title: Assessment of microcirculatory changes by use of sidestream dark field microscopy during hemorrhagic shock in dogs.
abstract: OBJECTIVE
  To directly assess microcirculatory changes associated with induced hemorrhagic shock by use of sidestream dark field microscopy (SDM) and correlate those values with concurrently measured macrovascular and blood gas variables in healthy anesthetized dogs.
  
  
  METHODS
  12 adult dogs.
  
  
  METHODS
  Dogs were anesthetized and splenectomized. Instrumentation and catheterization were performed for determination of macrohemodynamic and blood gas variables. Hemorrhagic shock was induced via controlled hemorrhage to a mean arterial blood pressure (MAP) of 40 mm Hg. Dogs were maintained in the shock state (MAP, 35 to 45 mm Hg) for 60 minutes. An SDM device was used to image microcirculation of buccal mucosa, and vascular analysis software was used to determine microcirculatory variables. These values were compared with other cardiovascular and blood gas variables to determine correlations.
  
  
  RESULTS
  Following hemorrhage, there was a significant decrease in microvascular variables (mean ± SD), including proportion of perfused vessels (82.77 ± 8.32% vs 57.21 ± 28.83%), perfused vessel density (14.86 ± 2.64 mm/m(2) vs 6.66 ± 4.75 mm/m(2)), and microvascular flow index (2.54 ± 0.52 vs 1.59 ± 0.85). Perfused vessel density individually correlated well with macrovascular variables, with heart rate (zero order, partial correlation, and part correlation coefficients = -0.762, -0.884, and -0.793, respectively) and oxygen extraction ratio (-0.734, -0.832, and -0.746, respectively) being the most important predictors.
  
  
  CONCLUSIONS
  SDM allowed real-time imaging of the microvasculature and has potential as an effective tool in experimental and clinical applications for monitoring microcirculatory changes associated with hemorrhagic shock and resuscitation in dogs.
authors: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA. peruski.1@osu.edu
authors: Ann M
authors: AM
authors: Peruski
authors: Edward S
authors: ES
authors: Cooper
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D004285:Dogs / Q000033:anatomy & histology*; D006339:Heart Rate; D008297:Male; D008833:Microcirculation; D008853:Microscopy / Q000379:methods*; D009061:Mouth Mucosa / Q000098:blood supply* / Q000503:physiopathology; D012771:Shock, Hemorrhagic / Q000503:physiopathology / Q000662:veterinary*