The passage of a hemodialysis filter affects hemorheology, red cell shape, and platelet aggregation.

We investigated the influence of the passage of a hemodialysis filter on red blood cells (RBCs), platelets, and hemorheological parameters. After one hour of hemodialysis, blood was drawn from 15 patients immediately ahead and behind the dialysis filter. RBCs were fixed for morphological analysis. Blood viscosity was measured with a Couette viscometer (LS-30, Contraves), RBC aggregation with a Myrenne aggregometer, platelet aggregation in flowing whole blood and in platelet rich plasma. The passage of the hemodialysis filter increased the hematocrit from 34.0 ± 3.8 to 44.6 ± 8.7% (p < 0.01). Discocytes decreased from 73 ± 9 to 60 ± 15%, while echinocytes/knizocytes were more abundant 24 ± 9% and 38 ± 15%, respectively, p < 0.01). Blood viscosity increased from 3.77 ± 0.52 to 6.75 ± 2.21 mPa.s (p < 0.01). The RBC aggregation index decreased from 25.8 ± 5.0 to 20.9 ± 5.6 (p < 0.05). These changes were less pronounced when the blood flow rate was reduced from 350 to 100 ml/min. Platelet aggregation was slightly increased in flowing whole blood, but decreased in platelet rich plasma. At the end of hemodialysis, a small increase in abnormally shaped RBCs, hematocrit, and whole blood viscosity persisted; platelet aggregation in flowing whole blood was reduced in all patients. We conclude that the passage of a hemodialysis filter induced RBC shape changes, increased the hematocrit, whole blood and plasma viscosity, decreased RBC aggregation, and affected platelet aggregation.

Aliskiren-associated acute renal failure with hyperkalemia.

We report the first case of acute renal failure with hyperkalemia associated with the recently marketed direct renin inhibitor aliskiren. To optimize blood pressure control, the antihypertensive medication of a 76-year-old hypertensive female patient was changed from the angiotensin II receptor antagonist irbesartan to aliskiren. Spironolactone was continued, as serum creatinine and potassium levels were initially normal. Two weeks later the patient presented with acute oliguric renal failure, symptomatic hyperkalemia and metabolic acidosis, necessitating emergency dialytic treatment. Unrecognized pre-existing renal insufficiency (CKD Stage 2 - 3) and the continuation of spironolactone were identified as predisposing risk factors.

How important is malnutrition? A prospective study in internal medicine.

BACKGROUND/OBJECTIVE: Data about the prevalence of malnutrition on hospital admission vary and follow-up data are scarce. We assessed the nutritional status of unselected patients on admission and discharge. SUBJECTS/METHODS: A total of 430 consecutively admitted patients were assessed and 168 patients hospitalized > or =6 days were reassessed on discharge. Assessment was carried out by the Mini Nutritional Assessment (MNA), weight and anthropometric measurements, bioelectrical impedance analysis, biochemical markers and a subjective clinical assessment by the physicians in charge. RESULTS: On admission, 47% of all patients were overweight (body mass index, BMI >25 kg m(-2)) and 8% underweight (BMI<18.5 kg m(-2)). In terms of the MNA 70% were adequately nourished, 20% were at risk for malnutrition and 10% were malnourished. By clinical judgment alone 18 (4.3%) malnourished patients according to MNA were missed. The 44 malnourished patients according to the MNA had significantly lower values for BMI, fat-free mass, fat mass, waist circumference, triceps skinfold thickness, hemoglobin, albumin, prealbumin, total cholesterol but higher values for C-reactive protein. Of the 168 patients staying > or =6 days in hospital, 57% lost and 39% gained weight. Only 1.9% of all patients (8 of 430) were malnourished and lost further weight during hospitalization. CONCLUSIONS: We found a low prevalence (10%) of malnourished patients on admission. Clinical judgment and to some extent anthropometrical measurement were helpful for assessing the nutritional status, laboratory values were not.