title: Proximal gastric response to small intestinal nutrients is abnormal in mechanically ventilated critically ill patients.
abstract: OBJECTIVE
  To determine the response of the proximal stomach to small intestinal nutrients in critically ill patients.
  
  
  METHODS
  Proximal gastric motility was measured in 13 critically ill patients (49.3 +/- 4.7 years) and 12 healthy volunteers (27.7 +/- 2.9 years) using a barostat technique. Recordings were performed at baseline, during a 60-min intra-duodenal infusion of Ensure (2 kcal/min), and for 2 h following the infusion. Minimum distending pressure (MDP), intra-bag volume and fundic wave activity were determined.
  
  
  RESULTS
  The MDP was higher in patients (11.7 +/- 1.1 vs 7.8 +/- 0.7 mmHg; P < 0.01). Baseline intra-bag volumes were similar in the 2 groups. In healthy subjects, a 'bimodal' proximal gastric volume response was observed. In patients, the initial increase in proximal gastric volume was small and delayed, but eventually reached a maximal volume similar to that of healthy subjects. In healthy subjects, the proximal gastric volume rapidly returned to baseline level after nutrient infusion (median 18 min). In contrast, the recovery of volume to baseline was delayed in critically ill patients (median 106 min). In 6 patients, the volume had not returned to baseline level 2 hours after nutrient infusion. In patients, fundic volume waves were less frequent (P < 0.05) and had lower amplitude (P < 0.001), compared to healthy subjects.
  
  
  CONCLUSIONS
  In critical illness, proximal gastric motor responses to small intestinal nutrient stimulation are abnormal.
authors.affiliation: Department of Gastroenterology, Hepatology and General Medicine, Royal Adelaide Hospital, South Australia.
authors.forename: Nam-Q
authors.initials: NQ
authors.lastname: Nguyen
authors.forename: Robert-J
authors.initials: RJ
authors.lastname: Fraser
authors.forename: Marianne
authors.initials: M
authors.lastname: Chapman
authors.forename: Laura-K
authors.initials: LK
authors.lastname: Bryant
authors.forename: Richard-H
authors.initials: RH
authors.lastname: Holloway
authors.forename: Rosalie
authors.initials: R
authors.lastname: Vozzo
authors.forename: Christine
authors.initials: C
authors.lastname: Feinle-Bisset
mesh_terms: D000328:Adult; D016638:Critical Illness / Q000628:therapy*; D004750:Enteral Nutrition / Q000009:adverse effects*; D005215:Fasting / Q000502:physiology; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009929:Organ Size; D012121:Respiration, Artificial; D013270:Stomach / Q000294:innervation / Q000473:pathology / Q000503:physiopathology*