title: Adverse effects of postoperative infusion of shed mediastinal blood.
abstract: BACKGROUND
  Postoperative infusion of shed mediastinal blood has been used in an effort to decrease blood usage after cardiac operations. Recent experience has suggested that this practice may actually lead to a delayed increase in bleeding.
  
  
  METHODS
  In a prospective, randomized study, 40 patients undergoing coronary artery bypass grafting with shed mediastinal blood collected in a cardiotomy reservoir were divided into two equal groups and studied during their first 4 hours in the intensive care unit. Shed mediastinal blood was directly infused in group I (n = 20), whereas in group II (n = 20), it was not. In group II, if a sufficient volume of red cells was present to allow processing (n = 5), washed red cells were infused. Variables studied before and after infusion were the amount of blood lost and infused, homologous blood transfused, complete blood count and differential, serum fibrinogen, fibrin split products, D-dimers, clotting factors, prothrombin time, activated partial thromboplastin time, thromboelastograms, plasma-free hemoglobin, complement factors C3 and C4, creatine kinase and its MB isoenzyme, and body temperature.
  
  
  RESULTS
  After infusion of shed mediastinal blood, elevated levels of fibrin split products and D-dimers were found in significantly more patients in group I. The thromboelastogram index was normal in 76% of patients in group II but in only 12.5% in group I. Group I also had an increase in band neutrophils, a greater number of febrile patients, higher serum levels of creatine kinase, its MB isoenzyme, and plasma-free hemoglobin, and greater blood loss during hours 3, 4, and 5 in the intensive care unit. The volume of red cells in shed mediastinal blood (hematocrit, 9% to 10%) was small, resulting in clinically insignificant autotransfusion when infused directly, and insufficient for cell processing in most patients.
  
  
  CONCLUSIONS
  These data support those in previous studies that direct infusion of shed mediastinal blood does not save substantial amounts of autologous red cells and can cause a delayed coagulopathy and other adverse effects that may be harmful to patients postoperatively.
authors.affiliation: Department of Surgery, Anesthesiology, University of Texas Medical Branch, Galveston 77555-0528, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Vertrees
authors.forename: V R
authors.initials: VR
authors.lastname: Conti
authors.forename: S D
authors.initials: SD
authors.lastname: Lick
authors.forename: J B
authors.initials: JB
authors.lastname: Zwischenberger
authors.forename: L B
authors.initials: LB
authors.lastname: McDaniel
authors.forename: G
authors.initials: G
authors.lastname: Shulman
mesh_terms: D000328:Adult; D000368:Aged; D001778:Blood Coagulation Disorders / Q000097:blood / Q000209:etiology; D001780:Blood Coagulation Tests; D001804:Blood Transfusion, Autologous / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D005260:Female; D005334:Fever / Q000209:etiology; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D008297:Male; D008482:Mediastinum; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D013916:Thrombelastography
chemical_list: D005338:Fibrin Fibrinogen Degradation Products