title: Experience of Circuit Survival in Extracorporeal Continuous Renal Replacement Therapy Using Small-Calibre Venous Cannulae.
abstract: To describe an experience of circuit survival in extracorporeal continuous renal replacement therapy using small-calibre (< 7 French gauge [F]) venous cannulae.
  
  
  
  An observational study.
  
  
  
  A multidisciplinary, university-affiliated PICU.
  
  
  
  Case note review of all continuous renal replacement therapy episodes (1998-2010), which used vascular access cannulae of an external diameter less than 7F, was performed.
  
  
  
  Forty-nine patients underwent continuous renal replacement therapy treatment during which circuit blood flow was delivered using either 5F or 6.5F double-lumen cannulae. One hundred thirty-nine circuits were employed (median per patient, 2; interquartile range, 1-3) in providing 4,903 hours of therapy (median duration of therapy, 43 hr; interquartile range, 22-86 hr); allowing for censoring, the median circuit survival time was 40 hours (95% CI, 28-66). Eighty-one circuits (58%) failed because of clotting/technical problems, equating to a circuit failure rate of 16.5 (95% CI, 13.3-20.5) per 1,000 hours of continuous renal replacement therapy. The probability of a circuit surviving 40 hours or greater was 50% with 43% (95% CI, 34-53%) expected to survive 60 hours or more. No significant relationship between circuit survival and the calibre of the cannula deployed was identified; however, placement of venous access in an internal jugular vein was associated with improved circuit survival.
  
  
  
  Contrary to previous reports, vascular access cannulae of a caliber less than 7F can support sufficiently prolonged continuous renal replacement therapy to make them a useful means of delivering renal support in neonates and small infants.
authors.affiliation: 1Paediatric Intensive care Unit, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom. 2Paediatric Intensive Care Unit, Birmingham Children's Hospital, Birmingham, United Kingdom. 3Department of Paediatric Critical Care Medicine, Dalhousie University, Halifax, Nova Scotia, Canada. 4Division of Epidemiology and Biostatistics, School of Medicine, University of Leeds, Leeds, United Kingdom.
authors.forename: Claire
authors.initials: C
authors.lastname: Westrope
authors.forename: Kevin Paul
authors.initials: KP
authors.lastname: Morris
authors.forename: Chor Yek
authors.initials: CY
authors.lastname: Kee
authors.forename: Margaret
authors.initials: M
authors.lastname: Farley
authors.forename: Sarah
authors.initials: S
authors.lastname: Fleming
authors.forename: Gavin
authors.initials: G
authors.lastname: Morrison
mesh_terms: D016638:Critical Illness; D004868:Equipment Failure / Q000706:statistics & numerical data; D005112:Extracorporeal Circulation / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D053208:Kaplan-Meier Estimate; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D017582:Renal Replacement Therapy / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome; D062666:Vascular Access Devices