title: A novel approach to monitor tissue perfusion: bladder mucosal PCO2, PO2, and pHi during ischemia and reperfusion.
abstract: OBJECTIVE
  The purpose of this study is to determine if monitoring urinary bladder PCO2, PO2, and calculated intramucosal pH would be a reliable index of tissue perfusion.
  
  
  METHODS
  This nonrandomized controlled study was conducted in a laboratory at a university medical center. Eight immature female Yorkshire pigs were studied with T-9 aortic cross-clamping for 30 minutes followed by a 60-minute period of reperfusion. Cystotomy was performed for placement of a Foley catheter and Paratrend 7 O2/CO2 sensor.
  
  
  RESULTS
  Baseline hemodynamic and metabolic measurements were obtained along with measurements of bladder mucosal PO2 and PCO2 (mean+/-SEM). Blood flow measured with microspheres confirmed absence of blood flow during occlusion and hyperemia during reperfusion. Bladder mucosal PO2 decreased from 42+/-14.0 mm Hg (5.6 kPa) to 1.3+/-1.3 mm Hg (1.4 kPa) during the 30-minute interval of ischemia. This was followed by an increase of bladder PO2 to greater than baseline values at the end of the reperfusion period. Bladder mucosal Pco2 increased from 57+/-4.7 mm Hg (7.6 kPa) to 117+/-7.1 mm Hg (15.6 kPa) (P < .05) during ischemia. During reperfusion the Pco2 returned to baseline levels (55+/-4.0 mm Hg [7.3 kPa]). Calculated bladder mucosal pHi declined from 7.31+/-0.04 to 7.08+/-0.05 (P < .05) during the ischemic period and after reperfusion pHi was 7.17+/-0.03.
  
  
  CONCLUSIONS
  Monitoring urinary bladder PO2, PCO2, or calculating pHi may provide a simple and reliable means of monitoring tissue perfusion.
authors.affiliation: Department of Anesthesiology, University of Alabama at Birmingham, 35233-6810, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Lang
authors.forename: D J
authors.initials: DJ
authors.lastname: Evans
authors.forename: L P
authors.initials: LP
authors.lastname: deFigueiredo
authors.forename: S
authors.initials: S
authors.lastname: Hays
authors.forename: M
authors.initials: M
authors.lastname: Mathru
authors.forename: G C
authors.initials: GC
authors.lastname: Kramer
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000032:analysis*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007511:Ischemia / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D008991:Monitoring, Physiologic / Q000379:methods*; D009092:Mucous Membrane / Q000098:blood supply / Q000378:metabolism; D010100:Oxygen / Q000032:analysis*; D015427:Reperfusion Injury / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D015203:Reproducibility of Results; D013552:Swine; D001743:Urinary Bladder / Q000098:blood supply* / Q000378:metabolism*
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen