ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on Twitter

Kidney Week

Abstract: TH-PO358

Comparison Between Online Clearance Monitoring (OCM) and Calculated kt/V in Adult Population on Hemodialysis

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Saleem, Sidra, DHMC, Lahore, Pakistan
  • Naveed, Haris, DHMC, Lahore, Pakistan
  • Mahmood, Asad, DHMC, Lahore, Pakistan
  • Rasool, Zain, DHMC, Lahore, Pakistan
  • Mansur, Abeera, DHMC, Lahore, Pakistan

Morbidity and mortality in hemodialysis patients is closely correlated to the delivered dialysis dose. The delivered dose is measured in maintenance hemodialysis patients either by blood samples to calculate Kt/V single pool or by measuring the ionic dialysance in real time using OCM. The aim of this study was to compare the quality of dialysis delivered by calculated kt/V obtained with the formula of lowrie(L) and Daugridas(D) with the results measured by Online Clearance Monitoring(OCM).


Using Fresenius 4008S machines equipped with OCM, we prospectively studied 42 hemodialysis patients from February 1, 2018 to April 30, 2018. All patients were on hemodialysis for more than three months. Pre and post dialysis urea samples were collected for estimation of Single pool Kt/V and compared with OCM. Patient information was collected and all data analysed using SPSS for windows software package.


The average age of the patients was 56.07 ±13.89 years and the mean duration of dialysis was 28.34 ±34.95 months. Mean blood flow rate was 307.67 ±45.87 mL/min. The mean Kt/V was 1.499 ±0.222 (p=0.000) and the mean OCM was 1.465 ±0.190 (p=0.000). We found a positive correlation between the two parameters i.e a Pearson’s Correlation: 0.83 (p=0.000) and an R square value of 0.645.We found that OCM is a good indicator of Kt/V. However, it underestimated Kt/V by 2.07%±8.53%.


Online Kt/V calculated by ionic dialysance is a useful method to estimate dialysis dose without the need of blood samples, however it slightly underestimates Kt/V. In clinical practice Kt/V is done on a monthly basis. Any change in the dialysis prescription would entail repeat labs. OCM can be performed at each dialysis session at no extra cost and in real time. Thus, it can prove to be a helpful tool in the assessment of dialysis adequacy.