Table 3.

Criteria for progression from twice-weekly to thrice-weekly HD*

Residual kidney function criteria €

1. Kidney urea clearance <2.5 mL/min/1.73 m2 #

2. Urine volume <500 mL/24 h #, despite optimized diuretic regimen

Clearance criteria by blood tests

3. Pre-HD serum K ≥5.8 mEq/L #, with or without EKG changes of hyperkalemia, despite treatment with oral K binder

4. Pre-HD serum Na ≤125 mEq/L #

5. Pre-HD serum bicarbonate level ≤17 mEq/L #, despite optimized treatment with oral sodium bicarbonate

6. Unable to attain spKt/V ≥1.20 #

7. Unable to attain total stdKt/V (kidney stdKt/V + dialysis stdKt/V) ≥2.10 #

Volume management criteria

8. Inter-dialytic weight gain ≥ 4% of target weight # , despite optimized diuretic regimen

9. Ultrafiltration rate ≥13 mL/kg/h #, despite optimized diuretic regimen

10. Post-HD residual weight ≥5% of target weight #, despite optimized diuretic regimen

11. Uncontrolled heart failure, which, in the opinion of the treating nephrologist, warrants more frequent HD

12. Uncontrolled hypertension, which, in the opinion of the treating nephrologist, warrants more frequent HD

Other clinical criteria

13. EKG abnormalities which, in the opinion of the treating nephrologist, are due to electrolyte and/or acid-base disequilibrium and require more frequent HD

14. Clinical event that requires ≥1 unplanned HD treatment for its resolution, believed to be related to twice-weekly HD

15. Clinical condition, which, in the opinion of the treating nephrologist, warrants more frequent HD

16. Non-adherence to timed urine collection for ≥2 consecutive occasions when timed urine collection was recommended by the treating providers and/or Site Investigators

17. Intravenous antibiotic administration required thrice-weekly with HD ¥

18. New condition rendering the patient with inability to perform timed urine collection (e.g., stroke, urinary incontinence)

EKG Electrocardiogram, HD Hemodialysis, spKt/V Single pool Kt/V, stdKt/V Standard Kt/V

Information accompanying superscript characters is found in the Additional file 2