title: Vascular Occlusion Test to Dynamically Assess Microcirculation During Normothermic Pulsatile Cardiopulmonary Bypass.
abstract: OBJECTIVE
  To evaluate parameters of the vascular occlusion test (VOT) before, during, and after pulsatile cardiopulmonary bypass (CPB).
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Single-center university hospital.
  
  
  METHODS
  Adult patients undergoing elective cardiac surgery with pulsatile CPB.
  
  
  METHODS
  An oximeter sensor and adult-sized pneumatic tourniquet were positioned at the right forearm. A VOT with a predefined ischemic time of 3 minutes was performed before, during, and after CPB. Changes in tissue oxygen saturation were recorded.
  
  
  RESULTS
  Thirty-four patients who underwent cardiac surgery were enrolled in the study. The lowest tissue oxygen saturation measured during the ischemic challenge differed among all 3 stages of surgery, with median values of 62.9% before, 57.5% during, and 59.3% after perfusion (p<0.05). Both occlusion (p<0.001) and reperfusion (p<0.05) slopes were steeper after bypass compared with before initiating bypass, whereas the reperfusion time remained constant among the different time points.
  
  
  CONCLUSIONS
  The microcirculatory function as demonstrated by changes in VOT parameters was enhanced during and after normothermic pulsatile CPB. Clinical relevance, however, needs to be further explored.
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center and Cardiovascular Research Institute, Maastricht, The Netherlands. Electronic address: nousjka.vranken@mumc.nl.
authors.forename: Nousjka P A
authors.initials: NP
authors.lastname: Vranken
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center and Cardiovascular Research Institute, Maastricht, The Netherlands.
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Ganushchak
authors.affiliation: Department of Anesthesiology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Henriëtte M
authors.initials: HM
authors.lastname: Willigers
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center and Cardiovascular Research Institute, Maastricht, The Netherlands.
authors.forename: Jos G
authors.initials: JG
authors.lastname: Maessen
authors.affiliation: Department of Cardiothoracic Surgery, Maastricht University Medical Center and Cardiovascular Research Institute, Maastricht, The Netherlands.
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Weerwind
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D002315:Cardiopulmonary Bypass; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D010092:Oximetry; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology*
keywords: ischemic challenge; microcirculation; pulsatile cardiopulmonary bypass; vascular occlusion test