title: Effect of an acute increase in PCO2 on splanchnic perfusion and metabolism.
abstract: OBJECTIVE
  To evaluate the acute effects of an increase in PCO2 on splanchnic tissue perfusion and metabolism.
  
  
  METHODS
  Clinical prospective study in the intensive care unit in a university clinic.
  
  
  METHODS
  Six patients with severe acute lung injury requiring mechanical ventilation. All patients had bilateral infiltrates on chest radiography, a PaO2/FIO2 ratio less than 200 mmHg, and stable hemodynamics without vasoactive drugs.
  
  
  METHODS
  PCO2 was increased 5-20% by an added dead space from baseline, followed by a return to baseline.
  
  
  RESULTS
  Splanchnic blood flow was measured using primed continuous infusion of indocyanine green dye with hepatic venous sampling and systemic hemodynamics by routine monitoring; we also determined the gastric mucosal-arterial PCO2 difference and splanchnic lactate/pyruvate exchange. PCO2 was increased by an added dead space; after 60 min all measurements were repeated; after return to baseline a third measurement followed. The increase in PCO2 had no significant effect on splanchnic blood flow or indices of perfusion and metabolism.
  
  
  CONCLUSIONS
  Our results suggest that acute moderate changes in PCO2 have no major effect on splanchnic perfusion and metabolism.
authors.affiliation: Department of Anesthesiology, University Clinic Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany. peter.kiefer@medizin.uni-ulm.de
authors.forename: P
authors.initials: P
authors.lastname: Kiefer
authors.forename: S
authors.initials: S
authors.lastname: Nunes
authors.forename: P
authors.initials: P
authors.lastname: Kosonen
authors.forename: J
authors.initials: J
authors.lastname: Takala
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000097:blood*; D007208:Indocyanine Green; D007362:Intensive Care Units; D008099:Liver / Q000378:metabolism; D008102:Liver Circulation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000097:blood*; D013152:Splanchnic Circulation / Q000502:physiology*
chemical_list: D002245:Carbon Dioxide; D007208:Indocyanine Green