Features and indications of various methods of continuous renal replacement therapy

During the 4 years from 1980 to 1983, 24 cases (15 males and 9 females, age 60 days to 82 years, or 61.4 years on average) received continuous renal replacement therapy at our center. The methods of therapy included non-machinery dialysis (NMD) and continuous hemodialysis (CHD), both continuous hemodialysis processes, continuous hemofiltration (CHF), and continuous ultrafiltration (CUF) with the primary intention of removing the water content by CHF without using replacement fluid. These methods of continuous renal replacement therapy were used either alone or in combination, and hemodialysis, either NMD or CHD, was performed in 17 of the 24 cases (71%). The CHD system, developed by the authors by using already existing equipment, is capable of interchanging CHD and CUF as desired. At a blood flow rate of 100ml/min and a dialysate flow rate of 50ml/min, the clearance of low molecular substances during CHD was 47.4±4.55ml/min for urea, 50.4±3.22ml/min for creatinine, and 47.4±4.50ml/min for uric acid. With the dialysate flow rate increased to 100ml/min, these values were increased to 72.3±2.65, 68.4±2.60, and 63.3±2.05ml/min, respectively. Bicarbonate dialysate was used and the composition remained stable and unchanged even 24 hours after preparation. In continuous renal replacement therapy, hemodialysis is better than hemofiltration, as the capability of removing low molecular substances is excellent and regulation of large volumes of ultrafiltrate and transfusion fluid is not necessary. Additionally, by combining CHD and CUF, it is possible to treat cases of renal failure with cardiovascular instability safely and easily.