Infrequent Dialysis: A Different Strategy to Incremental Dialysis.

To the Editor:

With regard to your recent publication,1, 2 I should like to highlight the nosological and methodological differences between “incremental hemodialysis” and “infrequent hemodialysis.” Indeed, infrequent dialysis embraces the full range of therapeutic options implemented with a schedule of less than thrice-weekly hemodialysis sessions, ideally integrated by a moderately low-protein diet. Incremental dialysis4, 5 is a strict program implemented following assessment of uremic status in a predialysis outpatient setting through a synergic nephrological and nutritional approach aimed at achieving an excellent nutritional status and preserving diuresis with a glomerular filtration rate (GFR) ranging between 5 and 10 ml/min per 1.73 m2.

Total weekly GFR should be calculated on the basis not only of urea clearance, but also taking into account the mean of urea/creatinine clearance. An incremental dialysis program may then be set up with the assistance of a skilled logistics team in charge of monitoring patient compliance and ensuring smooth running of the program. Initially, the Combined Diet Dialysis Program comprising once-weekly dialysis associated with a low-protein diet (0.6 g protein/kg per day) and administration of essential amino acids is implemented. On dialysis days, the patient is requested to consume a meal with approximately 1.4 g protein/kg per day per 1.73 m2. The Combined Diet Dialysis Program represents a dialytic "bridge" of variable duration aimed at ensuring good metabolic state and promoting quality of life. Dialysis dose is established in line with the outcome of GFR in a proportionally inverse manner. Recent studies4, 7 have demonstrated a lower mortality for incremental dialysis than thrice-weekly dialysis, and, thanks to the contribution of phosphaturia, a neutral balance of input/output phosphoric pool compared with thrice-weekly hemodialysis patients who lose residual renal function early. Reduced contact with proinflammatory/pro-oxidative stimuli secondary to hemodialysis may enhance preservation of GFR. Residual renal function has long been underestimated in spite of the exceptional efficacy displayed in purifying protein-bound uremic toxins compared with other forms of dialysis10, 11; indeed, residual renal function may contribute toward establishing a phosphoric balance resulting in a reduction of cardiovascular damage and direct phosphatic lesions of the renal parenchyma. Infrequent dialysis is indicated for use in patients maintaining a GFR <3 ml/min per 1.73 m2, particularly smaller patients. With regard to both methods, however, the additional time spent on clinical assessment will be recouped using the Combined Diet Dialysis Program due to a two-thirds reduction in hemodialysis costs equivalent to an annual saving per patient of more than $22,000.