title: Effectiveness of laser Doppler perfusion monitoring in the assessment of microvascular function in patients undergoing on-pump coronary artery bypass grafting.
abstract: OBJECTIVE
  To evaluate the effectiveness of single-point laser Doppler perfusion monitoring (LDPM) in the assessment of microvascular reactivity in the skin during cardiopulmonary bypass (CPB).
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Government-affiliated teaching hospital.
  
  
  METHODS
  Twenty male patients aged 60 ± 2 years who underwent coronary artery bypass grafting under CPB.
  
  
  METHODS
  The authors assessed the endothelium-dependent vasodilation of the skin microcirculation at the forehead and forearm using LDPM coupled with thermal hyperemia. This measurement was performed before and after the induction of anesthesia, during and after CPB, and 24 h after the end of the surgical procedure.
  
  
  RESULTS
  The basal values of microvascular flow before the induction of anesthesia were significantly higher in the skin of the forehead compared with that of the forearm. There were no significant alterations in microvascular reactivity throughout the recording periods for both recording sites, as assessed by the vasodilation range expressed as cutaneous vascular conductance (arbitrary perfusion units/mean arterial pressure).
  
  
  CONCLUSIONS
  Using LDPM, the authors showed that the microcirculatory bed of the skin of the forehead, which is readily accessible during cardiac surgery, is a suitable model for the study of microvascular reactivity and tissue perfusion in cardiovascular surgical procedures using CPB. This technique could, thus, be suitable for evaluating the effects of drugs or technical procedures on tissue perfusion during cardiac surgery under cardiopulmonary bypass.
authors.affiliation: National Institute of Cardiology, Ministry of Health.
authors.forename: Maria A M
authors.initials: MA
authors.lastname: Salgado
authors.affiliation: National Institute of Cardiology, Ministry of Health.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Salgado-Filho
authors.affiliation: National Institute of Cardiology, Ministry of Health.
authors.forename: José O
authors.initials: JO
authors.lastname: Reis-Brito
authors.affiliation: Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Lessa
authors.affiliation: National Institute of Cardiology, Ministry of Health; Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil. Electronic address: etibi@ioc.fiocruz.br.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tibirica
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D001026:Coronary Artery Bypass / Q000379:methods; D003430:Cross-Sectional Studies; D005542:Forearm / Q000098:blood supply; D005546:Forehead / Q000098:blood supply; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods / Q000706:statistics & numerical data*; D016896:Treatment Outcome
keywords: cardiopulmonary bypass; laser Doppler; perfusion monitoring; skin microvascular reactivity