Marsha Wolfson

Interaction Between Cyclosporine and Grapefruit Juice Requires Long‐Term Ingestion in Stable Renal Transplant Recipients

Study Objective. To examine the effect of the concurrent administration of increasing amounts of grapefruit juice, an inhibitor of drug metabolism, on the steady‐state pharmacokinetics of cyclosporine.

Use of Nutritional Supplements in Dialysis Patients

Nutritional concerns have played a major role in the management of patients with end-stage renal disease (ESRD) ever since the finding that reduced protein intake could ameliorate the symptoms of uremia and prolong life in the absence of renal replacement therapy (1). With the advent of chronic dialysis. the nutritional focus shifted to increasing intake in patients and to evaluating their nutritional status (2-7). Over the past several years, a large body of evidence has accrued which demonstrates that many patients with ESRD treated with maintenance hemodialysis or peritoneal dialysis are malnourished (2-8). This has occurred despite the wide availability of renal replacement therapy and the changes in patient management, which no longer calls for protein restriction but rather recommends a daily protein intake of 1.0-1.5 g/kg body weight/day (7). There is also a growing concern that poor nutrition may contribute to increased morbidity and mortality in maintenance dialysis patients. A recent study of a large population of dialysis patients in the United States found that serum albumin inversely correlated with mortality (8); the study concluded that malnutrition contributed to mortality in these patients. In addition, several other studies have suggested that poor nutritional status may adversely affect outcome in maintenance hemodialysis patients (4, 6). In order to improve the nutritional status of patients treated with maintenance hemodialysis, several approaches have been undertaken. These treatment strategies run the gamut from daily oral administration of a variety of nutritional supplements to total parenteral nutrition. The purpose of this review is to summarize the results of these studies in order to provide guidance as to the optimum nutritional management of patients with ESRD treated with maintenance hemodialysis.

Use of Water‐Soluble Vitamins in Patients with Chronic Renal. Failure

Little is actually known about the minimum daily requirement for most vitamins in the patient with end‐stage renal disease. Many of the studies reviewed suffer from lack of adequate control populations and differing methodologies, making comparisons between these studies difficult. However, patients with renal failure have many restrictions on their dietary intake, frequently suffer from intercurrent illness, and would seem to be at risk for vitamin deficiency. Also, metabolic abnormalities associated with the loss of kidney function may increase the daily requirements for certain vitamins. It is unlikely that dialysis losses of the water‐soluble vitamins alone could account for vitamin depletion, and these other factors are likely to play a much more important role.

Nutritional management of the continuous ambulatory peritoneal dialysis patient

C ONTINUOUS ambulatory peritoneal dialysis (CAPD) has emerged as a popular treatment modality for patients with end-stage renal disease. The nutritional requirements of peritoneal dialysis patients are unique and deserve special attention. Factors such as protein losses into the dialysate and glucose absorption from the dialysate may affect the nutritional status and dietary management of this group of patients.

The effect of vitamin B6 deficiency on food intake, growth, and renal function in chronically azotemic rats

Chronically uremic patients appear to have an increased nutritional requirement for vitamin B6, and vitamin B6 deficiency occurs frequently when such individuals do not receive supplements of this vitamin. Since manifestations of vitamin B6 deficiency in renal failure are not well defined, this study examined two aspects of the chronic renal failure syndrome which might be influenced by vitamin B6: impaired growth and progressive loss of renal function. We examined food intake, weight gain, the food efficiency ratio, degree of azotemia, and renal function in chronically azotemic rats pair-fed for 6 weeks either a vitamin B6-deficient diet or a diet containing a surfeit of vitamin B6. In the azotemic vitamin B6-deficient rats, as compared to the azotemic B6-replete rats, there was evidence of reduced appetite, decreased weight gain, a lower food efficiency ratio, increased azotemia, and a reduced glomerular filtration rate as estimated from the urea clearance or the mean of the urea and creatinine clearances. These findings suggest that vitamin B6 deficiency may contribute to decreased food intake, reduced growth, and lower renal function in animals with chronic renal insufficiency.

Recombinant Human Erythropoietin Utilization in Department of Veterans Affairs Dialysis Units

This study was carried out to determine the use of recombinant human erythropoietin (rHuEPO) in the Veterans Affairs dialysis program and any strategies being carried out to enhance its effectiveness. The data were collected from a survey that was conducted using a questionnaire sent to all Veterans Affairs dialysis programs. The survey included all patients treated with hemodialysis or peritoneal dialysis for at least 3 months and who were receiving rHuEPO for at least 3 months. Patients diagnosis, age, length of time of dialysis, mode of dialysis, length of rHuEPO treatment, route of administration, assessment of iron stores, use of iron supplementation, and use of androgens were assessed by this questionnaire and analyzed for their effect on dose required to achieve a target hematocrit. Subcutaneous administration resulted in a significantly lower dose requirement compared with the dose required when rHuEPO was administered intravenously. Concomitant use of androgens resulted in a lower dose requirement for rHuEPO when it was given intravenously, but not when rHuEPO was given subcutaneously. The dose required to maintain the hematocrit at the designated level appeared to increase with time of treatment.

SEVERE MALNUTRITION: I

A.Y. is a 56-year-old retired male airline pilot who presented with rapidly progressive renal failure in a single functioning (right) kidney. His left kidney had been obstructed by stones for several years and at presentation he had a left kidney double-1 stent. His creatinine had increased from 1.9 to 7.0 over the previous eight months. Physical examination revealed a well-developed, well-nourished male who had a blood pressure of 150195, pulse 80 and regular, and respirations of 12lmin. The rest of the physical exam was within normal limits. Laboratory studies revealed a blood urea nitrogen (BUN) of 70 mgldl, creatinine of 7.2 mgldl, glucose of 95 mgldl, and normal liver function tests with a normal serum albumin. His complete blood count (CBC) was remarkable for a hematocrit of 33%. Serum iron and total iron binding capacity (TIBC) were also normal. The underlying cause of his renal insufficiency was never delineated. He was initially begun on hemodialysis, but underwent placement of a continuous ambulatory peritoneal dialysis (CAPD) catheter and was to begin training in this procedure. He was given 1 g of ceftriaxone at the time of catheter placement to prevent catheter infection and subsequently developed severe diarrhea, secondary to C. diJicil infection. Despite this, the patient completed his dialysis training and hemodialysis was discontinued. Soon after he began CAPD, he also developed severe nausea and vomiting and was unable to eat. He was hospitalized and treated with intravenous fluids. His diarrhea resolved as did his nausea and vomiting. He was discharged from the hospital. A t home he began vomiting again. He refused initially to be hospitalized, but awoke 72 hr after discharge with sudden blindness in both eyes. A t presentation to the emergency room he was diagnosed with bilateral retinal artery emboli or thromboses. Vascu-

Assessment of Nutritional Status in Dialysis Patients

Malnutrition is common in patients treated with maintenance dialysis and appears to influence mortality in these patients. Thus, assessment of the nutritional status of dialysis patients is important if one is to make appropriate treatment interventions. This article describes the various parameters used in assessing the nutritional status of patients treated by hemodialysis and continuous ambulatory peritoneal dialysis. The usefulness of these parameters, as well as the pitfalls in their interpretation, are also reviewed.

Diet as culprit or therapy: Stone Disease, Chronic Renal Failure, and Nephrotic Syndrome

A number of renal disorders are amenable to dietary manipulation. This article reviews nutritional strategies for the management of renal stone disease, chronic renal failure, and nephrotic syndrome. The first portion discusses dietary factors that promote urolithiasis and dietary recommendations utilized in the medical management of stone disease. The second segment discusses the pathophysiology of the progression of renal disease and nutritional interventions to delay progression. Finally, the third portion examines losses of protein, vitamins, and minerals in the nephrotic syndrome and makes recommendations for replacement.

Safety of Weight Loss Diets in Peritoneal Dialysis Patients

An obese CCPD patient of mine wants to diet and lose weight. She uses all 2.5% dextrose dialysate, 12 L daily and weighs 68 kg. Given the obligate caloric load from the dextrose and the high‐protein needs, can such a patient diet safely?