title: Clinical assessment of the ultrasonographic measurement of antral area for estimating preoperative gastric content and volume.
abstract: BACKGROUND
  This prospective observational study aimed to assess the feasibility and performance of the ultrasonographic measurement of antral cross-sectional area (CSA) for the preoperative assessment of gastric contents and volume in adult patients and for the diagnosis of risk stomach (defined by the presence of solid particles and/or gastric fluid volume >0.8 ml/kg).
  
  
  METHODS
  A preoperative ultrasonographic measurement of the antral CSA was performed for each patient by a physician (L.B.) blinded to the history of the patient. Immediately after tracheal intubation, an 18-French multiorifice Salem tube was inserted and gastric contents were aspirated in five different patient positions; during this time, the patient's epigastrium was massaged and the tube was moved backward and forward in the stomach. The relationship between the antral area and the volume of aspirated gastric contents was analyzed, as was the performance of ultrasonographic measurement of antral area for the diagnosis of risk stomach.
  
  
  RESULTS
  The measurement of antral CSA was performed on 180 of 183 patients. A significant positive relationship between antral CSA and aspirated fluid volume was found. The cutoff value of antral CSA of 340 mm(2) for the diagnosis of risk stomach was associated with a sensitivity of 91% and a specificity of 71%. The area under the receiver operating characteristic curve for the diagnosis of risk stomach was 90%.
  
  
  CONCLUSIONS
  The ultrasonographic measurement of antral CSA could be an important help for the anesthesiologist in minimizing the risk of pulmonary aspiration of gastric contents due to general anesthesia.
authors.affiliation: University of Lyon, Claude Bernard Lyon 1, INSERM UMR 865, Lyon, France. lionel.bouvet@chu-lyon.fr
authors.forename: Lionel
authors.initials: L
authors.lastname: Bouvet
authors.forename: Jean-Xavier
authors.initials: JX
authors.lastname: Mazoit
authors.forename: Dominique
authors.initials: D
authors.lastname: Chassard
authors.forename: Bernard
authors.initials: B
authors.lastname: Allaouchiche
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Boselli
authors.forename: Dan
authors.initials: D
authors.lastname: Benhamou
mesh_terms: D005240:Feasibility Studies; D005260:Female; D005746:Gastric Emptying; D005766:Gastrointestinal Contents; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies; D011706:Pyloric Antrum / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014463:Ultrasonography