title: Impact of Incremental Perfusion Loss on Oxygen Transport in a Capillary Network Mathematical Model.
abstract: OBJECTIVE
  To quantify how incremental capillary PL, such as that seen in experimental models of sepsis, affects tissue oxygenation using a computation model of oxygen transport.
  
  
  METHODS
  A computational model was applied to capillary networks with dimensions 84 × 168 × 342 (NI) and 70 × 157 × 268 (NII) μm, reconstructed in vivo from rat skeletal muscle. FCD loss was applied incrementally up to ~40% and combined with high tissue oxygen consumption to simulate severe sepsis.
  
  
  RESULTS
  A loss of ~40% FCD loss decreased median tissue PO2 to 22.9 and 20.1 mmHg in NI and NII compared to 28.1 and 27.5 mmHg under resting conditions. Increasing RBC SR to baseline levels returned tissue PO2 to within 5% of baseline. HC combined with a 40% FCD loss, resulted in tissue anoxia in both network volumes and median tissue PO2 of 11.5 and 8.9 mmHg in NI and NII respectively; median tissue PO2 was recovered to baseline levels by increasing total SR 3-4 fold.
  
  
  CONCLUSIONS
  These results suggest a substantial increase in total SR is required in order to compensate for impaired oxygen delivery as a result of loss of capillary perfusion and increased oxygen consumption during sepsis.
authors: Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
authors: Graham M
authors: GM
authors: Fraser
authors: Department of Anesthesia and Perioperative Medicine, Critical Care Western, London Health Sciences Center, University of Western Ontario, London, Ontario, Canada.
authors: Michael D
authors: MD
authors: Sharpe
authors: Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
authors: Daniel
authors: D
authors: Goldman
authors: Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
authors: Christopher G
authors: CG
authors: Ellis
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002196:Capillaries / Q000378:metabolism*; D003198:Computer Simulation; D008955:Models, Cardiovascular; D010100:Oxygen / Q000378:metabolism*; D051381:Rats
chemical_list: D010100:Oxygen
keywords: blood flow; functional capillary density; oxygen delivery; oxygen transport; sepsis