Should the knowledge gained from the Frequent Hemodialysis Network (FHN) trials change dialysis practice?

This review summarizes findings of the recently published Frequent Hemodialysis Network (FHN) Daily and Nocturnal trials, and speculates about potential mechanisms causing differences in the results and implications for changes in clinical practice.

The FHN Daily and the Nocturnal trial differed in time of day, location and length of treatment, and also in degree of residual renal function as exclusion criterion.The two coprimary outcomes were a composite of mortality and change in left ventricular mass and physical component score of the Research and Development (RAND) Short Form (SF)-36, which both improved significantly in the Daily trial, but not in the Nocturnal trial. Secondary outcomes, such as interdialytic weight gain, blood pressure and predialysis serum phosphorus improved significantly in both trials. The results of the Daily trial were comparable to those in the literature describing improvements by salt restriction and volume control. Reasons for the lack of significance in the results of the Nocturnal trial are under intensive investigation at this point.

Salt restriction, improved volume control, and better phosphate control might prove to be important for better treatment of patients on hemodialysis. Additional analyses will provide further insight and implications for clinical practice.