Background. Available evidence suggests a reduced mortality risk for patients treated with high-volume postdilution hemodiafiltration (HDF) when compared with hemodialysis (HD) patients. As the magnitude of the convection volume depends on treatment-related factors rather than patient-related characteristics, we prospectively investigated whether a high convection volume (defined as ≥22 L/session) is feasible in the majority of patients (>75%). Methods. A multicenter study was performed in adult prevalent dialysis patients. Nonparticipating eligible patients formed the control group. Using a stepwise protocol, treatment time (up to 4 hours), blood flow rate (up to 400 mL/min) and filtration fraction (up to 33%) were optimized as much as possible. The convection volume was determined at the end of this optimization phase and at 4 and 8 weeks thereafter. Results. Baseline characteristics were comparable in participants (n = 86) and controls (n = 58). At the end of the optimization and 8 weeks thereafter, 71/86 (83%) and 66/83 (80%) of the patients achieved high-volume HDF (mean 25.5 ± 3.6 and 26.0 ± 3.4 L/session, respectively). While treatment time remained unaltered, mean blood flow rate increased by 27% and filtration fraction increased by 23%. Patients with <22 L/session had a higher percentage of central venous catheters (CVCs), a shorter treatment time and lower blood flow rate when compared with patients with ≥22 L/session. Conclusions. High-volume HDF is feasible in a clear majority of dialysis patients. Since none of the patients agreed to increase treatment time, these findings indicate that high-volume HDF is feasible just by increasing blood flow rate and filtration fraction.

Prescribing a HP diet resulted in a modest increase in actual protein intake, but increasing dialysis dose did not have a contributing effect. A HP diet or increasing the dialysis dose did not have a favourable effect on the nutritional status. A dietary protein intake of at least 0.9 g/kg IBW/day appears to be sufficient for adequately dialysed haemodialysis patients without overt malnutrition.

During online hemodiafiltration, patients are directly infused with sterile substitution solutions to maintain fluid balance. Adequate water treatment and a well-organized quality control process are essential to provide non-pyrogenic fluids with consistent optimal quality. We sought to assess water quality, the water treatment system, and the methods for surveillance of microbiological water quality in 10 Dutch dialysis centers that routinely treat patients with hemodiafiltration. Microbiological monitoring results (micro-organisms and endotoxins) were collected over a 1-year period representing 11,258 hemodiafiltration sessions covering 97 patients. In all centers, water purification was based on a reverse osmosis module in combination with a second reverse osmosis and/or an electrodeionizer. All centers regularly and routinely monitored the microbiological purity of the dialysis water with adequate analytical methods but with variable monitoring frequency. Microbiological assessments were compliant with reference quality levels in 3923 of 3961 samples. Our study suggests that non-pyrogenic substitution fluids can be produced online for a prolonged period of time. It is likely that the current Dutch Quality of Care Guideline has contributed to high-quality water treatment and a well-organized control process.

A 45-year-old man with end-stage renal disease due to polycystic kidney disease was admitted to the hospital because of recurrent abdominal pain, progressive peripheral motor neuron neuropathy, and respiratory failure. The diagnosis of acute intermittent porphyria was confirmed by an elevated porphyrin concentration in the urine and the presence of an R167Q mutation in the porphobilinogen deaminase gene. Use of hydroxyzine, weight loss, and/or a mild upper respiratory viral infection might have been the provoking factor of the acute intermittent porphyria. Treatment with intravenous hemin (3 mg/kg) and a high-carbohydrate diet (3000 kcal/d) had no clinical effect. Tetraplegia and chronic respiratory insufficiency developed, and the patient needed a pacemaker because of a symptomatic sinus bradycardia due to autonomic dysfunction. The patient died 10 months after the first manifestation of acute intermittent porphyria.