, Chicago, Illinois, USA.
authors.forename: Vibhu
authors.initials: V
authors.lastname: Sharma
authors.affiliation: 2 Southern Illinois University, Springfield, Illinois, USA.
authors.forename: Deepthi
authors.initials: D
authors.lastname: Gudivada
authors.affiliation: 1 John H. Stroger Hospital of Cook County, Chicago, Illinois, USA.
authors.forename: Renaud
authors.initials: R
authors.lastname: Gueret
authors.affiliation: 1 John H. Stroger Hospital of Cook County, Chicago, Illinois, USA.
authors.forename: John
authors.initials: J
authors.lastname: Bailitz
mesh_terms: D000328:Adult; D000368:Aged; D003422:Critical Care; D016638:Critical Illness / Q000628:therapy*; D004750:Enteral Nutrition; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D007362:Intensive Care Units; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D013270:Stomach / Q000000981:diagnostic imaging*; D014463:Ultrasonography
keywords: critical care; enteral nutrition; feed intolerance; gastric volume; nutritional support; tube feeds; ultrasonography