title: A pilot study of pepsin in tracheal and oral secretions.
abstract: BACKGROUND
  Because reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, it is reasonable to hypothesize that the detection of pepsin (the major gastric enzyme in gastric juice) in oral secretions may provide a relatively noninvasive method of predicting risk for aspiration.
  
  
  OBJECTIVE
  To describe the incidence of pepsin in oral and tracheal secretions collected concurrently from a sample of 50 gastric-fed patients undergoing mechanical ventilation.
  
  
  METHODS
  An exploratory descriptive design with a convenience sample from 4 medical and surgical intensive care units. An oral secretion and a tracheal secretion were collected concurrently from each patient (yielding a sample of 50 oral and 50 tracheal secretions). The tracheal secretions were obtained via the inline suction system with an attached sputum trap; oral secretions were obtained via a Yankauer suction tip with an attached sputum trap. All specimens were assayed for pepsin by the Western blot method.
  
  
  RESULTS
  Oral secretions from 10 patients (20%) and tracheal secretions from 2 patients (4%) were pepsin-positive. Both patients with pepsin-positive tracheal secretions also had pepsin-positive oral secretions. Pepsin was not found in the tracheal secretions from the remaining 8 patients with pepsin-positive oral secretions.
  
  
  CONCLUSIONS
  Although reflux of gastric juice into the oropharynx must precede its aspiration into the lungs, individual reflux events do not necessarily lead to aspiration. Thus, it is reasonable that we found pepsin 5 times more often in oral secretions than in tracheal secretions.
authors.affiliation: Barnes-Jewish Hospital, St Louis, MO 63108, USA. mes4143@bjc.org
authors.forename: Marilyn
authors.initials: M
authors.lastname: Schallom
authors.forename: Sally M
authors.initials: SM
authors.lastname: Tricomi
authors.forename: Yie-Hwa
authors.initials: YH
authors.lastname: Chang
authors.forename: Norma A
authors.initials: NA
authors.lastname: Metheny
mesh_terms: D000328:Adult; D004750:Enteral Nutrition / Q000009:adverse effects*; D005260:Female; D005750:Gastric Juice / Q000201:enzymology* / Q000378:metabolism; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000201:enzymology*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D009960:Oropharynx / Q000201:enzymology / Q000378:metabolism*; D010434:Pepsin A / Q000032:analysis*; D010865:Pilot Projects; D011015:Pneumonia, Aspiration / Q000209:etiology / Q000517:prevention & control; D012121:Respiration, Artificial / Q000009:adverse effects; D053120:Respiratory Aspiration / Q000503:physiopathology / Q000517:prevention & control; D014132:Trachea / Q000201:enzymology / Q000378:metabolism*
chemical_list: D010434:Pepsin A