title: Intermittent enteral feeding in mechanically ventilated patients. The effect on gastric pH and gastric cultures.
abstract: OBJECTIVE
  To evaluate the effect of intermittent (16 h/d) enteral feeding (IEF) on gastric pH and gastric microbial growth in mechanically ventilated patients.
  
  
  METHODS
  Prospective, case-controlled study.
  
  
  METHODS
  Medical ICU and infectious disease research laboratory in a university hospital.
  
  
  METHODS
  Thirteen mechanically ventilated patients receiving continuous enteral feeding (CEF).
  
  
  METHODS
  Gastric pH and quantitative gastric cultures were obtained while patients received CEF. Each patient's feeding schedule was changed to IEF. Daily gastric pH and quantitative gastric cultures were obtained for 5 consecutive days.
  
  
  RESULTS
  Gastric microbial growth was found in 85% (11/13) of patients receiving CEF. Implementation of IEF did not clear gastric microbial growth, as only one patient subsequently reverted to negative culture. Similar gastric microbial growth continued in 90% (10/11) of patients after institution of IEF. Gastric pH did not decrease with the administration of IEF (gastric pH with IEF, 3.8 +/- 0.6 vs 4.7 +/- 0.5 with CEF (not significant [NS]). The amount of microbial growth was also unchanged with IEF (total growth with IEF, 7.8 x 10(5) +/- 5.2 x 10(5) cfu/mL vs 8.7 x 10(5) +/- 4.6 x 10(5) cfu/mL with CEF) (NS). Thirty-eight percent (5/13) of patients developed new Gram-negative rod growth in gastric cultures while receiving IEF. Gram-negative rod isolates increased from 25% of total isolates (CEF) to 40% (IEF).
  
  
  CONCLUSIONS
  Our preliminary data suggest gastric pH was not lowered and existing microbial growth was not cleared in ventilated patients receiving IEF after previously receiving CEF. Further controlled study in a larger group of patients is necessary to determine whether IEF is of benefit in decreasing gastric colonization and nosocomial pneumonia.
authors.affiliation: Department of Medicine, University of Kansas Medical Center Kansas City, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Spilker
authors.forename: D R
authors.initials: DR
authors.lastname: Hinthorn
authors.forename: S K
authors.initials: SK
authors.lastname: Pingleton
mesh_terms: D000328:Adult; D000368:Aged; D001419:Bacteria / Q000302:isolation & purification; D016022:Case-Control Studies; D004750:Enteral Nutrition / Q000379:methods; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial; D013270:Stomach / Q000382:microbiology*