Circulating rather than adherent PMN are responsible for intra-dialyzer degranulation during haemodialysis: J.C. Bos, M.P.C. Grooteman, A.J. van Houte, M. Schoorl, M.J. Nubé. Departments of Haemodialysis and Immuno-haematology, Medical Centre, Alkmaar, Netherlands

Abstract

A continuous dialysis technique such as continuous arteriovenous hemodialysis (CAVHD) could be an interesting alternative to frequent intermittent hemodialysis to treat acute renal failure (ARF) secondary to tumor lysis syndrome (TLS). However, because of massive release of intracellular solutes in TLS, CAVHD clearances need to be increased to treat this syndrome. Continuous arteriovenous hemodialysis using a high dialysate flow rate at 4 L/hr was assessed in TLS and ARF associated with severe hyperphosphatemia. A 0.6-m2 hollow-fiber polyacrylonitrile dialyzer (Multiflow 60; Hospal, St-Léonard, Québec, Canada) was used. Blood urea nitrogen and serum creatinine levels decreased, respectively, from 102.5 to 27.2 mg/dL and from 3.1 to 1.8 mg/dL during the 36 hours of treatment. Serum urate concentration was normal at the beginning of treatment (4.5 mg/dL) and decreased to 2.1 mg/dl by the end of CAVHD. Serum phosphorus decreased from 16.7 to 4.4 mg/dL after the 36 hours of treatment. The calcium × phosphorus product decreased from 111.1 to 42.1 by 28 hours and remained under 50 thereafter. Serum potassium was easily controlled with the addition of 2.5 mEq/L of KCI in dialysate and replacement solutions. No rebound increases in phosphorus or potassium were noted after cessation of therapy. Continuous arteriovenous hemodialysis clearances of urea, creatinine, phosphorus, and urate were measured at 2-hour intervals for the first 24 hours and at 4-hour intervals for the remaining 12 hours. They were 53.0 ± 2.3 mL/min, 43.7 ± 2.2 mL/min, 40.4 ± 1.9 mL/min, and 39.3 ± 1.9 mL/min (n =15), respectively. The 24-hour CAVHD clearance of urea was 76 L, which is equivalent to 8.5 hours of conventional hemodialysis. Extraction of phosphorus and potassium with CAVHD was, respectively, 8.28 g and 188.5 mEq for 36 hours. In conclusion, CAVHD optimized by high dialysate flow rate becomes a powerful purifying technique for the treatment of ARF and TLS. It provides excellent continuous clearances of small molecular weight solutes, resulting in a rapid and sustained control of serum urate, potassium, and calcium × phosphorus product, avoiding the potentially deleterious rebound effects seen after hemodialysis.