The continuum home program concept.

The continuum home program concept aims to promote preservation of freedom for the individual patient, providing the opportunity to administer the therapy of choice in the patient's own environment. It strives for a continuation rather than a disruption of the patient's live. Continuum emphasizes matching the prescription to the patient's metabolic and psychological needs and strong consideration is given to economic realities and the best utilization of resources. Patients should be approached from the time of earliest referral and should be followed throughout their life with renal failure, regardless of therapy selection. The concept incorporates the traditional renal team members, as well as individuals responsible for the creation, manufacturing and delivery of products and services. It addresses patient recruitment, pre-ESRD education, general planning of dialysis, training tools and the timely creation of vascular or peritoneal access. The ideal program should provide a continuous flow of services where consideration for the patient's autonomy is always a priority.

Prescription writing: CAPD and PD plus.

The formulations of prescriptions for CAPD and PD plus are based on the theoretical constructs of equilibration dialysis and automated PD. There is good correlation between the predicted clearances and net ultrafiltration and those observed in clinical practice, particularly for patients with average peritoneal transport. Higher dialysate flows prescribed during APD to enhance small solute clearances and net ultrafiltration often result in reduced sodium removal due to sodium sieving. Sodium sieving can be minimized with APD through optimal prescriptions. The evidence supports the use of PD plus when adequacy targets cannot be achieved with CAPD.

Peritoneal dialysis solutions--at a crossroad.

After many decades of evolution and with many choices available for the formulation of peritoneal dialysis fluids (PDF), we find ourselves at a crossroads. A review of related developments, laboratory trials and clinical evaluations is offered to stimulate future research in this area. The information presented here raises more questions than it provides answers, but opens the door to innumerable possibilities for improvement. The search for a biocompatible osmotic agent designed to replace those currently used has been frustrating and is far from being considered a success. Research on cytokines and other mediators of inflammation produced a huge amount of interesting scientific knowledge that may help our understanding. However, it is unlikely that it will identify a specifically targeted anticytokine, or combination of them, designed to neutralize and/or reverse inflammatory changes resulting from the use of poorly biocompatible PDF. The development of low glucose degradation product (GDP) solutions by means of multi-chambered bags appear to be a step in the right direction and perhaps is the most significant improvement in this field in many decades. GDPs are important, but not the only offenders or the exclusive source of oxidative stress. Thus, the addition of antioxidants to PDF formulations, in our opinion, deserves further consideration. Additionally, repopulation of the mesothelial monolayer by means of periodic autotransplantation of mesothelial cells may well become a useful tool to prevent and/or correct membrane failure. We are fortunate to have choices at this crossroad, which we must evaluate rigorously.

Complications of peritoneal dialysis catheters: early and late.

The complications of peritoneal dialysis catheters are often due to errors made during the initial catheter insertion procedure. Other complications relate to the improper selection of the catheter type or size. Thus, many complications are preventable. This review summarizes the complications resulting from the insertion or presence of a PD catheter and classifies them as either early or late events. A short comment on early diagnosis and appropriate management is also provided.

Daily hemodialysis: a dialysis provider perspective.

Regardless of size, ownership or corporate structure, the goal of the dialysis provider is to deliver the best renal substitution therapy in the safest and most convenient manner, at a cost commensurate with reimbursement. This paper reviews the available data on daily hemodialysis, focusing on its ability to satisfy this goal. In addition, it examines the potential influence of frequency, time, and dose of dialysis on clinical outcomes of various series over the last 3 decades. The available data strongly suggest the clinical benefits of daily hemodialysis, but are not sufficient to show statistically better outcomes. Under the present reimbursement system, daily hemodialysis is not economically feasible in the United States. Prospective clinical trials designed to prove the benefits of these therapies and justify their reimbursement are needed.

Evolution of continuous flow peritoneal dialysis and the current state of the art.

Continuous flow peritoneal dialysis (CFPD) was first conceived more than three decades ago in an attempt to enhance peritoneal clearances using the continuous flow technique. Its progress was halted by technical limitations and by the high cost required to generate large volumes of dialytic solution. The recent demand for higher PD doses and technical innovations have revived the interest in this therapy. This article reviews the basic mechanical principles governing CFPD, its potential advantages and disadvantages, and the various methods to generate dialysate. Recent clinical experiences strongly suggest that CFPD can achieve higher small solute clearances than any modality of conventional PD or three times a week hemodialysis, and perhaps comparable to those obtained with daily hemodialysis. Attention can now be directed at improving peritoneal access and developing systems compatible with current reimbursement.

Single-pass continuous flow peritoneal dialysis using two catheters.

With a renewed interest in continuous flow peritoneal dialysis (CFPD), our standard practice of implanting a second catheter in those patients facing access failure provided us the opportunity to perform acute studies on CFPD in these patients, since it temporarily provided us with two catheters. Four patients were studied, with a total of five studies performed. A standard protocol was followed utilizing 1.5% dextrose solution, a 2 L fill, an inflow rate of 200 ml/min with a proportionate outflow for a 4-hour session. A full drain was performed at the end of the study. Our results provided us with a mean effective peritoneal clearance for urea (KpeU) and creatinine (KpeCr) of 40 ml/min and 28 ml/min, respectively, and a mean ultrafiltration rate (Qf) of 13.4 ml/min. Our average mass transfer coefficient (MTC) for urea was 40 ml/min, consistent with kinetic modeling and historical data. The Kpe, MTC, and Qf achieved are significantly higher than other investigators, which could possibly be explained by those obtained by two separate catheters resulting in adequate mixing of the dialysate. These clinical results provide a solid foundation for the future development of this PD modality.

Daily and nocturnal hemodialysis: how do they stack up?

A growing number of articles in the literature describe experiences using more frequent hemodialysis (HD), either short daily or long nocturnal. Most of these publications highlight successes obtained by these programs with a fragmented look at specific areas and outcomes. This review of published results from the use of these therapies shows that universal improvement is noted in dialysis adequacy, nutrition, quality of life, blood pressure control, fluid and electrolyte balance, and hospitalizations when these parameters are mentioned. However, data reporting is often incomplete. Most studies do not have adequate control groups, patient populations are often different from the standard HD population, and many have small numbers that preclude statistical significance. Nonuniformity of patient selection and study design prevents accurate comparison and pooling of patient data. In some cases, the same patients' data for the same periods of observation are reported in several studies. Despite data that can be characterized as preliminary and anecdotal, the results reported in this review show remarkable patient improvement worthy of serious consideration by the renal community. To reach a level of evidence that will be widely acceptable, the renal community needs to partner with such government institutions as the National Institutes of Health and the Health Care Financing Administration to study systematically the outcomes and costs associated with using more frequent HD. In the process, important ramifications of such a cooperative study, including potential changes in policy, need to be considered.

The treatment of anemia in peritoneal dialysis patients.

The management of anemia in patients with end-stage renal disease (ESRD) treated with peritoneal dialysis (PD) has gained increasing attention over the past decade, similar to patients on hemodialysis (HD). However, there are many differences between the 2 renal replacement therapies that pose unique challenges and solutions for monitoring, diagnosis and treatment of anemia in PD patients. These differences are not always evident and may be the result of different patient selection, physical, emotional and motivational factors, specific requirements of the modality or an indeterminate blend of infinite gradations of all these factors. This review will highlight current issues in anemia management in PD patients.

Peritonitis and antibiotic therapy in patients on cycler peritoneal dialysis--an update.

The increased use of automated peritoneal dialysis (APD) and the inherent differences between continuous ambulatory peritoneal dialysis (CAPD) and APD have generated interest in the treatment of peritonitis in cycler patients. This review considers variations in the incidence of peritonitis and in its microbiological spectrum among CAPD and APD patients, and discusses the potential causes for these variations, with emphasis on recent literature. Flow-pattern variances between CAPD and APD demand special considerations in the diagnosis of peritonitis. Multiple alternatives for the management of peritonitis in APD are discussed in light of recent clinical experiences and pharmacokinetic considerations.

Quality-of-life evaluation using Short Form 36: comparison in hemodialysis and peritoneal dialysis patients.

Short Form 36 (SF-36) is a well-documented health-related quality-of-life (HRQOL) instrument consisting of 36 questions compressed into eight scales and two primary dimensions: the physical and mental component scores. This tool was used to evaluate QOL among peritoneal dialysis (PD) and hemodialysis (HD) patients. The results of 16,755 HD and 1,260 PD patients (728 continuous ambulatory PD [CAPD] and 532 continuous cycling PD [CCPD]) completing an SF-36 during 1996 were analyzed. Three analyses of variance were performed, consisting of (1) no adjustment, (2) case mix (age, sex, race, and diabetes), and (3) case mix plus laboratory parameters. PD patients were younger (P < 0.001), a larger fraction were white (P < 0.001), fewer had diabetes (P < 0.001), and had lower serum albumin concentrations (P < 0.001) and higher creatinine, hemoglobin, and white blood cell count values (P < 0.001) than HD patients. Diabetes was present in a larger fraction of CCPD than CAPD patients (P < 0.001). HD and PD patients scored similarly for scales reflecting physical processes. PD patients scored higher for mental processes, but only after statistical adjustment for the laboratory measures. Scores on scales reflecting physical processes were worse, and those reflecting mental processes were better among CCPD than CAPD patients. HD and CAPD scores were similar. CCPD patients perceived themselves as more physically impaired but better adjusted than HD or CAPD patients. These descriptive data show that perception of QOL among PD and HD patients is similar before adjustment, but PD patients score higher for mental processes with adjustment. CCPD patients score worse for physical function and better for mental function than either CAPD or HD patients. We cannot, however, exclude the influence of therapy selection.