title: Prognostic impact of fecal pH in critically ill patients.
abstract: BACKGROUND
  We have reported that altered gut flora is associated with septic complications and eventual death in critically ill patients with systemic inflammatory response syndrome. It is unclear how fecal pH affects these patients. We sought to determine whether fecal pH can be used as an assessment tool for the clinical course of critically ill patients.
  
  
  METHODS
  Four hundred ninety-one fecal samples were collected from 138 patients who were admitted to the Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Japan. These patients were treated in the intensive care unit for more than 2 days. Fecal pH, fecal organic acids, and fecal bacteria counts were measured and compared by survived group and nonsurvived group, or nonbacteremia group and bacteremia group. Logistic regression was used to estimate relations between fecal pH, age, sex, or APACHE II score and mortality, and incidence of bacteremia. Differences in fecal organic acids or fecal bacteria counts among acidic, neutral, and alkaline feces were analyzed.
  
  
  RESULTS
  The increase of fecal pH 6.6 was significantly associated with the increased mortality (odds ratio, 2.46; 95% confidence interval, 1.25 to 4.82) or incidence of bacteremia (3.25; 1.67 to 6.30). Total organic acid was increased in acidic feces and decreased in alkaline feces. Lactic acid, succinic acid, and formic acid were the main contributors to acidity in acidic feces. In alkaline feces, acetic acid was significantly decreased. Propionic acid was markedly decreased in both acidic and alkaline feces compared with neutral feces. No differences were noted among the groups in bacterial counts.
  
  
  CONCLUSIONS
  The data presented here demonstrate that the fecal pH range that extended beyond the normal range was associated with the clinical course and prognosis of critically ill patients.
authors: Akinori
authors: A
authors: Osuka
authors: Kentaro
authors: K
authors: Shimizu
authors: Hiroshi
authors: H
authors: Ogura
authors: Osamu
authors: O
authors: Tasaki
authors: Toshimitsu
authors: T
authors: Hamasaki
authors: Takashi
authors: T
authors: Asahara
authors: Koji
authors: K
authors: Nomoto
authors: Masami
authors: M
authors: Morotomi
authors: Yasuyuki
authors: Y
authors: Kuwagata
authors: Takeshi
authors: T
authors: Shimazu
mesh_terms: D018806:APACHE; D016470:Bacteremia / Q000453:epidemiology; D016638:Critical Illness; D005243:Feces / Q000737:chemistry* / Q000382:microbiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015994:Incidence; D007362:Intensive Care Units; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis