title: Point-of-care assessment of microvascular blood flow in critically ill patients.
abstract: OBJECTIVE
  Sublingual microvascular videomicroscopy can assess tissue perfusion in critically ill patients; however, data analysis is currently limited to delayed off-line evaluation. We hypothesized that a real-time point-of-care (POC) determination of the microcirculatory flow index (MFI), an established metric for assessing microcirculatory perfusion, agrees well with the conventional off-line analysis.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Urban academic intensive care unit.
  
  
  METHODS
  A heterogeneous population of critically ill patients.
  
  
  RESULTS
  A single operator performed side stream darkfield videomicroscopy of the sublingual microcirculation and made a POC determination of MFI in real-time on a portable bedside monitor by assigning a score (0 = no flow to 3 = normal) to each quadrant of the image and averaging the four values. After image processing, de-identification and randomization, the same operator, blinded to the previous interpretation, repeated the MFI assessment by viewing an AVI-formatted image sequence on a 94 cm 1,080 pixel LCD monitor (reference standard). There were 205 paired measurements in 18 subjects. The POC and reference standard MFI had good agreement by Bland-Altman analysis [mean difference of -0.031, SD = 0.198 (95% CI, -0.43 to 0.37)]. The POC assessment was 94% sensitive and 92% specific for detecting impaired microvascular flow (defined a priori as an MFI < 2.5 based on previously published data).
  
  
  CONCLUSIONS
  A POC determination of MFI had good agreement with conventional off-line analysis, and was highly sensitive and specific for detecting impaired microvascular flow. This real-time technique may be useful in future clinical trials targeting impaired microcirculatory perfusion in critically ill patients.
authors: Department of Emergency Medicine, UMDNJ-Robert Wood Johnson Medical School at Camden, Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA. arnold-ryan@cooperhealth.edu
authors: Ryan C
authors: RC
authors: Arnold
authors: Joseph E
authors: JE
authors: Parrillo
authors: R
authors: R
authors: Phillip Dellinger
authors: Michael E
authors: ME
authors: Chansky
authors: Nathan I
authors: NI
authors: Shapiro
authors: David J
authors: DJ
authors: Lundy
authors: Stephen
authors: S
authors: Trzeciak
authors: Steven M
authors: SM
authors: Hollenberg
mesh_terms: D016638:Critical Illness; D006801:Humans; D008833:Microcirculation; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply*; D019095:Point-of-Care Systems; D011446:Prospective Studies; D012039:Regional Blood Flow