DefinePK

Abstract

Objective: To determine if urea kinetic modelling (Kt/V) by online clearance monitoring (OCM) could be used as an alternative to Kt/V calculated using Daugirdas equation.
Study Design: Cross-sectional study
Place and Duration of Study: Dialysis Unit, Combined Military Hospital Peshawar, Pakistan, Nov 2019 to Feb 2020.
Methodology: Outdoor patients on maintenance thrice-weekly hemodialysis were selected using non-probability convenience sampling. Body weight was measured and serum urea levels were checked before and after each haemodialysis session. Kt/V- Daugirdas was calculated using Calculate by QxMD android application. Kt/V online clearance monitoring was determined using the built-in online clearance monitoring module of Fresenius F4008 haemodialysis machines.
Results: Amongst 47 patients aged 55.47±13.66 years, 34(72.34%) were males. Patients were assessed during 63 hemodialysis sessions. Kt/V was 1.21±0.24 and 1.44±0.46 by online clearance monitoring and Daugirdas formula respectively (p<0.001). There was a positive correlation between the two (r=0.373, p=0.003). In 24(38.10%) sessions, both Kt/V online clearance monitoring and Kt/V Daugirdas targets of 1.2 (minimum) were achieved. Kt/V Daugirdas target was achieved more frequently than Kt/V online clearance monitoring (66.67% vs 46.03%; p=0.012). Kt/V Daugirdas targets were better attained amongst patients with arteriovenous fistula as compared to those tunneled dialysis catheters (74.00 vs 38.46%; p=0.015). This was not true for Kt/V online clearance monitoring targets (p=0.992).
Conclusion: Online clearance monitoring is non-invasive and can reliably be used to screen for hemodialysis adequacy even though it slightly underestimates Kt/V as compared to the Daugirdas formula.