title: Subcutaneous gas tensions closely track ileal mucosal gas tensions in a model of endotoxaemia without anaerobism.
abstract: OBJECTIVE
  Few comparative data exist on the responses of the subcutaneous and splanchnic circulations to evolving endotoxic shock. We therefore compared continuous subcutaneous pO(2) (pO(2sc)) and pCO(2) (pCO(2sc)) with simultaneous continuous gut luminal pCO(2) (pCO(2gi)) in an animal model of endotoxaemia and examined whether changes in gas tensions track tissue energy charge (EC).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Fourteen anaesthetized rats, 7 controls and 7 experimental.
  
  
  METHODS
  Controls were injected with saline, the experimental group with 20 mg/kg Klebsiella endotoxin. pCO(2sc), pO(2sc), and pCO(2gi) were measured continuously. Plasma lactate concentrations were measured at defined periods during the study. After 2 h ileal segments were snap frozen and assayed for tissue EC.
  
  
  RESULTS
  Endotoxaemia resulted in a significant decrease in mean arterial blood pressure (132+/-9 to 71+/-20 mmHg) and pO(2sc) (71+/-23 to 33+/-22 torr) and a significant increase in pCO(2gi) (58+/-10 to 90+/-20 torr) and pCO(2sc) (56+/-6 to 81+/-25 torr). During endotoxaemia pCO(2gi) was directly correlated with pCO(2sc) (R (2)=0.5) and inversely correlated with pO(2sc) (R (2)=0.63). Plasma lactate concentrations were significantly elevated from baseline in the endotoxin limb. The mean EC was not significantly different in the two groups.
  
  
  CONCLUSIONS
  Both subcutaneous tissue gas tensions and intestinal luminal carbon dioxide tensions are rapidly responsive during evolving hypodynamic endotoxic shock. Alterations in tissue gas tensions were not associated with dysoxia.
authors.affiliation: Department of Intensive Care, University of Queensland, Princess Alexandra Hospital, Woolloongabba and Wesley Hospital, Australia. bala_venkatesh@health.qld.gov.au
authors.forename: Bala
authors.initials: B
authors.lastname: Venkatesh
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Morgan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hall
authors.forename: Zolton
authors.initials: Z
authors.lastname: Endre
authors.forename: Desley
authors.initials: D
authors.lastname: Willgoss
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000378:metabolism; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000378:metabolism / Q000503:physiopathology*; D045823:Ileus / Q000503:physiopathology*; D007413:Intestinal Mucosa / Q000378:metabolism / Q000503:physiopathology*; D007710:Klebsiella Infections / Q000378:metabolism / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010100:Oxygen / Q000378:metabolism; D010313:Partial Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D040521:Subcutaneous Tissue / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D002245:Carbon Dioxide; D019344:Lactic Acid; D010100:Oxygen