Lower serum magnesium is associated with vascular calcification in peritoneal dialysis patients: a cross sectional study.

BACKGROUND: Coronary artery calcification (CAC) is highly prevalent among dialysis patients and is associated with increased cardiovascular and all cause mortality. Magnesium (Mg) inhibits vascular calcification in animal and in-vitro studies but whether the same effect occurs in humans is uncertain. METHODS: A single centre cross-sectional study of 80 prevalent peritoneal dialysis (PD) patients; on PD only for a minimum of 3 months. A radiologist blinded to patient status calculated their abdominal aortic calcification (AAC) scores on lateral lumbar spine radiographs, a validated surrogate for CAC. RESULTS: Eighty patients provided informed consent and underwent lumbar spine radiography. The mean serum Mg was 0.8 mmol/L (standard deviation 0.2) and mean AAC score 8.9 (minimum 0, maximum 24). A higher serum Mg level was associated with a lower AAC score (R 2 = 0.06, unstandardized coefficient [B] = -7.81, p = 0.03), and remained after adjustment for age, serum phosphate, serum parathyroid hormone, low-density lipoprotein cholesterol, smoking history, and diabetes (model adjusted R 2 = 0.36, serum Mg and AAC score B = -11.44, p = 0.00). This translates to a 0.1 mmol/L increase in serum Mg being independently associated with a 1.1-point decrease in AAC score. CONCLUSIONS: Our findings suggest that Mg may inhibit vascular calcification. If this association is replicated across larger studies with serial Mg and vascular calcification measurements, interventions that increase serum Mg and their effect on vascular calcification warrant further investigation in the PD population.

Meal phosphate variability does not support fixed dose phosphate binder schedules for patients treated with peritoneal dialysis: a prospective cohort study.

BACKGROUND: Removal of phosphate by peritoneal dialysis is insufficient to maintain normal serum phosphate levels such that most patients must take phosphate binders with their meals. However, phosphate 'counting' is complicated and many patients are simply prescribed a specific dose of phosphate binders with each meal. Therefore, our primary objective was to assess the variability in meal phosphate content to determine the appropriateness of this approach. METHODS: In this prospective cohort study, adult patients with ESRD treated with peritoneal dialysis and prescribed phosphate binder therapy were eligible to participate. Participants were excluded from the study if they were unable to give consent, had hypercalcemia, were visually or hearing impaired or were expected to receive a renal transplant during the time of the study. After providing informed consent, patients kept a 3-day diet diary that included all foods and beverages consumed in addition to portion sizes. At the same time, patients documented the amount of phosphate binders taken with each meal. The phosphate content of the each meal was estimated using ESHA Food Processor SQL Software by a registered dietitian. Meal phosphate and binder variability were estimated by the Intra Class Correlation Coefficient (ICC) where 0 indicates maximal variability and 1 indicates no variability. RESULTS: Seventy-eight patients consented to participate in the study; 18 did not complete the study protocol. The patients were 60 (± 17) years, predominately male (38/60) and Caucasian (51/60). Diabetic nephropathy was the most common cause of end stage kidney disease. The daily phosphate intake including snacks ranged from 959 ± 249 to 1144 ± 362 mg. The phosphate ICC by meal: breakfast 0.63, lunch 0.16; supper 0.27. The phosphate binder ICC by meal: breakfast 0.68, lunch 0.73, supper 0.67. CONCLUSION: The standard prescription of a set number of phosphate binders with each meal is not supported by the data; patients do not appear to be adjusting their binders to match the meal phosphate content. An easy to use phosphate counting program that assists the patient in determining the appropriate amount of phosphate binder to take may enhance phosphate control.

Successful Initiation of Dialysis with a 20-Year-Old Buried Peritoneal Dialysis Catheter: Case Report and Literature Review.

Buried peritoneal dialysis (PD) catheters are typically inserted several weeks or months before the anticipated need for dialysis. Occasionally, renal function unexpectedly stabilizes after the surgery, and a patient may go years before the catheter is needed. We report a case of successful initiation of PD with a twenty-year-old buried catheter. We outline the steps needed to optimize the catheter function and review the benefits of the buried PD catheter.

Complications and catheter survival with prolonged embedding of peritoneal dialysis catheters.

BACKGROUND: Our centre uses a modification of the Moncrief technique of embedding peritoneal dialysis (PD) catheters. We undertook this study to test the hypothesis that catheter survival on PD is a function of the time a catheter is left embedded prior to use. METHODS: Data were retrospectively abstracted from review of patient records of those who received a first PD catheter over a 5-year period. Patients were divided into tertiles based on the number of days between insertion of the catheter and exteriorization to create three equal groups representing early (group 1, 11-47 days), mid (group 2, 48-133 days) and late (group 3, 134-2041 days) exteriorization strategies. RESULTS: 435 embedded PD catheters were inserted, 349 were exteriorized and total observation period was 5624 patient-months. Time to catheter loss was shortest in group 1 and longest in group 2 (P = 0.04). The overall rate of primary catheter failure was 6% and was significantly different in the three groups (6.9% in group 1, 1.7% in group 2 and 9.4% in group 3, P = 0.04). The time to first episode of peritonitis was longest in group 3 and shortest in group 1 (group 1 versus group 3, P = 0.009; group 2 versus group 3, P = 0.03). Adjusted peritonitis rates, however, were not different between the three groups. CONCLUSIONS: Mechanical complications and catheter loss are associated with the length of time a catheter is embedded. We recommend insertion 6 weeks to 5 months ahead of the need for PD to maximize catheter survival.

Hospitalization Rates for Patients on Assisted Peritoneal Dialysis Compared with In-Center Hemodialysis.

BACKGROUND AND OBJECTIVES: Assisted peritoneal dialysis is a treatment option for individuals with barriers to self-care who wish to receive home dialysis, but previous research suggests that this treatment modality is associated with a higher rate of hospitalization. The objective of our study was to determine whether assisted peritoneal dialysis has a different rate of hospital days compared to in-center hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a multicenter, retrospective cohort study by linking a quality assurance dataset to administrative health data in Ontario, Canada. Subjects were accrued between January 1, 2004 and July 9, 2013. Individuals were grouped into assisted peritoneal dialysis (family or home care assisted) or in-center hemodialysis on the basis of their first outpatient dialysis modality. Inverse probability of treatment weighting using a propensity score was used to create a sample in which the baseline covariates were well balanced. RESULTS: The study included 872 patients in the in-center hemodialysis group and 203 patients in the assisted peritoneal dialysis group. Using an intention to treat approach, patients on assisted peritoneal dialysis had a similar hospitalization rate of 11.1 d/yr (95% confidence interval, 9.4 to 13.0) compared with 12.9 d/yr (95% confidence interval, 10.3 to 16.1) in the hemodialysis group (P=0.19). Patients on assisted peritoneal dialysis were more likely to be hospitalized for dialysis-related reasons (admitted for 2.4 d/yr [95% confidence interval, 1.8 to 3.2] compared with 1.6 d/yr [95% confidence interval, 1.1 to 2.3] in the hemodialysis group; P=0.04). This difference was partly explained by more hospital days because of peritonitis. Modality switching was associated with high rates of hospital days per year. CONCLUSIONS: Assisted peritoneal dialysis was associated with similar rates of all-cause hospitalization compared with in-center hemodialysis. Patients on assisted peritoneal dialysis who experienced peritonitis and technique failure had high rates of hospitalization.

Gabapentin-induced myopathy in 2 patients on short daily hemodialysis.

Gabapentin is an antiepileptic medication that also has been used for restless legs syndrome. The mechanism of action is unknown. The most commonly reported adverse effects of this medication include somnolence, dizziness, ataxia, fatigue, nystagmus, and tremor. Myalgia has been reported in 2% of gabapentin users compared with 1.9% of patients in placebo-controlled add-on trials. Two patients on short daily hemodialysis therapy developed neuromuscular symptoms and an elevation in creatine kinase levels after starting gabapentin therapy. To our knowledge, this is the first case report of an increase in creatine kinase level after the administration of gabapentin.

Team approach in a peritoneal dialysis unit provides better control of hypertension than in a hemodialysis unit.

Hypertension is one of the main factors contributing to morbidity and mortality in dialysis patients. Peritoneal dialysis (PD) patients have been reported to have lower blood pressure (BP) in the first 6 months or so of treatment. After that, their BP can be the same or higher than that seen in hemodialysis (HD) patients. We compared BP control between our PD patients and our HD patients. Systolic BP and pulse pressure were better controlled in PD patients; those PD patients required many fewer drugs. The difference was statistically significant. Anuric PD patients had a BP as good as that of the non anuric PD patients. Because PD is a constant treatment, fluid removal is much easier than in HD. To achieve good BP control, nurses, dieticians, and physicians must all have the same approach: that is, always to be aggressive in volume control as a first measure for achieving an adequate BP The team approach results in better BP control than that seen in HD.

Attractiveness, diagnostic ambiguity, and disability cues impact perceptions of women with pain.

PURPOSE/OBJECTIVE: This experimental study investigated how physical attractiveness, disability cue, and diagnostic ambiguity stereotypes impact perceptions of a patient's pain/disability and personality. RESEARCH METHOD/DESIGN: After viewing photographs of women pictured with or without a cane, accompanied by descriptions of the women's diagnosis (fibromyalgia or rheumatoid arthritis), 147 university students rated the women's pain/disability and personality. RESULTS: Analyses revealed that more attractive women received lower ratings on pain/disability and higher ratings (more positive) on personality. Moreover, those pictured with a disability cue got higher ratings on both pain/disability and personality, and those with medical evidence of pathology (less ambiguity) got higher ratings on pain/disability and lower ratings on personality. Examination of the 3 stereotypes in a single study enabled an evaluation of their interactions. An Attractiveness × Disability Cue × Diagnostic Ambiguity interaction for ratings of pain/disability revealed that the presence of both medical evidence and a disability cue were needed to override the strong "beautiful is healthy" stereotype. Significant 2-way interactions for ratings of personality indicated that the impact of the disability stereotype tends to be overshadowed by the attractiveness stereotype. CONCLUSION/IMPLICATIONS: The results indicate that these stereotypes have a large effect on perceptions of women with chronic pain and that attractiveness, a contextual variable unrelated to the pain experience, exerts an even stronger effect when there is less objective information available. This could have clinical ramifications for assessment and treatment of patients with chronic pain, which often occurs in the absence of "objective" medical evidence or any external cues of disability.

Fluoroscopic manipulation of peritoneal dialysis catheters: outcomes and factors associated with successful manipulation.

BACKGROUND AND OBJECTIVES: Mechanical failure of the peritoneal dialysis (PD) catheter is an important cause of technique failure. Fluoroscopic guidewire manipulation may be undertaken in an attempt to correct the failure. The purpose of this study was to determine the efficacy of fluoroscopic manipulation of previously embedded PD catheters, the factors associated with successful manipulation, and the complication rate associated with manipulation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A single-center, retrospective review of 70 consecutive PD patients undergoing fluoroscopic manipulation for mechanical failure of their PD catheter from June 2006 to February 2011 was undertaken. Logistic regression models were developed to determine the variables associated with successful manipulation. RESULTS: Of the 70 manipulations, 44 were successful (62.9%). In univariate analysis, catheters located in the pelvis compared with those in the upper abdomen (73.5% versus 42.9%, P=0.01) and catheters that were previously functional compared with those that failed at exteriorization (75.0% versus 46.7%, P=0.04) were more likely to be successfully manipulated. Time embedded, previous hemodialysis, and number of intra-abdominal surgeries were not correlated with likelihood of successful manipulation. In multivariate analysis, catheters located in the pelvis (P=0.01) and those with secondary failure (P=0.01) were more likely to successfully manipulated. Two of the patients developed peritonitis (2.9%), neither requiring cessation of PD. CONCLUSIONS: Fluoroscopic manipulation is an effective and safe therapy for failed PD catheters that are unresponsive to conservative treatment. Properly positioned catheters and those that were previously functional are more likely to be successfully manipulated.

Metabolic effects of incremental doses of intraperitoneal amino acids on automated peritoneal dialysis.

BACKGROUND: The use of amino acid (AA) dialysate to ameliorate protein-energy malnutrition has been limited by adverse metabolic effects. OBJECTIVE: We undertook this study to examine the acute metabolic effects of escalating doses of AAs delivered with lactate/bicarbonate dialysate on automated peritoneal dialysis (APD). PATIENTS AND METHODS: 12 APD patients were treated with conventional lactate-buffered dialysate (week 1), followed by lactate/bicarbonate-buffered dialysate (week 2), then 2 - 2.5 L 1.1% AA solution were added (week 3), and then an additional 2 - 2.5 L 1.1% AA were added (week 4). The primary outcomes were change in serum bicarbonate and pH, change in protein catabolic rate (PCR), and change in normalized ultrafiltration (milliliters/gram of carbohydrate infused). RESULTS: Serum bicarbonate rose from week 1 to week 2 (28.9 +/- 3.2 vs 26.9 +/- 4.1 mmol/L, p = 0.03). Addition of one bag of AAs led to a decline in plasma bicarbonate (26.9 +/- 2.1 vs 28.9 +/- 3.2 mmol/L, p < 0.01), which was further magnified by the addition of the second bag of AAs (23.8 +/- 2.7 vs 26.9 +/- 2.1 mmol/L, p < 0.01). Serum bicarbonate fell significantly by week 4 compared to week 1 (23.8 +/- 2.7 vs 26.9 +/- 3.2 mmol/L, p < 0.01) although there was no significant change in venous pH or PCR when week 4 was compared to week 1. Normalized ultrafiltration was stable for the first 3 weeks but rose significantly in week 4 compared to week 1 (5.32 +/- 2.30 vs 4.14 +/- 1.58 mL/g, p = 0.03). CONCLUSIONS: Higher doses of AAs mixed with newer bicarbonate/lactate dialysate on APD result in a small decrease in serum bicarbonate but improved normalized ultrafiltration. This merits further study as both a nutritional supplement and a glucose-sparing strategy.