Growing a peritoneal dialysis program: A single‐center experience

Abstract

The population of the United States is experiencing rapid growth of end-stage renal disease (ESRD) requiring renal replacement therapy (RRT). There were more than 548,000 ESRD patients in 2008, consuming 7% of the Medicare budget and $39.5 billion in total costs. With an annual growth of 6%, the ESRD population is projected to grow to more than 775,000 dialysis patients in 2020.1 RRT options include hemodialysis (HD), peritoneal dialysis (PD), and renal transplant. While renal transplant remains the RRT of choice, the proportion of ESRD patients receiving renal transplant has not changed in the past decade. With the increasing numbers of ESRD patients requiring dialysis, one would expect a proportionate growth of all dialysis modalities. However, while utilization of HD has progressively increased, there has been a steady decline in PD usage in the United States. Currently less than 7% of the U.S. dialysis patients use PD as their RRT modality.1 PD is associated with patient survival advantages when compared with HD during the first 2 years on dialysis.2-9 Unlike saw-tooth treatment with HD, PD delivers a more steady-state treatment, avoiding fluctuations in plasma volume and solutes, and is generally better tolerated by the patients with cardiovascular compromise. PD provides flexible schedules, thus allowing patients to work, travel, and participate in daytime activities. As PD does not involve needlesticks, patient anxiety is mitigated, arteriovenous access sites for future HD are preserved, and the risk of acquiring blood-borne infections such as hepatitis C and HIV are minimized. Additionally, residual renal function (RRF) is better preserved on PD than HD7-13 and is associated with improved outcomes. Furthermore, patients on PD have better long- and short-term transplant outcomes. Recent data suggest that compared with HD, PD patients have significantly lower incidence of delayed graft function, significantly lower requirement of dialysis in the post-transplant period, and better long-term transplant survival.7, 14-16 Moreover, PD is less expensive than HD on a per-patient per-year basis, with the difference estimated to be more than $20,000 based on the 2010 U.S. Renal Data System (USRDS) annual data report.1 Despite these advantages and lower costs, the number of patients on PD in the United States has progressively declined over the past 10 years17, 18 to below 7% of the total U.S. dialysis population, compared with other developed countries, where PD is being utilized in a much larger (15-30%) proportion of the dialysis population.1 The reasons for low utilization of PD in the United States are complex, but seem to be influenced by psychosocial and economic factors, lack of physician, surgeon, and nursing training, physician bias, and inadequate pre-ESRD education to the patients (Table I). Several of these factors are modifiable, and with a concerted effort PD utilization can be significantly increased. In order to expand PD utilization, it is imperative to develop a comprehensive infrastructure and support system for PD programs that will both enhance enrollment of patients who otherwise would have been excluded as PD candidates and eliminate loss of PD patients to HD. Implementation of such programs can contribute considerably to enhancing the PD population growth rate, as has been realized at the University of Texas (UT) Southwestern Medical Center/Davita PD program in Dallas. The PD utilization at our center has grown over 120% in the past 10 years, in stark contrast to the steady decline in PD utilization across the country over the same time period. One major reason for the steady regression of the U.S. PD population is a progressive decrease in the number of patients starting PD, notwithstanding the perception of U.S. nephrologists who believe that approximately 30% of the dialysis population should utilize PD.19 As noted above, the underutilization of PD is influenced by several factors such as patient education, training of physicians and surgeons in PD, financial incentives, and ownership of dialysis units (including units owned by large dialysis organizations [LDOs]), as well as demographic and psychosocial issues. Efforts should be made to understand these factors and implement appropriate measures to enhance the growth of a PD program Lack of pre-ESRD education is a key factor that has contributed to regression of PD population in the United States. The USRDS Dialysis Morbidity and Mortality Wave 2 (DMMS 2) study drew attention to the lack of pre-ESRD education among chronic kidney disease (CKD) patients. It was noted that among new ESRD patients initiating HD, only 25% of patients reported that PD was discussed with them before they started treatment for kidney failure.20 Since then, rates of discussion of PD among CKD patients have increased, as suggested by the recent Comprehensive Dialysis Study (CDS), comprising a cohort of incident patients beginning dialysis in the 2005-2007 period.21 In this study, it was observed that 61% of patients reported that PD had been discussed with them before the start of dialysis. However, only 11% of the patients informed about PD as an option actually chose this modality. This parallels the decline in PD utilization countrywide in the corresponding period. The low rate of PD acceptance among informed patients in the CDS is likely a result of the quality and quantity of information presented to the patients as a part of their pre-ESRD education. The importance of quality patient education is underscored by the results of the National Pre-ESRD Education Initiative (NPEI): 45% of the patients who received pre-ESRD education opted for PD and 33% actually started PD.22 Similarly, in a report from Hong Kong, 50% patients who were offered PD were reluctant to start PD initially but agreed after pre-dialysis counseling.23 Another report from the United Kingdom showed that close to 50% of patients who receive explanations for PD and HD through pre-dialysis counseling would choose PD.24 A multidisciplinary pre-ESRD education program that includes nephrologists, nurses, dieticians, and social workers can considerably enhance the growth of a PD program. We have developed a robust pre-ESRD patient education program at UT Southwestern Medical Center (Figure 1). At our center, patients with stage 4 CKD seen at renal clinics are referred to pre-ESRD education classes that comprise nurse educator, access nurse, pre-transplant coordinator, dietician, pharmacist, and social worker. Two sessions of classes are held (in both English and Spanish), and family members are encouraged to attend the sessions. The patients who show interest in PD are referred to the PD center for further evaluation and hands-on experience with the PD technique. At the same time, eligible patients are also referred for pre-transplant evaluation. University of Texas Southwestern Medical Center model for pre-ESRD (end-stage renal disease) education. See text for details. At the PD center, the patient and family meet with their peers, are shown a DVD about PD technique, and have the opportunity to have one-on-one meetings with the PD nurse, social worker, dietician, and nephrologist. Once the patient decides to pursue PD, the individual is referred to the access clinic for placement of the PD catheter and eventual initiation of PD. Between 2001 and 2004, 309 patients with CKD, who were provided pre-ESRD education at our program, were initiated on dialysis. Of these patients, 37% were initiated on PD, which is far greater than the proportion of U.S. dialysis patients starting PD (Figure 2).1 Through the use of our pre-ESRD program at UT Southwestern Medical Center, the number of PD patients has more than doubled at the UT Southwestern Medical Center/DaVita PD clinic over the past 10 years (Figure 3). Our experience suggests that high-quality patient education must begin in CKD stage 4, using a teamwork approach, to allow patients and families to understand various treatment options and make judicious decisions, thereby allowing orderly planned initiation of the appropriate RRT modality. Impact of pre-ESRD (end-stage renal disease) education on dialysis modality choice, University of Texas Southwestern Medical Center experience. Of the 309 patients who were provided pre-ESRD education during the period 2001–2004, 37% actually started on peritoneal dialysis (PD). With the pre-ESRD program, there has been a significant increase in the PD population at the center. In contrast to less than 7% prevalence in the United States,1 the PD population at the center comprises 26% of the total dialysis population. Growth of the University of Texas Southwestern Medical Center/DaVita PD program. At our peritoneal dialysis (PD) center, the number of patients has nearly doubled over the past 10 years. The growth of our PD program is in stark contrast to the nationwide trend, which shows a consistent decline in the PD population in the past two decades; currently less than 7% of all dialysis patients utilize PD as the renal replacement therapy.1 At our center, about 26% of all dialysis patients are on PD. It is well recognized that PD training during U.S. nephrology fellowships is inadequate, as highlighted by two studies.25, 26 It was observed that 29% of U.S. nephrology training programs had fewer than five PD patients per fellow, and that fellows spent less than 5% of their time receiving training in the care of PD patients in 14% of programs. When asked, only 32% of fellows stated that they had attended an outpatient PD clinic; 52% stated that their PD rotation was less than 4 weeks in duration; 24% of fellows had never initiated PD in a patient; 57% had initiated PD on fewer than five patients; and 38% felt training was inadequate. A practicing nephrologist who did not have adequate PD training will be reluctant to offer this therapy. In order to improve PD training, fellowship programs must provide adequate exposure to PD. Programs with small or no PD clinics should offer fellows elective rotation in centers with larger PD populations. The Residency Review Committee should consider the requirement of 5-10 PD patients per fellow to accredit a fellowship program. At UT Southwestern Medical Center, we have a dedicated PD rotation, and fellows spend at least 3 months over 2 years of their training attending PD rotation. During the rotation, they are exposed to all aspects of PD including routine care of patients, initiation of PD, PD training, evaluation for PD among CKD patients, and participation in multidisciplinary patient care plan meetings and quality assurance meetings. The fellows have consistently ranked the PD rotation as one of the most popular. Several fellows have started de novo PD programs or have expanded the existing PD programs after joining a nephrology practice Until recently, Medicare payments included a composite rate, which incorporated the dialysis procedure, supplies, routine laboratory tests, and personnel, and additional payments for “injectable” drugs such as erythropoietin, vitamin D analogs, and iron, on as-used basis. The potential profit margin of the dialysis provider depended heavily on the amount of injectable drugs used. Since there is a lower requirement of injectable medications in PD compared with HD, this made HD more profitable than PD for dialysis providers including the LDOs that treat more than 70% of U.S. dialysis patients. While LDOs in the United States increased by 53% between 1996 and 2004, with a corresponding increase in the number of patients undergoing HD in these units from 39% to 63%, there was no increase in the number of PD patients.27 The new payment system introduced by the government in 2011 will tighten payments by merging composite rate services as well as injectables, certain oral medications, laboratory tests currently not a part of composite services, and some other supplies such as blood products, into a single bundled payment. Thus PD, for which there is far less use of injectables and utilization of labor, may come out ahead of HD financially. Whether the introduction of the new payment system (with financial incentives for home-based dialysis therapies) will help in expanding the PD population in the United States remains to be seen. In order to expand the PD population, apart from increasing enrollment of new PD patients, it is extremely important to reduce the rate of PD technique failures that lead to transfer of patients to HD. It has been observed that a large proportion of dialysis patients transfer from PD to HD every year and that this could be a significant cause of the underutilization of PD in the United States (Table I).9, 28 Recurrent episodes of peritonitis, inadequate dialysis, or ultrafiltration (UF) failure as well as system issues and psychosocial reasons make up most of the reasons for the transfer to HD (Table I). PD-to-HD switch rates of more than 35% have been reported in the first 2 years in the United States.9 Strategies to prevent or resolve the issues that lead to transfer to HD may help with increasing PD utilization PD-related infections (including peritonitis) and catheter infections (exit site and tunnel infections) are the most frequent and important complications of PD, often resulting in catheter removal and discontinuation of PD, notwithstanding significant improvement in PD techniques. In a recent prospective study of 292 PD patients from 28 dialysis centers, it was found that the most common reason for the switch from PD to HD was related to infection (peritonitis and catheter infections) at 36.9%, followed by volume overload at 18.5%.29 The incidence of peritonitis ranges from one episode per 24.8 months to one episode every 46.4 months in various studies.30 No significant difference in risk of peritonitis has been observed with the design of catheters, surgical techniques used to place the catheters (laparoscopic versus open surgical), or location of catheter exit sites (pre-sternal or abdominal).31, 32 Quality improvement initiatives in PD, using a comprehensive approach that includes use of prophylactic antibiotics for peritonitis, exit site and catheter care, and training and retraining of patients can go long way in having positive effects on reducing rates of peritonitis and exit-site infection. PD outcomes can be further improved by implementation of continuous quality improvement (CQI) programs to track the root cause of peritonitis as well as rates of exit-site infection, peritonitis, and technique failure by careful data collection and providing feedback to the PD team so that appropriate interventions can be implemented. Higher infection rates should trigger a review of techniques and re-education of both patients and staff to ensure that the break-in technique is not contributing to high rates of peritonitis. By using these tools, it is possible for a center to significantly lower PD-related infection rates and technique failure. We have a robust CQI program at the UT Southwestern Medical Center/Davita PD center. Using such multidisciplinary approach, we have achieved excellent infection rates (one episode of exit site infection in 235 months at risk and one episode of peritonitis in 36 months at risk). Failure to maintain volume homeostasis is an important cause of PD technique failure. There is mounting evidence that with time, the UF capacity of the peritoneal membrane is progressively lost, with a concomitant increase in the peritoneal small-solute transport rate.33-35 The upsurge in small-solute transport reflects an increase in effective peritoneal surface area due to proliferation of capillaries as a result of prolonged exposure to bioincompatible PD solutions. Altered peritoneal membrane function has a significant impact on both technique and patient survival.33-37 As the prevalence of UF failure increases with PD vintage, it becomes the predominant reason for dropout in long-term PD patients.33-39 Reduced UF capacity leads to a chronic volume overload state with resultant congestive heart failure and cardiovascular mortality.39-41 Poor UF can also lead to low drain volumes and consequently to poor solute clearance and thus lower dialysis adequacy. In addition, patients with UF failure experience rapid absorption of glucose from the dialysate (with inhibition of appetite) and a greater loss of proteins in the dialysate leading to poor nutritional status and adverse outcomes.39-41 UF failure may be due to causes other than peritoneal membrane dysfunction. Dietary indiscretion, excessive sodium and fluid intake, inadequate dialysis prescription, loss of RRF without adjustments in dialysis prescription, and catheter malfunction are often the causes of chronic volume expansion. Protecting thre peritoneal membrane from the long-term toxic and metabolic effects of the conventional glucose-based solutions is a key objective to improve PD outcomes.42 The recent development of new, more biocompatible, PD solutions may help to preserve peritoneal membrane function, promote UF, improve nutritional status and hopefully improve overall PD outcomes.42 Unfortunately, these biocompatible solutions, with exception of icodextrin, have not yet been approved by the U.S. Food and Drug Administration (FDA) and are unavailable in the United States. Consequently, alternative approaches are required to maintain volume homeostasis in PD patients. Maintaining RRF is of paramount importance in PD patients, and rates of decline of RRF have been associated with all-cause mortality and technique failure.17, 42 Measures to maintain RRF such as avoiding nephrotoxic agents like non-steroidal anti-inflammatory agents, intravenous contrast, and aminoglycosides should be implemented as much as possible. Furthermore, recent studies have demonstrated a beneficial effect of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in preservation of RRF among PD patients; these should therefore be prescribed unless contraindicated.43, 44 Additionally, close attention to the prescription as well as frequent dietary counseling of the patient are essential to prevent fluid overload, improve overall outcomes, and reduce the incidence of technique failure. We recently observed that catheter-related mechanical complications are significantly associated with PD catheter failure.45 These complications include intraluminal/extraluminal catheter obstruction, catheter malpositioning, catheter migration, omental wrap around the catheter, catheter leakage, and catheter extrusion. Many causes of catheter malfunction such as extraluminal occlusion by the bladder or bowels can be prevented or corrected with the use of laxatives or by emptying the bladder. Intraluminal obstruction due to clots or a fibrin plug can be treated by injecting heparinized saline, or, if this is unsuccessful, by instillation of tissue plasminogen activator in the catheter. Appropriate laparoscopic or open surgical techniques can correct several other common mechanical problems such as omental wrapping, adhesion formation, catheter migration, and leaks. One-year actuarial catheter survivals of 80% should be expected using International Society for Peritoneal Dialysis standards.46 Superior catheter outcomes can be accomplished with proper patient management and the availability of surgical expertise. We have demonstrated excellent catheter survival rates at our center.45 In a retrospective study of 315 patients examining various risk factors associated with the survival of first PD catheters placed at our center between January 2001 and September 2009, we observed 1-year, 2-year, and 3-year PD catheter survival rates of 92.9%, 91.9%, and 91.1%, respectively. On further investigation of different variables in our study, we observed that PD catheter-related non-infectious complication was the single covariate that significantly reduced the catheter survival time. Each PD catheter-related problem increased the risk of catheter failure more than three times (hazard ratio 22.467; beta estimate 3.112). None of the other demographic (age, gender, race) or clinical characteristics (body mass index, diabetic status, co-morbidities, previous abdominal surgeries) or any infections (peritonitis, exit site, or tunnel) were found to be significantly associated with PD catheter survival.45 Our study suggests that, contrary to the general perception, morbid obesity, multiple abdominal surgeries, the presence of co-morbidities, and advanced age should not be considered barriers to patient selection for PD. Inclusion of the surgeon as a part of the multidisciplinary team caring for CKD and ESRD patients can lead to long-term success and growth of a PD program. In addition to an overall survival benefit of PD over HD, data from Canadian, Dutch, and U.S. registries show that the characteristics of a PD center have a significant impact on PD outcomes.47-49 A significant correlation has been observed between patient and technique survival and number of patients treated in a center. Using data from the comprehensive Dutch End-Stage Renal Disease Registry (RENINE), Huisman et al. showed that low technique survival rates occurred mainly in centers with less than 20 patients on PD; the relative risk for technique failure was 1.68 compared with larger centers.48 These results suggest that the degree of experience and specialization in a PD center has a strong impact on PD outcomes. It is suggested that a propensity to exploit technical and non-technical advances in PD increases directly with experience and that the centers become more adept at selecting patients to receive PD and treating their complications.49 This is illustrated by the excellent PD catheter outcomes at our PD center, which is one of the largest PD centers in the United States, treating about 120 patients.45 Most of the U.S. PD programs are small, however, typically comprising 10-15 PD patients. Most states and ESRD networks require one full-time nurse for 20-25 PD patients. Therefore, having a full-time nurse for smaller programs is not cost effective, and smaller centers usually utilize part-time staff caring for both PD and HD patients.50 This leads to a lack of expertise and comfort on the part of the staff treating PD patients, which in turn affects the decision to offer PD and may cause high patient dropout from the program. Patient outcomes and PD growth can be improved if smaller programs in a given geographical area can be consolidated into one large PD center that will allow staff to assume primary responsibility for patient care and develop expertise in treating patients with PD, thereby contributing to the growth of the program. PD continues to be underutilized in the United States for non-medical reasons such as complex psychosocial and economic factors, lack of physician training, physician bias, and inadequate pre-ESRD education to the patients. Modification of several of these factors can significantly improve PD utilization (Table II). Patient and physician education and comfort with using PD are critical. Minimizing episodes of PD-related infections, preserving the peritoneal membrane by using more biocompatible solutions and drugs such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, and careful management of volume status can reduce loss of PD patients to HD. Timely surgical interventions can prevent the malfunction and loss of PD catheters. Consolidating smaller PD facilities in a given geographical area into a single large PD center can further improve PD outcomes and PD growth. Finally, with the introduction of bundled payment for dialysis services, PD may emerge as a cost-effective therapy and interest may be rekindled in the dialysis community to consider PD as a viable RRT option.