title: Human albumin in extracorporeal prime: effect on platelet function and bleeding.
abstract: OBJECTIVE
  Synthetic starches have been positioned as an equivalent substitute for human albumin in extracorporeal prime, with both providing osmotic and oncotic pressure. Another effect of albumin is its ability to coat the synthetic surfaces of an extracorporeal circuit with a biopassivating protein monolayer. Whether this protein biopassivation has any benefit to the patient, assessed by platelet count, platelet function and 24-hour bleeding rate, is considered.
  
  
  METHODS
  Patients presenting for coronary artery bypass at a Canadian tertiary care hospital were randomized into two groups until a final study size of 20 patients was obtained. The Study Group received 2.5 g of human albumin in the extracorporeal prime and the Control Group remained protein free. Both groups included Voluven 6% as a synthetic starch. Blood samples were obtained at three intervals; Pre-bypass, During bypass (30 minutes after initiation of bypass), and Post-bypass. These samples were assayed for platelet function, platelet count and hemoglobin. Chest tube drainage over a 24-hour period was monitored.
  
  
  RESULTS
  Platelet count was significantly higher in the During sample in the Study Group (196 ± 56.5 x 10(9)/ml versus 160 ± 18.5 x 10(9)/ml, p<0.05), however, this difference was no longer significant with the Post-bypass sample (135 ± 36.0 x 10(9)/mL versus 127 ± 1 9 x 10(9)/mL). Platelet function assays (PFA) showed no significant differences. Chest tube drainage after 24 hours was significantly lower in the Study Group (586 ± 131.8 ml/24 h versus 741 ± 272.5 ml/24 h, p<0.05).
  
  
  CONCLUSIONS
  Human albumin can passivate the synthetic surfaces of the extracorporeal circuit, which is supported by observations of preserved platelet count and reduced chest tube drainage. Although some statistically significant benefits were observed, the practical benefits of passivating an extracorporeal circuit with human albumin may be minimal.
authors.affiliation: 1Memorial University of Newfoundland, St. John's, NL, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Kamra
authors.forename: A
authors.initials: A
authors.lastname: Beney
mesh_terms: D000418:Albumins / Q000008:administration & dosage*; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D002315:Cardiopulmonary Bypass / Q000295:instrumentation / Q000379:methods*; D005112:Extracorporeal Circulation / Q000379:methods*; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D000418:Albumins
keywords: blood platelets; cardiopulmonary bypass; coronary artery bypass surgery; serum albumin; thoracic surgery