. Author manuscript; available in PMC: 2022 Feb 4.

Published in final edited form as: Nephron. 2021 Feb 4;145(2):91–98. doi: 10.1159/000512846

Table 1.

Calculation of Total Effluent Fluid Rate according to CRRT Modality

CVVH: Total Ultrafiltration (UF) Rate (ml/hr) + Fluid Removal Rate (ml/hr)

■ Example: CVVH: 1400 ml/hr + 200 ml/hr
Effluent flow rate= 22.8 ml/kg/hr

CVVHD: Dialysate Rate (ml/hr) + Fluid Removal Rate (ml/hr)

■ Example: CVVHD: 1000 ml/hr + 200 ml/hr.
Effluent flow rate= 17.1 ml/kg/hr

CVVHDF: Total UF Rate (ml/hr) + Dialysate Rate (ml/hr) + Fluid Removal Rate (ml/hr)

■ Example: CVVHDF: 1400 ml/hr + 800 ml/hr + 200 ml/hr
Effluent flow rate= 34.2 ml/kg/hr

Dilution factor for Predilution: Plasma flow rate (ml/hr)/ [Plasma Flow Rate (ml/hr) + Pre-Filter Replacement Fluid Rate (ml/hr)]

Total Ultrafiltration (UF) Rate (ml/hr) = Pre-Filter Replacement Fluid Rate (ml/hr) + Post-Filter Replacement Fluid Rate (ml/hr)
Plasma Flow Rate (ml/hr) = Blood Flow Rate (ml/min) x 60 (min/hr) x (1-HCT); where HCT is the current hematocrit of the patient.

Example: Weight 70 kg, HCT= 30%, Blood Flow Rate= 150 ml/min, Pre-Filter Replacement= 1000 ml/hr, Post-Filter Replacement= 400 ml/hr, Dialysate rate 800 ml/hr, Fluid Removal Rate= 200 ml/hr