title: Red blood cell transfusion compared with gelatin solution and no infusion after cardiac surgery: effect on microvascular perfusion, vascular density, hemoglobin, and oxygen saturation.
abstract: BACKGROUND
  After cardiac surgery, red blood cell (RBC) transfusion may improve systemic hemodynamics and thereby microvascular blood flow and O2 delivery (DO2).
  
  
  METHODS
  In a nonrandomized prospective observational study on post-cardiac surgery patients, systemic hemodynamics and microvascular blood flow, vascular density (sidestream dark-field imaging), hemoglobin (Hb) content, and saturation (reflectance spectrophotometry) were measured before and 1 hour after start of transfusion of 1 to 2 units of leukoreduced RBCs (270±203 mL), 500 mL of gelatin solution, or control (no infusion), when patients were considered clinically hypovolemic with (RBC group, n=12) or without (gelatin group, n=14) anemia (Hb<10 g/dL) or not (n=13), respectively.
  
  
  RESULTS
  Systemic Hb was lower and increased in the RBC transfusion but not in gelatin and control groups. There were no differences in changes in systemic DO2, O2 uptake, and extraction between groups. RBC transfusion, compared with gelatin or control, increased medium-sized vascular density, Hb content, and saturation in the microcirculation, while blood flow remained unchanged. Changes of microvascular Hb and saturation paralleled changes in systemic Hb.
  
  
  CONCLUSIONS
  The data argue in favor of efficacy of RBC transfusion after cardiac surgery. RBC transfusion increases systemic Hb and this in turn increases medium-sized vascular density and DO2 in the sublingual microcirculation, independently of systemic hemodynamics and volume status.
authors: Department of Intensive Care, Free University Medical Center, Amsterdam, The Netherlands.
authors: Bektaş
authors: B
authors: Atasever
authors: Marjolein
authors: M
authors: van der Kuil
authors: Christa
authors: C
authors: Boer
authors: Alexander
authors: A
authors: Vonk
authors: Lothar
authors: L
authors: Schwarte
authors: Armand R J
authors: AR
authors: Girbes
authors: Can
authors: C
authors: Ince
authors: Albertus
authors: A
authors: Beishuizen
authors: A B Johan
authors: AB
authors: Groeneveld
mesh_terms: D000368:Aged; D001810:Blood Volume / Q000502:physiology; D006348:Cardiac Surgical Procedures; D015897:Comorbidity; D003422:Critical Care / Q000379:methods; D017707:Erythrocyte Transfusion; D005260:Female; D005780:Gelatin / Q000008:administration & dosage*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D020896:Hypovolemia / Q000097:blood* / Q000453:epidemiology / Q000628:therapy*; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009060:Mouth Floor / Q000098:blood supply; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control; D011446:Prospective Studies
chemical_list: D006454:Hemoglobins; D005780:Gelatin; D010100:Oxygen