Five years' experience of combination therapy: peritoneal dialysis with hemodialysis

The fundamental objective of dialysis is to maintain the dose of solute clearance and ultrafiltration (UF). When peritoneal dialysis (PD) patients cannot maintain the target dose of clearance [weekly Kt/V > 2.0, weekly creatinine clearance (CCr) > 60 L/1.73 m2], the dialysis dose needs to be increased. But the means of increasing the dose only by PD are limited, especially for patients with UF failure (UFF). Combination therapy--PD with hemodialysis (PD + HD)--is the simplest way to solve the problem. The purpose of PD + HD therapy is to support solute clearance and UF when PD alone cannot meet the necessary targets. Acute and transient dialysis cases should be excluded. The general prescription for PD + HD should be 5-6 days of PD weekly and 1 session of HD weekly. For determine the adequacy of PD + HD, we adopted the equivalent renal clearance (EKR), transforming the PD weekly Kt/V and then evaluating total clearance from both modalities. Of our 238 dialysis patients, 31 (13%) use combined therapy. Except for 1 patient that transferred from long-term HD, all of patients had been on PD for more than 60 months, and were experiencing uremic symptoms after decline of residual renal function. In 12 cases, the problem was lack of solute clearance; in 5 cases, it was UFF. High permeability was involved in 5 cases: 4 after long-term PD and 1 from the start of PD. Poor self-management occurred in 9 cases. Contributing factors included hernia, diaphragmatic intercourse, and severe heart failure with strict fluid control. Among the 31 patients, 8 used HD twice weekly. After combination therapy was started, the dialysis dose increased and body fluids became controllable. As a result, uremic symptoms improved and the patients' quality of life increased.