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Biomedical subjects

R Marcén

Publications and source records attributed to R Marcén.

At least 73 records · Page 4Linked to original sources
PubMed1993

Prognosis of acute tubular necrosis: an extended prospectively contrasted study.

The ability to predict the outcome in acute tubular necrosis (ATN) remains elusive despite considerable efforts. Accurate prediction is a crucial priority and has large economical and ethical implications, mainly to judge when treatment is futile and further efforts only prolong miserable agony. To analyze the influence of risk factors in the prognosis of ATN, we applied, in an initial phase, a prospective protocol of demographic data, cause of renal failure, diuresis, need of dialysis and clinical conditions in 228 patients using multiple linear and logistic regression models. In a control phase with 100 consecutive patients, we checked the accuracy of the results previously obtained, evaluating further the overall population of 328 patients in a synthetic phase. Finally, the validation of the equations obtained was verified in 25 patients from another hospital. As a complement of this 4-phase study, detailed statistical comparisons between both linear and logistic multiple regression models were undertaken. Correlation between probability of death obtained with equations from the initial phase applied to control patients and real evolution of these patients, survival or death, was excellent. The study of the synthetic phase revealed coma, assisted respiration, hypotension, oliguria and jaundice as having an independent positive influence on mortality and nephrotoxic etiology and normal consciousness on good prognosis. For the linear model, the same cut-off point of discriminant score (0.9) above which there were no chances for survival could be established in the 4 phases. With the logistic model, it only was found at later phases. The multiple linear was better than the logistic regression model in terms of better correlation with real mortality, better sensitivity and specificity intervals, easier use of discriminant cut-off point and better adjustment of distribution of standardized residuals to expected normal function. Early prognosis of ATN is possible and can be given using simple clinical features. A discriminant score allows to distinguish patients without chances for survival. The multiple linear is better than the logistic regression model in the prediction of the outcome in ATN.

Acute Disease↗
PubMed1992

Influence of cyclosporin A (CyA) on renal handling of urate.

Hyperuricaemia is a frequent side-effect of cyclosporin A (CyA) therapy in renal transplant patients, and gout arthritis is the cause of considerable morbidity among these patients. However, neither the potential predisposing factors nor the mechanisms of hyperuricaemia have been clearly elucidated. It has been reported that hyperuricaemia in patients on CyA is associated with a lowered glomerular filtration rate, or with a reduced urate clearance, due to an increase in the net tubular urate reabsorption or to a decrease in secretion. These conclusions are mostly supported by measurements of the basal clearance rate and fractional excretion of urate, but more precise studies of renal handling of urate by the renal tubule have seldom been performed. The purpose of our study was to investigate the prevalence of hyperuricaemia in our population of renal transplant patients, as well as the risk factors involved. Furthermore, we have evaluated the mechanism of hyperuricaemia by a combined pyrazinamide and probenecid test allowing a better evaluation of urate transport processes than pyrazinamide alone.

Adult↗
PubMed1992

Long-term beneficial effects of azathioprine addition to ongoing cyclosporine-prednisone protocol in renal transplantation.

Delayed addition of azathioprine (Aza) to an ongoing cyclosporine-prednisone protocol was started 11.3 +/- 9.9 months after renal transplantation in 31 patients. Group I (n = 10) had chronic renal function deterioration due to chronic rejection, group II (n = 11) had repeated or severe acute rejection episodes and group III (n = 10) had cyclosporine (Cs) toxicity despite drug tapering. In group I, SCr had risen over the 6 months prior to Aza addition (P < 0.05), renal function declining at a rate of -0.13 +/- 0.12 SCr(-1). In the 6 months post-Aza, renal function improved at a rate of 0.05 +/- 0.07 SCr(-1), and during the entire follow-up at a rate of 0.05 +/- 0.12 SCr(-1) (P < 0.01) with stable Cs levels. In group II the decline in renal function was greater, though the rate of decline was stopped after Aza. In group III, renal function improved in eight patients. After 23 +/- 12 months of follow-up, 15 patients had improved graft function, two were stable, 12 had worsened (nine on dialysis) and two had died. Amelioration of chronic graft dysfunction can be achieved by delayed addition of Aza to Cs-prednisone-treated renal allograft patients with chronic rejection or Cs toxicity, with long-term beneficial effects in a high proportion of patients.

Azathioprine↗
PubMed1992

Hemodynamic changes in the dog connected to a dialysis circuit: influence of the body temperature.

Eighteen sessions in 9 mongrel dogs were carried out to know the hemodynamic effects produced by body temperature variation, when blood passes through a dialysis circuit with a Cuprophan dialyzer, without dialysate contact. The decrease of 2 degrees C in body temperature caused a decrease in heart rate and cardiac index (-8.6 and -17.6%, respectively) without significant changes in blood pressure. The increase of 2 degrees C in body temperature increased the heart rate, the cardiac index and the first derivative of ventricular pressure (+14.8, +17.3 and +27.8%, respectively) with a decrease of 13.6% in the systemic vascular resistance. Blood pressure did not change significantly. We conclude that the dog maintains the hemodynamic stability by two different mechanisms: when body temperature rises, by increasing the cardiac index; when body temperature decreases, by increasing the systemic vascular resistance.

Animals↗
PubMed1992

Blood pressure after three different forms of correction of anemia in hemodialysis.

It is not known whether recombinant human erythropoietin has a direct, clinically apparent pressor effect in hemodialysis patients or whether hypertension developing or aggravated in these patients merely reflects increased hematocrit. We compared blood pressure after three different methods of partial correction of anemia in hemodialysis patients with similar baseline hematocrits (erythropoietin n = 12, intravenous iron alone n = 10, androgens n = 9). Shortly after the start of treatment and with a minimally increased hematocrit, the need for antihypertensive medication increased in the erythropoietin group. No such pressor effect was observed with iron or androgens. These data suggest a direct hypertensive effect of erythropoietin in some patients on hemodialysis.

Adult↗
PubMed1992

Hemodynamic and cardiac effects of erythropoietin in patients on regular dialysis.

The long-term impact of erythropoietin (EPO) treatment on cardiac structures and function was prospectively studied in eight hypertensive (Group I) and seven normotensive (Group II) patients on hemodialysis (HD). Doppler-echocardiograms were done before EPO and at two and twelve months of treatment. Mean hemoglobin (+/- SD) before EPO was 6.4 +/- 0.9; it rose significantly up to two months and then remained constant. At two months, cardiac index (CI) had significantly decreased, while peripheral vascular resistances increased. Five patients required increased antihypertensive drug treatment. No changes were seen in myocardial parameters at this short follow-up. After one year, left ventricular mass index (LVMi) decreased (p less than 0.05) in both groups concomitantly with a decrease in diastolic diameter and septum and posterior wall thicknesses. Basal LVMi was higher in Group I than in Group II, and after one year the regression was more marked in Group II. Left cardiac work showed prompt and steady improvement in both groups. Maintained partial correction of anemia with EPO during one year was associated with a return to normal of high CI, decreased left cardiac work and impressive regression of left ventricular hypertrophy.

Adolescent↗
PubMed1991

Evidence that addition of azathioprine improves renal function in cyclosporine-treated patients with allograft dysfunction.

Several approaches have been attempted to manage renal allograft dysfunction in cyclosporine-prednisone (CsA-Pred)-treated patients. Conversion to conventional therapy and perioperative triple drug have been associated with high rates of acute rejection episodes, infections, or neoplasms. We report our experience in delayed addition of azathioprine (1-2 mg/kg/day) to CsA/Pred protocol in three groups of patients. Group I (n = 9) had chronic renal function deterioration due to chronic rejection; group II (n = 10) had repeated or severe acute rejection episodes despite adequate CsA levels; and group III (n = 8) had CsA toxicity despite drug tapering. In group I, serum creatinine (SCr) had risen from 2.2 +/- 0.9 to 2.9 +/- 0.7 mg/dl over the 6 months prior to Aza addition (P less than 0.05), renal function declining at a rate of -0.14 +/- 0.12 Cr-1/year. In the 6-month post-Aza, renal function improved at a rate of 0.06 +/- 0.06 Cr-1/year and during the entire follow-up at a rate of 0.04 +/- 0.12 Cr-1/year (P less than 0.05) with stable CsA levels (288 +/- 167 vs. 251 +/- 172 ng/dl, NS). In group II response was worse, though the rate of declining renal function prior to Aza (-0.10 +/- 0.10 Cr-1/year) was almost stopped after Aza. In group III there was very good response to Aza addition, as 7 out of 8 patients improved graft function (baseline SCr 2.5 +/- 0.7 mg/dl vs. 1.9 +/- 0.6 mg/dl at last follow-up, P less than 0.05), with significantly decreased CsA levels (480 +/- 97 vs. 268 +/- 120, P less than 0.05). One patient from group II died from pneumonia, and 6 patients (1 from group I and 5 from group II) lost their grafts. Fifteen patients improved graft function, and 9 worsened after addition of Aza. The bad-responders had significantly higher SCr at baseline compared with the good-responders (3.8 +/- 1.8 vs. 2.7 +/- 0.6 mg/dl, P less than 0.01). Amelioration of chronic graft dysfunction can be achieved by delayed addition of Aza to CsA-Pred in patients with chronic rejection or CsA toxicity. This is accompanied by low rate of acute rejection, good patient and graft survival, and low rate of infections. A worse outcome can be seen in patients with high-baseline SCr levels, suggesting the need for addition of Aza in the initial chronic graft dysfunction.

Azathioprine↗
PubMed1991

Recurrence of IgA nephropathy with nephrotic syndrome after kidney transplantation.

Two patients on maintenance hemodialysis after terminal renal failure due to mesangial glomerulonephritis with IgA deposits and the nephrotic syndrome, received cadaver renal allografts. After several years of functioning transplants, both patients developed slowly progressive proteinuria and finally the nephrotic syndrome, 1 of them with renal function deterioration. Renal biopsies revealed findings indicating recurrence of the original disease.

Adult↗
PubMed1990

[Hepatitis C virus infection in patients treated with hemodialysis].

The prevalence of hepatitis C infection was evaluated (Ortho HCV Antibody ELISA Test) in 64 patients with chronic renal failure treated in a single hemodialysis unit. None of these patients was a carrier of hepatitis B virus nor of antibodies against human immunodeficiency virus. Antibodies against hepatitis C virus were detected in 11 patients (17%). The prevalence was higher in the 13 previously diagnosed of non A, non B hepatitis (77%) than in the 51 without previous hepatitis (2%) (p less than 0.001). A relationship between the infection rate and the number of previous blood transfusions was also observed: 5% in the patients without previous transfusions, 13% in the 30 patients who had received between 1 and 10 blood units and 40% in the 15 who had received more than 10 blood units (p less than 0.05). These data suggest that the hepatitis C virus may be responsible for most episodes previously diagnosed as non A, non B hepatitis, and that blood transfusions are the major risk factor.

Acute Disease↗
PubMed1990

Incidence and prognosis of acute renal failure in older patients.

Few studies have assessed the prevalence and outcome of acute renal failure (ARF) in the elderly. Among 437 ARF cases prospectively studied during a nine-year period in a nephrology department, 152 (35%) occurred in patients over 70 years of age (Group 1). Patients over 70 account for only 10.5% of all hospital admissions in our country, and prevalence of ARF was 3.5 times higher in these patients than in younger people. Acute tubular necrosis (ATN) was diagnosed in 40% of Group 1 and 52% of the younger patients (Group 2) (P less than .05), whereas prerenal ARF was found in 47% and 32%, respectively (P less than .001). Dehydration was the most frequent cause of prerenal ARF in the elderly (51%). The etiological distribution of ATN was similar in both groups, being of multifactorial origin in most cases. Oliguria was present in 49% of ATN in Group 1 and in 66% of Group 2 (P less than .05). There were no significant differences in dialysis needs. Mortality was higher in the elderly in all types of ARF, although differences did not reach statistical significance. Need for dialysis, mechanical respiration, decreased level of consciousness, and hypotension were associated with poor prognosis in both groups. Total recovery from ARF in older persons was less frequent and slower than in younger patients. It may be concluded that patients over 70 years of age are at high risk for developing ARF; nevertheless, age should not be used as a discriminating factor in therapeutic decisions concerning ARF.

Acute Kidney Injury↗
PubMed1990

Epidemiology of symptomatic hypotension in hemodialysis: is cool dialysate beneficial for all patients?

A prospective study on hypotension in hemodialysis was performed in 60 nondiabetic patients at two different dialysate temperatures during 12 months. A 37 degrees C bath (3,723 sessions) was used and after the first 6 months the temperature was changed to 35 degrees C (4,019 sessions). The prevalence of symptomatic hypotension was 15.3% and it was closely correlated with the presence of other symptoms. The most affected populations were women, patients over 55 years of age, patients with low body surface area and patients with a cardiovascular disease. A slight but significant decrease of symptomatic hypotension was seen by using a 35 degrees C dialysate (16.4 vs. 14.3%, p less than 0.01). In patients with frequent hypotension (in up to 30% of sessions), cool dialysate significantly reduced the incidence of the symptom (44.2 vs. 34.1%, p less than 0.001). These results were obtained in spite of a greater interdialysis weight gain at low temperature (2 +/- 0.6 vs. 1.9 +/- 0.7 kg, p less than 0.001). We consider that low-temperature dialysis is a simple, useful and economic procedure, especially for highly symptomatic patients. The association of cooling dialysate with higher sodium concentration, bicarbonate and special membranes could reduce dialysis symptoms dramatically.

Cold Temperature↗