Pharmacodynamics of 250 mg and 500 mg oral furosemide in peritoneal dialysis
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Residual renal function and diuresis preservation are associated with improved volume control and lower mortality in peritoneal dialysis (PD). Loop diuretics are used to maintain diuresis, although their optimal dosage remains unclear. This study aimed to compare the pharmacodynamics of a 250-mg and a 500-mg dose of oral furosemide in PD patients. 12 patients with a diuresis > 100 mL per day were randomized in a crossover pattern to successively receive an oral dose of 250 mg and 500 mg of furosemide. Twelve-hour natriuresis and diuresis were measured before and after each furosemide dose. Fractional excretion of sodium (FENa) and absolute sodium excretion increased after each dose, although these rises were not statistically significantly different (5.8% (250 mg) vs. 6.9% (500 mg), p = 0.57 for FENa and 42.6 mmol/12h (250 mg) vs. 70.8 mmol/12h (500 mg), p = 0.07 for absolute sodium excretion). Urinary volume was significantly increased after the 500-mg dose, whilst the difference did not reach statistical significance after the 250-mg dose. Furthermore, the higher dose was associated with a greater increase in diuresis than the lower dose (226 mL (250 mg) vs. 522 mL (500 mg), p = 0.04). Furosemide could be used at oral single doses reaching 500 mg in PD patients requiring greater volume control.

Retrospective Study Looking at Cinacalcet in the Management of Hyperparathyroidism after Kidney Transplantation.

Objectives. The primary objective of this study is to evaluate the use of cinacalcet in the management of hyperparathyroidism in kidney transplant recipients. The secondary objective is to identify baseline factors that predict cinacalcet use after transplantation. Methods. In this single-center retrospective study, we conducted a chart review of all patients having been transplanted from 2003 to 2012 and having received cinacalcet up to kidney transplantation and/or thereafter. Results. Twenty-seven patients were included with a mean follow-up of 2.9 ± 2.4 years. Twenty-one were already taking cinacalcet at the time of transplantation. Cinacalcet was stopped within the first month in 12 of these patients of which 7 had to restart therapy. The main reason for restarting cinacalcet was hypercalcemia. Length of treatment was 23 ± 26 months. There were only 3 cases of mild hypocalcemia. There was no statistically significant association between baseline factors and cinacalcet status a year later. Conclusions. Discontinuing cinacalcet within the first month of kidney transplantation often leads to hypercalcemia. Cinacalcet appears to be an effective treatment of hypercalcemic hyperparathyroidism in kidney transplant recipients. Further studies are needed to evaluate safety and long-term benefits.

Easy-to-use equations for the estimation of urine relative saturation in the assessment of risk of recurrence in urinary stones formers.

It is a fact that recurrence of urinary stones is a common medical problem. One of the key factors used in determining the risk of urinary stone-formation is the urine relative saturation in the major constituents of lithiasis. Nomograms were developed in the 1970's to estimate the relative saturation of urine. We present here easy-to-use mathematical equations derived from these nomograms. These equations can be integrated directly in the LIS of any laboratories, and can be used as a tool in the treatment and prevention of recurrent stone-formation.

Conversion of oral alfacalcidol to oral calcitriol in the treatment of secondary hyperparathyroidism in chronic hemodialysis patients.

PURPOSE: The optimal vitamin D3 therapy for the treatment of secondary hyperparathyroidism (SHPT) in chronic hemodialysis patients is still controversial. Recent studies suggest that uremia in end-stage renal disease is associated with enzymatic hepatic dysfunction altering 25-hydroxylation of vitamin D3. The goal of our study was to compare the efficacy of calcitriol, the fully hydroxylated active form of vitamin D3, to alfacalcidol which needs 25-hydroxylation to be effective, for the treatment of SHPT in chronic hemodialysis patients. METHODS: We retrospectively reviewed 45 chronic hemodialysis patients who were switched from oral alfacalcidol to oral calcitriol for the treatment of SHPT. Parathyroid hormone (PTH), serum calcium and serum phosphorus levels were compared pre- and post-conversion using paired Student's t tests. RESULTS: The mean dose of active vitamin D3 decreased from 3.50 mcg/week at baseline to 2.86 mcg (P < 0001) after the switch from alfacalcidol to calcitriol. PTH significantly decreased from 94.4 to 82.6 pmol/L (-11.8 pmol/L, P = 0.02). The mean corrected calcium increased from 2.17 to 2.25 mmol/L (+0.08 mmol/L, P < 0.001) without any clinically significant hypercalcemia, and phosphorus levels were stable. Results were similar in a subgroup of patients (n = 17) for whom the medication was administrated during the hemodialysis session, ensuring a complete compliance. CONCLUSIONS: According to our study, calcitriol in equal dosage is more effective than alfacalcidol in lowering serum PTH level in chronic hemodialysis patients. This suggests that calcitriol may be the optimal active vitamin D3 for the treatment of SHPT in chronic hemodialysis patients.

Pharmacokinetic and Dynamic of Furosemide in Peritoneal Dialysis Patients.

The aim of our study was to evaluate the efficacy and bioavailibility of a commonly used oral furosemide dose (500 mg) compared to a 250 mg intravenous (IV) dose in PD patients with significant residual renal function (urine volume > 100 mL). We also evaluated the immediate blood pressure effect in these patients. The data were obtained from a study we performed for the homologation of a 500-mg dose of furosemide by Health Canada.

The effect of lanthanum carbonate on metabolic acidosis in patients with chronic kidney disease stage IV, V and V-D.

PURPOSE: Hyperphosphatemia and metabolic acidosis are frequently encountered in advanced chronic kidney disease (CKD) patients. Correction of metabolic acidosis in patients with advanced CKD leads to a decrease in the progression of renal impairment and improves nutritional outcomes. Lanthanum carbonate is used for control of hyperphosphatemia. This study evaluated the effect of lanthanum carbonate on metabolic acidosis in CKD IV-V patients and in patients on dialysis. METHODS: Retrospective data of patients in whom lanthanum carbonate therapy was initiated were collected from 2009 to 2013 in a single dialysis center. Of the 79 patients in whom lanthanum carbonate was introduced, 51 patients were included in the analysis. Of the 51 patients, 39 patients received chronic hemodialysis, two patients received peritoneal dialysis therapy, and 10 patients had stage IV-V CKD not on dialysis. The primary outcome was the serum bicarbonate change after the introduction of lanthanum carbonate. RESULTS: There was a significant increase in mean serum bicarbonate concentration of 2.79 mmol/L (p ≤ 0.001) compared to baseline. The increase remained in the CKD IV-V patients (2.50 mmol/L, p = 0.005) and in the patients on dialysis (2.81 mmol/L, p < 0.001). Serum bicarbonate remained higher (p > 0.05) than baseline up to 6 months after lanthanum carbonate introduction. CONCLUSION: In this study, lanthanum carbonate introduction increased serum bicarbonate concentration in a small sample of CKD IV-V patients and in patients on dialysis. Further studies are needed to confirm this effect and investigate whether the correction of metabolic acidosis by using lanthanum carbonate in CKD IV-V patients can improve clinical outcomes.

Outcomes of Infection-Related Hospitalization according to Dialysis Modality.

BACKGROUND AND OBJECTIVES: Peritoneal dialysis (PD) is associated with an increased risk of infection-related hospitalization (IRH) compared with hemodialysis. The objective of this study was to compare mortality and overall readmission after an IRH between PD and hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This propensity score-matched retrospective cohort study assessed patients undergoing long-term dialysis patients, derived from the Canadian Organ Replacement Register and Régie de l'assurance maladie du Québec, who had at least one IRH between January 2001 and December 2007. Patients were followed until death, kidney transplantation, or end of the study period. To estimate the probability of receiving PD versus hemodialysis, propensity scores were obtained using multivariable logistic regression. Mortality and overall readmission risks after the initial IRH were compared using a Cox survival model. RESULTS: A total of 354 pairs of patients who had at least one IRH were matched for propensity score. During follow-up (median, 1.25 years), 138 hemodialysis patients (24.7/100 patient-years; 95% confidence interval [95% CI], 20.7 to 29.1) and 130 PD patients (21.2/100 patient-years; 95% CI, 17.7 to 25.1) died; 265 hemodialysis patients (144.6/100 patient-years; 95% CI, 127.7 to 163.1) and 299 PD patients (173.2/100 patient-years; 95% CI, 154.1 to 194.0) were readmitted for any cause; and 121 hemodialysis patients (29.7/100 patient-years; 95% CI, 24.7 to 35.5) and 168 PD patients (44.7/100 patient-years; 95% CI, 38.2 to 52.0) were readmitted for an infection. Compared with hemodialysis, PD was not associated with a different mortality risk after an IRH (hazard ratio [HR], 0.87; 95% CI, 0.69 to 1.11). PD was associated with a higher risk of infection-related overall readmission compared with hemodialysis (HR, 1.44; 95% CI, 1.14 to 1.81), but not with the risk of all-cause overall readmission (HR, 1.15; 95% CI, 0.98 to 1.36). CONCLUSIONS: PD was not associated with higher mortality or all-cause overall readmission following an IRH compared with hemodialysis, but PD patients were at higher risk of infection-related overall readmission after IRH. IRHs are associated with significant mortality and overall readmissions. Evaluation of strategies to reduce infections in both hemodialysis and PD recipients are needed to improve patient care and outcomes.

Difficulty of patient selection in a combined heart-kidney transplant: a case report.

Combined heart-kidney transplant has become an alternative for heart transplant candidates with significant chronic kidney disease. However, it is not clear which patients will benefit most from such intervention, and in whom cardiac transplant alone will be sufficient to restore adequate renal function. We report the case of a man with ischemic cardiomyopathy and chronic kidney disease who was wait-listed for heart-kidney transplant after acute decompensated heart failure and renal failure requiring hemodialysis. Because of unexpected circumstances, the kidney transplant was cancelled, and only a heart transplant was performed. Nonetheless, the kidney function rapidly improved beyond the levels before hospitalization and remains stable months after transplant. This case illustrates the difficulties in assessing the reversibility of kidney damage in the context of heart failure requiring transplant. This issue is primordial to improve selection of patients who will benefit most from combined heart-kidney transplant in a context of scarce organ allocation resources.

Comparison of oral and intravenous alfacalcidol in chronic hemodialysis patients.

BACKGROUND: Activated vitamin D is the mainstay of treatment for secondary hyperparathyroidism (SHPT) in chronic hemodialysis patients. However, the optimal route of administration is still debated. The aim of our study was to compare efficacy of oral vs intravenous (IV) administration of alfacalcidol in hemodialysis. A secondary objective was to determine the cost-effectiveness advantage of oral administration. METHODS: Eighty-eight chronic hemodialysis patients receiving IV alfacalcidol three times a week were included in the study. All were switched to the same dose of alfacalcidol given orally three times a week during the hemodialysis session. A budget impact analysis was performed. RESULTS: Mean patient age was 64 years old and 43% were males. The mean alfacalcidol dose administered was 2.1 µg three times a week. After three months, serum parathormone (PTH) levels decreased from 80 to 59 pmol/L (p = 0.001) and total serum calcium levels increased from 2.34 to 2.40 mmol/L (p = 0.002). After six months, total serum calcium levels were still significantly higher. Alfacalcidol dosage was significantly decreased during study period; the mean reduction was 0.44 µg per dose. Finally, oral administration was associated with an annual cost reduction of 197 678$CAN and an annual nursing time reduction of 25 days. CONCLUSION: Our findings support that switching IV to oral administration of alfacalcidol during hemodialysis sessions may lead to a similar control of SHPT with lower doses of activated vitamin D. This is a good strategy for optimizing compliance and may allow a dose reduction because of a greater efficacy to suppress PTH. Oral administration also has significant cost-effectiveness advantages.

Association between vitamin D receptor activator and the risk of infection-related hospitalizations among incident hemodialysis patients: a nested case-control study.

BACKGROUND: Patients suffering from chronic kidney disease are at greater risk of developing infection than the normal population, and infections are the second cause of mortality after cardiovascular complications in this population. Some reports suggest that the intake of active vitamin D might be beneficial to prevent infections. Therefore, we aimed to determine if the oral intake of vitamin D receptor activator (VDRA) is associated with a lower risk of infection-related hospitalization (IRH) among incident chronic hemodialysis patients. METHODS: We conducted a nested case-control study in a cohort of 4933 patients initiating chronic hemodialysis between 1 January 2001 and 31 December 2007 in Quebec, Canada, using administrative databases. We identified cases of hospital admission indicating an infection as main diagnosis on the hospital's discharge sheet. Up to 10 controls were randomly selected for each case. Association between oral VDRA use and risk of IRH was estimated using conditional logistic regression. RESULTS: We identified 1136 cases of IRH and 10396 controls during the study period. The intake of VDRA was not associated with the risk of being hospitalized due to an infection (odds ratio [OR], 1.07; 95% confidence interval [CI], 0.95-1.20). Using the prior 6-month cumulative dose of VDRA, we also found that a cumulative VDRA dose of less than 45 mcg (OR, 1.05; 95%CI, 0.92-1.19) or greater than 45 mcg (OR, 1.15; 95%CI, 0.96-1.36) was not associated with the IRH risk. CONCLUSIONS: The oral intake of VDRA was not associated with the risk of IRH in incident hemodialysis patients.

Association of dialysis modality with risk for infection-related hospitalization: a propensity score-matched cohort analysis.

BACKGROUND AND OBJECTIVES: Peritonitis is a well known complication of peritoneal dialysis (PD), whereas in hemodialysis (HD), bacteremia can be life threatening. Whether patients undergoing PD have higher risk than HD patients for infection-related hospitalizations (IRH) remains unknown. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A propensity score-matched retrospective cohort of patients undergoing long-term dialysis between January 2001 and December 2007 was assembled. Propensity scores were calculated using multivariable (demographic characteristics, smoking, body mass index, comorbid conditions, and laboratory data) logistic regression to estimate probability of receiving PD versus HD. A comparison of IRH risk by dialysis modality was estimated using a counting-process survival model. RESULTS: A total of 910 pairs of patients were matched by propensity scores. During a median follow-up of 2.1 years (interquartile range, 1.1-3.5 years), 341 patients were hospitalized once for an infection, 123 twice, and 106 at least three times. PD was associated with an increased risk for IRH compared with HD (propensity-matched hazard ratio [HR], 1.52). PD was associated with a reduced risk for septicemia (HR, 0.31) and pneumonia (HR, 0.58) but also an increased risk for dialysis-related infectious hospitalizations (HR, 3.44), defined as all cases of peritonitis and vascular access-related bacteremia, but not all septicemia cases. CONCLUSIONS: PD patients are at higher risk for IRH than are HD patients. This risk is mostly explained by dialysis-related infections. However, further studies are needed to evaluate whether the severity of those hospitalizations is similar and whether this increased risk for IRH is associated with worse outcomes.

Ten-year experience with fungal peritonitis in peritoneal dialysis patients: antifungal susceptibility patterns in a North-American center.

OBJECTIVE: To describe the clinical and microbiological features associated with fungal peritonitis in peritoneal dialysis (PD) patients at Hôpital Maisonneuve-Rosemont, from August 1996 to July 2006. METHODS: Cases were retrieved from the microbiology laboratory culture registry. Antifungal susceptibility was determined by the Clinical and Laboratory Standards Institute M27A3 method. RESULTS: Among 288 PD patients (total follow-up of 7258 patient-months), nine were found with fungal peritonitis. Candida spp were identified in all of them, with a majority of non-albicans Candida species. Resistance to fluconazole, itraconazole, or voriconazole was as frequent as potential resistance to amphotericin B. No isolate was resistant to caspofungin and one was resistant to micafungin. Prior bacterial peritonitis was frequent (67%). All patients had their PD catheter removed and all of them survived. CONCLUSIONS: In our institution, fungal peritonitis in PD patients is rare. All cases were caused by Candida species. Variable susceptibility patterns were observed, which may influence the initial empirical antifungal therapy and underscore the importance of individual speciation and susceptibility testing of invasive Candida isolates.

A case of an aortic dissection in a young adult: a refresher of the literature of this "great masquerader".

Aortic dissection is often misdiagnosed, especially among young patients, and it is associated with a high mortality rate. We present here a case of fatal acute aortic dissection in a young man who was misdiagnosed with pericarditis. We reviewed the literature of acute aortic dissection in young people and we focused particularly on clinical presentations, outcomes and investigations of aortic dissection. We report a case of a 33-year-old man with a history of uncontrolled hypertension with acute pleuretic chest pain who was transferred to our hospital for suspected pulmonary embolism and died of acute hemorragic pericardial effusion from an ascendant aortic dissection. We should never rule out aortic dissection off our differential diagnosis on the sole basis of a patient's young age.

Reduced hepatic synthesis of calcidiol in uremia.

Calcidiol insufficiency is highly prevalent in chronic kidney disease (CKD), but the reasons for this are incompletely understood. CKD associates with a decrease in liver cytochrome P450 (CYP450) enzymes, and specific CYP450 isoforms mediate vitamin D(3) C-25-hydroxylation, which forms calcidiol. Abnormal levels of parathyroid hormone (PTH), which also modulates liver CYP450, could also contribute to the decrease in liver CYP450 associated with CKD. Here, we evaluated the effects of PTH and uremia on liver CYP450 isoforms involved in calcidiol synthesis in rats. Uremic rats had 52% lower concentrations of serum calcidiol than control rats (P < 0.002). Compared with controls, uremic rats produced 71% less calcidiol and 48% less calcitriol after the administration of vitamin D(3) or 1alpha-hydroxyvitamin D(3), respectively, suggesting impaired C-25-hydroxylation of vitamin D(3). Furthermore, uremia associated with a reduction of liver CYP2C11, 2J3, 3A2, and 27A1. Parathyroidectomy prevented the uremia-associated decreases in calcidiol and liver CYP450 isoforms. In conclusion, these data suggest that uremia decreases calcidiol synthesis secondary to a PTH-mediated reduction in liver CYP450 isoforms.

Comparison of the prevalence of calcidiol insufficiency in predialysis and osteoporotic populations.

AIM: Calcidiol insufficiency is highly prevalent in chronic kidney disease (CKD) and osteoporotic patients. We assessed and compared calcidiol levels in these two groups from the same geographical area to differentiate environmental factors from characteristics related to CKD. METHODS: We measured calcidiol levels in 160 predialysis (group 1) and 53 osteoporotic (group 2) patients from a single center. Calcidiol insufficiency was defined as a level between 37.5 and 75 nmol/l and calcidiol deficiency was defined as a level below 37.5 nmol/l. RESULTS: In group 1, mean glomerular filtration rate (GFR), calcidiol, and parathyroid hormone (PTH) levels were 18.3 +/- 4.7 ml/min, 38.7 +/- 15.1 nmol/l, and 21.9 +/- 19.1 pmol/l. Calcidiol insufficiency and deficiency were present in 98.7% of patients. There was an inverse correlation between calcidiol and PTH levels (r = -0.25; P = 0.001). In group 2, mean GFR, calcidiol levels, and PTH levels were 68.6 +/- 17.6 ml/min, 73.8 +/- 27.1 nmol/l, and 4.23 +/- 1.83 pmol/l, respectively. Calcidiol insufficiency and deficiency were present in 50.9% of patients. There was an inverse correlation between calcidiol and PTH levels (r =-0.44; P = 0.02). CONCLUSION: In our predialysis population, calcidiol insufficiency and deficiency are present in almost every patient, being more common than previously reported. It is also more frequent than in a similar osteoporotic population, suggesting a cause unrelated to environmental factors. Interestingly, there is a significant inverse correlation between calcidiol and parathyroid levels in both populations. Further studies are needed to enable understanding of the mechanisms underlying calcidiol insufficiency.

Successful treatment of encapsulating peritoneal sclerosis with immunosuppressive therapy.

Encapsulating peritoneal sclerosis is a rare, but potentially lethal, complication of peritoneal dialysis. Treatment of patients with encapsulating peritoneal sclerosis is controversial. Conservative treatment carries a poor outcome, and immunosuppressive drugs are now used frequently. Most commonly, these immunosuppressive regimens include steroids with or without azathioprine or cyclosporine. Mycophenolate mofetil is a reversible DNA synthesis inhibitor that frequently replaces azathioprine in renal transplantation because of its improved immunosuppressive potency and better side-effect profile. We report 3 cases of encapsulating peritoneal sclerosis in continuous ambulatory peritoneal dialysis patients for which an association of prednisone and mycophenolate mofetil significantly modified the evolution of the disease. All 3 patients showed significant improvement within a month and are still alive more than 2 years after the diagnosis of encapsulating peritoneal sclerosis. None experienced a relapse or abdominal symptoms, and body weights are stable. This is the first report of 3 cases of successful treatment of patients with encapsulating peritoneal sclerosis with prednisone and mycophenolate mofetil.