title: Hemostasis changes during veno-venous extracorporeal membrane oxygenation for respiratory support in adults.
abstract: BACKGROUND
  We investigated the coagulation system in patients during extracorporeal membrane oxygenation (ECMO) initiated for respiratory failure and the influence of the ECMO circuit on coagulation tests; we compared different coagulation tests for monitoring unfractionated heparin (UH) therapy; we investigated whether or not coagulation parameters were predictive of bleeding during ECMO.
  
  
  METHODS
  Pilot study on twelve consecutive adult patients admitted at our general ICU for acute respiratory failure and placed on ECMO from November 2011 to October 2012. Coagulation tests were performed before ECMO start and daily, including day of circuit change and day of circuit removal. UH was monitored with activated partial thromboplastin time (APTT) ratio, at a therapeutic range of 1.5-2.0.
  
  
  RESULTS
  We observed no effect of ECMO circuit on coagulation parameters measured pre- and postlung, but platelet count decreased significantly over time (-82x10(3)/mmc, 95%CI 40-123). APTT showed a correlation with antifactor Xa activity, whereas other global coagulation tests such as activated clotting time, thromboelastography and endogenous thrombin potential did not. Major bleeding occurred in three patients but no difference in any coagulation parameter was observed between them and those who did not bleed.
  
  
  CONCLUSIONS
  This pilot study shows that ECMO initiated for respiratory support in adults does not change coagulation parameters. Over time a statistically significant reduction of platelet count was observed, possibly due to consumption within the circuit, consumption microangiopathy or the underlying patients' diseases. Although APTT was appropriate to monitor UH, major bleedings occurred and a lower therapeutic range may be advisable.
authors.affiliation: Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Ospedale Maggiore Policlinico, Milan, Italy - mauro.panigada@outlook.com.
authors.forename: Mauro
authors.initials: M
authors.lastname: Panigada
authors.forename: Andrea
authors.initials: A
authors.lastname: Artoni
authors.forename: Serena M
authors.initials: SM
authors.lastname: Passamonti
authors.forename: Alberto
authors.initials: A
authors.lastname: Maino
authors.forename: Cristina
authors.initials: C
authors.lastname: Mietto
authors.forename: Camilla
authors.initials: C
authors.lastname: L'Acqua
authors.forename: Massimo
authors.initials: M
authors.lastname: Cressoni
authors.forename: Massimo
authors.initials: M
authors.lastname: Boscolo
authors.forename: Armando
authors.initials: A
authors.lastname: Tripodi
authors.forename: Paolo
authors.initials: P
authors.lastname: Bucciarelli
authors.forename: Luciano
authors.initials: L
authors.lastname: Gattinoni
authors.forename: Ida
authors.initials: I
authors.lastname: Martinelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants; D001777:Blood Coagulation; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006487:Hemostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000628:therapy; D012131:Respiratory Insufficiency / Q000097:blood / Q000628:therapy
chemical_list: D000925:Anticoagulants