Israel Medical Association Journal

Background: Hemodialysis requires reliable, recurrent access to the circulatory system. Central venous tunneled dialysis catheters (TDC) are frequently used for patients receiving hemodialysis as a bridge to permanent vascular access or as a final option. TDC are prone to complications such as infection and dysfunction.

Objective: To assess the prevalence and predictors of TDC dysfunction in a cohort of chronic hemodialysis patients.

Methods: This single-center, retrospective study was based on data from an electronic database of chronic hemodialysis patients during 5 years of follow-up.

Results: A total of 625 TDC were inserted in 361 patients, of which 234 (37.4%) were replaced due to dysfunction. The main insertion site was the right internal jugular vein. Diabetes mellitus was an important predictor of TDC dysfunction and was significantly correlated with TDC extraction. Chronic anticoagulation and antiplatelet treatment did not affect the rate of TDC dysfunction or replacement.

Conclusions: TDC use for chronic dialysis patients is increasing and dysfunction is a major problem. In our study, we highlighted the high prevalence of TDC dysfunction and the need for further research to improve hemodialysis access as well as TDC patency and function.

Among patients admitted with acute decompensated heart failure (ADHF), deterioration of renal function with resulting acute kidney injury (AKI) is reported in up to 70% of patients with cardiogenic shock. Twenty percent of heart failure patients with AKI progress to dialysis (AKI-D). Optimal timing for initiation of renal replacement therapies (RRT) has been researched; however, minimal studies discuss guidelines for weaning from RRT [1]. Electronic monitoring of urine output (UO) may serve as a tool to aid in withdrawal from RRT. We present a case of ADHF with severe AKI requiring continuous renal replacement therapy (CRRT) where real-time electronic monitoring of UO was implemented for the first time to guide de-escalation therapy from CRRT until successful withdrawal.

Higher potency bisphosphonates, typically intravenous formulations, are given at lower doses for postmenopausal women. The treatment has improved compliance compared to daily oral therapy. Since bisphosphonates are exclusively excreted via the kidneys, intravenous formulation has been associated with deterioration of renal function, specifically in the setting of preexisting renal disease or concomitant use of nephrotoxic agents [1].

Carbamoyl phosphate synthetase 1 (CPS1; MIM *608307; E.C. 6.3.4.16) is the first rate-limiting enzyme of the urea cycle, an essential metabolic pathway for ammonia detoxification. CPS1 deficiency (CPS1-D) is characterized by severe hyperammonemia during disease exacerbations. During a metabolic crisis, children with CPS1-D are admitted with vomiting, altered mental status, and high serum levels of ammonia. Rapid normalization of ammonia level ameliorates neurological outcome [1,2]. The first-line treatment for hyperammonemia in these patients is ammonia scavengers in combination with citrulline or arginine and high-calorie supplementation while controlling protein intake [1].

Metastatic pulmonary calcinosis (MPC) is characterized by deposits of calcium in normal pulmonary parenchyma. Diffuse pulmonary calcinosis commonly occurs in hypercalcemia and/or hyperphosphatemia and is more commonly related to renal failure than primary hyperparathyroidism, skeletal metastases, or multiple myeloma [1]. Calcium depositions favor alkaline tissue and are thus more common in the upper lobes of the lung, which have a higher ventilation to perfusion ratio and a low capillary pCO₂, resulting in an alkaline pH [2]. Therefore, the most common radiographic manifestation consists of poorly defined nodular opacities bilaterally in the upper lung zones [3].

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: Advanced heart failure (HF) carries a high rate of recurrent HF hospitalizations and a very high mortality rate. Mechanical devices and heart transplantation are limited to a select few. Dialysis may be a good alternative for advanced HF patients with volume overload despite maximal pharmacological therapy.

Objectives: To assess the net clinical outcome of peritoneal dialysis or hemodialysis in patients with advanced HF.

Methods: We analyzed all advanced HF patients who were referred for dialysis due to volume overload in our institution. Patients were followed for complications, HF hospitalizations, and survival.

Results: We assessed 35 patients; 10 (29%) underwent peritoneal dialysis and 25 (71%) underwent hemodialysis; 71% were male; median (interquartile range) age was 74 (67–78) years. Estimated glomerular filtration rate was 20 (13–32) ml/min per 1.73 m². New York Heart Association functional capacity was III. Median follow-up time was 719 days (interquartile range 658–780). One-year mortality rate was 8/35 (23%) and overall mortality rate was 16/35 (46%). Three patients (9%) died during the first year due to line or peritoneal dialysis related sepsis, and 6 (17%) died during the entire follow-up. The median number of HF hospitalizations was significantly reduced during the year on dialysis compared to the year prior to dialysis (0.0 [0.0–1.0] vs. 2.0 [0.0–3.0], P < 0.001).

Conclusions: Dialysis is reasonably safe and significantly reduced HF hospitalization in advanced HF patients. Dialysis could be a good alternative for advanced HF patients with intractable volume overload.

Background: The reduced immune response of maintenance hemodialysis patients to coronavirus disease 2019 (COVID-19) vaccines is a major concern.

Objectives: To analyze the late (6 months after full vaccination) antibody response and compare it to early post-vaccination titer.

Methods: We conducted a multicenter prospective study of 13 hemodialysis units in Israel.

Results: We demonstrated that the low titers observed among ESRD patients 2–3 months after vaccination with the Comirnaty vaccine (median 63.8 AU/ml) declined to critically lower values 6 months after full vaccination. (Mediananti S antibodies, 31 AU/ml). Seropositivity significantly declined among hemodialysis patients from 89% to 74% (P < 0.0001), although it did not significantly change among controls.

Conclusions: We recommend all patients on hemodialysis receive a booster COVID-19 vaccine 6 months after the second dose.

Background: Among dialysis patients, occlusive mesenteric vascular disease has rarely been reported.

Objectives: To report on the experience of one center with regard to diagnosing and treating this complication.

Methods: The retrospective case-series involved six patients (3 females, 3 males; age 52–88 years; 5/6 were smokers) on chronic hemodialysis at a single center. All patients with symptoms suggestive of occlusive mesenteric disease and a subsequent angiographic intervention were included. Demographic, clinical, and laboratory data were collected from patient charts for the period before and after angioplasty and stenting of the mesenteric vessels. A Wilcoxon signed-rank test was used to compare the relevant data before and after the intervention.

Results: All participants had variable co-morbidities and postprandial abdominal pain, food aversion, and weight loss. CT angiography was limited due to heavy vascular calcifications. All underwent angioplasty with stenting of the superior mesenteric artery (4 patients) or the celiac artery (2 patients). All procedures were successful in resolving abdominal pain, malnutrition, and inflammation. Weight loss before was 15 ± 2 kg and weight gain after was 6 ± 2 kg. C-reactive protein decreased from 13.4 ± 5.2 mg/dl to 2.2 ± 0.4 mg/dl (P < 0.05). Serum albumin increased from 3.0 ± 0.2 g/dl to 3.9 ± 0.1 g/dl (P < 0.05). Two patients underwent a repeat procedure (4 years, 5 months, respectively). Follow-up ranged from 0.5–7 years.

Conclusions: Occlusive mesenteric ischemia occurs among dialysis patients. The diagnosis requires a high degree of suspicion, and it is manageable by angiography and stenting of the most involved mesenteric artery.

Background: Peritoneal dialysis (PD) is a treatment option for patients with end-stage renal disease (ESRD) and cardiorenal syndrome (CRS).

Objectives: To evaluate the outcome of this patient population.

Methods: A retrospective study was conducted of patients who underwent an open or laparoscopic insertion of a PD catheter at our institution between 2009 and 2017. Data included demographics, peri-operative parameters, and long-term outcome. Patient and technique survival curves are presented, including subgroup analysis by method of catheter insertion and techniques for infection prevention.

Results: The study population included 95 men and 42 women, aged 65.7 ± 12.4 years. Mean follow-up was 34.6 ± 27.3 months. Open insertion was performed in 113 cases, while 24 underwent laparoscopic insertion. There was no difference in technique survival between these groups (P = 0.943). Removal of the catheter was required in 66% of patients. Median technique survival was 12.1 months. Two-year technique survival was 37% and 5-year technique survival was 12%. The leading cause for catheter removal was infection (69%). Application of measures for prevention of infections were significantly associated with prolonged technique survival (P = 0.001). Technique survival after 2 years was 38% with the application of a single measure and 57% with the application of two measures (P = 0.001). CRS patients (n=24) had a significantly lower overall survival rate (2-year survival 20% vs. 74%, P = 0.001).

Conclusions: The method of catheter insertion has no effect on technique survival. Prevention of infections is the most significant factor for improving the technique survival rates.

Background: The potential for full rehabilitation following amputation among end-stage renal disease patients is poor.

Objectives: To evaluate the functional outcomes and survival among amputees treated with hemodialysis at the end of the rehabilitation procedure.

Methods: We recruited 46 patients after lower limb amputation. Of these individuals, 19 (41.3%) were treated with dialysis and 27 (58.7%) were non-dialysis-dependent patients (NDDP). Both groups were divided into three sub-groups according to their independence with regard to activities of daily living (ADL) and their ability to walk with prostheses.

Results: The survival of lower limb amputees treated with dialysis was shorter compared to NDDP. Survival after amputation among the NDDP who were fully or partially independent in ADL and with regard to mobility, was longer compared to the non-mobile amputees as with the patients treated with dialysis.

Conclusions: Survival was significantly longer in lower limb amputees NDDP and shorter in patients who did not achieve a certain level of functioning.

Background: Dialysate purity contributes to the inflammatory response that afflicts hemodialysis patients.

Objectives: To compare the clinical and laboratory effects of using ultrapure water produced by a water treatment system including two reverse osmosis (RO) units in series, with a system that also includes an ultrapure filter (UPF).

Methods: We performed a retrospective study in 193 hemodialysis patients during two periods: period A (no UPF, 6 months) and period B (same patients, with addition of UPF, 18 months), and a historical cohort of patients treated in the same dialysis unit 2 years earlier, which served as a control group.

Results: Mean C-reactive protein, serum albumin and systolic blood pressure worsened in period B compared to period A and in the controls.

Conclusions: A double RO system to produce ultrapure water is not inferior to the use of ultrapure filters.

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.