title: Aerophagia increases the risk of ventilator-associated pneumonia in critically-ill patients.
abstract: BACKGROUND
  Gastric residual volume in ventilated critically ill may complicate gut function. Over the years studies suggested to tolerate progressively higher residuals. The relationship between such volumes and the development of ventilator-associated pneumonia (VAP) is still under debate. No reports deal with the relevant anecdotal finding of air in the stomach. Aim of the present study is to test the role of air in the development of VAPs.
  
  
  METHODS
  Prospective observational trial in consecutive patients with a predicted length of ICU stay >3 days. The first 8 days of stay were studied. Sedation was targeted to have awake/cooperative patients. Early enteral nutrition was attempted. Gastric content was measured every 4 hours by 60 mL-syringe suction. Upper digestive intolerance (UDI) was defined as >2 consecutive findings of liquid >200 mL, aerophagia was defined as >2 consecutive findings of air >150 mL.
  
  
  RESULTS
  Three hundred sixty-four patients enrolled, 43 developed VAP (11.8%). Patients were sedated with enteral (76% total time), intravenous (6%) or both (28%) drugs. Conscious sedation was achieved in 54% of the observations. 326 patients began enteral nutrition during the first 24 hours (1000 kcal median calorie intake). 10% developed UDI, 15% had aerophagia. No association was found between VAP and UDI (P=0.78), while significant association was found between VAP and aerophagia (OR=2.88, P<0.01). A sensitivity analysis, excluding patients admitted with respiratory infection, confirmed the results.
  
  
  CONCLUSIONS
  High volumes of air in the stomach significantly increased the risk of developing VAP, while gastric residual volumes were not associated with the incidence of pneumonia.
authors.affiliation: Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italia - michele.umbrello@ao-sanpaolo.it.
authors.forename: A L
authors.initials: AL
authors.lastname: Destrebecq
authors.forename: G
authors.initials: G
authors.lastname: Elia
authors.forename: S
authors.initials: S
authors.lastname: Terzoni
authors.forename: G
authors.initials: G
authors.lastname: Angelastri
authors.forename: G
authors.initials: G
authors.lastname: Brenna
authors.forename: C
authors.initials: C
authors.lastname: Ricci
authors.forename: P
authors.initials: P
authors.lastname: Spanu
authors.forename: M
authors.initials: M
authors.lastname: Umbrello
authors.forename: G
authors.initials: G
authors.lastname: Iapichino
mesh_terms: D000334:Aerophagy / Q000150:complications*; D000368:Aged; D016638:Critical Illness; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology* / Q000209:etiology*; D011446:Prospective Studies; D012306:Risk; D013270:Stomach