Adequacy of CPD: comparing Kt/V and creatinine clearance

Presently, adequate dialysis in continuous peritoneal dialysis (CPD) patients is assessed by monitoring urea kinetics (Kt/V) or by measuring the total creatinine clearance (CC). Target Dialysis Outcome Quality Initiative (DOQI) goals are a weekly Kt/V of at least 2.0, and a CC of at least 60 L/wk per 1.73 m2. One hundred and four CPD patients in the New Haven continuous ambulatory peritoneal dialysis (CAPD) unit had their most recent Kt/V and CC reviewed. Of these patients, 58.7% attained the DOQI goals for Kt/V and CC, 14.4% had an acceptable Kt/V but low CC, 11.5% had an acceptable CC but low Kt/V, and 15.4% had both low Kt/V and low CC. A CC > 60 L/week per 1.73 m2 was associated with a residual renal function of > 25 L/wk per 1.73 m2. For a Kt/V of > 2.0, good residual renal function was helpful but not essential. A question left unanswered is whether patients with a low Kt/V and an adequate CC or low CC and acceptable Kt/V need more dialysis.