Trends, Outcomes, and Economic Implications of Peritoneal Dialysis-Associated Peritonitis: A National Cohort Study.

Introduction Peritoneal dialysis-associated peritonitis (PDAP) is a serious complication of peritoneal dialysis, associated with significant morbidity, modality transition, and mortality. Here, we provide an update on the national burden of this significant complication, highlighting trends in demographics, treatment practices, and in-hospital outcomes of PDAP from 2016 to 2020. Methods Utilizing a national all-payer dataset of hospitalizations in the US, we conducted a retrospective cohort study of adult hospitalizations with a primary diagnosis of PDAP from 2016 to 2020. We analyzed demographic, clinical, and hospital-level data, focusing on in-hospital mortality, PD catheter removal, length of stay, and healthcare expenses. Multivariable logistic regression adjusted for demographic and clinical covariates was employed to identify risk factors associated with adverse outcomes. Results There was a stable burden of annual PDAP admissions from 2016 to 2020. Healthcare expenditures associated with PDAP were high, totaling over $75,000 per admission. Additionally, our data suggest geographic inconsistencies in treatment patterns, with treatment at western and teaching hospitals associated with increased rates of catheter removal relative to northeastern and non-teaching centers and a mean cost of nearly $55,000 more in Western states compared to Midwest states. 23.2% of episodes resulted in removal of the PD catheter. Risk factors associated with adverse outcomes included older age, higher Charlson Comorbidity Index scores, peripheral vascular disease, and the need for vasopressors. Conclusion PDAP is a major cause of mortality among PD patients, and there is a vital need for future studies to examine the impact of hospital location and teaching status on PDAP outcomes, which can inform treatment practices and resource allocation.

Impact of Prior Abdominal Procedures on Peritoneal Dialysis Catheter Outcomes: Findings From the North American Peritoneal Dialysis Catheter Registry.

RATIONALE & OBJECTIVE: A history of prior abdominal procedures may influence the likelihood of referral for peritoneal dialysis (PD) catheter insertion. To guide clinical decision making in this population, this study examined the association between prior abdominal procedures and outcomes in patients undergoing PD catheter insertion. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults undergoing their first PD catheter insertion between November 1, 2011, and November 1, 2020, at 11 institutions in Canada and the United States participating in the International Society for Peritoneal Dialysis North American Catheter Registry. EXPOSURE: Prior abdominal procedure(s) defined as any procedure that enters the peritoneal cavity. OUTCOMES: The primary outcome was time to the first of (1) abandonment of the PD catheter or (2) interruption/termination of PD. Secondary outcomes were rates of emergency room visits, hospitalizations, and procedures. ANALYTICAL APPROACH: Cumulative incidence curves were used to describe the risk over time, and an adjusted Cox proportional hazards model was used to estimate the association between the exposure and primary outcome. Models for count data were used to estimate the associations between the exposure and secondary outcomes. RESULTS: Of 855 patients who met the inclusion criteria, 31% had a history of a prior abdominal procedure and 20% experienced at least 1 PD catheter-related complication that led to the primary outcome. Prior abdominal procedures were not associated with an increased risk of the primary outcome (adjusted HR, 1.12; 95% CI, 0.68-1.84). Upper-abdominal procedures were associated with a higher adjusted hazard of the primary outcome, but there was no dose-response relationship concerning the number of procedures. There was no association between prior abdominal procedures and other secondary outcomes. LIMITATIONS: Observational study and cohort limited to a sample of patients believed to be potential candidates for PD catheter insertion. CONCLUSION: A history of prior abdominal procedure(s) does not appear to influence catheter outcomes following PD catheter insertion. Such a history should not be a contraindication to PD. PLAIN-LANGUAGE SUMMARY: Peritoneal dialysis (PD) is a life-saving therapy for individuals with kidney failure that can be done at home. PD requires the placement of a tube, or catheter, into the abdomen to allow the exchange of dialysis fluid during treatment. There is concern that individuals who have undergone prior abdominal procedures and are referred for a catheter might have scarring that could affect catheter function. In some institutions, they might not even be offered PD therapy as an option. In this study, we found that a history of prior abdominal procedures did not increase the risk of PD catheter complications and should not dissuade patients from choosing PD or providers from recommending it.

The Association of Intra-Abdominal Adhesions with Peritoneal Dialysis Catheter-Related Complications.

BACKGROUND: This study investigated the association of intra-abdominal adhesions with the risk of peritoneal dialysis (PD) catheter complications. METHODS: Individuals undergoing laparoscopic PD catheter insertion were prospectively enrolled from eight centers in Canada and the United States. Patients were grouped based on the presence of adhesions observed during catheter insertion. The primary outcome was the composite of PD never starting, termination of PD, or the need for an invasive procedure caused by flow restriction or abdominal pain. RESULTS: Seven hundred and fifty-eight individuals were enrolled, of whom 201 (27%) had adhesions during laparoscopic PD catheter insertion. The risk of the primary outcome occurred in 35 (17%) in the adhesion group compared with 58 (10%) in the no adhesion group (adjusted HR, 1.64; 95% confidence interval [CI], 1.05 to 2.55) within 6 months of insertion. Lower abdominal or pelvic adhesions had an adjusted HR of 1.80 (95% CI, 1.09 to 2.98) compared with the no adhesion group. Invasive procedures were required in 26 (13%) and 47 (8%) of the adhesion and no adhesion groups, respectively (unadjusted HR, 1.60: 95% CI, 1.04 to 2.47) within 6 months of insertion. The adjusted odds ratio for adhesions for women was 1.65 (95% CI, 1.12 to 2.41), for body mass index per 5 kg/m 2 was 1.16 (95% CI, 1.003 to 1.34), and for prior abdominal surgery was 8.34 (95% CI, 5.5 to 12.34). Common abnormalities found during invasive procedures included PD catheter tip migration, occlusion of the lumen with fibrin, omental wrapping, adherence to the bowel, and the development of new adhesions. CONCLUSIONS: People with intra-abdominal adhesions undergoing PD catheter insertion were at higher risk for abdominal pain or flow restriction preventing PD from starting, PD termination, or requiring an invasive procedure. However, most patients, with or without adhesions, did not experience complications, and most complications did not lead to the termination of PD therapy.

Calciphylaxis and Kidney Disease: A Review.

Calciphylaxis is a life-threatening complication most often associated with chronic kidney disease that occurs as a result of the deposition of calcium in dermal and adipose microvasculature. However, this condition may also be seen in patients with acute kidney injury. The high morbidity and mortality rates associated with calciphylaxis highlight the importance to correctly diagnose and treat this condition. However, calciphylaxis remains a diagnosis that may be clinically challenging to make. Here, we review the literature on uremic calciphylaxis with a focus on its pathophysiology, clinical presentation, advances in diagnostic tools, and treatment strategies. We also discuss the unique histopathological features of calciphylaxis and contrast it with those of other forms of general vessel calcification. This review emphasizes the need for multidisciplinary collaboration including nephrology, dermatology, and palliative care to ultimately provide the best possible care to patients with calciphylaxis.

Periprocedural Peritonitis Prophylaxis: A Summary of the Microbiology and the Role of Systemic Antimicrobials.

BACKGROUND: Peritonitis is a leading complication of peritoneal dialysis (PD). One strategy that the International Society for Peritoneal Dialysis (ISPD) has used to help mitigate the morbidity and mortality associated with peritonitis is through prevention, including antibiotic prophylaxis utilization in high-risk situations. The aim of this study is to summarize our current understanding of postprocedural peritonitis and discuss the existing data behind periprocedural antibiotic prophylaxis, focusing primarily on PD catheter insertion, dental procedures, colonoscopies, upper endoscopies with gastrostomy, and gynecologic procedures. SUMMARY: The ISPD currently recommends intravenous antibiotics prior to PD catheter insertion, colonoscopies, and invasive gynecologic procedures, though prophylaxis has only demonstrated benefit in a prospective, randomized control setting for PD catheter insertion. However, multiple retrospective studies exist that support the use of antibiotic prophylaxis for the other 2 procedures. No specific antibiotic regimen has been established as most optimal to prevent peritonitis for any of the 3 procedures. Antibiotic coverage should include the Enterobacteriaceae family, as well as Gram-positive organisms commonly found on the skin flora for PD catheter insertion, anaerobes for colonoscopies, and common organisms from the urogenital flora in gynecologic procedures. Additionally, the ISPD currently recommends oral amoxicillin prior to dental procedures. There is currently no ISPD recommendation to provide antibiotic prophylaxis prior to an upper endoscopy with or without gastrostomy, though this is a potential area for research. KEY MESSAGES: PD patients are at high risk for developing peritonitis after typical procedures. Antibiotic prophylaxis is a potential strategy that the ISPD utilizes to prevent these infections. However, further research needs to be done to determine the optimal antibiotic regimen.

Urgent-start peritoneal dialysis results in fewer procedures than hemodialysis.

BACKGROUND: Peritoneal dialysis (PD) is an underutilized modality for hospitalized patients with an urgent need to start renal replacement therapy in the USA. Most patients begin hemodialysis (HD) with a tunneled central venous catheter (CVC). METHODS: We examined the long-term burden of dialysis modality-related access procedures with urgent-start PD and urgent-start HD in a retrospective cohort of 73 adults. The number of access-related (mechanical and infection-related) procedures for each modality was compared in the first 30 days and cumulatively through the duration of follow-up. RESULTS: Fifty patients underwent CVC placement for HD and 23 patients underwent PD catheter placement for urgent-start dialysis. Patients were followed on average >1 year. The PD group was significantly younger, with less diabetes, with a higher pre-dialysis serum creatinine and more likely to have a planned dialysis access. The mean number of access-related procedures per patient in the two groups was not different at 30 days; however, when compared over the duration of follow-up, the number of access-related procedures was significantly higher in the HD group compared with the PD group (4.6 ± 3.9 versus 0.61 ± 0.84, P < 0.0001). This difference persisted when standardized to procedures per patient-month (0.37 ± 0.57 versus 0.081 ± 0.18, P = 0.019). Infection-related procedures were similar between groups. Findings were the same even after case-matching was performed for age and diabetes mellitus with 18 patients in each group. CONCLUSIONS: Urgent-start PD results in fewer invasive access procedures compared with urgent-start HD long term, and should be considered for urgent-start dialysis.

The Nephrologist's Management of Renal Cell Carcinoma After Kidney Surgery.

Renal cell carcinoma is associated with chronic kidney disease as well as with common risk factors including hypertension and diabetes mellitus. Localized renal cell carcinoma is treated surgically and in these cases has a favorable prognosis. In particular, in those individuals with small renal masses (≤4 cm), preservation of kidney function should be prioritized. Postoperative chronic kidney disease or end-stage renal disease prevention should include baseline kidney function and risk factor assessment, nontumor renal biopsy, as well as counseling on treatment options to discuss maximizing kidney function preservation. Postnephrectomy prognosis can be determined with repeat laboratory and clinical assessment. Ultimately, early involvement of the nephrologist in a multidisciplinary team including the urology team will enable the reduction of postsurgical kidney disease related morbidity and potentially mortality.

Quantifying the risk of insertion-related peritoneal dialysis catheter complications following laparoscopic placement: Results from the North American PD Catheter Registry.

BACKGROUND: Peritoneal dialysis (PD) is a more cost-effective therapy to treat kidney failure than in-center hemodialysis, but successful therapy requires a functioning PD catheter that causes minimal complications. In 2015, the North American Chapter of the International Society for Peritoneal Dialysis established the North American PD Catheter Registry to improve practices and patient outcomes following PD catheter insertion. AIMS: The objective of this study is to propose a methodology for defining insertion-related complications that lead to significant adverse events and report the risk of these complications among patients undergoing laparoscopic PD catheter insertion. METHODS: Patients undergoing laparoscopic PD catheter insertion were enrolled at 14 participating centers in Canada and the United States and followed using a Web-based registry. Insertion-related complications were defined as flow restriction, exit-site leak, or abdominal pain at any point during follow-up. We also included infections or bleeding within 30 days of insertion, and any immediate postoperative complications. Adverse events were categorized as PD never starting or termination of PD therapy, delay in the start of PD therapy or interruption of PD therapy, an emergency department visit or hospitalization, or need for invasive procedures. Cause-specific cumulative incidence functions were used to estimate risk. RESULTS: Five hundred patients underwent laparoscopic PD catheter insertion between 10 November 2015 and 24 July 2018. The cumulative risk of insertion-related complications 6 months from the date of insertion that led to an adverse event was 24%. The risk of flow restriction, exit-site leak, and pain at 6 months was 10.2%, 5.7%, and 5.3%, respectively. PD was never started or terminated in 6.4% of patients due to an insertion-related complication. Leaks and flow restrictions were most likely to delay or interrupt PD therapy. Flow restrictions were the primary cause of invasive procedures. Fifty percent of the complications occurred before the start of PD therapy. CONCLUSIONS: Insertion-related complications leading to significant adverse events following laparoscopic placement of PD catheters are common. Many complications occur before the start of PD. Insertion-related complications are an important area of focus for future research and quality improvement efforts.

Vitamin D and cinacalcet are associated with increased survival in peritoneal dialysis but not with residual renal function preservation
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BACKGROUND: Active vitamin D and cinacalcet, a treatment for secondary hyperparathyroidism and also with potential anti-inflammatory properties, have been associated with lower risk of death among dialysis patients. Vitamin D has also been described to decrease proteinuria in CKD patients. This study aims to assess the relationship of vitamin D and cinacalcet with survival and residual renal function preservation among peritoneal dialysis patients. MATERIALS AND METHODS: In a retrospective peritoneal dialysis cohort of 581 subjects, we assessed if vitamin D and cinacalcet therapy are associated with increased risk of death and residual renal function loss using Kaplan-Meier analysis and Cox proportional hazard analysis. RESULTS: Vitamin D treatment was associated with a 56% reduction in the risk of death (HR 0.44, 95% CI 0.28 - 0.67) and cinacalcet also with a 54% lower risk of death (HR 0.46, 95% CI 0.31 - 0.69) in multivariate models adjusting for each other. Hyperphosphatemia (> 6 mg/dL) was associated with an 85% increase in mortality (HR 1.85, 95% CI 1.30 - 2.65). Neither vitamin D (HR 1.04, 95% CI 0.45 - 2.39) nor cinacalcet (HR 0.74, 95% CI 0.45 - 1.20) were associated with a lower risk of anuria. CONCLUSION: Vitamin D and cinacalcet therapy was associated with a lower risk of death but not anuria, beyond other known risk factors among peritoneal dialysis patients.
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Correction to: Residual Renal Function and Obstructive Sleep Apnea in Peritoneal Dialysis: A Pilot Study.

The original version of this article unfortunately contained a mistake in the article title. The correct article title is "Residual Renal Function and Obstructive Sleep Apnea in Peritoneal Dialysis: A Pilot Study".

Residual Renal Function and Obstructive Sleep Apnea in Peritoneal Dialysis: A Pilot Study.

PURPOSE: Obstructive sleep apnea is common in patients with end-stage renal disease, and there is increasing evidence that clinical factors specific to end-stage renal disease contribute pathophysiologically to obstructive sleep apnea. It is not known whether circumstances specific to dialysis modality, in this case peritoneal dialysis, affect obstructive sleep apnea. Our study aimed to investigate the prevalence of obstructive sleep apnea in the peritoneal dialysis population and the relevance of dialysis-specific measures and kidney function in assessing this bidirectional relationship. METHODS: Participants with end-stage renal disease who were treated with nocturnal automated peritoneal dialysis for at least 3 months were recruited from a hospital-based dialysis center. Laboratory measures of dialysis adequacy, peritoneal membrane transporter status, and residual renal function were gathered by chart review. Patients participated in a home sleep apnea test using a level III sleep apnea monitor. RESULTS: Of fifteen participants recruited, 33% had obstructive sleep apnea diagnosed by apnea-hypopnea index ≥ 5 events per hour of sleep. Renal creatinine clearance based upon 24-h urine collection was negatively correlated with apnea-hypopnea index (ρ = - 0.63, p = 0.012). There were no significant associations between anthropometric measures, intra-abdominal dwell volume, or peritoneal membrane transporter status and obstructive sleep apnea measures. CONCLUSIONS: The prevalence of obstructive sleep apnea and sleep disturbances is high in participants receiving peritoneal dialysis. Elevated apnea-hypopnea index is associated with lower residual renal function, whereas dialysis-specific measures such as intra-abdominal dwell volume and peritoneal membrane transporter status do not correlate with severity of obstructive sleep apnea.

Physical Activity in Kidney Transplant Recipients: A Review.

Physical activity has known health benefits and is associated with reduced cardiovascular risk in the general population. Relatively few data are available for physical activity in kidney transplant recipients. Compared to the general population, physical activity levels are lower overall in kidney recipients, although somewhat higher compared to the dialysis population. Recipient comorbid condition, psychosocial and socioeconomic factors, and long-term immunosuppression use negatively affect physical activity. Physical inactivity in kidney recipients may be associated with reduced quality of life, as well as increased mortality. Interventions such as exercise training appear to be safe in kidney transplant recipients and are associated with improved quality of life and exercise capacity. Additional studies are required to evaluate long-term effects on cardiovascular risk factors and ultimately cardiovascular disease outcomes and patient survival. Currently available data are characterized by wide variability in the interventions and outcome measures investigated in studies, as well as use of small sample-sized cohorts. These limitations highlight the need for larger studies using objective and standardized measures of physical activity and physical fitness in kidney transplant recipients.

High-Output Cardiac Failure and Coronary Steal With an Arteriovenous Fistula.

Creation of an arteriovenous access for hemodialysis can provoke a sequence of events that significantly affects cardiovascular hemodynamics. We present a 78-year-old man with end-stage renal disease and concomitant coronary artery disease previously requiring coronary artery bypass grafting including a left internal mammary graft to the left anterior descending artery, ischemic cardiomyopathy with left ventricular systolic dysfunction, and severe aortic stenosis who developed hypotension unresponsive to medical therapy after recent angioplasty of his ipsilateral arteriovenous fistula for high-grade outflow stenosis. This case highlights the long-term effects of dialysis access on the cardiovascular system, with special emphasis on complications such as high-output cardiac failure and coronary artery steal syndrome. Banding of the arteriovenous fistula provided symptomatic relief with a decrease in cardiac output. Avoidance of arteriovenous access creation on the ipsilateral upper extremity in patients with a left internal mammary artery bypass graft may prevent coronary artery steal syndrome.

Rapid Change in Residual Renal Function Decline Is Associated with Lower Survival and Worse Residual Renal Function Preservation in Peritoneal Dialysis Patients.

The survival advantage observed among peritoneal dialysis patients early on after dialysis initiation has been largely attributed to residual renal function (RRF) preservation due to higher baseline residual function and fewer comorbidities. We hypothesize that a rapid decline in RRF is associated with higher risk of anuria and mortality. In a retrospective cohort study of 581 subjects on peritoneal dialysis with longitudinal prevalent data, we assessed whether RRF change over time, in addition to baseline RRF, increased risk of mortality and anuria using Kaplan-Meier analysis and Cox proportional hazard analysis to control for known risk factors. Rapid RRF decline (≥ 0.09 decline) over a 12-month period was associated with a 2.6-fold increase in the risk of death (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.66 - 4.07, compared with < 0.09 decline) and a 2-fold increase in anuria (HR 2.06, 95% CI 1.24 - 3.42). Each quartile of increasing severity of RRF decline over a 12-month period increased risk incrementally for death (2nd quartile: HR 3.04, CI 1.26 - 7.34; 3rd quartile: HR 4.01, CI 1.71 - 9.83; 4th quartile HR 5.78, CI 2.10 - 15.9) and generally for anuria (quartiles with HR 5.72 - 7.21). The escalating risk of mortality and anuria was greater for those with diabetes mellitus. In conclusion, rapid decline in RRF over a 12-month period increased the risk of mortality and likewise anuria, beyond previously established risk factors for mortality and anuria. The impact on mortality and RRF preservation was particularly severe for those with diabetes mellitus.

Does size matter? Kidney transplant donor size determines kidney function among living donors.

BACKGROUND: Kidney donor outcomes are gaining attention, particularly as donor eligibility criteria continue to expand. Kidney size, a useful predictor of recipient kidney function, also likely correlates with donor outcomes. Although donor evaluation includes donor kidney size measurements, the association between kidney size and outcomes are poorly defined. METHODS: We examined the relationship between kidney size (body surface area-adjusted total volume, cortical volume and length) and renal outcomes (post-operative recovery and longer-term kidney function) among 85 kidney donors using general linear models and time-to-chronic kidney disease data. RESULTS: Donors with the largest adjusted cortical volume were more likely to achieve an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 over a median 24-month follow-up than those with smaller cortical volumes (P <0.001), had a shorter duration of renal recovery (1.3-2.2 versus 32.5 days) and started with a higher eGFR at pre-donation (107-110 versus 91 mL/min/1.73 m2) and immediately post-nephrectomy (∼63 versus 50-51 mL/min/1.73 m2). Similar findings were seen with adjusted total volume and length. CONCLUSIONS: Larger kidney donors were more likely to achieve an eGFR ≥60 mL/min/1.73 m2 with renal recovery over a shorter duration due to higher pre-donation and initial post-nephrectomy eGFRs.

Renal Mass and Localized Renal Cancer: AUA Guideline.

PURPOSE: This AUA Guideline focuses on evaluation/counseling and management of adult patients with clinically localized renal masses suspicious for cancer, including solid-enhancing tumors and Bosniak 3/4 complex-cystic lesions. MATERIALS AND METHODS: Systematic review utilized research from the Agency for Healthcare Research and Quality and additional supplementation by the authors and consultant methodologists. Evidence-based statements were based on body of evidence strength Grade A/B/C (Strong/Moderate/Conditional Recommendations, respectively) with additional statements presented as Clinical Principles or Expert Opinions. RESULTS: Great progress has been made since the previous guidelines on management of localized renal masses were released (2009). The current guidelines provide updated, evidence-based recommendations regarding evaluation/counseling of patients with clinically localized renal masses, including the evolving role of renal mass biopsy. Given great variability of clinical, oncologic and functional characteristics, index patients are not utilized and the panel advocates individualized counseling/management. Management options (partial nephrectomy/radical nephrectomy/thermal ablation/active surveillance) are reviewed including recent data about comparative effectiveness and potential morbidities. Oncologic issues are prioritized while recognizing that functional outcomes are of great importance for survivorship for most patients with localized kidney cancer. A more restricted role for radical nephrectomy is recommended following well-defined selection criteria. Priority for partial nephrectomy is recommended for clinical T1a lesions, along with selective use of thermal ablation, particularly for tumors ≤3.0 cm. Important considerations for shared decision-making about active surveillance are explicitly defined. CONCLUSIONS: Several factors should be considered during counseling/management of patients with clinically localized renal masses, including general health/comorbidities, oncologic potential of the mass, pertinent functional issues and relative efficacy/potential morbidities of various management strategies.