Israel Medical Association Journal

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: Late nephrology referral, before initiation of dialysis treatment, is associated with adverse outcome.

Objectives: To investigate the implications of late nephrology referral on mortality among dialysis patients in Israel.

Methods: We retrospectively analyzed 200 incident dialysis patients. Patients were defined as late referrals if they started dialysis less than 3 months after their first nephrology consultation. Survival rates and risk factors for mortality were analyzed

Results: The early referral (ER) group comprised 118 patients (59%) and the late referral (LR) group 82 patients (41%). The mortality rate was 44.5% (53 patients) in the ER and 68% (n=56) in the LR group. The 4 year survival rate was 41.1% in the ER and 18.7% in the LR group (P < 0.0001). The mortality rate increased with late nephrology referral (HR 1.873, 95%CI 1.133–3.094), with age (HR 1.043 for each year, 95%CI 1.018–1.068), with diabetes (HR 2.399, CI 1.369-4.202), and with serum albumin level (HR 0.359 for an increase of each 1 g/dl, 95%CI 0.242–0.533). The median survival time was higher for the ER group in women, in patients younger than 70, and in diabetic patients. A trend for longer survival time was found in non-diabetic patients. Survival time was not increased in early referred patients older than 70 and in male patients.

Conclusions: Late nephrology referral is associated with an overall higher mortality rate in dialysis patients. The survival advantage of early referral may have a different significance in specific subgroups. The timing of nephrology referral should be considered as a modifiable risk factor for mortality in patients with end-stage renal disease. 

Objectives: To assess the results of endovascular revascularization for lower extremity ischemia in dialysis patients.

Methods: We conducted a retrospective review of all dialysis patients who underwent endovascular treatment for critical limb ischemia (CLI) in our institution between 2007 and 2011. Data collected included comorbidities, clinical presentation, anatomic distribution of vascular lesions, amputation and survival rates.

Results: We identified 50 limbs (41 patients). Indications included: gangrene in 22%, non-healing wounds in 45%, rest pain in 31%, and debilitating claudication in 4%. Mean follow-up was 12 months (1–51 months). Nineteen patients required amputations. Freedom from amputation at 5 years was 40%. Factors associated with amputation included non-healing wounds or gangrene (68% and 36% respectively) and diabetes (P < 0.05). The survival rate was 80% after 5 years.

Conclusions:  Despite improvement in endovascular techniques for lower extremity revascularization, the incidence of limb salvage among dialysis patients remains poor, resulting in a high rate of major amputations. 

Background: Acute renal failure (ARF) is a common complication in critically ill children. It is known as an important predictor of morbidity and mortality in this population. Data on the factors affecting the choice of renal replacement therapy (RRT) modality and its impact on mortality of children with ARF[1] are limited.

Objectives: We retrospectively studied 115 children with ARF necessitating RRT[2] during the period 1995–2005 to evaluate the effect of several prognostic factors as well as RRT type on their immediate outcome.

Methods: The data collected from charts included demographics, primary disease, accompanying medical conditions, use of vasopressor support, indications for dialysis, RRT modality, and complications of dialysis. Categorical variables were analyzed using chi-square or Fisher’s exact tests. Variables associated with mortality (P < 0.1) at the univariable level were studied by a multivariable logistic regression model.

Results: The most common cause of ARF was congenital heart disease (n=75). RRT modalities included peritoneal dialysis (PD) (n=81), hemodialfiltration (HDF) (n=31) and intermittent hemodialysis (IHD) (n=18). Median RRT duration was 4 days (range 1–63 days). Overall mortality was 52.2%. IHD[3] was associated with the best survival rate (P < 0.01 vs. PD[4] and HDF[5]), while children treated with HDF had the worse outcome. Hemodynamic instability and systemic infections were associated with greater mortality, but the rate of these complications did not differ between the study groups.

Conclusions: Our results suggest that IHD[6] when applied to the right patient in an appropriate setting may be a safe and efficient RRT modality in children with ARF. Randomized prospective trials are needed to further evaluate the impact of different RRT modalities on outcome in children with ARF.

Background: Peritonitis is a major complication of chronic peritoneal dialysis therapy. It is recommended that each center monitor infection rates in order to define the local microbiological profile and implement an appropriate empiric antibiotic regimen.

Objectives: To analyze the microbiological profile of peritonitis in our pediatric dialysis unit and identify local predisposing factors.

Methods: In this retrospective study we reviewed the files of children treated with chronic PD[1] during the 10 year period 1997–2007.

Results: Eighty peritonitis episodes were recorded in 29 children (20 male, 9 female) aged 0.1–18.5 years (median 11.75) treated with peritoneal dialysis for 6–69 months (median 19) for a total of 578 patient-months. The annual peritonitis rate was 1.66/patient. The main pathogens were coagulase-negative Staphyloccocus (32.5%) and Pseudomonas spp. (16%), which were also cultured in most cases (64–69%) from the exit site during the 3 months preceding peritonitis. No peritonitis occurred in 31% of the patients (median age 12.5 years). All patients less than 5 years old had at least one peritonitis episode. Contaminating conditions (gastrostomy, enuresis, diaper use), found in 44% of the study group, and first infection within 6 months from starting PD were significantly associated with an increased peritonitis rate (P = 0.01, P = 0.009, respectively). Recurrent peritonitis led to a switch to hemodialysis in 18% of patients. There were no deaths.

Conclusions: The risk factors for peritonitis in our study were: first infection within less than 6 months from starting treatment, Pseudomonas exit-site colonization, and contaminating conditions (gastrostomies, diaper use, enuresis). These susceptible subgroups as well as very young age (< 5 years) at starting PD should be especially targeted during training of caregivers and follow-up to prevent later complications.  

[1] PD = peritoneal dialysis

Background: Patients with end-stage renal disease are at high risk of mycobacterial infection.

Objectives: To analyze the difficulties in reaching an accurate diagnosis of tuberculosis in dialysis patients.

Methods: We conducted a retrospective follow-up of patients who attended our peritoneal and hemodialysis units during the 10 year period 1995–2005.

Results: Our dialysis unit diagnosed 10 cases of tuberculosis caused by Mycobacterium tuberculosis and 9 cases of Mycobacterium other than tuberculosis. In the former group, five patients had mycobacterium in the sputum, which was diagnosed by intraabdominal mass biopsy in one, culture of the gastric juices in one, and pleural fluid culture or pleural biopsy in three. One of these patients was suffering from pleural TB[1] as well as Potts disease. Of the patients with Mycobacterium other than tuberculosis, five were diagnosed by sputum cultures, three by urine cultures and one in peritoneal fluid. Differences in treatment and outcome were also reviewed.

Conclusions: The diagnosis of TB in dialysis patients should be approached with a high index of suspicion. It is clear that extensive diagnostic procedures are required to ensure an accurate diagnosis of the disease. Tuberculosis incurs a significant added burden due to the need for isolation of infected patients within the dialysis unit. Treatment of patients with Mycobacterium other than tuberculosis should be addressed individually.

Background: Peritoneal dialysis is a widely accepted route for renal replacement. With the advent of endoscopy, many surgical techniques for the prevention of catheter failure have been proposed.

Objectives: To evaluate the outcomes of patients undergoing laparoscopic Tenckhoff catheter implantation, using the pelvic fixation technique.

Methods: Data analysis was retrospective. All procedures were performed under general anesthesia. A double-cuffed catheter was inserted using two 5 mm trocars and one 10 mm trocar, fixing its internal tip to the dome of the bladder and its inner cuff to the fascia. Catheter failure was defined as persistent peritonitis/exit-site/tunnel infection, severe dialysate leak, migration or outflow obstruction.

Results: LTCI[1] was performed in 34 patients. Mean patient age was 65 ± 17 years. In 12 of the 34 patients the indication for LTCI was end-stage renal failure combined with NYHA class IV congestive heart failure. Operative time was 35 ± 15 minutes. A previous laparotomy was performed in 9 patients. Hospital stay was 1.5 ± 0.6 days. The first continuous ambulatory peritoneal dialysis was performed after 20 ± 12 days. Median follow-up time was 13 months. There were several complications, including 5 (14%) exit-site/tunnel infections, 27 episodes (0.05 per patient-month) of bacterial peritonitis, 3 (9%) incisional hernias, 1 case of fatal intraabdominal bleeding, 2 (5.8%) catheter migrations (functionally significant), and 10 (30%) cases of catheter plugging, 8 of which were treated successfully by instillation of urokinase and 2 surgically. A complication-mandated surgery was performed in 8 patients (23.5%). The 1 year failure-free rate of the catheter was 80.8%. One fatal intraabdominal bleeding was recorded.
Conclusions: LTCI is safe, obviating the need for laparotomy in high risk patients. Catheter fixation to the bladder may prevent common mechanical failures

Background: Advanced glycation end products, formed by the non-enzymatic glycation of proteins with reducing sugars, are thought to play a pathogenetic role in the vascular complications of diabetes, uremia and atherosclerosis. β2-microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis. AGE[1]-modified β2m[2] has been found in amyloid deposits of long-term hemodialysis patients. AGE-modified β2m has also been shown to enhance chemotaxis and increase tumor necrosis factor-alpha and interleukin-1 beta secretion by circulating and tissue monocytes/macrophages.

Objectives: To investigate the effect of AGE-modified β2m and AGE-human serum albumin on TNF-α[3] and IL-1β[4] secretion by human peritoneal macrophages derived from patients on continuous ambulatory peritoneal dialysis.

Methods: Human PMØ[5] were isolated from peritoneal dialysis effluent of stable CAPD[6] patients and were incubated for 24 hours with AGE-modified β2m, β2m, AGE-HSA[7], HSA or lipopolysaccharide. TNF-α or IL-1β secretion was measured by enzyme-linked immunosorbent assay in cell-free culture supernatants.

Results: Both AGE-modified β2m and AGE-HSA significantly increased TNF-α and IL-1β secretion by human PMØ in a dose-dependent manner (50–200 μg/ml). In contrast, β2m or HSA had no such stimulatory effect on TNF-α secretion but had a small significant increase in IL-1β secretion.

Conclusions: AGE-modified β2m promotes in vitro TNF-α and IL-1β secretion by human PMØ of CAPD patients. Activation of these macrophages by AGE-modified β2m may be a contributory factor to the morphologic changes and altered permeability of the peritoneal membrane in long-term CAPD. 

Objectives: To investigate the effect of low calcium dialysis on post-dialysis hypertension in view of an evident link between serum calcium and blood pressure in both normal renal function and chronic renal failure patients.

Methods: We evaluated 19 chronic hemodialysis patients in whom both post-dialysis hypertension and PDHCa[1] were observed. We investigated changes in serum total calcium, ionized calcium, intact parathormone levels and arterial blood pressure in response to 4 weeks low calcium dialysis as a treatment for PDHCa.

Results: When PDHT[2] patients were treated with low calcium dialysis, post-dialysis blood pressure was significantly decreased compared to pre-dialysis values (155.3 ± 9.7/82.2 ± 7.9 mmHg pre-dialysis vs. 134.1 ± 20.8/80 ± 8.6 mmHg post-dialysis, P = 0.001). Additionally, post-dialysis blood pressure was significantly lower than post-dialysis blood pressure prior to the low calcium dialysis treatment (176.1 ± 15/86 ± 10.8 mmHg post-standard dialysis, 134.1 ± 20.8/80 ± 8.6 mmHg after low calcium dialysis, P = 0.001). A decline in post-dialysis serum calcium (2.34 ± 0.2 vs. 2.86 ± 0.12 mmol/L, P = 0.04) and ionized calcium (1.17 ± 0.12 vs. 1.3 ± 0.06 mmol/L, P = 0.03) compared to pre-dialysis levels was also achieved by this treatment, with no significant changes in iPTH[3] levels.

Conclusions: These data suggest a role for low calcium dialysis in treating acute serum calcium elevation and post-dialysis hypertension in patients receiving maintenance hemodialysis.