Israel Medical Association Journal

Background: Reliable vascular access is a fundamental tool for providing effective hemodialysis. Vascular access dysfunction is associated with increased morbidity and mortality among hemodialysis patients. Current vascular access guidelines strongly recommend creating an arteriovenous fistula (AVF) as the first option; however, a substantial proportion of new AVFs may not be usable.

Objectives: To assess possible predictors of primary and secondary failure of vascular access.

Methods: This retrospective cohort study included all vascular access sites created at Meir Medical Center from 2006 through 2012. Vascular access site, primary and secondary failure rates, and relevant demographic and clinical data were recorded during 60 months of follow-up.

Results: A total of 612 vascular accesses were created and followed for a median of 32 ± 29.4 months. Of these, 490 (80%) were suitable for initiating hemodialysis. Vascular access site was the most important predictor of primary failure but did not predict secondary failure. Co-morbidities such as diabetes mellitus and congestive heart failure, as well as the use of antiplatelet agents did not predict primary or secondary failure. Preoperative vascular mapping using Doppler ultrasonography was performed in 36.4% of cases and was not associated with lower rates of primary or secondary failure.

Conclusions: Vascular access site is an important predictor of primary failure. We did not find a benefit of pre-operative vessel mapping or chronic antiplatelet therapy in terms of decreasing primary and secondary failure rates. Physicians should carefully consider the characteristics of the patient and blood vessels before creating vascular access in patients requiring chronic hemodialysis.

Background: Anemia management strategies among chronic hemodialysis patients with high ferritin levels remains challenging for nephrologists.

Objectives: To compare anemia management in stable hemodialysis patients with high (≥ 500 ng/ml) vs. low (< 500 ng/ml) ferritin levels

Methods: In a single center, record review, cohort study of stable hemodialysis patients who were followed for 24 months, an anemia management policy was amended to discontinue intravenous (IV) iron therapy for stable hemodialysis patients with hemoglobin > 10 g/dl and ferritin ≥ 500 ng/ml. Erythropoiesis-stimulating-agents (ESA), IV iron doses, and laboratory parameters were compared among patients with high vs. low baseline ferritin levels before and after IV iron cessation.

Results: Among 87 patients, 73.6% had baseline ferritin ≥ 500 ng/ml. Weekly ESA dose was greater among patients with high vs. low ferritin (6788.8 ± 4727.8 IU/week vs. 3305.0 ± 2953.9 IU/week, P = 0.001); whereas, cumulative and monthly IV iron doses were significantly lower (1628.2 ± 1491.1 mg vs. 2557.4 ± 1398.9 mg, P = 0.011, and 82.9 ± 85 vs. 140.7 ± 63.9 mg, P = 0.004). Among patients with high ferritin, IV iron was discontinued for more than 3 months in 41 patients (64%) and completely avoided in 6 (9.5%).ESA dose and hemoglobin levels did not change significantly during this period.

Conclusions: Iron cessation in chronic hemodialysis patients with high ferritin levels did not affect hemoglobin level or ESA dose and can be considered as a safe policy for attenuating the risk of chronic iron overload.

Background: Idiopathic membranous nephropathy (IMN) is one of the most common causes of nephrotic syndrome (NS) in Caucasian adults. Most patients have good renal prognosis, but 30–40% may progress to end stage renal disease (ESRD). 

Objectives: To evaluate the efficacy and safety of immunosuppressive treatment (IST) in high-risk patients.

Methods: All IMN patients diagnosed by kidney biopsy from 2004–2010 were included. Clinical and laboratory data were collected at each follow-up visit. Risk assessment for renal progression classified patients as high risk if: 24 hour protein excretion > 6 g/day, estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2, and severe disabling or life-threatening clinical symptoms of NS were present.

Results: Among 290 biopsies, 37 patients (12.7%) were IMN. They were allocated to the high-risk IST group (n=16) or low-risk supportive treatment (ST) group (n=21) according to the likelihood of developing renal failure. Mean follow-up was 47 ± 17.3 months. Complete and partial remission rate was 68.7% for high-risk IST vs. 90.4% for low-risk ST. In the high-risk IST group, eGFR was significantly lower at 30 months (65.5 ± 28.6 vs. 85.3 ± 21.6 at baseline, P < 0.05). Four high-risk patients reached ESRD. In the low-risk ST group, eGFR remained stable at 30 and 60 months. 

Conclusions: This study showed a high remission rate for IMN. IST with prednisolone and cyclophosphamide provided favorable renal outcomes in most high-risk patients. The very high remission rate obtained in the low-risk patients confirms the adequacy of supportive treatment in this group.

Background: Upper respiratory tract infection (URTI) occurs frequently in the general population and is considered a benign self-limited disease. Dialysis patients constitute a high risk population whose morbidity and mortality rate as a result of URTI is unknown. 

Objectives: To assess the local incidence, morbidity and mortality of URTI in dialysis patients compared to the general population. 

Methods: In this retrospective cohort study we reviewed the charts of all chronic dialysis patients diagnosed with URTI at Meir Medical Center, Kfar Saba, Israel during the 2014–2015 winter season. 

Results: Among 185 dialysis patients, 40 were found to be eligible for the study. The average age was 66.1 ± 15.7 years, and the co-morbidity index was high. Influenza A was the most common pathogen found, followed by rhinovirus, respiratory syncytial virus and para-influenza. Of the 40 patients 21 (52.5%) developed complications: pneumonia in 20%, hospitalization in 47.5%, and respiratory failure requiring mechanical ventilation in 12.5%. Overall mortality was 10%. General population data during the same seasonal period showed a peak pneumonia incidence of 4.4% compared to 20% in the study population (P < 0.0001). 

Conclusions: The study findings show that compared to the general population, URTI in dialysis patients is a much more severe disease and has a higher complication rate. Influenza A, the most common pathogen, is associated with a worse prognosis. 

 

Background: Primary aldosteronism is a common cause of non-renal secondary hypertension. A correct diagnosis results in curing the hypertension or targeting appropriate pharmacotherapy. In patients with low renin resistant hypertension (after treatment with three or more different anti-hypertensive drugs the blood pressure remains above 140/90 mmHg), screening for aldosteronism is mandatory.

Objectives: To demonstrate that normal blood levels of potassium in resistant hypertensive patients do not exclude the possible presence of hyperaldosteronism, and to suggest the use of the plasma aldosterone concentration (ng/dl)/plasma renin activity (ng/ml/hour) ratio in screening for hyperaldosteronism.

Methods: Blood tests, suppression and stimulation tests (2 L normal saline IV/4 hours and 20 mg furosemide IV for 60 minutes in a standing position) were systematically performed in 20 low renin normokalemic resistant hypertensive patients. None had renal disorders, known endocrine abnormalities or heart failure. They did not receive anti-hypertensive drugs affecting PAC[1] or PRA[2]. Basal PRA and PAC were measured twice: PAC after saline infusion and PAC/PRA after stimulation.

Results:. PAC/PRA above 50 was used to denote hyperaldosteronism. Serum K was 4 ± 0.07 mM/L, PAC 22.8 ± 1.8 ng/dl, PRA 0.13 ± 0.02 ng/ml/hour, PAC/PRA 190 ± 22 (above 100 in 17). After suppression PAC decreased from 25 ± 1.8 to 11 ± 1 ng/dl (normal <5 ng/dl). Stimulation did not affect PRA and PAC/PRA. Abdominal computed tomography scan revealed normal adrenal glands in 15 patients. Spironolactone (116 ± 60 mg/day) normalized blood pressure in all patients; it was used as a single therapy in 8, and in association with only one anti-hypertensive drug in the remaining 12 patients. In one patient the treatment was discontinued due to the presence of hyperkalemia.

Conclusions: Low renin resistant hypertension associated with normokalemia may be due to hyperaldosteronism. Normal aldosterone levels in the basal condition do not exclude the possibility of hyperaldosteronism. Using a PAC/PRA ratio above 50 as a screening test can aid the physician in deciding when to perform dynamic tests, thus increasing the sensitivity of the diagnosis of hyperaldosteronism. CT scan is frequently normal. Targeted pharmacotherapy leads to a normalization of blood values.