title: Microvascular response to red blood cell transfusion in patients with severe sepsis.
abstract: OBJECTIVE
  Microvascular alterations may play a role in the development of multiple organ failure in severe sepsis. The effects of red blood cell transfusions on microvascular perfusion are not well defined. We investigated the effects of red blood cell transfusion on sublingual microvascular perfusion in patients with sepsis.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  A 31-bed, medical-surgical intensive care unit of a university hospital.
  
  
  METHODS
  Thirty-five patients with severe sepsis requiring red blood cell transfusions.
  
  
  METHODS
  Transfusion of one to two units of leukocyte-reduced red blood cells.
  
  
  RESULTS
  The sublingual microcirculation was assessed with an Orthogonal Polarization Spectral device before and 1 hr after red blood cell transfusion. Red blood cell transfusions increased hemoglobin concentration from 7.1 (25th-75th percentile, 6.7-7.6) to 8.1 (7.5-8.6) g/dL (p < .01), mean arterial pressure from 75 (69-89) to 82 (75-90) mm Hg (p < .01), and oxygen delivery from 349 (278-392) to 391 (273-473) mL/min.M (p < .001). Microvascular perfusion was not significantly altered by transfusion, but there was considerable interindividual variation. The change in capillary perfusion after transfusion correlated with baseline capillary perfusion (Spearman-rho = -.49; p = .003). Capillary perfusion was significantly lower at baseline in patients who increased their capillary perfusion by >8% compared with those who did not (57 [52-64] vs. 75 [70-79]; p < .01), while hemodynamic and global oxygen transport variables were similar in the two groups. Red blood cell storage time had no influence on the microvascular response to red blood cell transfusion.
  
  
  CONCLUSIONS
  The sublingual microcirculation is globally unaltered by red blood cell transfusion in septic patients; however, it can improve in patients with altered capillary perfusion at baseline.
authors.affiliation: Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Brussels, Belgium.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Sakr
authors.forename: Marialuisa
authors.initials: M
authors.lastname: Chierego
authors.forename: Michaël
authors.initials: M
authors.lastname: Piagnerelli
authors.forename: Colin
authors.initials: C
authors.lastname: Verdant
authors.forename: Marc-Jacques
authors.initials: MJ
authors.lastname: Dubois
authors.forename: Marc
authors.initials: M
authors.lastname: Koch
authors.forename: Jacques
authors.initials: J
authors.lastname: Creteur
authors.forename: Antonino
authors.initials: A
authors.lastname: Gullo
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.forename: Daniel
authors.initials: D
authors.lastname: De Backer
mesh_terms: D000368:Aged; D001793:Blood Preservation; D004907:Erythrocyte Deformability; D017707:Erythrocyte Transfusion / Q000379:methods; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply*; D011446:Prospective Studies; D018805:Sepsis / Q000628:therapy*; D013997:Time Factors