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.

Retroperitoneal fibrosis: retrospective descriptive study on clinical features and management.

INTRODUCTION: Retroperitoneal fibrosis (RPF) is a rare condition characterized by the presence of inflammatory and fibrous retroperitoneal tissue that often encases the ureters or abdominal organs. This study describes the clinical characteristics, diagnostic methods, and treatments and their effects on renal function. METHODS: We conducted a retrospective analysis of patients diagnosed with RPF at Maisonneuve-Rosemont Hospital. RESULTS: We identified 17 patients with RPF between 1998 and 2013. Eight patients were females (47%), and the mean age was 62±18 years. Eleven patients were idiopathic. Back pain was the most common symptom. All diagnoses were made based on the finding of a retroperitoneal mass on the computed tomography scan. Three patients had histological diagnosis of RPF and seven patients had unspecific changes on their biopsy. Twelve patients needed double-J stents, three patients had a temporary percutaneous nephrostomy, two patients had to have a nephrectomy for refractory ureteral obstruction, and one patient required hemodialysis. Ten patients with idiopathic RPF received medical treatment. In the treated group, only two patients had complete remission of the disease and five patients had improvement of their lesions. There were no deteriorations and only one relapse. Seven patients did not receive any treatment; two of them achieved complete remission, one of them deteriorated, and two of them had no changes. CONCLUSION: Most of our cases of RPF were idiopathic. Almost all treated patients received prednisone and seemed to respond, at least partially. There was a lot of heterogeneity in patient management, which makes it difficult to compare treatment effects. However, treated patients seemed to have more favorable outcomes than those who were not.

Presumed paradoxical embolus in a patient with diabetic ketoacidosis.

Thrombotic complications figure among the most frequent causes of mortality in diabetic ketoacidosis (DKA) and hyperosmolar state. We report the case of a 55-year-old woman presenting with DKA whereby a newly discovered patent foramen ovale was found due in part to the observation of bilateral deep vein thrombosis in legs, bilateral multiple pulmonary embolisms, and left subclavian acute artery thrombosis. Diabetes is known as a hypercoagulability state, and DKA is rising as a risk factor for vascular events. The importance of prophylactic anticoagulation should be emphasized in this setting.

Tinzaparin reduces health care resource use for anticoagulation in hemodialysis.

Anticoagulation is required during hemodialysis to prevent thrombus formation within the extracorporeal circuit. The low-molecular-weight heparin tinzaparin is more expensive than unfractionated heparin (UFH) in Canada but more convenient to administer. We conducted a time-and-motion study to test the hypothesis that tinzaparin may reduce nursing time and total health care costs compared with UFH. Data on health care resource use associated with anticoagulation during hemodialysis for chronic renal failure were collected at an academic hospital in Quebec. Nursing time was recorded for 8 nurses performing 16 dialysis sessions for 4 patients receiving tinzaparin and 4 receiving UFH (2 dialysis sessions per patient). Nurses had ≥ 1 year of experience supervising hemodialysis. We estimated total annual costs of nursing time and health care resources (anticoagulants, medical supplies, and laboratory testing) associated with anticoagulation. In sensitivity analyses, drug costs were varied ± 30% of their base-case values. Estimated annual nursing times per patient were 0.8 vs. 11.5 hours in the first year and 0.6 vs. 10.2 hours in subsequent years for tinzaparin vs. UFH, respectively. Annual drug costs per patient were CAD 898.56 for tinzaparin and 546.75 for UFH. Estimated total annual costs were CAD 1061.03 vs. 1012.71 in the first year and CAD 917.75 vs. 895.23 in subsequent years for tinzaparin vs. UFH, respectively. Use of tinzaparin was cost saving relative to UFH if tinzaparin price was reduced 30%. Most of the price differential between tinzaparin and UFH is offset by substantial time savings to nephrology nurses.