title: Bubble chamber clotting during continuous renal replacement therapy: vertical versus horizontal blood flow entry.
abstract: BACKGROUND
  The continuous renal replacement therapy (CRRT) bubble trap chamber is a frequent site of clotting.
  
  
  OBJECTIVE
  To assess clot formation when comparing our standard 'vertical' blood entry chamber (BEC) with a new 'horizontal' BEC.
  
  
  METHODS
  Adult ICU patients requiring CRRT were treated with the vertical BEC and then a similar subsequent cohort with the horizontal BEC in continuous veno-venous haemofiltration mode.
  
  
  RESULTS
  40 chambers were assessed for each design. Circuit life was 13.9 ± 9.5 h for the vertical and 17.7 ± 15.9 h for the horizontal BEC (p = 0.33). APTT, however, was higher for the horizontal BEC (55.7 ± 34.7 vs. 37.4 ± 9.0, p < 0.002) and no difference in circuit life was found after multivariable analysis. A clotting score ≥3 was observed in 85% of all chambers. There was no difference in chamber clotting score (vertical 3.6 ± 1.03 vs. horizontal 3.8 ± 1.0, p = 0.5). In addition, no difference was found when scores were divided into two groups using a 'likelihood' to clot analysis (p = 1.0).
  
  
  CONCLUSIONS
  CRRT horizontal BEC were not associated with less clotting compared to our standard vertical BEC.
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, Vic., Australia. ian.baldwin@austin.org.au
authors.forename: Ian
authors.initials: I
authors.lastname: Baldwin
authors.forename: Nigel
authors.initials: N
authors.lastname: Fealy
authors.forename: Paula
authors.initials: P
authors.lastname: Carty
authors.forename: Martin
authors.initials: M
authors.lastname: Boyle
authors.forename: Inbyung
authors.initials: I
authors.lastname: Kim
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
mesh_terms: D001777:Blood Coagulation; D006440:Hemofiltration / Q000009:adverse effects / Q000379:methods; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D011446:Prospective Studies; D017582:Renal Replacement Therapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods