title: Automated electronic monitoring of circuit pressures during continuous renal replacement therapy: a technical report.
abstract: BACKGROUND
  Automated electronic monitoring and analysis of circuit pressures during continuous renal replacement therapy (CRRT) has the potential to predict failure and allow intervention to optimise function.
  
  
  METHODS
  Current CRRT machines can measure and store pressure readings for downloading into databases and for analysis. We developed a procedure to obtain such data at intervals of 1 minute and analyse them using the Prismaflex CRRT machine, and we present an example of such analysis.
  
  
  RESULTS
  We obtained data on pressures obtained at intervals of 1 minute in a patient with acute kidney injury and sepsis treated with continuous haemofiltration at 2 L/hour of ultrafiltration and a blood flow of 200 mL/minute. Data analysis identified progressive increases in transmembrane pressure (TMP) and prefilter pressure (PFP) from time 0 until 33 hours or clotting. TMP increased from 104 mmHg to 313 mmHg and PFP increased from from 131 mmHg to 185 mmHg. Effluent pressure showed a progressive increase in the negative pressure applied to achieve ultrafiltration from 0 mmHg to -168 mmHg. The inflection point for such changes was also identified. Blood pathway pressures for access and return remained unchanged throughout.
  
  
  CONCLUSIONS
  Automated electronic monitoring of circuit pressure during CRRT is possible and provides useful information on the evolution of circuit clotting.
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia. ian.baldwin@austin.org.au.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Baldwin
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia.
authors.forename: Guijun
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia.
authors.forename: Aiko
authors.initials: A
authors.lastname: Tanaka
authors.affiliation: Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
mesh_terms: D001331:Automation; D019992:Databases as Topic; D004582:Electronics, Medical; D004868:Equipment Failure; D006801:Humans; D011312:Pressure; D017582:Renal Replacement Therapy