[Guidelines for automated manual infusion: a practical way of prescribing postdilution on-line hemodiafiltration]. / Pauta de infusión manual automatizada: una forma práctica de prescribir la hemodiafiltración on-line posdilucional.

Post-dilution on-line hemodiafiltration (OL-HDF) is the most efficient infusion mode to obtain maximum clearances of uremic toxins, with a recommended manual infusion flow (Qi) of 25% of the blood flow with the main limitation that causes alarms by hemoconcentration throughout the session. Recent technical advances allow automatic prescription of Qi if hematocrit and total protein (TP) values are specified. As these analytical results are not possible to obtain in each dialysis session, a practical way to prescribe Qi is to make an automatic prescription adjusting the hematocrit and total protein values at the beginning of the session to obtain the manual prescription required and we will call it automatic-manual prescription. The aim of this study was to compare manual Qi with automatic-manual Qi in postdilution OL-HDF. 30 patients (16 men and 14 women), 59.9 +/- 15 years old, in hemodialysis program for 50.1 +/- 67 months were included. Every patient underwent four OL-HDF sessions, two with manual Qi (4008-S and 5008 monitors) and two with automatic-manual Qi (A-M), one with the same Qi and one with manual Qi +20 (A-M+20). The same usual dialysis parameters were maintained: helixone dialyzer, dialysis time of 266 +/- 39 minutes, blood flow of 420 +/- 36. Recirculation, Kt and intradialysis alarms were measured at each session. No significant differences in the fistula recirculation or dialysis dose measured using Kt. Total infusion volume was 24.9 +/- 4 (4008 S), 23.4 +/- 4 L (5008) with manual Qi, 23.6 +/- 4 L (A-M) Qi (NS) and 25.8 +/- 5 L (A-M+20). Only 14% of patients had no incidents. The number of alarms was significantly higher with manual prescription 55 alarms with 4008 and 40 with 5008 vs. AM (11) p < 0.01) and A-M+20 (16 alarms) We concluded that automatic-manual Qi is a practical way for post-dilutional OL-HDF prescription where the same efficiency and total reinfusion volume with an important reduction of intradialysis alarms are obtained, allowing to rise Qi by 20% without increasing intradialysis alarms.

[Control of hypertension refractory to medical management by means of short daily hemodialysis]. / Control de HTA refractaria a tratamiento médico con hemodiálisis corta diaria.

Hypertension is a very frequent complication in patients in hemodialysis. A high percentage of the patients on standard hemodialysis remain hypertense in spite of intensive pharmacologic treatment. We presented the case of a hypertense patient with difficult control in spite of antihypertensive treatment with five drugs and several secondary complications. The change to a short daily hemodialysis was successful to hypertension control and allowed a gradual suspension of drugs.

[How much should dialysis time be increased when catheters are used?]. / ¿Cuánto tiempo es necesario aumentar la prescripción de hemodiálisis con la utilización de catéteres?

SUMMARY: The use of central catheters in hemodialysis patients as a permanent vascular access has increased during the last years, reaching numbers of around 7% of prevalent patients and between 25% of incident patients. Although the current catheters allow higher sanguineous flows with smaller incidence of infectious complications and dysfunction, the dose of dialysis that is reached is still inferior to that obtained with native arterio-venous fistula (AVF) and grafts. The aim of the present study was to evaluate the possible additional time supposed by dialysis using central venous catheters with respect to habitual vascular access as a consequence of the lesser blood flow (Qb) and the irregularity of its function (frequent lowering of the Qb and necessity of inverting the lines on many occasions). A total of 48 patients (31 men/17 women) with an average age of 61,6 +/- 14 years old (rank: 28-83), 20 with tunnelled catheter and the remaining with AVF, were included in the study. All the patients were dialyzed in the modality of high flux hemodialysis with a polisulphone of 1,9 m2 dialyzer, dialysis time of 240 minutes, dialysate flow 500 ml/min and monitors equipped with ionic dialysance (ID) with the objective of obtaining a Kt of 45 litres with each one of the different vascular accesses. The patients with AVF received 3 sessions, with variations of Qb to 300, 350 and 400 ml/min. The patients with tunnelled catheter received two sessions, to the maximum Qb, one with normal connection and other with inverted one. In the results obtained it is possible to emphasize that only the patients with AVF and 400 ml/min reached the objective of 45 L of Kt. The patients with AVF needed to increase 12 minutes of hemodialysis with a Qb of 350 ml/min and 28 minutes with a Qb of 300 ml/min; the catheters on normal position needed to increase 24 minutes and finally in the inverted catheters an increase of 59 minutes was necessary to reach the same Kt objective. We concluded that the patients dialyzed with central catheters on average needed to increase by 30 minutes the time of dialysis if the catheter worked in a normal position but 60 minutes if the arterio-venous lines were inverted so as to reach the minimum dose of dialysis.

[Long-term hemodialysis in acute barbiturate intoxication (author's transl)]. / Hemodiálisis de larga duración en la intoxicación barbitúrica.

From 1975 to 1978, ten patients were on long-term hemodialysis due to acute barbiturate intoxication. Duration of hemodialysis varied from 16 to 40 hours (mean 23 +/- 9.4 hours). Phenobarbital was the most common type of barbiturate ingested (6 out of 10 patients), and diazepam the drug most frequently taken in association with barbiturates (3 out of 10 patients). All patients were in a state of deep unconsciousness (coma II: 1 case; coma III: 5 cases; coma IV: 4 cases), and all of them required endotracheal intubation. Seven patients needed the assistance of automatic intermittent positive-pressure respirator. Two patients presented hypothermia, and another a peripheral collapse. Long-term hemodialysis was well tolerated without major complications. Significant decreases of barbiturate levels were obtained in all cases (before hemodialysis: 7.3 +/- 1.9 mg/dl, after hemodialysis: 1.8 +/- 1.2 md/dl, corresponding to the pattern of secobarbital used to refer the results). No correlation was observed between initial levels of barbiturates and number of hours of long-term hemodialysis required. Neurologic symptoms improved in all cases. Eight patients were conscious after hemodialysis had been discontinued, and only two patients remained unconscious (coma I). Intratracheal tube could be removed in six patients, but positive-pressure respirator could be took away from all cases. Complete recovery was achieved in eight patients. Two patients died on the 2nd. and 8th. postdialysis days due to respiratory distress. Long-term hemodialysis has proven of value in the treatment of severe barbiturate intoxication, particularly better to conventional hemodialysis.

Focal segmental glomerular sclerosis in two patients with Addison's disease: any more than fortuitous development of glomerular disease?

Adjustment of the mineralocorticoid activity under substitution therapy is of primary importance in Addison's disease. We report the clinical and biological conditions of 2 patients with Addison's disease who developed nephrotic proteinuria during their deficient mineralocorticoid state. Renal biopsy was performed and the specimens processed using conventional histochemistry, Congo red staining, and indirect immunofluorescence. The renal biopsy specimens showed focal segmental glomerular sclerosis and nodular deposits of IgM and C3. Negative for Congo red staining. Serum complement, circulating immune complexes, and anti-DNA and hepatitis B and C and human immunodeficiency virus antibodies were all normal or negative. Absence of vesicoureteral reflux was assessed by X-ray studies. Our observations suggest that deficiency in mineralocorticoid substitution therapy inducing a status of hyperreninemia could play a role in the development of focal segmental glomerulosclerosis in patients with Addison's disease.

Plasmapheresis induced recovery from renal failure in mesangiocapillary glomerulonephritis of acute onset.

Plasmapheresis (PE) was used in the treatment of three patients with biopsy proven mesangiocapillary glomerulonephritis (MCGN) of acute onset and renal failure. The percent of glomeruli with extracapillary proliferation varied from 40 to 90 per cent. Following PE, there were reductions in serum creatinine of 66 per cent, 61 per cent and 82 per cent in patients, one, two and three respectively. Plasmapheresis proved effective in a second episode of renal failure in patient three. After the completion of PE, renal function has remained stable in all patients for periods ranging from two to 12 months. However, haematuria and heavy proteinuria persist in every case. PE appears to facilitate recovery from renal failure in MCGN of acute onset, possibly by removing circulating mediators of acute inflammatory glomerular damage.

Desferrioxamine induced aluminium removal in haemodialysis.

This study evaluates if the use of high flux membranes and the type of dialysate influences aluminium removal in haemodialysis. Aluminium kinetics and dialysance were determined in baseline conditions and after infusion of desferrioxamine. The free diffusible fraction of plasma aluminium correlated significantly with the plasma aluminium post desferrioxamine, independently of the type of membrane or dialysate used. Aluminium removal therefore depends on the plasma concentration reached and the dialysate concentration. High flux membranes do not improve aluminium removal in vivo.