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Biomedical subjects

J López Pedret

Publications and source records attributed to J López Pedret.

12 recordsLinked to original sources

[Superior vena cava thrombosis in a patient on hemodialysis].

We present a patient with end-stage renal disease on maintenace hemodialysis through a permanent catheter (Permcath) on the right subclavian vein. One month after the catheter placement the patient exhibited a superior vena cava syndrome due to a pericatheter thrombosis. The patient was initially managed with anticoagulation with early clinical improvement. Nevertheless, the reappearance of the symptoms forced the removal of the catheter and percutaneous angioplasty of the superior vena cava. After those measures and anticoagulation with coumarin the patient remains stable with complete clinical resolution and angiographical improvement.

Angioplasty, Balloon↗

Defective radioresistant suppressor cell activity in hemodialysis patients.

The immunologic alterations in patients on hemodialysis are only partially understood. We studied the Concanavalin A (Con A) induced suppressor cell activity of irradiated and nonirradiated cells in a mixed lymphocyte culture. Peripheral blood lymphocytes from 18 normal individuals and 14 patients on regular hemodialysis were incubated with two different concentrations of Con A (10 micrograms and 40 micrograms of Con A/million cells). Irradiated and nonirradiated cells were then tested for their capacity to suppress a standard MLC. The proliferative response to phytohemagglutinin, pokeweed mitogen and Con A was also determined. Suppressor cell activity of nonirradiated cells in hemodialysis patients was similar to that of controls, at both concentrations of Con A, while irradiated cells of hemodialysis patients showed a suppressor cell activity significantly lower than that of the controls, at a Con A concentration of 40 micrograms/10(6) cells (25.78 +/- 18.86% vs. 46.05 +/- 9.79%, p less than 0.001). The proliferative response of lymphocytes from hemodialysis patients to the three mitogens, did not show any difference when compared with normal controls. The normal proliferative response of lymphocytes from hemodialysis patients to mitogens and the normal suppressor cell activity of nonirradiated cells, suggest a normal T cell function. The abnormal suppressor cell activity in irradiated cells indicate that the radioresistant population has a functional defect. The cell responsible for this suppressor defect probably belongs to the monocyte/macrophage population because of its relative radioresistance.

Adult↗

Increase in serum potassium caused by beta-2 adrenergic blockade in terminal renal failure: absence of mediation by insulin or aldosterone.

To test the hypothesis that beta-blockade might impair potassium (K) tolerance in terminal renal failure we gave propranolol, and then atenolol, to a group of 12 clinically stable non-diabetic patients on chronic haemodialysis and on a constant diet containing approximately 50 mEq of K/day. Propranolol, 60 to 80 mg/day for 10 days induced a significant increase in predialysis serum K from 5.1 +/- 0.1 to 5.8 +/- 0.2 mEq/L (p less than 0.005). Atenolol (50 mg/day for 10 days) in the same group of patients did not produce a significant change in predialysis serum K (5.5 +/- 0.2 vs 5.2 +/- 0.2 mEq/L). Both propranolol and atenolol decreased heart rate but neither drug induced significant changes in plasma aldosterone, arterial pH, serum insulin or blood glucose. Thus in haemodialysis patients, beta-2 adrenergic blockade by propranolol is associated with a significant increase in serum K not mediated by pH, aldosterone or insulin, and probably due to inhibition of intracellular K uptake. Selective beta-1 adrenergic blockade by atenolol at low doses does not change serum K, and therefore, if indicated, cardioselective beta-blockers might be preferable to nonselective drugs in haemodialysis patients.

Adult↗

[Hemodialysis and complement (author's transl)].

After observing alterations in the activity of the serum complement in patients undergoing periodic hemodialysis, the authors performed a preliminary study to determine repeatedly the activity of C3, C4, and CH50 in 44 patients. They discovered a consistent drop in C3 and CH50 while C4 remained normal. An attempt to explain these findings with information from the literature offered no more than a hypothesis for further study. While the possibility of a decline in the synthesis of the complement factors cannot be disregarded, the authors believe it is much more probable that they are consumed at a rate higher than normal. Since the C4 factor does not appear to be involved, activation is probably along the alternative pathway. Defective synthesis cannot be attributed to liver disease because the latter is not always present and because there is no relationship between C3 levels and levels of albumin or the presence of hepatopathy. The literature was reviewed for data that might support the idea that the complements in these patients are activated continuously by some process in connection with dialysis, by chemical products employed for to clean the machines, by commonly administered drugs, etc. Because so few data could be found on the subject, the authors consider that is necessary to study these mechanisms and their repercussions over a longer period of time.

Acute Kidney Injury↗

[Non-convulsive status epilepticus secondary to adjusted cefepime doses in patients with chronic renal failure].

Fever is one of the most frequent causes of hospital admission in patients with end-stage renal disease. Lack of an identified source of infection and/or lack of clinical response to the first empirical antibiotic treatment favour the use of broader spectrum antibiotics. The availability of fourth-generation cephalosporins (e.g. cefepime) and the increasing incidence of bacterial resistances to classical antibiotics has increased their use in the clinical practice. We present two cases of non-convulsive status epilepticus in patients with advanced chronic renal failure who received cefepime at doses corrected for the degree of renal function according to the manufacturer's instrument as. The clinical symptoms included shouthough, processes, disorientation, loss of attention, and the later appearance of myoclonus. In both cases the electroencephalogram (EEG) was compatible with non-convulsive epileptic status. After cefepime withdrawal there was a clinical remission of symptoms and normalization of the EEG. It is concluded that cefepime treatment can induce a non-convulsive epileptic status in patients with advanced chronic renal failure. Pharmacokinetic studies are urgently needed to clearly define the appropriate dose of cefepime in patients with advanced chronic renal failure.

Aged↗

[Vascular access in Spain: analysis of its distribution, morbidity, and monitoring systems].

Vascular access disfunction causes a therapeutic emergency with different implications in patients and care givers. The aim of this study was to know the distribution of different kinds of vascular access between prevalent hemodialysis patients, the proportion of incident patients that holds a permanent vascular access, the monthly hospital ratio for access repair and the use of surveillance systems of vascular access adequacy in the different Centers. This is a National survey that shows results of a questionnaire sent to all hemodialysis units in Spain on september 1999. Eighty-eight units answered the questionnaire (42%) providing information about 5,476 prevalent patients. Of these patients, 81% receives treatment through an arteriovenous fistula, 10% uses a central catheter and 9% a graft. Only 56% of incident patients have a permanent vascular access. Reasons for catheter use between prevalent patients were exhaustion of vascular sites in 42%, maduration of permanent access in 24%, thrombosis of the access in 14% and another reasons in 19%. Patients monthly hospitalization ratio for vascular repair was 3%, that might represent more than 5,600 hospital ingress by year. More than 80% of the Units releases different surveillance programs of access adequacy, 69% by fiscal detection problems, 47% by dynamic alterations and 18% by dilution and imaging procediments. The conclusions of this survey are that arteriovenous fistula is the most used vascular access in Spain. Almost half of the patients do not have vascular access in use for the beginning of hemodialysis. Exhausted vascular sites is the primary reason for central catheter using. A great proportion of Units are employing programs for access monitoring.

Catheters, Indwelling↗