Calcium metabolism in adult outpatients with epilepsy receiving long-term anticonvulsant therapy

Long-term anticonvulsant drug therapy may lead to abnormalities of calcium metabolism resulting in osteomalacia. The prevalence and severity of altered calcium metabolism was studied in an adult outpatient population of persons with epilepsy receiving anticonvulsant therapy for a minimum of 2 years. Assessment of calcium metabolism was based on serum concentrations of calcium, phosphorus, alkaline phosphatase and 25-hydroxycholecalciferol and of plasma parathyroid hormone, intestinal absorption of isotopic calcium and skeletal bone mineral mass as determined by in vivo neutron activation or x-ray photodensitometry.

Thirty-nine patients who had been receiving anticonvulsant therapy for an average of 20 years were studied; none had clinical evidence of metabolic bone disease. Decreased serum calcium concentration was noted in 10%, decreased serum phosphorus concentration in 10% and elevated serum alkaline phosphatase concentration in 44%. The mean serum 25-hydroxycholecalciferol concentration was significantly lower (P < 0.001) than in a control group (11.6 v. 19.6 mg/mL). None of 18 patients studied had an increased plasma concentration of parathyroid hormone, and only 1 of 17 patients had decreased intestinal absorption of isotopic calcium. Bone mineral mass was decreased in 44% of 32 patients studied.

It was concluded that long-term treatment with anticonvulsant drugs leads to mild abnormalities of calcium metabolism and decreased bone mineral mass in a substantial percentage of adult outpatients with epilepsy. These abnormalities probably predispose the patients to the development of clinically significant metabolic bone disease.

     

Chronic peritoneal dialysis.

Since the introduction of the permanent peritoneal catheter, interest in chronic peritoneal dialysis is increasing. The automatic peritoneal dialysis cycler and the reverse osmosis peritoneal dialysis machine have been other development that made chronic peritoneal possible. Chronic peritoneal dialysis is indicated for the children, the elderly, those without hemodialysis access sites, those living along (for home dialysis) and the diabetics, whose retinopathy seems to progress less on peritoneal dialysis than on hemodialysis. Patients awaiting a kidney transplant can be maintained equally satisfactorily on peritoneal dialysis as on hemodialysis. Because of its simplicity almost any patient can be trained for home peritoneal dialysis, and a high incidence of rehabilitation can be achieved. A flow rate of 4 1/hr with 21 exchanges, 40 hours a week, seem to the ideal dialysis requirements. Complications of chronic peritoneal dialysis include those related to the permanent catheter such as one or two way obstruction and those related the dialysis itself. The latter can be either acute (i.e. peritonitis etc.) or chornic such as neuropathy, renal osteodystrophy, anemia etc. Integrated with hemodialysis and transplantation, peritoneal provides the nephrologists with the ability to treat his patients with the most appropriate treatment.     

Peritoneal catheter exit-site infections: predisposing factors, prevention and treatment

Catheter-related infections, exit-site-tunnel infections and peritonitis remain the Achilles heel of peritoneal dialysis. Although the overall incidence of peritoneal-dialysis-related infectious complications has been reduced since the introduction of the Y-set and double bag system, approximately one-fifth of peritonitis episodes are associated with catheter exit-site and tunnel infections. Since its development in 1968, the Tenckhoff catheter has become one of the most widely used peritoneal catheters, and many have proposed that a number of modifications have made it a better choice. Controversies concerning the effect on exit-site infections of catheter(s) with one or two cuffs, with straight, coiled, Swan-Neck, or other modifications led to the randomized controlled studies that are reviewed in this paper. Several studies have confirmed that mupirocin, applied at the exit-site as part of regular exit-site care, reduces the risk of S. aureus exit-site and tunnel infections. Recently, the emergence on a world-wide basis of mupirocin-resistant S. aureus (MuRSA) in peritoneal dialysis patients has brought this prophylactic strategy into question. However the low frequency of resistant organisms after four years of mupirocin prophylaxis suggests that we can continue its use with annual surveillance. Once established, exit-site infections may respond to appropriate treatment, but if not the only option may be catheter removal and replacement. Although peritonitis risk has decreased over the past decade, mainly due to improvements in connection technology, exit-site and tunnel infections have not. An exit-site infection that does not respond to treatment may lead to tunnel infection and to persistent peritonitis, which may require catheter removal and occasionally discontinuation of the peritoneal dialysis. Therefore it is important to be familiar with these factors that predispose to exit-site infection and to know how to prevent and to treat such infections. This review will discuss factors that predispose to catheter-related exit-site infections, techniques of exit-site care, and ways to prevent exit-site infection, with emphasis on S. aureus infections and their treatment.     

Prevalence and pathogenesis of hypokalemia in patients on chronic peritoneal dialysis: One center's experience and review of the literature

International Urology and Nephrology -     

Renal cell carcinoma in peritoneal dialysis patients

Renal cell carcinoma is a rare but serious complication in ESRD patients. In these patients the incidence of renal cell carcinoma (RCC) is 20-40 times higher than in the general population. We performed a retrospective study to measure the incidence rate, prevalence, characteristics and survival among our peritoneal dialysis (PD) patients diagnosed with renal cell carcinoma. The study was carried out among 607 patients who were on the PD program from January 1997 to June 2002. RCC was detected in eight patients (four males and four females) with mean age of 52.1 +/- 10.6 years. Among these eight patients four were new cases that were diagnosed before the patients were started on dialysis (three in native kidneys and one in a transplanted kidney). In the other four patients the RCC was diagnosed after they had been on dialysis for 33-204 months (mean 60.75 +/- 50.48). We found an incidence rate of 1.3 per 1000 patients per year and a prevalence of 1.3%. Six of the eight patients had renal cysts. Tumor size was less than 7 cm in seven patients and in the other patient it was 8.5 cm. Seven of eight patients were alive at the time of study with a survival time ranging from 3-138 months (mean 122.25 +/- 88.2) months. In one patient, the RCC metastasised to the scalp, and, in two other patients, the tumors subsequently involved the second kidney. A cardiovascular complication was the cause of one death. Two patients received a renal transplant 36 and 66 months after diagnosis. We conclude that despite the low rate of metastases and mortality in our study, regular ultrasonography should be added to the follow-up of PD patients. Renal transplantation can be considered in these ESRD patients with RCC; however, close follow-up for metastases is recommended.     

President's message to New Members of the International Society for Geriatric Nephrology and Urology

Editorial Introduction

President's message to New Members of the International Society for Geriatric Nephrology and Urology     

Contents Volume 32, No. 3 (2001); SECTION TWO: GERIATRIC NEPHROLOGY AND UROLOGY, (Editor-in-Chief: Dimitrios G. Oreopoulos)

Table of Contents

Contents Volume 32, No. 3 (2001); SECTION TWO: GERIATRIC NEPHROLOGY AND UROLOGY, (Editor-in-Chief: Dimitrios G. Oreopoulos)