title: Labeled acetate to assess intestinal absorption in critically ill patients.
abstract: OBJECTIVE
  To compare the absorption of carbon-13(13C) acetate-enriched nutrients with D-xylose absorption.
  
  
  METHODS
  Prospective cohort observational study.
  
  
  METHODS
  Surgical intensive care unit of a university hospital.
  
  
  METHODS
  A total of 24 critically ill patients requiring enteral nutritional support.
  
  
  METHODS
  The patients were divided into three groups according to the route of 13C acetate administration: 1) gastric, 2) jejunal, and 3) intravenous. D-xylose was administered via the same route as enteral nutrition.
  
  
  RESULTS
  13C acetate absorption and oxidation were reflected by pulmonary 13CO2 excretion. Breath 13CO2 isotopic enrichment was measured by mass spectrometry. 13C acetate absorption was rapid, and D-xylose absorption was depressed in all three groups, compared with the normal values (p <.0001). Breath CO isotopic enrichment was similar after intravenous and jejunal administration but slightly delayed during the first 240 mins after gastric administration (p <.01). Enteral feeding was well tolerated: mean energy delivery amounted to 77%, 88%, and 86% of measured resting energy expenditure on days 1-3.
  
  
  CONCLUSIONS
  Gastric and jejunal 13C acetate are rapidly absorbed in critically ill surgical patients requiring enteral nutrition, contrasting with a depressed or delayed D-xylose absorption. 13CO2 recovery kinetics was similar after jejunal or intravenous 13C acetate and slightly depressed after gastric administration. Further studies are required to determine the value of labeled nutrients to assess gastric emptying and intestinal absorption.
authors.affiliation: Surgical Intensive Care Unit-Department of Surgery, University Hospital-CHUV, Lausanne, Switzerland.
authors.forename: René L
authors.initials: RL
authors.lastname: Chioléro
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Revelly
authors.forename: Mette M
authors.initials: MM
authors.lastname: Berger
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Cayeux
authors.forename: Phippe
authors.initials: P
authors.lastname: Schneiter
authors.forename: Luc
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D001944:Breath Tests / Q000379:methods; D002247:Carbon Isotopes / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics*; D016638:Critical Illness; D004750:Enteral Nutrition; D005746:Gastric Emptying; D005774:Gastrostomy; D006801:Humans; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D007408:Intestinal Absorption; D007553:Isotope Labeling; D007582:Jejunostomy; D008286:Malabsorption Syndromes / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D013058:Mass Spectrometry; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D014994:Xylose / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*
chemical_list: D000085:Acetates; D002247:Carbon Isotopes; D014994:Xylose