Prediction of reduction in predialysis concentrations due to interdialysis weight gain.

There is little quantitative information about the influence of weight change before and during hemodialysis on the concentration of proteins, lipoproteins, lipids, enzymes and other dialysis-resistant compounds in blood. We studied the concentration of 12 such compounds before and at the end of high-flux hemodialyses, 1.5 h after the start and 1, 2 and 3 h postdialysis and have developed formulae for roughly predicting the near steady-state 2-3 h postdialysis concentration. For hemoglobin, albumin, total protein and total cholesterol, the relationship of mean change in concentration to weight loss in groups was linear, and the % increase in concentration correlation correlated with % weight reduction (r = 0.64-0.81 and p = 0.002-0.0002). Correlations with ultrafiltration rate were comparable. By 3 h postdialysis values were relatively stable; the average fall in concentration for theses 4 compounds was 25% from end dialysis. The simplest formula we found which roughly predicts the % increase in concentration from predialysis to 3 h postdialysis is to multiply the % loss in body weight in kg during dialysis by 3.3. More accurate formulae were developed using combined and specific regression equations relating % weight loss during dialysis to % concentration rise. Mean values for alkaline phosphatase, triglycerides, lipoprotein (a), high-density lipoprotein cholesterol, calcium, apolipoprotein B, bilirubin and aspartate aminotransferase also rose appreciably during dialysis with significant increases for the first five. With major interdialytic weight gain, the reduction in predialysis concentrations of hemoglobin and cholesterol may be enough to inappropriately modify treatment decisions about anemia (e.g. erythropoietin) or hypercholesterolemia, and to cause false concern about the concentration of albumin for nutrition and prognosis. Major weight gain may also contribute to concentration changes in numerous other compounds resistant to dialysis.

In search of sterile, endotoxin-free dialysate.

Sterile dialysate, free of endotoxin (ET) and other cytokine inducing factors, will probably become a future standard. High-flux dialysis with bicarbonate and reuse has the membrane, the pressures, and bacteriologic potential for ET fragments to pass from dialysate to the blood side of the membrane with activation of monocytes and production of cytokines. Ultrafiltration through polysulfone filters has been shown to remove bacteria, ET, and its fragments and other cytotoxic inducing factors. The authors found that in spite of sterile, ET-free, reverse osmosis (RO) water, ET was usually present at the dialyzer inlet and arose from the RO storage tank water with bacteria < 30 CFU/ml, in spite of repeated disinfection. The authors now remove bacteria, ET, and fragments from RO tank water with a 5 mu cellulose filter followed by ultrafiltration with a Fresenius F-80 polysulfone dialyzer inserted between the wall RO delivery port and each delivery system. At the dialyzer inlet, monthly bacterial counts were < 30 cfu/ml, and ET values (n = 38) were not detectable in 89% and < 0.5 EU/ml in 11%. The F-80 filters were used for 180+ dialyses along with the 5 mu filters, which replaced the frequently endotoxin contaminated 10 mu filters in the Monitral-S delivery systems. The costs did not increase.

Staphylococcal epidermidis infection of a hemodialysis button-graft complex controlled by vancomycin for 11 months.

A 54 year old woman had a Bentley DiaTAP button implanted in her thigh for hemodialysis access. She had been started on continuous ambulatory peritoneal dialysis (CAPD) because of intractable vascular access problems. Unfortunately, CAPD had to be discontinued because of fungal peritonitis. Transplantation had not been possible because of circulating cytotoxic antibodies. The prosthetic complex soon became infected with Staphylococcus epidermidis and blood cultures were intermittently positive for 11 months. However, with continuing vancomycin therapy she remained in her usual state of health, without side effects from vancomycin, until venous thrombosis resolved and it became possible to remove the infected prosthetic complex and implant a button in an arm. As a last resort, it may be possible to maintain a patient on dialysis in reasonable health with a DiaTAP button graft complex infected with Staphylococcus epidermidis and intermittent positive blood cultures using long term vancomycin therapy. Such management probably would not be appropriate for any other organism.

Acute renal failure in an infant with congenital neuroblastoma - successful treatment by hemodialysis.

Acute renal failure developed in an infant aged 30 days during chemotherapy and irradiation for hepatic neuroblastoma (IV-S). Acute hemodialysis via a profunda femoris - long saphenous vein shunt was accomplished on 9 occasions in this 4 kg infant. The complications of septicemia and acute respiratory embarrassment caused by hepatomegaly were treated by appropriate antibiotic treatment, creation of a temporary ventral hernia and assisted ventilation. Careful attention to correct pediatric hemodialysis technique, as described, can permit long-term survival if the underlying disorder is also amenable to treatment.