Building and validation of a prognostic model for predicting extracorporeal circuit clotting in patients with continuous renal replacement therapy

Int Urol Nephrol. 2014 Apr;46(4):801-7. doi: 10.1007/s11255-014-0682-5. Epub 2014 Mar 18.


Purpose: To develop a predictive model for circuit clotting in patients with continuous renal replacement therapy (CRRT).

Methods: A total of 425 cases were selected. 302 cases were used to develop a predictive model of extracorporeal circuit life span during CRRT without citrate anticoagulation in 24 h, and 123 cases were used to validate the model. The prediction formula was developed using multivariate Cox proportional-hazards regression analysis, from which a risk score was assigned.

Results: The mean survival time of the circuit was 15.0 ± 1.3 h, and the rate of circuit clotting was 66.6 % during 24 h of CRRT. Five significant variables were assigned a predicting score according to the regression coefficient: insufficient blood flow, no anticoagulation, hematocrit ≥0.37, lactic acid of arterial blood gas analysis ≤3 mmol/L and APTT < 44.2 s. The Hosmer-Lemeshow test showed no significant difference between the predicted and actual circuit clotting (R (2) = 0.232; P = 0.301).

Conclusions: A risk score that includes the five above-mentioned variables can be used to predict the likelihood of extracorporeal circuit clotting in patients undergoing CRRT.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Anticoagulants / administration & dosage
  • Area Under Curve
  • Blood Coagulation*
  • Blood Gas Analysis
  • Catheter Obstruction / etiology
  • Equipment Failure*
  • Extracorporeal Circulation*
  • Hematocrit
  • Humans
  • Lactic Acid / blood
  • Models, Theoretical*
  • Predictive Value of Tests
  • ROC Curve
  • Renal Replacement Therapy / instrumentation
  • Renal Replacement Therapy / methods*
  • Risk Adjustment
  • Time Factors


  • Anticoagulants
  • Lactic Acid