title: Survival time of ECMO circuits on and off bleeding protocol: is there a higher risk of circuit clotting?
abstract: OBJECTIVE
  Bleeding is a dreaded complication of extracorporeal membrane oxygenation (ECMO). At our institution, we use a bleeding protocol (BP) with or without ε-amino caproic acid (ACA) for certain prophylactic or therapeutic indications. Subjectively, we have felt that placing a child on bleeding protocol shortens the circuit life because of clot formation. In this study, we evaluated the impact of BP with and without ACA on the survival time of the ECMO circuit.
  
  
  METHODS
  A retrospective analysis of all ECMO patients treated in our institution from 2000 to 2008 was performed. An event was defined as a change of the ECMO circuit for thrombosis. The times until occurrence of an event were noted for children off (standard) or on bleeding protocol (BP) and ACA (BP+ACA). Survival curves were generated for each of these study groups and compared using the log rank test.
  
  
  RESULTS
  A total of 164 patients were treated with ECMO during the study period. 32 events were noted in the standard, 20 in the BP, and 25 in the BP+ACA group. Mean survival time of the circuit was 10.5 ± 3.8 days for the standard, 8.6 ± 3.4 days for the BP, and 9.9 ± 4.6 days for BP+ACA protocols. The corresponding Kaplan-Meier survival curves are shown. The log rank test showed no significant differences between groups (standard vs. BP p=0.12; standard vs. BP+ACA p=0.92).
  
  
  CONCLUSIONS
  We found no evidence that instituting a bleeding protocol with or without aminocaproic acid shortens circuit times. Clotting of the ECMO unit should not be a major concern when placing a patient on a bleeding protocol.
authors.affiliation: Children's Hospital of Alabama, University of Alabama at Birmingham, Pediatric Surgery, Birmingham, AL 35233, USA. oliver.muensterer@chsys.org
authors.forename: O J
authors.initials: OJ
authors.lastname: Muensterer
authors.forename: D
authors.initials: D
authors.lastname: Laney
authors.forename: K E
authors.initials: KE
authors.lastname: Georgeson
mesh_terms: D000614:Aminocaproates / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects*; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects*; D005260:Female; D006470:Hemorrhage / Q000209:etiology* / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors
chemical_list: D000614:Aminocaproates