Factors Affecting Flow-Mediated Vasodilatation in Hemodialysis Patients

Clinical manifestation of overt vascular disease may be preceded for years by endothelial dysfunction. Objective: This study was undertaken to evaluate endothelial function in ESRD patients and correlation between endothelial function and clinical and biochemical parameters. Methods: 32 stable ESRD patients (male : female = 16 : 16, average age: 55.2 ± 13.0) on hemodialysis were included. A 10‐MHz ultrasound transducer was used to image the brachial artery. Brachial artery diameter was measured, and reactive hyperemia was induced by inflation to 250 mmHg for 5 min and then deflation of a pneumatic cuff. After release of the cuff, brachial artery diameter was measured. Results: In the entire study population and non‐diabetic group, the %FMD (% flow‐mediated dilatation, % change of brachial artery diameter between before and after cuff inflation) did not show any significant correlation with duration of dialysis, age, hypertension, albumin, CRP, total cholesterol, LDL and HDL cholesterol, and triglyceride. However, the %FMD of diabetic patients was lower than that of non‐diabetics. Among the patients with diabetes, the group of patients with FMD of <5.2% showed significant lower serum albumin and significantly higher ln(CRP) levels compared to the group of patients with FMD ≥5.2%. The %FMD showed significant positive correlation with serum albumin level and significant negative correlation with ln(CRP) in diabetic patients. Conclusion: These findings suggest that endothelial dysfunction, estimated by FMD, was significantly more prominent in diabetic ESRD, especially with low serum albumin and high CRP levels.     

Clinical Characteristics of Upper Gastrointestinal Bleeding in Hemodialysis Patients

Upper gastrointestinal bleeding (UGIB) frequently occurs in hemodialysis (HD) patients. But, clinical characteristics of UGIB in HD patients are not well reported yet.
Objective:  This study was designed to compare the clinical characteristics of UGIB between HD patients and normal population with intact renal function.
Methods:  This study enrolled 24 HD patients with UGIB. Age- and sex-matched 26 patients with UGIB and normal renal function were selected as control group during the same period. Of the cases with UGIB, esophageal variceal bleedings due to liver cirrhosis were excluded in this study. We investigated the results of treatment and UGIB-associated mortality for 3 months after the event and then compared previous gastrointestinal (GI) symptoms (Sx), endoscopic findings, treatment results, and mortality between HD patients and control.
Results:  The results are summarized in the table.  

     

Role of Genetic Factors in Vascular Access Thrombosis in Hemodialysis Patients

Vascular access thrombosis is a frequent complication in hemodialysis (HD) patients. Genetic mutations, inflammation, and changes in the vascular wall are some factors that are thought to increase thrombosis risk. In this study, we tested for possible relationships between vascular thrombosis and some known thrombophilic mutation/polymorphisms in coagulation factors [factor V Leiden (FVL), prothrombin (Pt) G20210A, methylene tetrahydrofolate reductase (MTHFR C677T), factor XIII (F-XIII) Val34Leu, alpha-fibrinogen (AF) Thr312Ala, factor VII (F-VII) R353Q] and angiotensin I converting enzyme (ACE) gene in our HD patients. Patients who had experienced at least 3 episodes of AVF thrombosis composed of the study group, and patients who had never encountered this complication composed of the control group. None of the patients in either group had a history of diabetes mellitus, atherosclerosis, dialysis-related amyloidosis, or vasculitis. In order to find the frequency of F-XIII Val34Leu, AF Thr312Ala, and F-VII R353Q polymorphisms in our population, we also searched persons without renal disease or history of thrombosis (normal group). Results are summarized in Table. There was a tendency toward thrombotic mutation/polymorphisms in the study group for FVL, Pt G20210A, ACE I/D, and AF Thr312Ala. We suggest that patients who develop recurrent AVF thrombosis should be screened for the above-mentioned factors and investigated for other possible risk factors. This screening would allow more effective focus on prophylaxis.  

     

Clinical Consequences of Intermittent Elevation of C-Reactive Protein Level in Hemodialysis Patients

The presence of persistently high C‐reactive protein (CRP) levels is well known to be associated with a state of inflammation, malnutrition, and erythropoietin resistance in hemodialysis (HD) population. Meanwhile, a substantial group of patients present with intermittent elevations of CRP levels, and its clinical consequences are unclear. We designed this study to compare the inflammatory and nutritional parameters and erythropoietin requirements in HD patients with persistent or intermittent CRP elevation and those with CRP levels in without. We included 100 HD patients [age: 48.4 ± 14.3 years; HD duration: 69.3 ± 49.0 months (minimum 12 months)]. The 6‐month retrospective clinical and laboratory data were retrieved from the patient records, and those with chronic inflammatory disease, malignancy, infectious complications, and surgery were excluded. The monthly determined CRP levels (at least 6 for each patient) were reviewed, and the patients were grouped according to their CRP levels as those with persistent (group 1), intermittent (at least one level of CRP 10 mg/L) (group 2), and those with CRP in normal ranges set by the laboratory (group 3). We compared the fibrinogen, ICAM‐1, VCAM‐1, albumin, prealbumin, normalized protein catabolic rate (nPCR), interdialytic weight gain (IDWG), and rHuEPO/kg/Hct results of the patient groups. The patient groups revealed significant differences in terms of fibrinogen (p < 0.001), albumin (p < 0.0001), prealbumin (p < 0.007), ICAM‐1 (p < 00.2) levels and nPCR (p < 0.03), IDWG (p < 0.02), and rHuEPO/kg/Hct (p < 0.03) values. Group 2 presented to be in risk of inflammation and malnutrition with a decrease in albumin levels and nPCR and presence of rHUEpo resistance when compared to patients in group 3. We conclude that, similar to HD patients with persistently high CRP levels, those with intermittent elevation of CRP must also be considered to be in a state of chronic inflammatory response associated with malnutrition and erythropoietin resistance. This signifies the importance of regulatory monitoring of CRP in HD population.     

Is There Any Relationship between Serum Levels of IL‐10 and Atherosclerosis in Hemodialysis Patients?

Background:  Cardiovascular complications due to atherosclerosis (AS) are the major cause of mortality in hemodialysis (HD) patients. Inflammation may play an important role in the development of AS. Several studies have demonstrated the association of acute-phase proteins and cytokines with AS in the general population and in HD patients. Interleukin-10 (IL-10) is an anti-inflammatory cytokine. The aim of study was to compare serum levels inflammatory and anti-inflammatory indicators in HD patients according to the presence or absence of AS.
Methods:  Thirty-three HD patients were enrolled. AS was defined as the detection of plaques by Doppler ultrasonography. The patients were subgrouped according to the presence or absence of plaques. Serum levels of IL-1, IL-2, IL-6, IL-10, C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) were measured. The factors for AS such as age, gender, hypertension, hyperlipidemia, and HD duration were also evaluated.
Results:  We found that the patients with AS had significantly higher hs-CRP and lower IL-10. Blood pressure values were also increased in patients with AS. Additionally, there was an increased correlation between CRP and IL-10.
Conclusions:  AS(+) patients undergoing HD had low serum levels of anti-inflammatory cytokine IL-10 and high serum levels of hs-CRP. These results may suggest that the limitation of anti-inflammatory response in atherosclerotic uremic patients is a triggering or contributing factor for AS.     

Changes of Plasma Amino Acid Profile in Hemodialysis Patients

Background:  The aim of this study was to investigate the influence of HCV on two markers of systemic inflammation, serum CRP, and interleukin-6 (IL-6) in HD patients.
Methods:  The study included 118 HD patients (47% males, age 47 ± 13 years, 9% diabetics) who were treated by on standard HD for at least 6 months. The patients were divided in two groups, depending on the presence (HCV+) or absence (HCV–) of serum antibodies against HCV. Serum albumin (S-Alb), plasma high sensitivity CRP (hsCRP), IL-6, and alanine aminotransferase (ALT) were measured, and the values were compared with 22 healthy controls.
Results:  The median of hsCRP, IL-6, and the hsCRP/IL-6 ratio were: 3.5 vs. 2.1 mg/L, p < 0.05; 4.3 vs. 0.9 pg/mL, p < 0.0001; and 0.8 vs. 2.7 pg/mL, p < 0.0001 for patients and controls, respectively. Age, gender, S-Alb, IL-6, and hsCRP did not differ between the HCV+ and HCV– patients. However, HCV+ patients had higher ALT (29 ± 21 vs. 21 ± 25 UI/L) and had been a longer time on HD (6.1 ± 3.0 vs. 4.0 ± 2.0 years) (p < 0.0001), respectively. Moreover, HCV+ patients had a significantly lower median hsCRP/IL-6 ratio (0.7 vs. 0.9; p < 0.05) as compared to the HCV group.
Conclusion:  The finding that the hsCRP/IL-6 ratio was lower in HCV+ patients than in HCV– patients suggests that hsCRP may be a less useful marker of inflammation in HCV+ patients and that a different cut-off value for hsCRP may be required to define inflammation in HD patients.     

Cirrhosis Ameliorates Renal Osteodystrophy in Patients on Regular Hemodialysis

Cirrhosis (Cir) is often associated with chronic renal failure (CRF) in Egyptian patients on regular hemodialysis (RHD). This is largely attributed to hepatosplenic schistosomiasis and concomitant Hepatitis C viral infection. As the liver has a major role in vitamin D3 activation, we designed this study to envisage the impact of Cir on renal osteodystrophy (ROD). It included 130 consecutive age‐ and gender‐matched subjects in 4 categories. Group I: 39 patients (34 male and 5 female; mean age 48.8 years) with Cir normal renal function; group II: 37 patients (30 male and 7 female; mean age 49.0 years) with CRF and normal liver function, on RHD for a mean duration of 6 ± 3.9 years; group III: 41 patients (30 male and 11 female; mean age 50.7 years) with CRF and concomitant Cir, stable on RHD for a mean duration of 7.0 ± 4.0 years; and group IV: 16 normal volunteers (13 male and 3 female; mean age 46.3 years). The prevalence of diabetes as well as previous infection with schistosomiasis was similar in all patient groups and that of HCV infection was alike in groups I and III. In all subjects, conventional parameters of liver and renal function were tested; in addition to measurement of serum total protein, albumin, calcium, phosphate, total and bone‐specific alkaline phosphatase (B‐ALP), parathormone (PTH), 5‐hydroxycholecalciferol (5HD), 1,25‐dihydroxycholecalciferol (1,25HD), Cross Laps (CXL) as a marker of bone resorption, and aminoterminal propeptide of type I procollagen (PINP) as a measure of bone formation. Bone mineral density (BMD) was measured by either Dual Energy X‐ray Absorptiometry (DEXA) or Computerized Tomography (CT). Group II patients displayed the typical CRF profile comprising hypocalcemia, hyperphosphatemia, increased total and bone‐specific alkaline phosphatases, high PTH and 25HD, low 1,25HD, increased PINP as well as CXL, and generally decreased BMD. Cir (Group III) significantly (p value at least <0.5) modified this profile in several aspects: it checked hypocalcemia (mean 8.8 vs. 7.9 mg/dL in groups II and III, respectively), hyperphosphatemia (5.15 vs. 4.9 mg/dL), and the elevation of B‐ALP (62 vs. 30.5 μg/L) and PTH (89 vs. 78 pg/mL). It lowered the serum level of 25HD (18.7 vs. 13.7 ng/mL), augmented the deficiency of 1,25HD (13.4 vs. 8.0 pg/mL), did not appreciably affect the increase in bone formation (PINP 77.9 vs. 75.5 ng/mL), but ameliorated its excessive resorption (CXL 21 860 vs. 30 328 pmol/L) noticed in group II. This was associated with amelioration of the dialysis‐associated osteopenia (70 vs. 33.5%) and increased incidence of osteosclerosis (30 vs. 61%), as measured by bone mineral density. Conclusion: Our data indicate that Cir ameliorates ROD through decreased bone resorption. This is associated with better tolerance to 1,25HD deficiency, which initiates the cascade of hypocalcemia, hyperparathyroidism, and increased bone resorption in CRF. Such tolerance may reflect upregulation of vitamin D receptors as a consequence of the humoral perturbation supervening in Cir, involving IGF‐1, estrogens, or other vitamin D metabolites as 24,25 HD.     

Survival of End-Stage Renal Disease Diabetic Patients on Hemodialysis

Purpose: To analyze survival and causes of mortality in end‐stage renal disease (ESRD) diabetic patients treated by hemodialysis. Methods: Data of 1203 ESRD hemodialyzed patients between 1975 and 2002 were analyzed, 116 patients were excluded and 1087 patients included in the study. We studied the prevalence of the diabetic nephropathy, the rate of survival and causes of death by comparing diabetic patients with a control group of patients without diabetes. Results: Among the 1087 patients requiring dialysis, 272 (25%) were diabetic and 815 non‐diabetic whose causal nephropathy was nephroangiosclerosis 32%, glomerulonephritis 15%, chronic interstitial nephropathy 14%, and others 14%. The diabetics were older at the beginning of dialysis than non‐diabetic patients: 60.33 ± 11.39 years vs. 52.23 ± 17.20 years, p < 0.001. Average time on dialysis is more important in non‐diabetic than diabetic group [5.90 ± 5.73 years vs. 2.71. ± 2.48 years, p < 0.001]. The rate of death was higher in diabetics than in control group [71.7% vs. 55.8%, respectively, p < 0.003]. The difference in survival between the two groups remains significant for the same age. Death caused by cardiovascular disorders is higher in diabetics (68.8%) than non‐diabetics (31.2%) (p < 0.05). Among death causes, stroke is the most frequent cause in diabetics (18.4% vs. 11.6%) in non‐diabetics, p < 0.05. Death by heart failure and infections is higher in diabetics but the difference is not statistically significant (12.3% in diabetics vs. 9.4% in non‐diabetics for heart failure and 13.8% vs. 11.4% for infections). Death due to neoplasms is higher in non‐diabetics (4.39% vs. 1.02% in diabetics, p < 0.05). Conclusion: In our cohort, mortality in diabetic patients is higher than in non‐diabetic patients. Cardio‐vascular disorders are the most cause of death in diabetics and above all stroke, whereas mortality due to neoplasms is higher in non‐diabetic patients. Diabetes is an important risk factor of mortality in hemodialysis patients.     

Effect of Vitamin E Dialyzer Membrane on Anemia in Hemodialysis Patients

Red blood cell (RBC) survival in patients on chronic maintenance hemodialysis (HD) has been reported to be shortened due to the oxidative damage of RBC membrane. The use of antioxidants might help in the control of anemia and reduce the erythropoietin (EPO) dose needed. Objective: The objective was to determine the effects of vitamin E‐bonded dialyzer membrane (VEM) on anemia and EPO requirements in chronic HD patients. Patients and methods: We prospectively studied 19 stable patients on HD (8 males, age 58.47, range 31–76 years) who were shifted from other dialyzer membranes to VEM for 6 months. At baseline they were given a mean dose of EPO of 90.6 ± 51 U kg^–1 BW^–1 week^–1. Clinical data, dry body weight corrected pre‐dialysis RBC, hemoglobin, reticulocytes, serum iron and ferritin, complete biochemistry, iPTH, and CRP were studied at 3 and 6 months, while therapy scheme was reevaluated monthly. Results: A significant rise, compared to the baseline, was found in hemoglobin and in RBC at 3 months of treatment (12.44 ± 1.16 g/dL vs. 11.2 ± 1.2 g/dL, p = 0.002; and 4.01 ± 0.53 × 10⁶/μL vs. 3.64 ± 0.5 × 10⁶/μL, p < 0.05) and at the end of follow‐up (12.17 ± 1.33 g/dL vs. 11.2 ± 1.2 g/dL, p < 0.05; and 4.03 ± 0.53 × 10⁶/μL vs. 3.64 ± 0.5 × 106/μL, p < 0.05). No significant change in serum iron and ferritin, reticulocytes, EPO dose used, iPTH, Kt/V, or CRP was found at the end of follow‐up compared to the baseline (68.8 ± 17 mg/dL vs. 67.9 ± 18 mg/dL, p = NS; 421 ± 296 mg/dL vs. 478 ± 359 mg/dL, p = NS; 3.76 ± 0.89 × 10⁴/μL vs. 3.82 ± 0.78 × 10⁴/μL, p = NS; 90.2 ± 53 U kg^–1 BW^–1 week^–1 vs. 90.6 ± 51 U kg^–1 BW^–1 week^–1, p = NS; 157 ± 43 pg/dL vs. 148 ± 56 pg/dL, p = NS; 1.21 ± 0.22 vs. 1.2 ± 0.17, p = NS; 7.15 ± 5.42 mg/L vs. 15.38 ± 29.8 mg/L, p = NS, respectively). Conclusions: Despite the small number of patients and the short time interval of treatment, an antioxidant effect of VEM apparently achieved early a better control of anemia in HD patients.     

Pre‐ and Post Hemodialysis Procalcitonin Levels and Their Relationships with Immunoregulatory,Proinflammatory Cytokines in Chronic Hemodialysis Patients

Arteriosclerosis is characterized by stiffening of arteries. The incremental elastic modulus (Einc) measurement is a good marker of arterial wall stiffness. Arteriosclerosis is characterized by stiffening of arteries. Metabolic, inflammatory, and hemodynamic alterations cause structural changes and vascular complications in end‐stage renal disease. The aim of the present study was to evaluate the factors that may affect the development of arteriosclerosis by measurement of Einc in hemodialysis (HD) patients. Thirty‐two patients (16 men and 16 women) on chronic HD with a mean age of 42.2 ± 19.3 (range, 15–80) were included in the study. The carotid Einc was measured to determine arteriosclerosis by high‐resolution echo‐tracking system. Einc measurement was calculated from transcutaneous measurements of carotid arterial internal diameter and wall thickness and carotid pulse pressure. Common carotid compliance (CCC) and distensibility (CCD) were determined from changes in carotid artery diameter during systole and simultaneously measured carotid pulse pressure. Serum levels of calcium (Ca), phosphorus (P), parathormone (PTH), ferritin, C‐reactive protein (CRP), predialysis systolic blood pressure (SBP), predialysis diastolic blood pressure (DBP), pulse pressure (PP), age, HD duration, CCC, and CCD were correlated with Einc in all patients. A significant positive correlation was found between Einc and age (r = 0.40, p < 0.02), SBP (r = 0.39, p < 0.02), PP (r = 0.40, p < 0.02), Ca (r = 0.43, p < 0.01), CRP (r = 0.38, p < 0.02). As expected, Einc was correlated inversely with CCD (r = ?0.77, p < 0.0001). The correlation between Einc and HD duration, DBP, ferritin, P, PTH, and CCC was not significant. In conclusion, the stiffening of carotid artery in HD patients is related not only to hemodynamic changes (increased SBP and PP) but also to metabolic (increased Ca) and inflammatory (increased CRP) responses. Carotid Einc is an accepted independent risk factor for cardiovascular mortality. Because of the positive correlation between Einc and serum Ca, vitamin D and Ca‐containing P binder should be used carefully in HD patients.     

Impact of Ischemic Heart Disease on Early Access Failure in Nondiabetic Hemodialysis Patients

Lynchburg Nephrology Dialysis Inc. started its nightly home hemodialysis (NHHD) program in September 1997.
Purpose of study:  To evaluate episodes of exit site infections, catheter sepsis, safety, and longevity of accesses for patients doing NHHD.
Methods:  If IJ catheter was chosen, patient was started on Coumadin 2 mg/day when catheter was placed. If catheter malfunctioned, it was locked with a thrombolytic agent and Coumadin was adjusted to meet a goal INR of 1.5–2.25. If the problem persisted, the catheter was exchanged. For catheters, the B-D InterLink device was used to prevent air emboli and infection, and a locking device was used to prevent disconnects. If AV fistula was used, 4 buttonholes were established using 16 gauge needles. If AV graft was used, patients were taught the ladder cannulation technique using 16 gauge needles.
Results:  As of September 1, 2003, 45 patients have completed training and have performed 27,063 treatments at home. Total catheter time at home was 930 months. Total AV fistula and AV graft time at home was 190 and 20 months, respectively. Upon completion of training, 34 patients were using tunneled IJ catheters, 10 using AV fistulas, and 1 using an AV graft. The IJ catheter exit site and sepsis infection rate was 0.35 and 0.49 episodes/1000 patient days, respectively. Average catheter life was 8.5 months with the longest 66.7 months and the shortest 0.2 months. The AV fistula and graft exit site and sepsis infection rates were 0.16 and 0 episodes/1000 patient days, respectively. Catheter complications included 1 episode of disconnect due to patient's failure to use locking device, 1 episode of central stenosis, and 1 episode of intracranial hemorrhage, due to prolonged INR, with resolution of symptoms.
Conclusion:  Data support that tunneled IJ catheters, AV fistulas, and AV grafts were effective and safe permanent accesses for patients on NHHD.     

A Report on 4 New Cases of Nephrogenic Fibrosing Dermopathy in Chronic Hemodialysis Patients

Nephrogenic fibrosing dermopathy (NFD) is a rare entity affecting patients with renal failure, often on chronic dialysis or after transplantation (TXP). The patient profile at risk for this debilitating condition is yet undefined as is the role of renal failure in its etiology. We diagnosed 4 chronic hemodialysis (HD) patients with NFD. A 55-year-old Caucasian male on HD for 5 years, secondary to diabetic nephropathy, developed woody, indurated skin of the extremities, decreased mobility, and wheelchair dependence. He died within 1 year. A 66-year-old African-American male with diabetes, hypertension, and pancreatic cancer developed thick indurated skin on his extremities after being on HD for approximately 20 months. He died 3 months later from sepsis. A 26-year-old Caucasian female on HD for approximately 10 years, secondary to hyperoxaluria-induced renal failure, had undergone combined liver and kidney TXP with primary nonfunction of the renal TXP. She succumbed to cholangitis approximately 1 year after progressive skin thickening and joint contractures were noted. A 75-year-old Caucasian female with renal failure secondary to recurrent hemolytic uremic syndrome and TXP failure was dialysis dependent for 6 years. Over a 3-month period, she developed skin changes consistent with NFD and entered hospice care secondary to marked deterioration in her quality of life. In all of these cases, skin changes were restricted to the extremities, sparing the trunk, face, and internal organs. Skin biopsy findings included thickened dermis with particularly thickened collagen bundles, mucin deposition, and fibroblast proliferation and were distinct from scleromyxedema and scleroderma. Autoimmune disease workup was negative. Indeed, NFD is a novel cutaneous fibrosing disorder of progressively debilitating nature in patients with renal failure that needs further clinical and pathological characterization.     

The Effect of Frequent and Occasional Dialysis-Associated Hypotension on Survival of Patients on Hemodialysis

Hyperphosphatemia and poor uremia control are established cardiovascular risk factors in patients with end-stage renal disease (ESRD) associated with impaired endothelial dependent and independent vasodilation (EDV and EIV). Nocturnal hemodialysis [6 × 8 h/week] augments dialysis dose and offers normal phosphate (Pi) balance. We hypothesized that NHD would restore EDV (endothelial function) and EIV (vascular smooth muscle cell function) by simultaneously improving uremia and Pi control. 2 groups of ESRD patients (mean age 41 ± 2 years) stratified according to their baseline plasma Pi levels (normal Pi <1.8 mM, high Pi >1.8 mM) were studied. Dialysis dose (Kt/V per session), plasma Pi, blood pressure (BP) and brachial artery responses to reactive hyperemia (EDV), and sublingual nitroglycerin (EIV) were examined before, 1 and 2 months after conversion from conventional hemodialysis (CHD) [3 × 4 h/week] to NHD. After 2 months, NHD increased dialysis dose (from 1.24 ± 0.06 to 2.04 ± 0.08; p = 0.02) and lowered BP (from 140 ± 5/82 ± 3 to 119 ± 1/71 ± 3, p = 0.01) in all patients. In patients with adequate Pi control during CHD, EDV was normalized after 1 month of NHD. In contrast, in the high Pi group, 1 month of NHD was sufficient to reduce plasma phosphate levels, but 2 months of NHD was required for EDV to improve.  

     

Low Serum Parathyroid Hormone Is a Predictor of Early Death after Hip Arthroplasty in Hemodialysis Patients

Background and Purpose:  Colloid osmotic pressure (COP) in plasma rises by ultrafiltration during hemodialysis, and it consequently causes plasma refilling in which water moves from interstitial tissue to capillary space. Although hemodynamic stability is one of the important factors for good dialysis outcome, no informative and convenient indicators are available other than monitoring of blood pressure. Thus, we measured COP during hemodialysis whether COP can be used as an indicator for the hemodynamic status in comparison with hematocrit (Ht). Plasma osmolality, ultrafiltration volume, and the alteration of blood pressure were also measured to examine whether COP is associated with them.
Method:  Sixteen patients hospitalized in this hospital were examined. Amongst them, 10 patients underwent both dialysis and ultrafiltration, while 4 patients received only dialysis and 2 patients were with ultrafiltration only by extracorporeal ultrafiltration method. Ultrafiltration was performed with constant speed to the dry weight for 4 h. The measurements of COP, plasma osmolality, Ht levels, and blood pressure were performed at 30 min (12.5% of the total water removal), 1 h (25%), 2 h (50%), and 3 h (75%) after the start of hemodialysis and also at the end of dialysis (100%).
Result:  COP markedly rose by 26.0% (±13.3%) in the patients who received both dialysis and ultrafiltration, whereas Ht rose by only 13.6% (±5.21%). And the curve for COP increase was sigmoid shape, whereas that for Ht showed linear change. On the other hand, in the patients whose Ht levels showed low values, the curves for both COP and Ht showed similar pattern.
Conclusion:  These results suggest that COP is a more sensitive indicator to be monitored for the hemodynamic status than Ht during hemodialysis.     

Regional Anticoagulation with Sodium Citrate in Pediatric Patients on Intermittent Hemodialysis Therapy with Bleeding Risks

Heparin‐free anticoagulation in hemodialysis (HD) is advocated for patients with clotting abnormalities and risk of bleeding. Objective: First publication on regional citrate anticoagulation (RCA) in children. RCA is free from systemic effects, guarantees excellent dialyzer life, but requires careful monitoring. Methods: We report on 3 patients treated by intermittent RCA HD (4 h each, high‐flux dialyzer F40, Fresenius): (1) 17‐year‐old boy (renal transplant failure, access via cubital Cimino fistula) after hypertensive intra‐cerebral hemorrhage (2 sessions); (2) 13‐year‐old girl (hemolytic uremic syndrome, access via jugular vein Shaldon catheter) after abdominal surgery and bleeding (8 sessions); and (3) 7‐year‐old boy (hyperoxaluria, access via PermCath^® jugular vein catheter) after renal transplant biopsy (3 sessions). Sodium citrate 30% was infused into the extra corporeal circuit (blood flow 150 mL/min) before dialyzer (initial flow 30 mL/min) and calcium gluconate 10% for antidote into venous line near of catheter or fistula (initial flow 40 mL/min). Post‐dialyzer extracorporeal serum Ca⁺⁺ (aim < 0.3 mmol/L) and pre‐dialyzer intra‐corporeal Ca⁺⁺ (aim > 0.9) were measured for every 30 min. Serum Na⁺, K⁺, base excess (BE), blood flow, blood pressure, heart rate, and blood out‐flow and in‐flow pressure were also monitored. Results: For adequate RCA (mean extracorporeal serum Ca⁺⁺ 0.24 ± 0.04 mmol/L), a mean citrate flow of 36.1 ± 5.9 mL/h and a mean calcium substitution rate of 40.8 ± 3.4 mL/h were needed. Intra‐corporeal Ca⁺⁺ was kept at 1.10 ± 0.07 mmol/L. Extracorporeal activated clotting time (ACT) was 194 ± 41 and intra‐corporeal ACT 90 ± 12 sec. Serum Na⁺, K⁺, and BE during HD were 138 ± 2, 3.5 ± 0.3, and ?0.6 ± 1.1 mmol/L, respectively. Mean arterial blood pressures of patients 1–3 were 117 ± 5, 103 ± 5, and 102 ± 6 mmHg. All patients were stable and without any bleeding during HD. The only adverse event was 1 episode of hypocalcemia (Ca⁺⁺ < 0.6 mmol/L) cured by stopping dialysis. Conclusions: Local anticoagulation with sodium citrate during intermittent HD can be applied safely in children and adolescents.     

Accuracy of Doppler Ultrasonography in Measuring Radial Artery Wall Thickness in Hemodialysis Patients: Comparison with Histologic Examination

Increased radial artery wall thickness (RAWT) is considered to be associated with early failure of radiocephalic arteriovenous fistula (AVF) as well as coronary artery atherosclerosis in hemodialysis patients. Therefore, exact measurement of RAWT by noninvasive method before the operation is very important.
Objective:  This study was designed to evaluate accuracy of Doppler ultrasonography in measuring RAWT in hemodialysis patients.
Methods:  This study enrolled 21 hemodialysis patients undergoing radiocephalic AVF operation for the first time. We measured RAWT (intima-media thickness) using high-resolution Doppler ultrasonography at the wrist before the AVF operation. We obtained specimens of the radial artery during the AVF operation and then measured RAWT by histologic examination.
Results:  Mean age of the patients was 60 ± 13 years and the number of females was 7 (33.3%). Mean values of RAWT measured by Doppler ultrasonography and histologic examination were 485 ± 93 μm (300–700 μm) and 426 ± 106 μm (300–700 μm), respectively. The value of RAWT of Doppler sonographic measurement well correlated with that of histologic measurement (r = 0.800, p < 0.001).
Conclusion:  Our data suggest that Doppler ultrasonography is an effective tool in measuring RAWT in hemodialysis patients before AVF operation.     

Results of Daily Hemodialysis in Catanzaro: 12-Year Experience With 22 Patients Treated For More Than One Year

Since 1985, we have been treating patients with daily hemodialysis (D-HD). We report our results with 22 patients treated on D-HD and daily home hemodialysis (DHHD) for a long-term period. Patients had very good survival of native forearm arteriovenous fistula access, and upper arm access with superficialized basilic vein. One access survived 18 years: 8 years on standard hemodialysis (STND-HD) and 10 years on D-HD. Only two fistulas failed. Blood pressure control in 12 hypertensive patients was obtained without antihypertensive drugs in 8 and with fewer medications in 4. Hematocrit and hemoglobin improved in all patients. Cardiothoratic index decreased in all patients, and we noticed a reduction in the most important echocardiographic indices in 12 patients with cardiac hypertrophy: intraventricular septum thickness, left ventricle posterior wall thickness, left ventricle internal diastolic diameter, and left atrium diameter. Data also showed improvement in nutritional status. For the most part, the levels of hormones normalized, with regular menstrual cycles in women and good sexual function in men. In our experience both elderly and young patients with severe cardiovascular diseases, severe hypertension or hypotension, anemia, and nutritional problems can, with D-HD, achieve good quality of life and start work again. D-HD, in our opinion, is the treatment of choice for patients without comorbid conditions, because good metabolic control, good nutrition, and a more normal hormonal status allow them to feel well and to have an almost normal lifestyle.     

On Stress Intensity Factors of Multiple Cracks at Small Distances in 2-D Problems

In the present work a method is proposed to predict stress intensity factors (SIFs) of strongly interacting cracks at spacings that are substantially smaller than crack lengths. The method is intended for applications where cracks are observed in stack-like/staggered arrangements as in damage patterns of some natural materials with dense lamellar microstructures. The new calculation procedure is inspired by the analytical method of Kachanov (1987) that due to its simplicity has shown to be a powerful tool for analysis of crack interactions. Although in 3-D the accuracy of Kachanov’s method remains good at quite close spacings, in 2-D problems it, however, quickly drops as the distance between cracks decreases, underestimating the effect of crack interactions, especially in ordered staggered arrangements. In this work we introduce new modeling assumptions that are suited for problems where stress fields have high gradients – a typical situation in the case of closely spaced parallel cracks. The accuracy of the method is examined on the example of two stacked cracks. The use of SIFs for estimation of material elastic compliance is also discussed.