Can renal replacement be deferred by a supplemented very low protein diet?

Patients with chronic renal failure are commonly started on renal replaceme nt therapy (RRT) as soon as (or, in some centers, before) the usual criteri a for severity are met, i.e., GFR <10 ml/min for nondiabetic patients and < 15 ml/min for diabetic patients. To determine whether RRT can safely be def erred beyond this point, adults with all types of chronic renal failure who met these criteria on presentation (23 patients) or who reached these leve ls of severity during treatment (53 patients) were managed conservatively u ntil RRT was judged necessary by their chosen dialysis or transplantation t eam, without input into this decision from the present authors. Patients we re prescribed a very low protein diet (0.3 g/kg) plus supplemental essentia l amino acids and/or ketoacids and followed closely. The intervals between the time at which GFR became less than 10 ml/min (15 ml/min in diabetic pat ients) and the date at which renal replacement therapy was started were use d as estimates of renal survival on nutritional therapy. Kaplan-Meier analy sis showed median renal survival of 353 d. Acidosis and hypercholesterolemi a were both predictive of shorter renal survival. Signs of malnutrition did not develop. Final GFR averaged 5.6 +/- 1.9 ml/min. Two patients died; thu s, annual mortality was only 2.5%. Hospitalizations totaled 19 in 93 patien t-years of treatment, or 0.2 per year. Thus, these well motivated patients with GFR <10 ml/min (<15 ml/min in diabetic patients) were safely managed b y diet and close follow-up for a median of nearly 1 yr without dialysis. It is concluded that further study of this approach is indicated.