Experimental determination of urea kinetics parameters during hemodialysis

Three methods to estimate urea distribution volume and generation rate from blood samples taken during hemodialysis are compared. Two techniques are based on an analytic solution of a double-pool urea kinetics model using seven samples (reference method) or three samples (new clinical method). The third one is based on urea mass-balance and is largely used in clinical practice. The results obtained from hemodialysis sessions show that the urea generation rate is accurately estimated by both methods. The total distribution volume is still accurately estimated by the new clinical method while it is systematically underestimated by the urea mass-balance. Finally, the new method also provides reliable estimates for the dialyzer clearance