title: Sublingual microcirculation is impaired in post-cardiac arrest patients.
abstract: OBJECTIVE
  We hypothesized that microcirculatory dysfunction, similar to that seen in sepsis, occurs in post-cardiac arrest patients and that better microcirculatory flow will be associated with improved outcome. We also assessed the association between microcirculatory dysfunction and inflammatory markers in the post-cardiac arrest state.
  
  
  METHODS
  We prospectively evaluated the sublingual microcirculation in post-cardiac arrest patients, severe sepsis/septic shock patients, and healthy control patients using Sidestream Darkfield microscopy. Microcirculatory flow was assessed using the microcirculation flow index (MFI) at 6 and 24h in the cardiac arrest patients, and within 6h of emergency department admission in the sepsis and control patients.
  
  
  RESULTS
  We evaluated 30 post-cardiac arrest patients, 16 severe sepsis/septic shock patients, and 9 healthy control patients. Sublingual microcirculatory blood flow was significantly impaired in post-cardiac arrest patients at 6h (MFI 2.6 [IQR: 2-2.9]) and 24h (2.7 [IQR: 2.3-2.9]) compared to controls (3.0 [IQR: 2.9-3.0]; p<0.01 and 0.02, respectively). After adjustment for initial APACHE II score, post-cardiac arrest patients had significantly lower MFI at 6-h compared to sepsis patients (p<0.03). In the post-cardiac arrest group, patients with good neurologic outcome had better microcirculatory blood flow as compared to patients with poor neurologic outcome (2.9 [IQR: 2.4-3.0] vs. 2.6 [IQR: 1.9-2.8]; p<0.03). There was a trend toward higher median MFI at 24h in survivors vs. non-survivors (2.8 [IQR: 2.4-3.0] vs. 2.6 [IQR: 2.1-2.8] respectively; p<0.09). We found a negative correlation between MFI-6 and vascular endothelial growth factor (VEGF) (r=-0.49, p=0.038). However, after Bonferroni adjustment for multiple comparisons, this correlation was statistically non-significant.
  
  
  CONCLUSIONS
  Microcirculatory dysfunction occurs early in post-cardiac arrest patients. Better microcirculatory function at 24h may be associated with good neurologic outcome.
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States.
authors.forename: Yasser G
authors.initials: YG
authors.lastname: Omar
authors.forename: Michael
authors.initials: M
authors.lastname: Massey
authors.forename: Lars W
authors.initials: LW
authors.lastname: Andersen
authors.forename: Tyler A
authors.initials: TA
authors.lastname: Giberson
authors.forename: Katherine
authors.initials: K
authors.lastname: Berg
authors.forename: Michael N
authors.initials: MN
authors.lastname: Cocchi
authors.forename: Nathan I
authors.initials: NI
authors.lastname: Shapiro
authors.forename: Michael W
authors.initials: MW
authors.lastname: Donnino
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006323:Heart Arrest / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply*; D011446:Prospective Studies; D012772:Shock, Septic / Q000503:physiopathology; D013997:Time Factors
keywords: Microcirculation; Post-cardiac arrest