title: Real-time detection of gastric insufflation related to facemask pressure-controlled ventilation using ultrasonography of the antrum and epigastric auscultation in nonparalyzed patients: a prospective, randomized, double-blind study.
abstract: BACKGROUND
  The authors sought to determine the level of inspiratory pressure minimizing the risk of gastric insufflation while providing adequate pulmonary ventilation. The primary endpoint was the increase in incidence of gastric insufflation detected by ultrasonography of the antrum while inspiratory pressure for facemask pressure-controlled ventilation increased from 10 to 25 cm H2O.
  
  
  METHODS
  In this prospective, randomized, double-blind study, patients were allocated to one of the four groups (P10, P15, P20, and P25) defined by the inspiratory pressure applied during controlled-pressure ventilation: 10, 15, 20, and 25 cm H2O. Anesthesia was induced using propofol and remifentanil; no neuromuscular-blocking agent was administered. Once loss of eyelash reflex occurred, facemask ventilation was started for a 2-min period while gastric insufflation was detected by auscultation and by real-time ultrasonography of the antrum. The cross-sectional antral area was measured using ultrasonography before and after facemask ventilation. Respiratory parameters were recorded.
  
  
  RESULTS
  Sixty-seven patients were analyzed. The authors registered statistically significant increases in incidences of gastric insufflation with inspiratory pressure, from 0% (group P10) to 41% (group P25) according to auscultation, and from 19 to 59% according to ultrasonography. In groups P20 and P25, detection of gastric insufflation by ultrasonography was associated with a statistically significant increase in the antral area. Lung ventilation was insufficient for group P10.
  
  
  CONCLUSIONS
  Inspiratory pressure of 15 cm H2O allowed for reduced occurrence of gastric insufflation with proper lung ventilation during induction of anesthesia with remifentanil and propofol in nonparalyzed and nonobese patients. (Anesthesiology 2014; 120:326-34).
authors: From the University of Lyon, Claude Bernard Lyon 1, INSERM UMR 865, and Department of Anesthesia and Intensive Care, Édouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France (L.B.); University of Lyon, Claude Bernard Lyon 1, and Department of Anesthesia and Intensive Care, Édouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France (M.-L.A., C.A., E.B., and B.A.); University of Lyon, Claude Bernard Lyon 1, CNRS UMR 5558, and Department of Biostatistics, Hospices Civils de Lyon, Lyon, France (R.E. and M.R.); and University of Lyon, Claude Bernard Lyon 1, and Department of Anesthesia and Intensive Care, Femme Mère Enfant Hospital, Hospices Civils de Lyon, Bron, France (D.C.).
authors: Lionel
authors: L
authors: Bouvet
authors: Marie-Laure
authors: ML
authors: Albert
authors: Caroline
authors: C
authors: Augris
authors: Emmanuel
authors: E
authors: Boselli
authors: René
authors: R
authors: Ecochard
authors: Muriel
authors: M
authors: Rabilloud
authors: Dominique
authors: D
authors: Chassard
authors: Bernard
authors: B
authors: Allaouchiche
mesh_terms: D000328:Adult; D000368:Aged; D058109:Airway Management; D000465:Algorithms; D019412:Anatomy, Cross-Sectional; D000771:Anesthesia, Intravenous; D001314:Auscultation / Q000379:methods*; D002849:Chromatography, Gas; D003199:Computer Systems; D004311:Double-Blind Method; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D007327:Insufflation; D007431:Intraoperative Complications / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D017214:Laryngeal Masks; D008297:Male; D008875:Middle Aged; D011336:Probability; D011446:Prospective Studies; D011706:Pyloric Antrum / Q000000981:diagnostic imaging; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000379:methods; D013270:Stomach / Q000000981:diagnostic imaging*; D014463:Ultrasonography