title: Increased ileal-mucosal-arterial PCO2 gap is associated with impaired villus microcirculation in endotoxic pigs.
abstract: OBJECTIVE
  To investigate whether an increased ileal-mucosal-arterial PCO2 gap (delta PCO2) during hyperdynamic porcine endotoxemia is associated with impaired villus microcirculation.
  
  
  METHODS
  Prospective, randomized, controlled, experimental study.
  
  
  METHODS
  Animal research laboratory.
  
  
  METHODS
  Twenty-two domestic pigs.
  
  
  METHODS
  After baseline measurements, anesthetized and ventilated pigs received continuous i.v. endotoxin (ETX, n = 12) for 24 h or placebo (SHAM, n = 10).
  
  
  RESULTS
  Before, as well as 12 and 24 h after, the start of endotoxin or saline portal venous blood flow (QPV, ultrasound flow probe) and lactate/pyruvate ratios (L/P), the ileal-mucosal-arterial delta PCO2 (fiberoptic sensor) and bowel-wall capillary hemoglobin O2 saturation (%Hb-O2-cap, remission spectrophotometry) were assessed together with intravital video records of the ileal-mucosal microcirculation (number of perfused/heterogeneously perfused/unperfused villi) using orthogonal polarization spectral imaging (CYTOSCAN A/R) via an ileostomy. At 12 and 24 h endotoxin infusion, about half of the evaluated villi were heterogeneously or unperfused which was paralleled by a progressive significant increase of the ileal-mucosal-arterial delta PCO2 and portal venous L/P ratios, whereas QPV as well as both the mean %Hb-O2-cap and the %Hb-O2-cap frequency distributions remained unchanged. By contrast, in the SHAM-group, mucosal microcirculation was well-preserved, and none of the other parameters were influenced.
  
  
  CONCLUSIONS
  We conclude that an increased ileal-mucosal-arterial delta PCO2 during porcine endotoxemia is related to impaired villus microcirculation. A putative contribution of disturbed cellular oxygen utilization resulting from "cytopathic hypoxia" may also assume importance.
authors.affiliation: Sektion Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinik für Anästhesiologie, Parkstrasse 11, 89075, Ulm, Germany.
authors.forename: I F
authors.initials: IF
authors.lastname: Tugtekin
authors.forename: P
authors.initials: P
authors.lastname: Radermacher
authors.forename: M
authors.initials: M
authors.lastname: Theisen
authors.forename: M
authors.initials: M
authors.lastname: Matejovic
authors.forename: A
authors.initials: A
authors.lastname: Stehr
authors.forename: F
authors.initials: F
authors.lastname: Ploner
authors.forename: K
authors.initials: K
authors.lastname: Matura
authors.forename: C
authors.initials: C
authors.lastname: Ince
authors.forename: M
authors.initials: M
authors.lastname: Georgieff
authors.forename: K
authors.initials: K
authors.lastname: Träger
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000097:blood* / Q000503:physiopathology*; D004927:Escherichia coli Infections / Q000097:blood* / Q000503:physiopathology*; D005260:Female; D007082:Ileum / Q000098:blood supply* / Q000503:physiopathology*; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008638:Mesenteric Arteries / Q000503:physiopathology*; D008833:Microcirculation / Q000503:physiopathology; D008859:Microscopy, Polarization; D011169:Portal Vein / Q000503:physiopathology; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000097:blood; D013053:Spectrophotometry; D013552:Swine
chemical_list: D002245:Carbon Dioxide; D019344:Lactic Acid; D019289:Pyruvic Acid