title: Near-infrared spectroscopy to assess microvascular dysfunction: A prospective pilot study in cardiac surgery patients.
abstract: OBJECTIVE
  The diagnosis of microvascular dysfunction remains challenging after cardiac surgery. We hypothesized that peripheral near-infrared spectroscopy (NIRS) monitoring in combination with a vascular occlusion test could reliably assess postoperative microvascular dysfunction in that setting.
  
  
  METHODS
  Twenty-two patients undergoing cardiac surgery with cardiopulmonary bypass and 10 healthy volunteers were prospectively investigated. Relevant NIRS parameters (regional tissue oxygen saturation, desaturation, and resaturation rates) were recorded the day before surgery (D-1), at the arrival in the intensive care unit (postoperative day [POD] 0) and on POD 1 and POD 2.
  
  
  RESULTS
  No difference in NIRS parameters was found at baseline between healthy volunteers and cardiac surgical patients. Absolute values of regional tissue oxygen saturation significantly increased at POD 0 and POD 1 when compared with D-1: 78% (75%-81%) and 75% (73%-78%) vs 68% (64%-72%), P < .001. No statistical difference was evidenced within the postoperative period in desaturation and resaturation rates compared with D-1: desaturation rate, 0.11% · s(-1) (0.08-0.14) and 0.15% · s(-1) (0.08-0.22) vs 0.14% · s(-1) (0.10-0.17), P = .233, and resaturation rate, 0.76% · s(-1) (0.41-1.11) and 0.77% · s(-1) (0.53-1.02) vs 0.79% · s(-1) (0.61-0.97), P = .453. The use of postoperative norepinephrine infusion did not change the results.
  
  
  CONCLUSIONS
  Peripheral NIRS monitoring in combination with a vascular occlusion test failed to assess cardiopulmonary bypass-induced microvascular dysfunction.
authors.affiliation: Pôle Réanimations Anesthésie SAMU/SMUR, CHU de Caen, Avenue de la Côte de Nacre, Caen, France.
authors.forename: Kelly
authors.initials: K
authors.lastname: Monthé-Sagan
authors.affiliation: Pôle Réanimations Anesthésie SAMU/SMUR, CHU de Caen, Avenue de la Côte de Nacre, Caen, France.
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Fischer
authors.affiliation: Service de Chirurgie Cardiaque, CHU de Caen, Avenue de la Côte de Nacre, Caen, France.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Saplacan
authors.affiliation: Pôle Réanimations Anesthésie SAMU/SMUR, CHU de Caen, Avenue de la Côte de Nacre, Caen, France.
authors.forename: Jean-louis
authors.initials: JL
authors.lastname: Gerard
authors.affiliation: Pôle Réanimations Anesthésie SAMU/SMUR, CHU de Caen, Avenue de la Côte de Nacre, Caen, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Hanouz
authors.affiliation: Service d'Anesthésie-Réanimation, Hôpital Cardiovasculaire et Pneumologique Louis Pradel, Hospices Civils de Lyon, Lyon, France. Electronic address: jean-luc.fellahi@chu-lyon.fr.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Fellahi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D016022:Case-Control Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D010865:Pilot Projects; D011184:Postoperative Period; D011446:Prospective Studies; D012867:Skin / Q000098:blood supply*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D055815:Young Adult
keywords: Cardiac surgery; Microvascular dysfunction; NIRS monitoring; Regional tissue oxygen saturation; Vascular occlusion test