The value of ventricular gradient for predicting pulmonary hypertension and mortality in hemodialysis patients.

Pulmonary hypertension (PHT) is associated with increased mortality in hemodialysis (HD) patients. The ventricular gradient optimized for right ventricular pressure overload (VG-RVPO) is sensitive to early changes in right ventricular overload. The study aimed to assess the ability of the VG-RVPO to detect PHT and predict all-cause and cardiac mortality in HD patients. 265 selected HD patients were enrolled. Clinical, biochemical, electrocardiographic, and echocardiographic parameters were evaluated. Patients were divided into normal and abnormal VG-RVPO groups, and were followed-up for 3 years. Abnormal VG-RVPO patients were more likely to be at high or intermediate risk for PHT, were older, had longer HD vintage, higher prevalence of myocardial infarction, higher parathormone levels, shorter pulmonary flow acceleration time, lower left ventricular ejection fraction, higher values of left atrial volume index, left ventricular mass index, and peak tricuspid regurgitant velocity. Both all-cause and CV mortality were higher in abnormal VG-RVPO group. In multivariate Cox analysis, VG-RVPO remained an independent and strong predictor of all-cause and CV mortality. In HD patients, abnormal VG-RVPO not only predicts PHT, but also all-cause and CV mortality.

The relationship between serum level of N-terminal pro-B-type natriuretic peptide and nutritional status, and inflammation in chronic hemodialysis patients.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-pro BNP), a biomarker of heart failure, is involved in regulation of the body fluid homeostasis and vascular tone. The purpose of this study was to investigate the relationship between serum level of NT-pro BNP and nutritional status, inflammation and hydration in patients on maintenance hemodialysis (HD). MATERIALS AND METHODS: The study involved 97 HD patients (mean age: 65.3 +/- 13.9 years, HD duration: 36.3 +/- 43.5 months). Blood tests comprised the measurements of serum levels of NT-pro BNP, interleukin-6 (IL-6), human soluble tumor necrosis factor receptor I (s TNF RI), hemoglobin (Hb), albumin (alb) and urea. Furthermore, normalized protein catabolic rate (n PCR), body mass index (BMI), mean arterial blood pressure (MAP), adequacy of HD (Kt/V), and interdialytic body weight gain (IBWG) were calculated. In addition, NT-pro BNP was measured in a healthy control group (CG; n = 24, mean age 49.5 +/- 15.0 years). Hydration status was determined by bioimpedance analysis (BIA). RESULTS: Irrespective of gender, NT-pro BNP levels were markedly elevated in HD patients compared with CG (15879.2 +/- 14033.3 pg/ml vs. 73.45 +/- 23.56 pg/ml; p < 0.00001). NT-pro BNP was unrelated to any measures of body fluid compartments. Multivariate regression analysis revealed that only four parameters (nPCR, Hb, MAP, and total time on HD) influenced serum NT-pro BNP levels. CONCLUSION: While there was only moderate direct association of NT-pro BNP with hydration status, it was elevated in patients with intensive catabolism, severe anemia, higher MAP and longer total duration of HD.

Relative blood volume changes during haemodialysis estimated from haemoconcentration markers.

Relative blood volume (RBV) monitoring is frequently used in haemodialysis patients to help guide fluid management and improve cardiovascular stability. RBV changes are typically estimated based on online measurements of certain haemoconcentration markers, such as haematocrit (HCT), haemoglobin (HGB) or total blood protein concentration (TBP). The beginning of a haemodialysis procedure, i.e. filling the extracorporeal circuit with the patient's blood (with the priming saline being infused to the patient or discarded) may be associated with relatively dynamic changes in the circulation, and hence the observed RBV changes may depend on the exact moment of starting the measurements. The aim of this study was to use a mathematical model to assess this issue quantitatively. The model-based simulations indicate that when the priming saline is not discarded but infused to the patient, a few-minute difference in the moment of starting RBV tracking through measurements of HCT, HGB or TBP may substantially affect the RBV changes observed throughout the dialysis session, especially with large priming volumes. A possible overestimation of the actual RBV changes is the highest when the measurements are started within a couple of minutes after the infusion of priming saline is completed.

Effect of recombinant human erythropoietin on adrenergic activity in normotensive hemodialysis patients.

Ten normotensive hemodialysis patients with severe anemia participated in the study. Human recombinant erythropoietin (rHuEpo) was administered i.v. 3 times a week in doses of 50 U/kg of body weight. During 12 weeks of observation, the mean hematocrit value increased from 19%, before start of therapy, to 32%. Simultaneous monitoring of serum plasma noradrenaline (NA) concentration showed an elevation from 202 to 281 pg/ml. An increase of NA concentration after a cold pressure stimulating test (CP) was not statistically significant after as compared to before treatment, but became statistically significant after 12 weeks of rHuEpo therapy (281 pg/ml before to 441 pg/ml after CP test, p < 0.01). The mean arterial blood pressure increased from 92 - 109 mmHg after 12 weeks of rHuEpo therapy (p < 0.001). We have demonstrated significantly increased NA blood concentrations after 12 weeks of rHuEPO therapy in normotensive patients, which correlated with increased MAP. This may suggest that the observed increase of noradrenaline concentration as a vasoactive substance after the CP test may contribute to hypertension during rHuEPO therapy.

Effect of vitamin E modified cellulose membrane on human lymphocyte, monocyte, and granulocyte CD11b/CD18 adhesion molecule expression during hemodialysis.

Chronic renal failure induces a clinical state of immunodefi ciency that also depends upon a wide spectrum of dialysis membranes used during hemodialysis. Previous studies have shown that cellular immunodeficiency is caused by malfunc tion of the antigen presenting cells (monocytes or granulocytes). Subsequent activation of rolling mononuclear leuko cytes results in up-regulated expression of CD11b/CD18 (Mac-1) on endothelial cells. It is postulated that a VitE coated dialysis membrane might minimize the membrane biocompatibility, thereby generating a smaller amount of re active oxygen species (ROS). The purpose of this study was to evaluate the expression of the CD11b/CD18 adhesion mole cule on lymphocytes, monocytes, and granulocytes during HD in 10 patients, using flow cytometric analysis. The study protocol included the measurement of molecule expression using cellulose membrane (Clirans RS15, TERUMO Corp. Japan), and the same membrane coated by vitamin E (Exce brane, Clirans E15, TERUMO Corp., Japan) during 20 dialysi sessions each. Lymphocyte CD11 b/CD1 8 (Mac-1) expression did not change with either dialyzer type. However, monocyt (p = 0.046) and granulocyte (p = 0.018) CD11b/CD18 ex pression in the post HD period was significantly lower using the vitamin E coated membrane compared with the contro cellulose membrane. Our findings suggest a significant de crease in activation and migration of monocytes and granu locytes when using a vitamin E coated cellulose membrane.

Relative underestimation of fluid removal during hemodialysis hypotension measured by whole body bioimpedance.

Whole body bioimpedance is considered helpful in monitoring the removal of excess body water by ultrafiltration in hemodialysis patients. In this study, the cumulative, estimated decrease in extracellular volume (V(est)) modeled from whole body bioimpedance data was compared with measured volume (Vmeas) removed by ultrafiltration (UFR = 1.01 +/- 0.31 L/hr) in 12 patients during 36 high efficiency hemodialysis treatments. In the mean, estimated (V(est) = 3.0 +/- 1.4 L) and measured volumes (Vmeas = 3.4 +/- 1.1 L) correlated linearly: V(est) = 1.05 x Vmeas - 0.60, r2 = 0.68. Patients developed hypotension in half the treatments. Except for a larger decrease in systolic blood pressures in hypotensive (34 +/- 24 mmHg) vs. stable (14 +/- 15 mmHg) treatments, patient and treatment characteristics were not different between groups. However, at the end of hemodialysis, the difference V(est) - Vmeas was -0.8 +/- 0.9 L in hypotensive, and only 0.1 +/- 0.4 L in stable patients (p < 0.05). The difference between V(est) and Vmeas can be explained by a predominant removal of excess body water from central body compartments such as the trunk and the central blood volume during hypotension. These compartments are not adequately measured by whole body bioimpedance techniques. However, this information could be helpful in identifying patients with delayed peripheral fluid removal that may occur when either target weight is too low or UFR rates are too high.

Plasma catecholamine concentration and dopamine-beta-hydroxylase activity during haemodialysis with acetate or bicarbonate at different sodium concentrations in hypotensive patients.

Plasma catecholamines (noradrenaline, adrenaline, dopamine) and dopamine-beta-hydroxylase were investigated in hypotensive haemodialysis patients treated with different sodium dialysate concentrations in acetate or bicarbonate fluids. The present results suggest that most physiological reactions could be obtained in patients treated with equimolar sodium concentration in blood and dialysis fluids in both kinds of acetate and bicarbonate.

[Use of bioimpedance spectroscopy techniques for monitoring fluid balance in patients with end stage renal failure]. / Zastosowanie techniki bioimpedancji elektrycznej w ocenie stanu nawodnienia u pacjentów ze schylkowa niewydolnoscia nerek.

Adequate body hydration is considered the key element of fluid management in critically ill patients including group with end stage renal failure. Bioimpedance technique is widely used as a non-invasive, simple and accurate method to measure body composition. The purpose of the paper was to prescribe the using of single, and multifrequency bioimpedance spectroscopy technique for estimation of fluid balance in end-stage renal patients. We also discussed some measurements and data modelling problems, including postural change effect, and intercompartmental fluid shift during dynamic monitoring of fluid balance.

[Selected aspects of rehabilitation programs for hemodialyzed patients in the United States ]. / Wybrane aspekty programów rehabilitacji w Stanach Zjednoczonych u pacjentów hemodializowanych.

The purpose of the paper was to evaluate some aspects of U.S. rehabilitation programs, and medical health systems legislatives initiatives in the patients with end-stage renal diseases treated with hemodialysis. We signalized potential problems, and complications of rehabilitation in such group of patients. The potential improvement in quality of life after intradialysis, and interdialysis rehabilitation was discussed.

[Chronic venous occlusion in hemodialysis-related fistula: diagnosis and endovascular treatment]. / Przewlekla zakrzepica przetoki dializacyjnej--diagnostyka i leczenie metoda wewnatrznaczyniowej rekanalizacji.

The main reasons of fistula dysfunction are stenosis and thrombosis. There are two kinds of thrombosis: acute and chronic. Acute thrombosis is total fistula occlusion while chronic occlusion is partial venous occlusion with collateral veins, which lead to impair fistula's function. 450 dialysis fistulas were referred to US (ultrasound) examination. Among 392 patients with fistula dysfunction, 71 presented chronic venous occlusion in hemodialysis shunt. 35 patients were qualified to endovascular recanalization. The mean length of the occluded segment was 3-35 cm (subclavian vein 2-4 cm). 38 patients underwent angiography (35 before endovascular treatment). Technique of recanalization included antegrade venous puncture, insertion guidewire (0.021'), catheter (5 Fr), balloon catheter (5-8 mm) and in 2 cases stent placement. Colour Doppler allowed to diagnose 34 (97%) cases of chronic venous occlusion in hemodialysis shunt. Decrease of mean flow volume in brachial artery--709 +/- 395 ml/min. (50-1500 ml/min) was statistically significant (p = 0.0015). Normal mean flow volume was 1242 +/- 641 ml/min. 20 of 35 recanalization procedures were performed successfully. The main reason of failure was perforation or false channel. Mean primary patency was 75% after 3 months. Mean cumulative was 85% (10/12) after 6 months. Chronic venous occlusion is often present in hemodialysis shunt and reduces flow volume. Percutaneous recanalization results aren't magnificent but there is only kind treatment for many patients with fistula failure.

[Effect of arterio-venous fistula blood flow dynamics on ECG abnormalities in chronic hemodialysis patients]. / Wplyw dynamiki przeplywu przetoki tetniczo-zylnej na zmiany elektrokardiograficzne u chorych hemodializowanych z powodu krancowej niewydolnosci nerek.

UNLABELLED: The dialysis doses is mostly dependent on well functional permanent vascular access. From the other hand high vascular access blood flow (Qva) may induce cardiac problems in HD patients. The purpose of this study was to investigate the effect of vascular access dynamics on electrocardiographic abnormalities in hemodialysis patients. Therefore, forty non-diabetic, HD patients, with native vascular access (VA) were divided into two equal groups; with Qva > 1500 ml/min (group A), and also Qva < 1500 ml/min (group B). The average of VA survival period was 28 +/- 18 (mean +/- SE) (group A), and 29 +/- 15 (months) (group B). The Qva measurements monitoring by color Doppler sonography included also: maximal velocity (Vmax), time average of maximal velocity (TAMX), pulsate index (PI), and resistive index (RI). Kt/V index was calculated, as classical parameter of adequacy, and also shunt recirculation using 3 urea samples was measured. For estimation of cardiac function we used M-mode echocardiography, and 24-hours ECG (Holter) monitoring. The occurrence of ventricular (VE), and supraventricular extrasystoles (SVE), ST-T, and ST characteristic as well were monitored by 24-hours Holter. CONCLUSIONS: 1. In the group with high Qva (A) we observed significantly higher number of VE, and also of SVE recorded by Holter monitoring compared with the low Qva group (B). 2. The mean number of patients with ST-T changes was higher in group A (12 vs. 7), but number of patients with recorded by Holter ST depression, and ST elevation between investigated groups were similar. 3. The mean number of ventricular arrhythmias of Lown classified as 4A, and 4B of Lown grading was significantly higher in the group with high Qva (A).

[Basic terminology for describing hemodialysis fistula]. / Podstawowe mianownictwo dotyczace przetoki dializacyjnej.

Many specialists: nephrologists, surgeons, radiologists and nurses pay much attention to dialyzed patient using different terminology. The presented work establishes the principal rules of describing hemodialysis fistula to find convergence in terminology.

[Effect of vitamin E-modified membrane on expression of coreceptors CD4, CD8 on lymphocytes in chronic hemodialysis patients]. / Wplyw celulozowej blony dializacyjnej pokrytej witamina E na ekspresje koreceptorów CD4, CD8 na limfocytach u pacjentów z przewlekla niewydolnoscia nerek leczonych hemodializami.

Chronic renal failure induces a clinical state of cellular and humoral immunodeficiency that also depends on the time duration of blood contact with the wide spectrum of dialysis membranes use during long-term hemodialysis treatments. In end stage renal failure (ESRD) patients it is possible to induct state of chronic inflammation mostly caused by leukocytes and complement activation. It is postulated that the vitamin E-coated dialysis membrane minimalizes unbiocompatible reactions that generate smaller amounts of reactive oxygen species (ROS). The purpose of this study was to analyze the effect of classical and vitamin E coated cellulose membranes on the expression of CD 4 and CD 8 adhesion molecules on lymphocytes during HD in 10 patients using flow cytometric analysis. The study protocol included the measurement of molecules expression using cellulose membrane (Clirans RS15, TERUMO Corp., Japan), and the same membrane coated by vitamin E (Excebrane, Clirans E15, TERUMO Corp., Japan) during 20 dialysis sessions with each kind of membrane. During dialysis with classical cellulose membrane, significant decrease of lymphocyte serum level and increase of lymphocyte CD4 expression was observed. During the session with vitamin E coated membranes we did not observe any significant changes in serum CD4, CD8, CD4+8+ lymphocyte level, and also lymphocyte CD4, and CD8 expression on lymphocytes. Our findings suggest the potential role of vitamin E-coated cellulose membrane to minimalize negative reaction of the T lymphocyte subpopulation in ESRD patients treated on long-term dialysis.

[Measurement of fluid compartments using electrical bioimpedance for assessment of target weight in hemodialysis patients]. / Pomiar przestrzeni wodnych za pomoca techniki bioimpedancji elektrycznej w celu oszacowania wagi oczekiwanej u pacjentów hemodializowanych.

The prescription of optimal hydration status in hemodialysis patients remains a much disputed topic in dialysis treatment. In particular, assessment of the patients optimal weight ("target weight") poses considerable difficulties. Multifrequency bioimpedance spectroscopy analysis (BIS) has been recommended as a non invasive, practical, and relatively non expensive method to determine hydration and nutritional status in patients on maintenance hemodialysis (HD). In the current study we used whole body BIS analysis for determination of body water (BW) compartments; total body water (TBW), extracellular water (ECW), and intracellular water (ICW) in 133 healthy adults, and in 227 hemodialysis patients with end-stage renal disease. BIS results were compared to anthropometric measurements. Our results showed strong correlation between TBW measured by BIS in control group in comparison to anthropometric calculation (p = 0.001). In HD patients we observed higher range of TBW, and TBW/ECW ratio (from 15.6 to 56.1 L and from 0.33 to 0.78), as measured by BIS at pre-HD, and also post-HD period (TBW ranged from 13.1 to 56.2 L, ECW/TBW ratio ranged from 0.33 to 1.27). The TBW BIS results did not correlate with anthropometric calculation. We postulate using of multi-frequency bioimpedance technique in precise determination of fluid compartments and in consequence in the assessment of "target weight" in hemodialysis population.

Effects of serotonin-active drugs on prolactin secretion in male rats.

The effects of several serotonin acting drugs on serum prolactin levels were studied in male rats. Administration of the serotonin precursor, 5-hydroxytryptophan (5-HTP; 250 mg/kg ip) or pargyline (5 mg/kg ip) with 5-HTP (100 mg/kg ip) significantly increased serum prolactin concentration. Pretreatment of rats with the serotonin agonist, quipazine (10 mg/kg ip) caused increase in serum prolactin levels. Depletion of serotonin stores by pretreatment with p-chloro-phenylalanine methyl-ester (PCPA; 3 x 300 mg/kg ip) significantly prevent the effect of quipazine on prolactin levels. Serotonin uptake blocker, fluoxetine (10 mg/kg ip) produces an increase in the prolactin concentrations of the serum. Administration of the reserpine (2.5 mg/kg sc) did not affect serum prolactin levels. Both serotonin receptor blockers, cyproheptadine (0.5 mg/kg ip) and pizotifen (1 mg/kg ip) caused a week decrease in the serum prolactin levels. Significant changes in concentrations of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in brain of rats pretreated with above serotonin-active drugs were found. These results indicate that serotonergic system can modify secretion of prolactin.

The obtention of vascular access on the arm for hemodialysis.

The chronic dialysis is the way of replacing the lost kidney function. Well functioning vascular access is the prerequisite for chronic hemodialysis treatment. The arteriovenous fistulas are the optimal form of vascular access. In patients, in whom the usual sites for fistula have been exhausted the vascular fistula on the arm was placed. 53 dialysis accesses were performed on the arm between 1989 and 1999. All subcutaneous fistulas were created by the junction of the cephalic vein with brachial artery, just above the cubital fossa on the anterior surface of the arm. All anastomoses were created in the operating room under local anesthesia. The preferred route for exposure of cephalic vein was making the single incision along the arm. When the distal part of cephalic vein has been ligated and divided, the adequate space for the graft in the tunnel was performed. End-to-end anastomosis between the distal end of vein and side of brachial artery was completed using the suture material. In 50 hemodialysed patients the regular flow through the arteriovenous fistula was observed. Fistula thrombosis occurred in 2 cases. In 4 examined patients we observed blood extravasation in the subcutaneous tissue, where the tunnel was created. In 5 patients the local cellulitis was noted. The late vascular complications were evaluated in 15 cases. Aneurysms were revealed clinically in 3 patients and false aneurysm occurred in 2 patients. The described late complications required no surgical correction. The anterior side of the arm is the best place for arteriovenous access used for hemodialysis, in patient without the possibilities of surgical creation of the forearm's fistula.

Effect of ultrafiltration on peripheral urea sequestration in haemodialysis patients.

BACKGROUND: Ultrafiltration (UF) is assumed to enhance urea removal during haemodialysis (HD) because of convective transport and because of contraction of urea distribution volume. However, UF-induced blood volume reduction has been hypothesized to enhance peripheral urea sequestration and post-dialysis urea rebound (PDUR), possibly reducing HD effectiveness. The effect of UF on PDUR was investigated in this study. METHODS: Nine HD patients were studied on two subsequent treatment days. The first HD was performed with UF (UF-rate=0.78+/-0.27 l/h), and the second treatment without UF. Serial measurements of serum water urea nitrogen concentration, arterial blood pressures (BP), and relative blood volume changes (BV%) were obtained over the duration of HD. RESULTS: BP and BV% decreased with UF (BP(sys)= -9%, BP(dia)=-8%, BP(mean)=-9%, BV%=-15%) but increased or remained unchanged without UF (BP(sys)= 9%, BP(dia)=12%, BP(mean)=11%, BV%=1%). PDUR was 28.6+/-9.6% without UF, and increased in every single patient with UF (40.7+/-13.2%, P<0.01). Modelled perfusion of the peripheral low-flow compartment decreased from 1.45+/-0.54 l/min without UF to 0.91+/-42 l/min with UF (P<0.05), thereby explaining an enhanced two-compartment effect and increasing PDUR. CONCLUSION: The significant increase in the two-compartment effect of urea kinetics observed in current HD accompanied by UF can be explained by compensatory, intradialytic blood flow redistribution induced by blood volume reduction. Because of the link between UF and blood flow, limited solute clearance treatment modes that optimize fluid removal such as variable UF will also have favourable effects on delivered dose of dialysis.