Online convective therapies: results from a hemofiltration trial.

With the introduction of the on-line preparation of dialysis fluids, the hemofiltration technique, which has never had a widespread diffusion in its old version with the infusion bags, has gained a new interest. We planned a prospective, randomized, 3-year-long study comparing survival and morbidity in ultrapure bicarbonate dialysis (BD) with on-line predilution hemofiltration (HF). Since comorbidity is one of the main factors limiting survival, the study was addressed to patients with a severe degree of comorbidity. The paper presents the preliminary results of the trial. Sixty-four patients were enrolled and randomized to either BD (N = 32) or HF (N = 32). Mean age and dialysis vintage were comparable. Twenty patients died during the study, 12 in BD and 8 in HF. The relative risk of death was 11% higher in patients treated with BD compared to those in the HF group (p < 0.005). The number of hospitalisation events per single patient was lower, even though not significantly, in HF compared to BD (1.94 + 1.26 in HF vs 2.48 + 1.98 in BD, p = NS). As concerns biochemistry, apart from beta-2-microglobulin, any other substantial difference was not found during the study, though the small solute concentration was generally a little more elevated in HF than in BD. Dialysis hypotension showed a trend to decrease in both the dialysis modalities up to near half of the trial, then, during the last year, it remained quite stable in HF, while, on the contrary, it increased in the BD group. By the end of the protocol, patients in HF showed a 2.5% incidence of acute dialysis hypotension, while patients in BD had 23%.

Acute bilateral renal vein thrombosis superimposed on calcified thrombus of the inferior vena cava in a patient with membranous lupus nephritis.

We report a case of membranous lupus nephritis with a previous history of long-standing nephrotic syndrome which developed an acute renal failure due to bilateral renal-vein thrombosis superimposed on a calcified thrombus of the inferior vena cava eight years after the diagnosis. The occurrence of acute renal-vein thrombosis is a possible but rarely described complication of systemic lupus erythematosus. The presence of a calcified thrombus of the inferior vena cava has been described in only one adult patient until now. An aggressive thrombolytic therapy with urokinase permitted the fresh thrombus to be dissolved with a marked improvement in renal function.

Hypertension in end-stage renal failure: role of sympathetic nervous system, sodium balance and renal pressor system.

120 subjects, including 16 normal volunteers, 23 essential hypertensive and 81 uraemic patients (34 before the start of haemodialysis and 47 during maintenance haemodialysis) were studied in order to evaluate the interrelationship between mean arterial pressure (MAP) and total exchangeable sodium (NaE), plasma renin activity (PRA) and plasma catecholamines (PC). Significant positive correlations were noted between MAP and PRA and between MAP and PC in the total group of uraemic patients. In patients under conservative treatment MAP correlated significantly with NaE and PRA. Multiple regression analysis demonstrated that the combined effect of NaE and PRA accounted for 50 per cent of the levels of MAP. In patients undergoing chronic haemodialysis MAP lost any correlation with NaE. In these patients the presence of hypertension seemed to be related to the values of PRA and PC. PC increased after two hours of walking and hypertensive patients had higher increments than normotensive patients. These data might support an important role for the adrenergic system in the maintenance of hypertension in dialysis patients.

Plasma renin activity in essential hypertension (a critical approach to its significance).

A study of the frequency distribution of plasma renin activity (PRA) in 123 patients with essential hypertension (EH) produced no evidence of a distinct subpopulation with low renin levels, whether the samples were taken from supine or upright patients. Applying an arbitrary classification criterion, however, low PRA levels were found in 30.1% of patients. There were no significant differences in mean blood pressure, 24-h sodium excretion, and age when groups with low, normal or high PRA levels were compared. The incidence of PRA hyporesponsiveness was similar in the three groups of patients, but increased with age. In the female there was apreponderance of low PRA levels. It is concluded that EH with low PRA levels is not a separate diagnostic entity and, when PRA is low in a hypertensive subject, the possible effects of age, blood pressure, and sex ought to be taken into account before other causes of low PRA are postulated.