Stability of the Combination of Ceftazidime and Cephazolin in Icodextrin or pH Neutral Peritoneal Dialysis Solution

♦ Introduction: The objective of this study was to investigate the stability of ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral peritoneal dialysis (PD) solution.♦ Methods: Ceftazidime and cephazolin were injected into either a 7.5% icodextrin or pH neutral PD bag to obtain the concentration of 125 mg/L of each antibiotic. A total of nine 7.5% icodextrin or pH neutral PD bags containing ceftazidime and cephazolin were prepared and stored at 1 of 3 different temperatures: 4°C in a domestic refrigerator; 25°C at room temperature; or 37°C (body temperature) in an incubator. An aliquot was withdrawn immediately before (0 hour) or after 12, 24, 48, 96, 120, 144, 168 and 336 hours of storage. Each sample was analyzed in duplicate for the concentration of ceftazidime and cephazolin using a stability-indicating high-performance liquid chromatography technique. Ceftazidime and cephazolin were considered stable if they retained more than 90% of their initial concentration. Samples were also assessed for pH, colour changes and evidence of precipitation immediately after preparation and on each day of analysis.♦ Results: Ceftazidime and cephazolin in both types of PD solution retained more than 90% of their initial concentration for 168 and 336 hours respectively when stored at 4°C. Both of the antibiotics lost more than 10% of the initial concentration after 24 hours of storage at 25 or 37°C. There was no evidence of precipitation at any time under the tested storage conditions. Change in the pH and color was observed at 25 and 37°C, but not at 4°C.♦ Conclusion: Premixed ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral PD solution is stable for at least 168 hours when refrigerated. This allows the preparation of PD bags in advance, avoiding the necessity for daily preparation. Both the antibiotics are stable for at least 24 hours at 25 and 37°C, permitting storage at room temperature and pre-warming of PD bags to body temperature prior to its administration.     

The Occurrence of Increased Intraperitoneal Volume Events in Automated Peritoneal Dialysis in the US: Role of Programming,Patient/User Actions and Ultrafiltration

♦ Background, objectives and methods: Increased intraperitoneal volume (IIPV) can occur during automated peritoneal dialysis (APD). The contribution of factors such as cycler programming and patient/user actions to IIPV has not been previously explored. The relationship between IIPV and cycler programming, patient/user actions, and ultrafiltration over a two-year period was investigated using US data from Baxter cyclers. Drain/fill volume ratios of > 1.6 to ≤ 2.0 and > 2.0 were defined as Level I and Level II IIPV events, respectively.♦ Results: Level I IIPV events occurred in 2.39% of standard and 4.73% of small fill volume therapies, while Level II IIPV events occurred in 0.26% and 1.33% of therapies, respectively. IIPV events occurred significantly more often in association with tidal peritoneal dialysis (PD) compared to non-tidal PD therapies. In tidal therapies, IIPV events were primarily related to suboptimal programming of total ultrafiltration volume. Factors that increased the odds of IIPV events during standard therapies included programming the initial drain volume target to < 70% of the last fill, and setting minimum drain volumes to < 85% of the fill volume. Bypass of initial drain by patients/users was also associated with a significant increase in the odds of IIPV events in non-tidal, but not tidal PD. An increase in the odds for IIPV was also seen for standard therapies within the highest (> 1,245 mL) versus the lowest (< 427 mL) quartile of ultrafiltration. Similar trends were seen in small fill volume therapies. Clinical presentations associated with IIPV events were not assessed.♦ Conclusions: IIPV events are more frequent in tidal and small fill volume therapies. The greatest potential for IIPV occurred when the total ultrafiltration was set too low for the patient’s UF requirements during tidal therapy. Patient/user bypass of drains without reaching the target drain volume contributes significantly to IIPV events in non-tidal PD therapies. Poorly functioning PD catheters may be central to the cycler programming and patient/user actions that lead to IIPV.     

Peritoneal Dialysis Reduces the Number of Hospitalization Days in Heart Failure Patients Refractory to Diuretics

♦ Background: Previous small studies have reported favorable results of peritoneal dialysis (PD) in the setting of chronic refractory heart failure (CRHF). We evaluated the impact of PD in a larger cohort of patients with CHRF where end-stage renal disease was excluded.♦ Methods: All patients who received PD therapy for CRHF between January 1995 and December 2010 in two medical centers in France were included in this retrospective study. Baseline characteristics were compared with clinical parameters during the first year after initiation of PD. Mortality, safety, and sustainability of PD were also analyzed.♦ Results: The 126 patients included had a mean age of 72 ± 11 years and an estimated glomerular filtration rate of 33.5 ± 15.1 mL/min/1.73 m2. Mean time on PD was 16 ± 16.6 months. During the first year, patients with a left ventricular ejection fraction (LVEF) of 30% or less experienced improvement in cardiac function (30% ± 10% vs 20% ± 6%, p < 0.0001). We observed a significant reduction in the number of days of hospitalization for acute decompensated heart failure after PD initiation (3.3 ± 2.6 days/patient-month vs 0.3 ± 0.5 days/patient-month, p < 0.0001). One-year mortality was 42%.♦ Conclusions: In CRHF, PD significantly reduces the number of days of hospitalization for acute heart failure. Improved LVEF may have led to the comparatively good 1-year survival in this cohort.     

The Association Between Arterial Stiffness and Fluid Status in Peritoneal Dialysis Patients

♦ Objectives: In this study our aim was to evaluate the relationship between degree of fluid status and arterial stiffness measured by pulse wave velocity (PWV) in peritoneal dialysis (PD) patients. Fluid status was determined by different methods including fluid overload measured by bioimpedance (Body Composition Monitor, BCM), calf normalized resistivity (CNR), plasma N-terminal fragment of B-type natriuretic peptide (NT-proBNP) and extracellular to intracellular water ratio (ECW/ICW).♦ Methods: Sixty PD patients were evaluated. They were stratified into normo- and hypervolemic groups according to their fluid overload (FO). CNR was calculated from resistance at 5 kHz using calf bioimpedance spectroscopy. Arterial stiffness was assessed by PWV. Additionally, all patients underwent transthoracic echocardiography and had levels of NT-proBNP measured.♦ Results: PWV was higher in the hypervolemic compared to normovolemic patients (9.99 ± 2.4 m/sec vs 7.48 ± 2.3 m/sec, p < 0.001). Hypervolemic patients had higher NT-proBNP levels (3065 ± 981 pg/mL vs 1095 ± 502 pg/mL, p < 0.001), a higher ratio of ECW/ICW; (0.93 ± 0.11 vs 0.81 ± 0.08, p < 0.001) and lower CNR (13.7 ± 2.4 vs 16.0 ± 3.3 W m³/kg^*10^-2, p = 0.005). NT-pro BNP level, ECW/ICW ratio, relative FO, and left ventricular (LV) mass index were positively and CNR negatively correlated with PWV. Relative FO and CNR independently predicted PWV in multivariate analysis adjusted for age, duration of PD, body mass index and mean arterial pressure.♦ Conclusions: Arterial stiffness is increased in fluid-overloaded PD patients. Our results indicated that fluid status is an independent predictor of PWV.     

Lifetime Costs for Peritoneal Dialysis and Hemodialysis in Patients in Taiwan

♦ Background: This study compared the lifetime costs for peritoneal dialysis (PD) and hemodialysis (HD) patients in Taiwan.♦ Methods: Using the National Health Insurance (NHI) database of all end-stage renal disease patients on maintenance dialysis registered from July 1997 to December 2005, we matched eligible PD patients with eligible HD patients on age, sex, and diabetes status. The matched patients were followed until 31 December 2006. Patients were excluded if they were less than 18 years of age, had been diagnosed with cancer before dialysis, or had been dialyzed at centers or clinics other than hospitals. Outcomes—including life expectancy, total lifetime costs, and costs per life-year paid by the NHI—were estimated and compared.♦ Results: The 3136 pairs of matched PD and HD patients had a mean age of 53.2 ± 15.4 years. The total lifetime cost for PD patients (US$139 360 ± US$8 336) was significantly lower than that for HD patients (US$185 235 ± US$9 623, p < 0.001). Except for patients with diabetes (who had a short life expectancy), the total lifetime cost was significantly lower for PD patients than for HD patients regardless of sex and age (p < 0.01).♦ Conclusion: In Taiwan, the total lifetime costs paid by the NHI were lower for PD than for HD patients.     

Blood Pressure Measurement in Peritoneal Dialysis: Which Method Is Best?

♦ Background: The optimal approach to monitoring blood pressure (BP) in the peritoneal dialysis (PD) population is unclear. Ambulatory BP monitoring reliably predicts prognosis, but can be inconvenient. The accuracy of home BP monitoring in this population is unproven. The automated BpTRU device (BpTRU Medical Devices, Coquitlam, BC, Canada), which provides an average of up to 6 successive in-office BP measurements, has not been studied in this patient group.♦ Methods: We studied 17 patients (average age: 54 ± 12 years; 12 men, 5 women; 94% on automated PD) attending a single center. All patients underwent office, home, BpTRU, and ambulatory BP measurement. The reference standard for analysis was daytime ambulatory BP. Correlation between the referent method and each comparator method was determined (Pearson correlation coefficient), and Bland-Altman scatter plots depicting the differences in the BP measurements were constructed.♦ Results: Mean office BP (126.4 ± 16.9/78.8 ± 11.6 mmHg) and BpTRU BP (123.8 ± 13.7/80.7 ± 11.1 mmHg) closely approximated mean daytime ambulatory BP (129.3 ± 14.8/78.2 ± 7.9 mmHg). Mean home BP (143.8 ± 15.0/89.9 ± 28.1 mmHg) significantly overestimated mean daytime systolic BP by 14.2 mmHg (95% confidence interval: 4.3 mmHg to 24.1 mmHg; p = 0.008). Bland-Altman plots demonstrated poorest agreement between home BP and daytime ambulatory BP. No patient had “white-coat hypertension,” and only 1 patient had false-resistant hypertension. Most patients showed abnormal nocturnal dipping patterns (non-dipping: n = 11; reverse-dipping: n = 5; normal dipping: n = 1).♦ Conclusions: We report a novel finding that BP measurement using the BpTRU device is more accurate than home BP measurement in a PD population. Potential explanations for this observation include poor home BP measurement technique, use of poorly validated home BP measurement devices, or a reduced prevalence of white-coat effect among PD patients. Our study also confirms that, in the PD population, BP measurements vary considerably with patient location, time of day, and measurement technique.     

Can Dialysis Patients Be Accurately Identified Using Healthcare Claims Data?

♦ Background: While health insurance claims data are often used to estimate the costs of renal replacement therapy in patients with end-stage renal disease (ESRD), the accuracy of methods used to identify patients receiving dialysis — especially peritoneal dialysis (PD) and hemodialysis (HD) — in these data is unknown.♦ Methods: The study population consisted of all persons aged 18 - 63 years in a large US integrated health plan with ESRD and dialysis-related billing codes (i.e., diagnosis, procedures) on healthcare encounters between January 1, 2005, and December 31, 2008. Using billing codes for all healthcare encounters within 30 days of each patient’s first dialysis-related claim (“index encounter”), we attempted to designate each study subject as either a “PD patient” or “HD patient.” Using alternative windows of ± 30 days, ± 90 days, and ± 180 days around the index encounter, we reviewed patients’ medical records to determine the dialysis modality actually received. We calculated the positive predictive value (PPV) for each dialysis-related billing code, using information in patients’ medical records as the “gold standard.”♦ Results: We identified a total of 233 patients with evidence of ESRD and receipt of dialysis in healthcare claims data. Based on examination of billing codes, 43 and 173 study subjects were designated PD patients and HD patients, respectively (14 patients had evidence of PD and HD, and modality could not be ascertained for 31 patients). The PPV of codes used to identify PD patients was low based on a ± 30-day medical record review window (34.9%), and increased with use of ± 90-day and ± 180-day windows (both 67.4%). The PPV for codes used to identify HD patients was uniformly high — 86.7% based on ± 30-day review, 90.8% based on ± 90-day review, and 93.1% based on ± 180-day review.♦ Conclusions: While HD patients could be accurately identified using billing codes in healthcare claims data, case identification was much more problematic for patients receiving PD.     

Pilot Experience in Senegal with Peritoneal Dialysis for End-Stage Renal Disease

♦ Introduction: Peritoneal dialysis (PD) is occasionally used in western sub-Saharan Africa to treat patients with end-stage renal disease (ESRD). The present study is a retrospective review of the initial six years’ experience with PD for ESRD therapy in Senegal, a West African country with a population of over 12 million.♦ Material and Methods: Single-center retrospective cohort study of patients treated with PD between March 2004 and December 2010. Basic demographic data were collected on all patients. Peritonitis rates, causes of death and reasons for transfer to hemodialysis (HD) were determined in all patients.♦ Results: Sixty-two patients were included in the study. The median age was 47 ± 13 years with a male/female ratio of 1.21. Nephrosclerosis and diabetic nephropathy were the main causes of ESRD. The mean Charlson score was 3 ± 1 with a range of 2 to 7. Forty five peritonitis episodes were diagnosed in 36 patients (58%) for a peritonitis rate of 1 episode/20 patient-months (0.60 episodes per year). Staphylococcus aureus and Pseudomonas aeruginosa were the most commonly identified organisms. Touch contamination has been implicated in 26 cases (57.7%). In 23 episodes (51%), bacterial cultures were negative. Catheter removal was necessary in 12 cases (26.6%) due to mechanical dysfunction, fungal or refractory infection. Sixteen patients died during the study.♦ Conclusion: Peritoneal dialysis is a suitable therapy which may be widely used for ESRD treatment in western sub-Saharan Africa. A good peritonitis rate can be achieved despite the difficult living conditions of patients. Challenges to the development of PD programs include training health care providers, developing an infrastructure to support the program, and developing a cost structure which permits expansion of the PD program.     

Structured Outpatient Peritoneal Dialysis Catheter Insertion Is Safe and Cost-Saving

♦ Background: Data about outcomes and costs for peritoneal catheter insertion on an outpatient basis are scarce.♦ Methods: Using patient files, all peritoneal dialysis (PD) catheter insertions performed between 2004 and 2009 in a single-center tertiary care institution for adult patients were located. Patient demographics, complications, hospitalizations, survival, and treatment modality changes were recorded. Procedure-related expenses were valued as actual production costs.♦ Results: During the study period, 106 PD catheters were inserted. In 46 cases, the patients were admitted electively for catheter insertion; 19 catheters were placed during admission for other medical reasons; and 41 catheters were placed on an outpatient basis. Among the study patients (54.7 ± 16.0 years of age), 45% were diabetic. Early (<30 days) catheter-related complications occurred in 22% of patients. The incidences of technique failure and any complication within 90 days were 10% and 38% respectively. The occurrence of complications was not statistically significantly different for outpatients and electively admitted patients. Average costs for catheter insertion were higher in electively hospitalized patients than in outpatients (€2320 ± €960 vs €1346 ± €208, p < 0.000).♦ Conclusions: Compared with an inpatient procedure, outpatient insertion of a PD catheter results in similar outcomes at a lower cost.     

The Role of Monitoring Vancomycin Levels in Patients with Peritoneal Dialysis-Associated Peritonitis

♦ Background: There is limited available evidence regarding the role of monitoring serum vancomycin concentrations during treatment of peritoneal dialysis (PD)-associated peritonitis.♦ Methods: A total of 150 PD patients experiencing 256 episodes of either gram-positive or culture-negative peritonitis were included to investigate the relationship between measured serum vancomycin within the first week and clinical outcomes of cure, relapse, repeat or recurrence of peritonitis, catheter removal, temporary or permanent transfer to hemodialysis, hospitalization and death.♦ Results: Vancomycin was used as an initial empiric antibiotic in 54 gram-positive or culture-negative peritonitis episodes among 34 patients. The median number of serum vancomycin level measurements in the first week was 3 (interquartile range; IQR 1 – 4). The mean day-2 vancomycin level, measured in 34 (63%) episodes, was 17.5 ± 5.2 mg/L. Hospitalized patients were more likely to have serum vancomycin levels measured on day 2 and ≥ 3 measurements in the first week. The peritonitis cure rates were similar between patients with < 3 and ≥ 3 measurements in the first week (77% vs 57%, p = 0.12) and if day-2 vancomycin levels were measured or not (68% vs 65%, p = 0.84). The average day-2 (18.0 ± 5.9 vs 16.6 ± 3.2, p = 0.5), first-week average (18.6 ± 5.1 vs 18.6 ± 4.3, p = 0.9) and nadir (14.5 ± 4.1 vs 13.6 ± 4.2, p = 0.5) vancomycin levels were comparable in patients who did or did not achieve peritonitis cure. Similar results were observed for all other clinical outcomes.♦ Conclusion: The clinical outcomes of gram-positive and culture-negative peritonitis episodes are not associated with either the frequency or levels of serum vancomycin measurements in the first week of treatment when vancomycin is dosed according to International Society for Peritoneal Dialysis (ISPD) Guidelines.     

Longitudinal Changes in Health-Related Quality of Life Scores in Brazilian Incident Peritoneal Dialysis Patients (BRAZPD): Socio-economic Status Not a Barrier

♦ Background and Objectives: A large proportion of the patients on peritoneal dialysis (PD) in Brazil have low levels of education and family income. The present study assessed whether education level and family income are associated with baseline and longitudinal changes in health-related quality of life (HRQOL) scores during the first year of PD therapy.♦ Methods: We evaluated 1624 incident patients from the Brazilian Peritoneal Dialysis Multicenter Study (BRAZPD) at baseline, and 486 of them after 12 months. The SF-36 was used to determine HRQOL and the Karnofsky index (KI), physical performance.♦ Results: At baseline, patients received high KI scores compared with scores on the SF-36. The means of the mental and physical components at baseline and after 12 months were 39.9 ± 10.5 compared with 38.7 ± 11.7 and 41.8 ± 9.6 compared with 40.7 ± 9.8 respectively, which were not statistically different. A multivariate regression analysis showed that age, sex, diabetes, and cardiovascular disease were predictors of the mental component (respectively, β = 0.12, p < 0.001; β = 0.11, p < 0.001; β = -0.08, β = 0.007; and β = -0.07, p = 0.007) and that age, sex, diabetes, cardiovascular disease, hemoglobin, glucose, and creatinine were predictors of the physical component (respectively, β = -0.28, p < 0.001; β = 0.06, p = 0.009; β = -0.09, p = 0.002; β = -0.09, p = 0.001; β = 0.07, p = 0.004; β = -0.05, p = 0.040; and β = 0.05, p = 0.040). Education level and family income were not significantly associated with HRQOL (mental and physical components) in the multivariate regression.♦ Conclusions: The results indicate that, as predictors, family income and education level have no impact on HRQOL, supporting the idea that socio-economic status should not be a barrier to the selection of PD as a treatment modality in Brazil.     

Low-Polydispersity Glucose Polymers as Osmotic Agents for Peritoneal Dialysis

♦ Background:

Peritoneal dialysis (PD) solutions containing icodextrin as the osmotic agent have advantages during long dwells. The glucose polymers that constitute icodextrin are a heterogeneous mix of molecules with a polydispersity [ratio of weight-average to number-average molecular weight (Mw/Mn)] of approximately 2.6. The present study evaluates whether modifications in the polydispersity and concentration of glucose polymers can improve ultrafiltration (UF) without an associated increase in carbohydrate absorption (CA).

♦ Methods:

Computer simulations using a three-pore model of peritoneal transport during a long dwell in PD patients predict that, in general, compared with 7.5% icodextrin, glucose polymers with a Mw greater than or equal to 7.5 kDa, a polydispersity less than 2.6, and concentrations greater than 7% could achieve higher UF without higher CA. Based on the simulations, we hypothesized that, compared with 7.5% icodextrin, glucose polymers with a Mw of 18 – 19 kDa and a polydispersity of 2.0 at 11% concentration could achieve higher UF without a higher CA. We tested this hypothesis in experimental studies using 8-hour dwells in New Zealand White rabbits. In those studies, UF was measured by complete fluid collection, and CA was measured by subtracting the total carbohydrate in the collected fluid from the carbohydrate initially infused.

♦ Results:

The UF was higher with 11% 19 kDa glucose polymer than with 7.5% icodextrin (mean ± standard deviation: 89 ± 31 mL vs 49 ± 15 mL; p = 0.004) without higher CA (5.2 ± 0.9 g vs 5.0 ± 0.9 g, p = 0.7). Similar results were seen with the 11% 18 kDa glucose polymer, which, compared with 7.5% icodextrin, resulted in higher UF (mean ± standard deviation: 96 ± 18 mL vs 66 ± 17 mL; p < 0.001) without higher CA (4.8 ± 0.7 g vs 5.2 ± 0.6 g, p = 0.2).

♦ Conclusions:

The findings demonstrate that, compared with 7.5% icodextrin solution, long-dwell PD solutions containing 11% glucose polymers with a Mw of 18–19 kDa and a polydispersity of 2.0 can provide higher UF without higher CA.     

Continuous Ambulatory Peritoneal Dialysis in Limpopo Province,South Africa: Predictors of Patient and Technique Survival

♦ Introduction and aim: Continuous ambulatory peritoneal dialysis (CAPD) is not a frequently used modality of dialysis in many parts of Africa due to several socio-economic factors. Available studies from Africa have shown a strong association between outcome and socio-demographic variables. We sought to assess the outcome of patients treated with CAPD in Limpopo, South Africa.♦ Methods: This was a retrospective study of 152 patients treated with CAPD at the Polokwane Kidney and Dialysis Centre (PKDC) from 2007 to 2012. We collected relevant demographic and biochemical data for all patients included in the study. A composite outcome of death while still on peritoneal dialysis (PD) or CAPD technique failure from any cause requiring a change of modality to hemodialysis (HD) was selected. The peritonitis rate and causes of peritonitis were assessed from 2008 when all related data could be obtained.♦ Results: There were 52% males in the study and the average age of the patients was 36.8 ± 11.4 years. Unemployment rate was high (71.1%), 41.1% had tap water at home, the average distance travelled to the dialysis center was 122.9 ± 78.2 kilometres and half the patients had a total income less than USD ($)180 per month. Level of education, having electricity at home, having tap water at home, body mass index (BMI), serum albumin and hemoglobin were significantly different between those reaching the composite outcome and those not reaching it (p < 0.05). The overall peritonitis rate was 0.82/year with 1-year, 2-year and 5-year survival found to be 86.7%, 78.7% and 65.3% (patient survival) and 83.3%, 71.7% and 62.1% (technique survival). Predictors of the composite outcome were BMI (p = 0.011), serum albumin (p = 0.030), hemoglobin (p = 0.002) and more than 1 episode of peritonitis (p = 0.038).♦ Conclusion: Treatment of anemia and malnutrition as well as training and re-training of CAPD patients and staff to prevent recurrence of peritonitis can have positive impacts on CAPD outcomes in this population.     

Peritoneal Dialysis for Children with Acute Kidney Injury in Lagos,Nigeria: Experience with Adaptations

♦ Introduction: International professional groups are supporting the training of physicians in developing countries in nephrology, including peritoneal dialysis (PD). This report documents the impact of such efforts in the provision of manual PD for children with acute kidney injury (AKI) in a public hospital in Lagos, Nigeria.♦ Methods: Medical records of all children with AKI managed with PD between July 2010 and March 2013 were reviewed.♦ Results: Seventeen children with a mean (SEM) age of 3.8 (0.8) years received PD for 0 - 18 days; about half were infants. PD was provided manually, frequently with intercostal drains as catheters. Blockage of catheters and peritonitis occurred in 4 (23.5%) and 2 (11.8%) children, respectively. Eight (47.1%) of the 17 children had resolution of AKI and were discharged from hospital. In 4 (57.1%) of the 7 children who died, PD was performed for ≤ 2 days.♦ Conclusion: PD for childhood AKI is feasible in resource-constrained regions with fairly good outcome. Blockage of catheter was the most common complication encountered.     

Intraperitoneal Fluid Overestimates Hydration Status Assessment by Bioimpedance Spectroscopy

♦ Background: Bioimpedance spectroscopy (BIS) is a valuable tool to assess nutrition and volume status in peritoneal dialysis (PD) patients. However, data about the influence of intraperitoneal fluid on body composition measures are conflicting, and there is no clear consensus about whether the abdomen should be drained before the procedure. We designed a comparison study to detect the influence of intra-abdominal fluid on BIS results.♦ Methods: We performed 73 pairs of BIS measurements in 34 stable PD patients, first with the peritoneum filled with a 1.36% glucose dialysate solution and then after the solution was drained. Patients stayed in the supine position for 10 minutes before the BIS procedure, and the electrodes were not moved between measures. Clinical and demographic data were collected, as were analytic parameters of nutrition and volume status.♦ Results: Fluid overload is overestimated when BIS is performed with a full abdomen (1.82 ± 1.73 L vs 1.64 ± 1.68 L, p = 0.043). We also found a spurious overestimation in extracellular water (16.40 ± 3.21 L vs 16.24 ± 3.16 L, p < 0.001) and in relative overhydration (8.29% ± 6.96% vs 7.14% ± 6.79%, p = 0.017). No differences in intracellular water or parameters of nutrition were found. We observed negative correlations for the extracellular water overestimation with age (r = –0.245, p = 0.037), serum B-type natriuretic peptide (r = –0.366, p = 0.036), body mass index (r = –0.248, p = 0.035), and lean tissue index (r = –0.427, p = 0.001). The difference in extracellular water correlated only with body mass index (r = –0.259, p = 0.039). We also found that, assessed at 50 KHz, whole-body impedance (–4.52 ± 8.37, p = 0.001) and phase angle (–0.08 ± 0.23 degrees, p = 0.002) were both lower when BIS was performed in patients with a full abdomen.♦ Conclusions: Fluid overload is overestimated by BIS when performed in patients with dialysate in the peritoneum. The observed differences are greater in younger, more poorly nourished, or less overhydrated patients. If more precise results are required, we suggest that the abdomen be drained before BIS is performed.     

Serum Concentrations of p-Cresyl Sulfate and Indoxyl Sulfate,but Not Inflammatory Markers,Increase in Incident Peritoneal Dialysis Patients in Parallel with Loss of Residual Renal Function

♦ Background: High serum concentrations of the protein-bound uremic retention solutes p-cresyl sulfate (PCS) and indoxyl sulfate (IndS) and inflammation are associated with increased cardiovascular morbidity and mortality in chronic kidney disease. Renal clearance contributes to up to 80% of the total clearance of PCS and IndS in peritoneal dialysis (PD) patients. Cross-sectional studies evaluating the impact of residual renal function (RRF) on serum concentrations of PCS, IndS, and circulating inflammatory markers have yielded conflicting results.♦ Methods: To clarify this issue, we carried out a prospective observational cohort study in incident PD patients (n = 35; 19 men; mean age: 55 ± 17 years). Midday blood samples were collected and analyzed for total serum PCS, IndS, C-reactive protein, and high-sensitivity interleukin 6. Peritoneal and renal clearances were calculated from urine and dialysate collections, and RRF was calculated as the mean of renal urea nitrogen and creatinine clearances. Patients were assessed 1, 6, 12, and 24 months after PD start. Differences between time points were analyzed using linear mixed models (LMMs).♦ Results: Residual renal function declined significantly over time (LMM p < 0.0001). Peritoneal clearances of both toxins tended to increase, but did not compensate for the declining renal clearances. Serum concentrations of PCS and IndS increased significantly over time (LMM p = 0.01; p = 0.0009). In contrast, total mass removal of both toxins remained stable. Circulating inflammatory markers did not change over time.♦ Conclusions: Our data indicate that serum concentrations of PCS and IndS, but not inflammatory markers, increase in incident PD patients in parallel with loss of RRF.     

Can EPS Development Be Avoided with Early Interventions? The Potential Role of Tamoxifen—A Single-Center Study

♦ Background: Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). Identification of patients at high risk for EPS (“EPS-prone”) and delivery of appropriate interventions might prevent its development. Our aim was to evaluate the clinical characteristics and outcomes of all EPS and EPS-prone patients diagnosed at our PD unit.♦ Methods: For a 30-year period representing our entire PD experience, we retrospectively identified all patients with EPS (diagnosed according to International Society for Peritoneal Dialysis criteria) and all patients defined as EPS-prone because they met at least 2 established criteria (severe peritonitis, PD vintage greater than 3 years, severe hemoperitoneum, overexposure to glucose, and acquired ultrafiltration failure).♦ Results: Of 679 PD patients, we identified 20 with EPS, for an overall prevalence of 2.9%. Mean age at diagnosis was 50.2 ± 16.4 years, with a median PD time of 77.96 months (range: 44.36 - 102.7 months) and a median follow-up of 30.91 months (range: 4.6 - 68.75 months). Of patients with EPS, 10 (50%) received tamoxifen, 10 (50%) received parenteral nutrition, and 2 (10%) underwent adhesiolysis, with 25% mortality related to EPS. Another 14 patients were identified as EPS-prone. Median follow-up was 54.05 months (range: 11.9 - 87.04 months). All received tamoxifen, and 5 (36%) received corticosteroids; none progressed to full EPS. We observed no differences in baseline data between the groups, but the group with EPS had been on PD longer (84 ± 53 months vs 39 ± 20 months, p = 0.002) and had a higher cumulative number of days of peritoneal inflammation from peritonitis (17.2 ± 11.1 days vs 9.8 ± 7.9 days, p = 0.015). Overall mortality was similar in the groups. The incidence of EPS declined during our three decades of experience (5.6%, 3.9%, and 0.3%).♦ Conclusions: Being a serious, life-threatening complication of PD, EPS requires high suspicion to allow for prompt diagnosis and treatment. Early detection of EPS-prone states and delivery of appropriate intervention might prevent EPS development. Tamoxifen seems to be a key strategy in prevention, but caution should be used in interpreting our results. Additional randomized controlled studies are needed.     

The Role of Monitoring Gentamicin Levels in Patients with Gram-Negative Peritoneal Dialysis-Associated Peritonitis

♦ Background: There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis.♦ Methods: Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis.♦ Results: Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure.♦ Conclusion: Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure.     

Hand Hygiene in Peritoneal Dialysis Patients: A Comparison of Two Techniques

♦ Introduction and Objectives: Hand hygiene is essential for preventing peritoneal dialysis (PD)-related infections. The present study compared the effectiveness of two hygiene techniques in reducing the number of colony-forming units (CFUs) on the hands of patients undergoing PD.♦ Methods: In this controlled clinical trial, 22 participants enrolled in the same PD program underwent a two-hand evaluation for microbiologic flora. Participants participated in two treatments: a) simple hand hygiene plus antiseptic hand hygiene, in which the patients washed their hands with water and glycerin soap for 1 minute and then rubbed and dried their hands with 70% ethyl alcohol gel; and b) antiseptic hand hygiene, in which the patients rubbed their hands with 70% ethyl alcohol gel until fully dry. To sample distal finger surfaces, we asked the participants to touch sheep blood agar plates directly.♦ Results: The CFU count for both hands was significantly higher in the regular hygiene group than in the gel-only group [69.0 (16.0 - 101.0) CFU vs 9.0 (2.2 - 55.5) CFU, p < 0.010]. Growth of coagulase-negative Staphylococcus colonies was significantly higher in right-hand cultures from the regular hygiene group than in those from the gel-only group [69.5 (26.25 - 101.0) CFU vs 9.5 (1.0 - 41.7) CFU; p < 0.050].♦ Conclusions: Among patients undergoing PD, using 70% ethyl alcohol gel to cleanse the hands may be more effective than following the regular hygiene recommendations in reducing bacterial populations.     

Body Mass Index and Mortality Risk in Asian Peritoneal Dialysis Patients in Hong Kong—Impact of Diabetes and Cardiovascular Disease Status

♦ Background: Obesity increases mortality in the general population, but improves survival in hemodialysis patients. In peritoneal dialysis (PD) patients, the reported effect is controversial. We investigated the effect of body mass index (BMI) on patient survival in Asian PD patients.♦ Methods: The survival of incident Asian PD patients from 2001 to 2008 in a single center in Hong Kong was analyzed retrospectively. Baseline demographic and clinical data were collected from patient records. Patients who had a total Kt/V below 1.7 or who died within 6 months were excluded. The BMI was categorized using the World Health Organization recommendation for Asian populations.♦ Results: In the 274 study patients [154 men (56%); 138 with diabetes (50.4%); mean age: 63.4 ± 14.6 years; mean BMI: 21.97 ± 3.23 kg/m²; 37 underweight (13.5%); 35 obese (12.8%)], the relative risk (RR) for mortality [adjusted for age, diabetes status, and cardiovascular disease (CVD)] was similar for the normal and overweight groups, but higher for the underweight (RR: 1.909; p = 0.028) and obese groups (RR: 1.799; p = 0.048). The increased mortality in obese patients was more prominent in patients with diabetes (RR: 1.9 vs 1.19 in patients without diabetes; p = 0.074 and 0.76 respectively), and in patients with CVD (RR: 8.895 vs 1.642 in patients without CVD; p = 0.012 and 0.122 respectively).♦ Conclusions: In Asian PD patients, the relationship between BMI and mortality was U-shaped, with higher mortality in the underweight and obese patients. The negative impact of obesity was more prominent in patients with diabetes and CVD.