The effects of frequent nocturnal home hemodialysis: the Frequent Hemodialysis Network Nocturnal Trial.

Prior small studies have shown multiple benefits of frequent nocturnal hemodialysis compared to conventional three times per week treatments. To study this further, we randomized 87 patients to three times per week conventional hemodialysis or to nocturnal hemodialysis six times per week, all with single-use high-flux dialyzers. The 45 patients in the frequent nocturnal arm had a 1.82-fold higher mean weekly stdKt/V(urea), a 1.74-fold higher average number of treatments per week, and a 2.45-fold higher average weekly treatment time than the 42 patients in the conventional arm. We did not find a significant effect of nocturnal hemodialysis for either of the two coprimary outcomes (death or left ventricular mass (measured by MRI) with a hazard ratio of 0.68, or of death or RAND Physical Health Composite with a hazard ratio of 0.91). Possible explanations for the left ventricular mass result include limited sample size and patient characteristics. Secondary outcomes included cognitive performance, self-reported depression, laboratory markers of nutrition, mineral metabolism and anemia, blood pressure and rates of hospitalization, and vascular access interventions. Patients in the nocturnal arm had improved control of hyperphosphatemia and hypertension, but no significant benefit among the other main secondary outcomes. There was a trend for increased vascular access events in the nocturnal arm. Thus, we were unable to demonstrate a definitive benefit of more frequent nocturnal hemodialysis for either coprimary outcome.

The use of gastric electrical signals for algorithm for automatic eating detection in dogs.

Food ingestion increases fundic impedance (FI) and reduces antral slow wave rate (SWR). Our aim was to determine if such changes can be integrated into an algorithm for automatic eating detection (AED). When incorporated in implantable medical devices, AED can time treatment to food intake without need for patient input. Four dogs were implanted with fundic and antral electrodes, connected to an implantable recording device. Changes in FI and SWR induced by fixed meals of different weights were determined, and were used to build an AED algorithm. Its performance was then tested on the same animals given an ad libitum access to food. The effects of gastric balloon distension and nitroglycerin on SWR and FI were also tested. Fixed meals reduced SWR in a weight-dependent manner, R(2) = 0.936, P < 0.05 baseline compared to 50, 100, 200 and 400 g. Meals increased FI above baseline in a weight-dependent manner; R(2) = 0.994, P < 0.05 baseline compared to 200 and 400 g. During ad libitum intake, the AED algorithm detected 86% of all meals > or =15 g. Gastric distension reduced SWR and increased FI. Nitroglycerin reduced SWR. AED, using changes in FI and gastric SWR is feasible. Changes in FI and SWR are induced primarily by the presence of food in the stomach.

Circadian patterns of gastric electrical and mechanical activity in dogs.

Gastric motor function assessment, in humans and animals, is typically performed for short recording periods. The aim of this article was to monitor gastric electrical and motor activity in the antrum and fundus simultaneously, for long periods, using a new implantable system. Ten dogs were implanted with fundic and antral electrodes for assessment of impedance and electrical activity. Dogs were studied while in cages, for periods of 22-26 h. From late evening and until feeding on the next day, slow wave (SW) rhythm demonstrated a distinct pattern of intermittent pauses (mean duration = 22.8 +/-4.1 s) that delineated groups of SW's. Phasic increases in fundic tone were seen mostly in association with SW pauses, and were highly correlated with antral contractions, R(2) = 0.652, P < 0.05. The SW rate (events per minute) in the postprandial period, fasting and night time was 4.2 +/- 0.2, 5 +/- 0.2 and 4.7 +/- 0.3, respectively, P < 0.05 postprandial vs other periods. Antral and fundic mechanical activities were highly correlated during fasting, particularly at night. This novel method of prolonged gastric recording provides valuable data on the mechanical and electrical activity of the stomach, not feasible by current methods of recording. During fasting, fundic and antral motor activities are highly correlated and are associated with periodic pauses in electrical activity.

Frequent Hemodialysis Network (FHN) randomized trials: study design.

Observational studies suggest improvements with frequent hemodialysis (HD), but its true efficacy and safety remain uncertain. The Frequent Hemodialysis Network Trials Group is conducting two multicenter randomized trials of 250 subjects each, comparing conventional three times weekly HD with (1) in-center daily HD and (2) home nocturnal HD. Daily HD will be delivered for 1.5-2.75 h, 6 days/week, with target eK(t)/V(n) > or = 0.9/session, whereas nocturnal HD will be delivered for > or = 6 h, 6 nights/week, with target stdK(t)/V of > or = 4.0/week. Subjects will be followed for 1 year. The composite of mortality with the 12-month change in (i) left ventricular mass index (LVMI) by magnetic resonance imaging, and (ii) SF-36 RAND Physical Health Composite (PHC) are specified as co-primary outcomes. The seven main secondary outcomes are between group comparisons of: change in LVMI, change in PHC, change in Beck Depression Inventory score, change in Trail Making Test B score, change in pre-HD serum albumin, change in pre-HD serum phosphorus, and rates of non-access hospitalization or death. Changes in blood pressure and erythropoiesis will also be assessed. Safety outcomes will focus on vascular access complications and burden of treatment. Data will be obtained on the cost of delivering frequent HD compared to conventional HD. Efforts will be made to reduce bias, including blinding assessment of subjective outcomes. Because no large-scale randomized trials of frequent HD have been previously conducted, the first year has been designated a Vanguard Phase, during which feasibility of randomization, ability to deliver the interventions, and adherence will be evaluated.

The impact of various cycling regimens on phosphorus removal in chronic peritoneal dialysis patients.

BACKGROUND: The National Kidney Foundation Dialysis Outcome Quality Initiative clinical practice guidelines have suggested that serum phosphate levels be maintained at < or =5.5 mg/dL in patients maintained on dialysis. Over 45% of anuric patients maintained on CAPD have serum phosphate levels >5.5 mg/dL. The present study was designed to address the question whether phosphate removal could be enhanced by increasing the dialysate volume during cycler peritoneal dialysis therapy. METHODS: Medically stable patients maintained on chronic peritoneal dialysis therapy, who were high or high-average transporters and had serum phosphate levels > or =5.5 mg/dL, were invited to participate in the study. The protocol involved measuring phosphate and creatinine clearances at weekly intervals on three different cycler prescriptions consisting of 7 and 12 full cycles or 24 cycles with 50% tidal PD (TPD) over 9 hours. Ten patients agreed to participate. Those patients (n=7) with a BMI > 22 had 2 liter (L) fill volumes and 14 L of total dialysate (7 cycles of 2 L) or 24 L total dialysate (12 cycles of 2 L or 50% TPD with 24 cycles).The patients (n=3) with a BMI < 20 had 1.2 L fill volumes and 8.4 L total dialysate (7 cycles) or 14.4 L total dialysate (12 cycles of 1.2 L or 50% TPD with 24 cycles). RESULTS: The mean age (+/- SD) of the study patients was 50.8 (+/- 9.3) years. There were 6 females, 6 Caucasians and 4 African-Americans. The mean weight of the patients was 71.5 (+/- 24.2) kg and mean height 1.65 (+ 7.6) meters. The mean BMI was 18.3 (+/- 1.27) in the < 20 BMI group and 30.3 (+/- 6.6) in the > 22 BMI group. The mean phosphate clearance (L/night/1.73m 2 ) increased from 3.96 (+/- 1.16) with 7 cycles to 4.71 (+ 1.81) with 12 cycles and 4.51 (+/- 1.61) with 50% TPD. Creatinine clearance (L/night/1.73m 2 ) was 4.74 (+/- 1.74) with 7 cycles, 6.06 (+/- 2.04) with 12 cycles and 5.61 (+/- 2.01) with TPD. CONCLUSION: The present study indicates that there is a significant, 19% (P < 0.005) rise in phosphate clearance by increasing dialysate volume 71% from 7 cycles to 14 cycles compared to a 27% increase in creatinine clearance. With tidal PD, phosphate clearance increased by 12% (p=NS) and creatinine clearance increased 18 % (p, 0.02). This increase in phosphate clearance translates into <50 mg net phosphate removal in 9 hours, assuming a serum phosphate of 6 mg/%. Thus, increasing dialysis cycles and volume results in only a minimal increase in net phosphate removal.

Method for studying development of colonization and infection of dialysis catheters.

Microbial colonization and infection of dialysis catheters is the major cause of catheter failure. The present study aimed to develop a method to permit the study of microbial biofilm formation and antibiotic prophylaxis and therapy. Standard silicon rubber and silver-impregnated catheters were sectioned into 1 mm slices and placed into 1-cm x 2-cm culture slide chambers. Fresh clinical isolates were obtained from infected patients and suspended in concentrations of 10(3), 10(6), and 10(9) colony forming units (CFU) per milliliter in a variety of liquid suspending culture media, which included serum protein constituents. Antibiotics could be added to the suspending fluid to determine prophylactic activity, or at any time thereafter to determine therapeutic activity. The catheter sections were incubated with the microbial challenge for 6 hours, 12 hours, 24 hours, and 48 hours and then washed in flowing distilled water to remove unattached biofilm. They were then stained with acridine orange, which fluoresces microbial DNA, and were examined by confocal scanning laser microscopy. Biofilm formation, representing colonization and infection, were quantified by comparing the fluorescent pixel analysis of the uninoculated control with the challenged catheter. The method was reproducible and permitted quantitative analysis. Standard silicon rubber catheters demonstrated greater biofilm formation than silver-impregnated catheters. The method examines the factors involved in microbial colonization and infection, and in antibiotic prophylaxis and therapy.

Parameters of high bone-turnover predict bone loss in renal transplant patients: a longitudinal study.

BACKGROUND: Osteoporosis is a serious complication of kidney transplantation. Various factors have been postulated to contribute to posttransplant bone loss, among them treatment with corticosteroids, the use of cyclosporine and cyclosporine-like agents, and persistent hyperparathyroidism. In a previous cross-sectional study of long-term renal transplant recipients, we observed that osteoporosis or osteopenia was present in 88% of patients. Because biochemical markers of bone formation (serum osteocalcin) and bone resorption (urine pyridinoline, PYD, and deoxypyridinoline, DPD) were elevated in the majority of study subjects, we hypothesized that elevated rates of bone-turnover contribute to posttransplant bone loss in long-term renal transplant patients. This study was performed to examine this hypothesis. METHODS: The study population was composed of 62 patients who were more than 1-year postrenal transplantation and who had preserved renal function. They were followed prospectively for 1 year. Biochemical markers of bone-turnover were measured at study entry, and patients were classified as having high bone-turnover based on elevated urinary levels of at least one marker of bone resorption (i.e., PYD or DPD) and/or serum osteocalcin (group 1). If none of these were present, they were classified as having normal bone-turnover (group 2). Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DEXA) at time of entry into the study and again after 1 year of follow-up. The changes in BMD at the lumbar spine, hip, and wrist over the period of the study were compared between the high and normal bone-turnover groups. RESULTS: Forty-three patients (69%) were classified as having high bone-turnover (Group 1), and 19 patients (31%) were classified as having normal bone-turnover (Group 2). There was a statistically significant difference in change in BMD between the two groups at the lumbar spine (-1.11+/-0.42%, high bone-turnover, vs. 0.64+/-0.54%, normal bone-turnover; P=0.02) and the hip (-0.69+/-0.38%, high bone-turnover, vs. 1.36+/-0.66%, normal bone-turnover; P=0.006). Whereas group 2 had stable bone mass, group 1 exhibited bone loss at these skeletal sites. CONCLUSIONS: Our results indicate that bone loss is greater in renal transplant recipients with elevated biochemical markers of bone-turnover, suggesting that these markers may be useful in identifying patients at risk for continued bone loss. These data support the hypothesis that continued bone loss in long-term renal transplant recipients is associated with high bone-turnover. If accelerated bone resorption does play a role in posttransplant bone loss, this would provide a strong rationale for use of antiresorptive therapy for the prevention and treatment of this complication.

Patient safety in end-stage renal disease: How do we create a safe environment?

The Institute of Medicine estimated that 44,000 to 98,000 hospitalized patients die annually as a direct result of preventable medical errors. Errors occur because competent practitioners are human, and the systems we design are imperfect. Improving patient safety requires acknowledging medical errors, encouraging the reporting of errors, and improving systems to reduce the likelihood of future errors. Several challenges must be addressed to accomplish this goal. The definition of medical errors must be widely agreed on and accepted. Adverse outcomes are often the result of multiple systems failures. Therefore systems analysis, not blaming an individual, should be the focus of error reduction. A "culture of safety" should be created, which encourages reporting errors and "near-misses." An effective reporting system has 2 components, one for public accountability for errors that result in serious injury and another for confidential reporting of mistakes that have the potential for serious injury. Regulatory protection from discovery must be established for voluntary error and near-miss reporting systems. In the nephrology community, novel uses of technology should be sought to prevent errors, human factors leading to errors should be identified and anticipated, and patterns of interaction at the machine-human interface should be studied. Progress in improving patient safety has occurred in some areas, such as pharmacy services. Such known and tested patient safety practices should be deployed in dialysis facilities. Success in improving patient safety will require leadership, collaborative efforts among the many stakeholders in the ESRD program, and adequate allocation of resources.

Identification and treatment of depression in a cohort of patients maintained on chronic peritoneal dialysis.

Depression is the most commonly encountered psychological problem in patients with end-stage renal disease (ESRD). Depression has recently been shown to significantly impact on the morbidity and mortality of patients undergoing therapy for ESRD. The present study was designed as a pilot study to evaluate the feasibility of screening a large cohort of patients maintained on chronic peritoneal dialysis (CPD) for depression and then pharmacologically treating those patients assessed to have clinical depression. One hundred thirty-six patients maintained on CPD in our CPD unit were screened for depression using the Beck Depression Inventory (BDI), a self-administered questionnaire. Patients with scores of 11 or greater were referred to a trained psychiatric interviewer for further evaluation to confirm the diagnosis of clinical depression and determine whether the patient was a candidate for antidepressant medication. Sixty-seven patients had BDI scores of 11 or greater, and 60 of these patients were asked to participate in further evaluation and possible therapy. Only 27 patients agreed to further study and were evaluated by a trained psychiatric interviewer for clinical depression. Twenty-three of these patients were assessed to have clinical depression, and 22 patients were eligible for antidepressant medication based on their scores on the Hamilton Depression Scale and psychiatric interview. Eleven patients completed a 12-week course of therapy with antidepressant medication, and their BDI scores decreased from a mean of 17.1 +/- 6.9 (SD) to a mean of 8.6 +/- 3.2. Seven patients were treated with sertraline, 2 patients with bupropion, and 2 patients with nefazodone. It is concluded that (1) depression is commonly present in patients maintained on CPD, (2) the BDI is a useful tool to use to screen for clinical depression, and (3) clinical depression is treatable with medication in this patient population.

Continuous peritoneal dialysis and the extended care facility.

The projected disproportionate increase in the number of elderly patients reaching end-stage renal disease constitutes a dramatic change in dialysis demographics. The nursing home or extended care facility (ECF) will become an increasingly important feature of care for both rehabilitation and long-term patient management. For continuous peritoneal dialysis (CPD), the ECF has been critically evaluated in only a single specialized, university-based, geriatric facility that included trained peritoneal dialysis nurses providing care. We have trained multiple ECF personnel in 10 community-based ECFs to provide all CPD-related therapy for 93 patients between November 1993 and December 1998, for a total of 289.3 patient-months. All ECFs have maintained their CPD program. Outcome measures, including hospitalization, mortality, technique failure, and peritonitis rates, show the success and feasibility of using community-based ECFs for CPD. The use of multiple ECFs for CPD appears to offer distinct advantages over solo structured ECF programs without jeopardizing outcomes. A highly structured CPD education program for ECF personnel by nephrology staff is manageable and appears critical for the success of maintaining CPD in the ECF.

Residual renal function in a large cohort of peritoneal dialysis patients: change over time, impact on mortality and nutrition.

OBJECTIVE: Residual renal function contributes importantly to total solute clearance in peritoneal dialysis (PD) patients. This study was designed to examine the progression of residual renal function over time and its impact on nutrition and mortality in PD patients in the six New England states (ME, NH, VT, CT, MA, RI) comprising End Stage Renal Disease (ESRD) Network 1. DESIGN: As part of the ESRD Clinical Indicators Project, data on 990 PD patients in Network 1 were abstracted from data supplied by dialysis units in the fourth quarter of 1997. This included demographic information; dose of PD in L/day; weekly renal, dialysis, and total Kt/V urea; weekly renal, dialysis, and total creatinine clearance (CCr); serum albumin level; and mortality and transplantation information. Data collection was repeated in the second and fourth quarters of 1998 and in the second quarter of 1999. PATIENTS: 990 PD patients in Network 1. OUTCOME MEASURES: The change in total and renal solute clearances over time, the relationship between renal clearance and mortality, and the relationship between renal clearance and nutritional status, as represented by serum albumin. RESULTS: Over the 2-year period, mean weekly renal Kt/V urea and weekly renal CCr dropped significantly. To examine the effect of residual renal function on mortality, patients were divided into high and low (above and below the median) weekly renal Kt/V urea and weekly renal CCr groups. Patients above the median levels of both weekly renal Kt/V urea and weekly renal CCr had a significantly decreased risk of dying during the observation period, after controlling for age, gender, serum albumin level, and diabetic status [OR for high vs low renal Kt/V urea 0.54 (CI 0.34 - 0.84), OR for high vs low renal CCr 0.61 (CI 0.40 - 0.94)]. The mean weekly renal Kt/V urea was significantly and directly correlated with the mean serum albumin level by Spearman rank correlation (R = 0.133, p < 0.001), as was the mean weekly renal CCr (R = 0.115, p < 0.001). CONCLUSIONS: Residual renal function is an important contributor to total solute clearance in PD patients. Even at low levels it is linked to decreased mortality and better nutritional status.

Tidal peritoneal dialysis: comparison of different tidal regimens and automated peritoneal dialysis.

BACKGROUND: The National Kidney Foundation Dialysis Outcomes Quality Initiative (DOQI) clinical practice guidelines have suggested minimal weekly Kt/V urea and creatinine clearance goals for peritoneal dialysis patients maintained on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). Achieving these goals may present problems, particularly in larger patients whose residual renal function declines. Thus, modifications of the dialysis regimen, such as tidal peritoneal dialysis (TPD), have been developed. However, the ability of TPD to improve the efficiency of the dialysis procedure remains uncertain. METHODS: Stable, cycling peritoneal dialysis patients were placed into two groups to study the effectiveness of different TPD prescriptions on peritoneal clearances of urea and creatinine. The volume of dialysis solution used and the duration of therapy were fixed in the two groups. Comparisons were made to conventional APD using multiple hourly cycles in which spent dialysis solution was completely drained with each cycle. Group I patients received a total of 15 L of PD solution over 9.5 hours in the dialysis unit. These patients received 10, 25, and 50% TPD and APD on four separate days. Group II patients received 24 L of PD solution over 9.5 hours. These patients received 25 and 50% APD on separate days in the dialysis unit. Peritoneal dialysis clearances for urea (pKt/V) and creatinine (pCCr) levels were calculated for both groups. The results were then analyzed to determine whether there was any significant difference among the various prescriptions. RESULTS: The data in the group I patients indicated a mean daily pKt/V of 0.22 +/- 0.03 with 10% TPD, 0.23 +/- 0.02 with 25% TPD, 0.25 +/- 0.02 with 50% TPD, and 0.26 +/- 0.02 with APD. Paired t-test analysis for pKt/V demonstrated that 10 and 25% TPD resulted in significantly lower values than 50% TPD and APD (P < 0.05). Mean daily pCCr L/24 h/1.73 m2 was 6.03 +/- 0.72 for 10% TPD, 6.34 +/- 0.83 for 25% TPD, 6.65 +/- 0.51 for 50% TPD, and 7.01 +/- 0.96 for APD; these differences were not significantly different. The data in the group II patients demonstrated a mean daily pKt/V of 0.28 +/- 0.03 with 25% TPD, 0.29 +/- 0.05 with 50% TPD, and 0.30 +/- 0.05 for APD. The mean daily pCCr was 6.69 +/- 0.47 for 25% TPD, 8.09 +/- 1.30 for 50% TPD, and 7.63 +/- 1.13 for APD. There were no statistical differences for pKt/V and pCCr within the 24 L group. CONCLUSION: When the duration of therapy and volume of dialysate volume are kept constant, TPD does not result in an improvement in clearances compared with conventional APD, at least with dialysate volumes up to 24 L.

Patient assessment of quality of care in a chronic peritoneal dialysis facility.

The percentage of patients with end-stage renal disease (ESRD) maintained on chronic peritoneal dialysis (CPD) in the United States remains well less than the percentage in several other countries. Furthermore, there has recently been a decline in the percentage of patients with ESRD in the United States undergoing CPD. The reasons for this decline are uncertain, and investigators have implicated problems with the kinetics of peritoneal dialysis, peritonitis and exit-site infections, and psychosocial stresses imposed by the therapy. Few studies, however, have considered the role of the dialysis facility itself and patient perceptions of the facility as contributing to problems with the long-term acceptance of CPD. This study is designed to examine patients' perceptions of the organization and structure of the peritoneal dialysis facility and their interactions with the facility, focusing attention on areas of patient satisfaction and dissatisfaction with the facility. The study was conducted in a large, freestanding peritoneal dialysis program in an urban area that currently treats 140 patients undergoing CPD. Thirty patients were randomly selected to participate in the present study. A structured interview that included open-ended questions was administered and tape-recorded by a trained interviewer not affiliated with the dialysis unit. Patient responses were then reviewed by two investigators, and a taxonomy of patient satisfaction and dissatisfaction was developed, using a modification of the classification proposed by Concato and Feinstein. Patient responses were then categorized according to the taxonomy. The most frequently cited areas of patient satisfaction included the amount of information and instruction provided by the staff (n = 30), personal atmosphere of the facility (n = 30), efficiency of delivery of the dialysis supplies (n = 23), and availability of the primary nurse (n = 18). The importance of the nurse-patient interaction was emphasized by all 30 patients, whereas the physician-patient interaction was cited by only 14 patients. The most frequently cited area of dissatisfaction noted by all 30 patients concerned the dialysis regimen itself. The present study focuses attention on patient perceptions of their CPD facility, identifying areas of satisfaction and dissatisfaction. The analysis is important not only in providing a framework for CPD facilities with which to review their own interactions with CPD patients, but also for identifying those areas that require attention to maintain the long-term viability of CPD therapy.

Chronic renal insufficiency: current understandings and their implications.

Chronic renal insufficiency (CRI) is underrecognized and undertreated even in sophisticated health care systems. This is particularly distressing in light of the growing number of effective interventions available to slow the progression of kidney disease and ameliorate many of its comorbid conditions. Progress, to a certain extent, is impeded by the lack of generally accepted definitions, clear diagnostic criteria, and practical screening tests. Available epidemiologic data suggest that 800,000 Americans have creatinine levels >/=2.0 mg/dL and over 6 million have levels >/=1.5 mg/dL. Population-based surveys show that age, male gender, and black race are predictors of kidney disease. For reasons that are not well understood, the incidence of kidney failure has nearly doubled over the last 15 years, indicating a parallel increase in CRI. This trend has significant economic implications. Other implications of CRI related to the use and availability of health care resources are appropriate referrals to nephrologists and early intervention to optimize care of patients with CRI. A multipronged approach to providing optimal care involves interventions that may delay the progression of renal dysfunction, proactive prevention of uremic complications, measures to forestall the progress of comorbid conditions, and timely preparation of patients for renal replacement therapy. Early recognition of CRI, expeditious referral for specialty care, and the utilization of a comprehensive program of care optimization will help meet the nation's goals as articulated in the National Institutes of Health's Healthy People 2010: Chronic Kidney Disease.

Posttransplant bone disease: evidence for a high bone resorption state.

Loss of bone is a significant problem after renal transplant. Although bone loss in the first post transplant year has been well documented, conflicting data exist concerning bone loss after this time. It is equally unclear whether bone loss in long-term renal transplant recipients correlates with bone turnover as it does in postmenapausal osteoporosis. To examine these issues, we conducted a cross-sectional study to define the prevalence of osteoporosis in long-term (> 1 year) renal transplant recipients with preserved renal function (mean creatinine clearance 73 +/- 23 ml/min). Bone mineral density (BMD) was measured at the hip, spine and wrist by DEXA in 69 patients. Markers for bone formation (serum osteocalcin) and bone resorption [urinary levels of pyridinoline (PYD) and deoxypyridinoline (DPD)] were also measured as well as parameters of calcium metabolism. Correlations were made between these parameters and BMD at the various sites. The mean age of the patients was 45 +/- 11 years. Eighty eight percent of patients were on cyclosporine (12% on tacrolimus) and all but 2 were on prednisone [mean dose 9 +/- 2 mg/day)]. Osteoporosis (BMD more than 2.5 SD below peak adult BMD) at the spine or hip was diagnosed in 44% of patients and osteopenia was present in an additional 44%. Elevated levels of intact parathyroid hormone (i PTH) were observed in 81% of patients. Elevated urinary levels of PYD or DPD were present in 73% of patients and 38% had elevated serum levels of osteocalcin. Levels of calcium, and of 25(OH) and 1,25(OH)2 vitamin D were normal. In a stepwise multiple regression model that included osteocalcin, PYD, DPD, intact PTH, age, years posttransplant, duration of dialysis, cumulative prednisone dose, smoking, and diabetes: urinary PYD was the strongest predictor of bone mass. These results demonstrate that osteoporosis is common in long-term renal transplant recipients. The data also suggest that elevated rates of bone resorption contribute importantly to this process.

Incidence of peritonitis in chronic peritoneal dialysis patients infused with intravenous iron dextran.

BACKGROUND: The Dialysis Outcomes Quality Initiative (DOQI) guidelines, published in 1997, emphasize the need for careful monitoring of iron stores and for provision of adequate iron replacement therapy to achieve target goals of hemoglobin concentration in end-stage renal disease (ESRD) patients, especially those treated with recombinant erythropoietin (rHuEPO). Intravenous iron dextran (IVID) therapy, which has long been used in hemodialysis patients, is increasingly being used in chronic peritoneal dialysis (CPD) patients. In 1997, we began using this form of iron therapy for our CPD patients. However, because considerable data exists to show a relationship between iron metabolism and acute infections, we questioned whether IVID infusion placed our patients at greater risk for peritonitis, the leading cause of death and patient drop-out from CPD therapy. OBJECTIVE: To evaluate the relationship between iron and infection, we studied episodes of peritonitis in CPD patients who were infused with IVID. DESIGN: In a retrospective study of adult CPD patients who received IVID during 1998, we investigated the occurrence of peritonitis episodes and the spectrum of causative organisms. Patients with a hemoglobin level of < 12.5 g/dL who also had a ferritin level < 100 ng/mL or a transferrin saturation level < 20% (or both) and who did not respond to oral iron therapy, were administered between 0.5 g and 1.0 g of IVID in an outpatient hospital setting. We calculated the expected and observed number of peritonitis episodes in these patients within 30, 60, and 90 days after infusion of IVID. RESULTS: During the study period, 56 patients received 77 doses of IVID, with 14 patients requiring 2 or more infusions. Of the 77 doses, 71 were given as a 1-g bolus. The IVID was well tolerated by all patients. Within 90 days of IVID administration, 14 patients developed peritonitis: 6 episodes occurred within 30 days, 7 episodes occurred between 31 and 60 days, and 1 episode occurred between 61 and 90 days after the IVID dosing. The peritonitis rate for patients not receiving IVID was 1 episode per 13.7 patient-months. Taking this rate as the "expected" rate, the expected number of episodes of peritonitis for the study population was 5.6 episodes within 30 days, 11.2 episodes within 60 days, and 16.8 episodes within 90 days following IVID administration. The difference between the expected and observed rates of peritonitis in patients who were dosed with IVID was not statistically different. The spectrum of organisms seen in the peritonitis episodes in the study population was not significantly different from that seen in the peritonitis episodes in our CPD unit population. CONCLUSIONS: There is evidence that IVID infusion therapy can improve anemia and reduce rHuEPO requirements in CPD patients, usually without adverse reaction and without exposing patients to an increased risk of peritonitis. More research is needed in the area of potential increased risk of infection in ESRD patients who are (1) infused with large doses of IVID, and (2) iron-overloaded.