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PubMed2000

[Effect of macrophage nitric oxide on the ultrafiltration failure of long-term peritoneal dialysis].

OBJECTIVE: The regulation of macrophage nitric oxide on peritoneal lymphatic stomata was studied for revealing the mechanism of ultrafiltration failure during long-term peritoneal dialysis. METHODS: (1) The model of peritoneal dialysis was created by using peritoneal dialysate; (2) Dynamic measurements of nitric oxide (NO) were made during peritoneal dialysis and its cessation; (3) The pathological change of the peritoneal mesothelium in different dialysis time was observed by scanning electron microscope (SEM); (4) Dynamic changes of the peritoneal lymphatic stomata were studied during this experiment by using a computer image processing system attached to SEM. RESULTS: Numerous macrophages went into the peritoneal cavity through the lymphatic stomata to form a lot of milky spots during peritoneal dialysis. A great quantity of NO produced by macrophages damaging mesothelial cells and increasing numbers and density of lymphatic stomata. After 40 days of peritoneal dialysis, the diameters of the lymphatic stomata were significantly increased in Bieffe group (P < 0.05). During cessation of peritoneal dialysis, few macrophage milky spots were observed and NO quantity was gradually decreased. Then the mesothelium damage began to repair and the peritoneal lymphatic stomata tended to become normal. CONCLUSIONS: Our data demonstrate that a great quantity of NO produced by macrophages would damage peritoneal mesothelium and relax lymphatic stomata which enhance lymphatic reabsorption from the peritoneal cavity so as to make ultrafiltration failure on long-term peritoneal dialysis.

Absorption↗
PubMed2003

Relation of ventricular late potentials and intradialytic changes in serum electrolytes, ultrafiltration, left ventricular ejection fraction and left ventricular mass index in haemodialysis patients.

BACKGROUND: End-stage renal failure patients on haemodialysis (HD) suffer from increased risk of sudden cardiac death. Abnormal late potentials (LP) on signal-averaged electrocardiogram (SAAECG) has proved valuable for identification of increased risk of malignant ventricular tachyarryhythmias in various settings of patients. Abnormalities in LP were reported in HD patients, but their role is still not clear. The aim of the study was to evaluate: 1. the influence of HD on SAECG, 2. the correlation of intradialytic changes of serum electrolytes, weight change and ultrafiltration with intradialytic changes of LP, 3. the correlation of left ventricular ejection fraction (LVEF) and left ventricular mass index (LVMI) with LP before and after HD. METHODS: LP (parameters fQRSd, RMS40, LAS40) were obtained in 39 patients in sinus rhythm within one hour before and after chronic maintenance HD. Patients with permanent atrial fibrillation or on antiarrhythmic therapy (other than betablockers) were excluded. Echocardiography was performed within three days before HD. RESULTS: No difference in fQRSd before and after HD was found. Postdialytic RMS40 (47.0 +/- 30.1 microV vs 37.1 +/- 22.6 microV, p < 0.05) and LAS40 (25.9 +/- 9.7 ms vs 30.8 +/- 12.5 ms, p < 0.05) significantly improved. Weak significant negative correlation between intradialytic Na change and fQRSd change was found (R = -0.33, p < 0.05). Correlations between intradialytic changes of other electrolytes (K, Ca, P. Mg) and individual LP parameters were nonsignificant. There was no correlation found between intradialytic weight change/ultrafiltration and intradialytic differencies of SAECG. LVEF was weakly inversely correlated with predialytic fQRSd (R = -0.37, p < 0.05) and postdialytic fQRSd (R = -0.35, p < 0.05). LVMI was weakly positively correlated with predialytic fQRSd (R=0.39, p < 0.05) and postdialytic fQRSd (R = 0.40, p < 0.05). LVEF respectively LVMI did not correlate neither with RMS40 nor with LAS40 before or after HD. CONCLUSIONS: SAECG partially improved in end-stage renal failure patients after HD (RMS40 and LAS40 but not fQRSd). Intradialytic differencies of SAECG were not correlated neither with ultrafiltration nor with weight change. Pre-/postdialytic fQRSd inversely correlated with LVEF and positively correlated with LVMI. Further controlled, prospective studies investigating the impact of LP on HD patient care are needed. (Tab. 6, Ref. 19.).

Echocardiography↗
PubMed2005

Use of the Quest Myocardial Protection System (MPS) for modified ultrafiltration during pediatric cardiac surgery.

Modified ultrafiltration generally is considered a standard of care for treating children undergoing cardiopulmonary bypass for congenital heat surgery. Different methods, incorporating a variety of devices and technologies, have been described. The present report describes a technique of modified ultrafiltration using arterial-venous flow with the Quest Myocardial Protection System (MPS).

Child↗
PubMed2006

Ultrafiltration techniques and CPB: what we know and what we think we know.

Unfortunately there have been very few prospective randomized studies comparing the clinical outcomes of patients treated with large volume ultrafiltration. Given the shortage of impressive clinical outcome data and the varying results of mediator removal studies, the application of ultrafiltration as a therapeutic technique is still a controversial topic. A few researchers have suggested that different membrane materials may have significantly different mediator removal potential. One important future direction for research in this area should include a comprehensive comparison of different membrane materials with regard to their clinical performance.

Animals↗
PubMedDate not supplied

What is the link between poor ultrafiltration and increased mortality in anuric patients on automated peritoneal dialysis? Analysis of data from EAPOS.

BACKGROUND: Primary analysis of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS) found that patients with daily ultrafiltration (UF) below a predefined target of 750 mL at baseline experienced increased mortality and continuing low UF over 2 years. SETTING: Multicenter, prospective observational study of prevalent, functionally anuric patients on automated peritoneal dialysis (APD) treated to predefined standards. METHODS: Secondary data analysis to determine clinical covariates that might support a link between poor UF and outcome, including pattern of comorbidity, prescription, nutrition as determined by Subjective Global Assessment (SGA), membrane function, and blood pressure (BP). Ultrafiltration was treated as a categorical (comparing patients above and below target at baseline) and continuous dependent variable in univariate and multivariate regression. The relationship between BP and survival was also explored. RESULTS: Of 177 patients recruited from 28 centers across Europe, 43 were below the UF target at baseline. Compared to those above target, there were no differences in the spread of comorbidity, type of APD prescription, SGA, BP, hemoglobin, HCO3, or parathyroid hormone, at baseline or at any later time. At baseline, plasma calcium and, at 12 months, plasma phosphate were lower in the low UF group. There was a weak positive correlation between baseline systolic or diastolic BP and UF, which remained on multivariate analysis but accounted for just 9% of the variability in BP. There was no clear relationship between baseline BP and survival, although, if anything, low BP was associated with earlier death. Poor UF was associated with lower mean dialysate glucose concentration during the first 4 months and with consistently worse membrane function. CONCLUSIONS: The increased mortality associated with poor UF is likely multifactorial and not easily explained by clear differences in comorbidity, nutritional state, or other indices of treatment at baseline. The lower plasma phosphate suggests a subsequent fall in appetite. Poor BP control is unlikely to be the explanation, and a link between lower BP, reduced UF, and earlier death is suggested. Failure to achieve adequate UF due to worse membrane function remains an important and potentially reversible or preventable cause.

Anuria↗
PubMed2006

Use of the Hemobag for modified ultrafiltration in a Jehovah's Witness patient undergoing cardiac surgery.

Modified ultrafiltration is an important technique to concentrate the patient's circulating blood volume and the residual whole blood in the extracorporeal circuit post-cardiopulmonary bypass. The Hemobag system is a device cleared by the US Food and Drug Administration and represents a novel and safe modification of traditional modified ultrafiltration systems. It is quick and easy to operate by the perfusionist during the hemoconcentration process. Hemoconcentration is accomplished by having the Hemobag "recovery loop" circuit separate from the extracorporeal circuit. This allows the surgeons to continue with surgery, decannulate, and administer protamine simultaneously while the Hemobag is in use. The successful use of the Hemobag in a Jehovah's Witness patient has not been previously described in the literature. This case report describes how to set up and operate the Hemobag in a Jehovah's Witness patient undergoing cardiac surgery that requires an extracorporeal circuit.

Aged↗
PubMed1990

Serotonin in the control of blood pressure and ultrafiltration in CAPD.

Urinary 5-OH-Indoloacetic acid (5-HIAA) indicates the turnover of almost all circulating serotonin (5-HT), a potent vasoactive agent. We tried to investigate the possible excretion of 5-HIAA in the dialysate of CAPD patients and its possible effects on blood pressure control (BP) and/or ultrafiltration (UF). The 24 h excretion of 5-HIAA in the urine of 10 patients with chronic renal failure (CRF) and 8 healthy persons (CONTROL), and in the dialysate of 15 patients on CAPD was measured by FPIA. In CRF 5-HIAA excretion was less than that in control (p less than 0.01). In CAPD patients two distinct patterns of 5-HIAA excretion were found. Patients with high excretion (greater than 6 mg) had high BP and low UF, while those with low excretion (less than 3.14) had low BP, high UF and frequent hypotensive episodes. Excretion of 5-HIAA in the dialysate had a negative correlation with UF (r = -0.779, p less than 0.001) and a positive correlation with B.P. (r = 0.487, n.s.). A highly significant (p less than 0.01) correlation between BP and UF was also found. As no differences between the two groups in factors that could affect UF or BP were found, the implication that 5-HT affects ultrafiltration and/or BP regulation is suggested.

Blood Pressure↗
PubMedDate not supplied

Less symptomatic hypotension using blood volume controlled ultrafiltration.

Symptomatic hypotension due to ultrafiltration (UF) is one of the most frequent unwanted side effects of dialysis therapy. Using hemoglobinometry for continuous monitoring of blood volume (BV), ultrafiltration rate (UFR) can be adapted to actual changes in BV. A control system is shown in which UFR is set according to a predefined profile of BV. The conditions of control are: relative BV shall decrease steadily; BV shall decrease rapidly during the first 60 min of dialysis, thereafter decrease in BV should be less; UFR shall be as high as possible; and dry weight should be obtained within a given time. Application of this controlled UF method in 10 dialysis patients shows significantly fewer hypotensive periods and muscle cramps compared to conventionally constant UFR. It is concluded that BV controlled UF is an important step toward optimizing dialysis therapy.

Blood Flow Velocity↗
PubMed1990

[Application of ultrafiltration during cardiopulmonary bypass].

The ultrafiltration (UF) was employed in 20 patients undergoing open-heart operation with cardiopulmonary bypass (CPB). The number of controls was 10. The average UF duration was 24.7 +/- 9.6 min (12-49) and the average amount of ultrafiltrate was 1433.5 +/- 482.6 ml (650-2,350 ml). The volume load of UF group was similar with that of the control group. The output volume of UF group was greater than that of the control group (P less than 0.01). After UF, the degree of increase in hematocrit, plasma albumin and total plasma protein was 33.8%, 34.7%, and 26.0%, respectively. Moreover, we did not find any abnormal increase in blood viscosity. No additional adverse actions of UF were found.

Adolescent↗
PubMedDate not supplied

[Hemodiafiltration with high-level ultrafiltration versus hemodialysis. Longitudinal study].

A group of well nourished young patients was examined during 2 longterm consecutive high efficiency dialytic schedules to detect possible clinical and biochemical differences. The patients were first studied during hemodialysis with a 1.2 m2 cuprophan membrane and blood flow of 400 ml/min and, then, during hemodiafiltration with an ultrafiltration rate greater than 100 ml/min by using high permeability membranes with a surface greater than or equal to 1.4 m2. As expected by the higher clearances obtained on hemodiafiltration, this technique resulted in a significant reduction of dialysis time and of BUN and serum creatinine, associated with a significant increase of hemoglobin, possibly related to a better deintoxication. Furthermore, the dry body weight decreased significantly during hemodialysis, whereas it increased significantly during hemodiafiltration, despite unchanged dietary habits, indicating possible differences in the nutrients utilization during the 2 dialytic schedules. Therefore, in chronically dialyzed patients, highly permeable synthetic membranes should be preferred to cuprophan because of a supposed better biocompatibility and should be used with the highest ultrafiltration rate in order to obtain a better dialytic efficiency and to avoid the risk of backfiltration.

Adult↗
PubMed1989

[Peroperative ultrafiltration in complete repair of ventricular septal defect in infants].

Ventricular septal defect in infants induces peroperative fluid overload (particularly extravascular lung water overload) which causes some morbidity after surgical closure of the defect. Thirty infants undergoing the conventional complete correction procedure were retrospectively compared with 32 infants operated upon using ultrafiltration at the end of the cardiopulmonary bypass. There was no difference between the two groups in biological data, haemodynamic parameters and either morbidity or mortality. Nevertheless, a clinical impression of smooth follow-up in patients with ultrafiltration encourages to carry out a prospective and randomized study.

Extracorporeal Circulation↗
PubMed1989

[Effect of isolated ultrafiltration on plasma hormone levels in patients with heart failure resistant to drug therapy].

The positive action exerted by isolated ultrafiltration on 69 patients with refractory heart failure was shown to be due to the complex interaction of effects produced by ultrafiltrate removal. Among the effects, a leading role is played by therapy for hyperaldosteronism and reduction of antidiuretic hormone levels along with improvement of the functional status of the liver and heart.

Adult↗
PubMedDate not supplied

The bioartificial kidney: progress towards an ultrafiltration device with renal epithelial cells processing.

The combination of an ultrafiltration device with an exchanger whose semipermeable hollow fibres are covered with renal epithelial cells is proposed as a design for a bioartificial kidney. We first demonstrated that continuous ultrafiltration can be maintained for relatively long periods in the absence of anticoagulation. As a second step, we report here the feasibility of attaching and growing two lines of kidney epithelial cells (MDCK and LLC-PK1) on two different semipermeable materials, an acrylic copolymer and a polysulphone. Cells seeded on acrylic copolymer hollow fibres reach confluence within three weeks. Depending on the chemical and/or physical properties of the polymer, the cells show distinct differentiated morphology, which may influence their ability to perform specialized tasks.

Bioprosthesis↗
PubMed1970

Use of a rapid ultrafiltration technique in the determination of plasma glycerol.

The use of plasma ultrafiltrates in the enzymatic analysis of glycerol has been compared with filtrates prepared by using metaphosphoric acid and heat denaturation. The results which were obtained with these three methods of deproteinization are comparable; however, the membrane ultrafiltration technique is the simplest of the procedures and yields an undiluted filtrate which is free of foreign ions.

Filtration↗
PubMed1994

[Body fluid withdrawal with isolated ultrafiltration effects persistent improvement of functional capacity in patients with chronic congestive heart failure. Furosemide does not produce the same result].

In moderate congestive heart failure pulmonary overhydration may be detected at chest X-ray even if therapy is optimized to keep the urinary output normal and to prevent weight gain and dependent edema formation. Removal of overhydration of the lung may help to define its significance. This study was aimed at investigating whether a subclinical accumulation of fluid in the lung interstitium in moderate congestive heart failure interferes with the patient's functional capacity, and whether furosemide is able to promote reabsorption of the excessive fluid. Patients whose digoxin, oral furosemide and ACE-inhibitor therapeutic regimen was kept constant, were randomly allocated to ultrafiltration (8 cases) or iv bolus (mean dose = 248 mg) of supplemental furosemide (8 cases). The amount of body fluid removed with each method approximated 1.600 ml. Functional performance was assessed with cardiopulmonary exercise tests. Soon after fluid withdrawal with either procedure the filling pressures of the two ventricles and body weight were reduced and plasma renin activity, norepinephrine and aldosterone were augmented. After furosemide hormones remained elevated in the subsequent 4 days, and, during this period, patients had positive water metabolism, recovery of the elevated ventricular filling pressures, recurrence of lung congestion without any improvement in functional capacity. In ultrafiltrated patients, renin, norepinephrine and aldosterone fell below control values within the first 48 hours and water metabolism was equilibrated at a new set point (less fluid intake and diuresis without weight gain). Functional capacity in these patients was improved through favorable circulatory and ventilatory adjustments consequent on reabsorption of lung water. This may also have restored the ability of the lung to clear norepinephrine, thus restraining its facilitation of renin release. Improvement persisted at 3 months after the procedure. In congestive heart failure the set point of fluid balance is altered despite oral furosemide; supplemental iv furosemide does not shift the set point, at least in the presence of ACE-inhibition; excessive, although silent, lung water limits the functional capacity of the patient.

Aged↗
PubMedDate not supplied

[Food protein quality. III Enzymatic ultrafiltrate digest (EUD) aminoacid index (author's transl)].

An aminoacid index for protein quality evaluation is presented, using a new model of enzymatic digestion of proteins in vitro. The EUD index is obtained determining on the ultrafiltrate the available aminoacids after digestion with pepsin, trypsin, pancretin and erepsin in an Amicon ultrafiltration cell. A very high correlation is obtained between EUD index and the biological values of 10 protein or food protein samples. The experimental validity of this in vitro method allow his utilization for direct evaluation of protein quality instead of the more complicated and time consuming biological tests.

Amino Acids↗
PubMed1993

Determinants of glomerular ultrafiltration in cats.

To investigate the determinants of glomerular ultrafiltration, renal micropuncture studies were performed in 9 cats. Mean single nephron glomerular filtration rate (SNGFR), directly measured in outer cortical nephrons, was 29.4 +/- 3.0 nl/min. This was similar to the estimated value for SNGFR (31.3 +/- 4.6 nl/min) obtained by dividing left kidney total glomerular filtration rate (1.41 +/- 0.12 ml/min/kg of body weight) by left glomerular count (175,200 +/- 13,600 glomeruli/kidney). In micropuncture studies performed at mean renal perfusion pressure of 101.3 +/- 1.0 mm of Hg, the glomerular capillary hydrostatic pressure was 58.0 +/- 1.4 mm of Hg. The glomerular transcapillary hydrostatic pressure gradient (40.0 +/- 1.8 mm of Hg) exceeded colloid osmotic pressure at the efferent end of the glomerular capillaries (28.4 +/- 2.1 mm of Hg) in all cats studied, indicating existence of positive effective filtration pressure throughout the glomerular capillary bed. These results indicate that glomerular capillary pressure is sufficiently high to prevent forces from reaching filtration pressure equilibrium in feline outer cortical nephrons. Thus, the value of SNGFR in feline nephrons depends on the glomerular transcapillary hydrostatic pressure gradient and the glomerular ultrafiltration coefficient.

Animals↗
PubMed1995

Slow continuous ultrafiltration (SCUF)--the safe and efficient treatment for patients with cardiac failure and fluid overload.

Slow Continuous ultrafiltration (SCUF) was first used in 1980 as an alternative mode of fluid removal for patients with oliguric acute renal dysfunction from whatever causes. The advantage of this treatment is that haemodynamic parameters remain stable in the presence of significant removal of fluid. We are describing our experience in 7 patients [age: 57 +/- 9 years; 4 male, 3 female] with cardiac failure and fluid overload who had undergone 8 sessions of SCUF. All of them had renal impairment and were resistant to diuretics. Blood lines were attached to a Kawasumi Renak-E dialyser (Cuprophane membrane) in series using Gambro AK10 dialysis blood pump. The following parameters were monitored: Blood pump (Qb): 175 +/- 26 ml/min, time (T): 393 +/- minutes. Venous pressure averaged a55 +/- 24 mmHg. We achieved ultrafiltration of 2,189 +/- 699 ml/session or 5.5 +/- 1.7 ml/hr. There was no significant change in blood pressure [systolic pre: 143 +/- 14, post: 136 +/- 13 mmHg, not significant; diastolic pre: 87 +/- 10, post: 83 + 10 mmHg, not significant and pulse rate [pre: 87 +/- 9 vs post: 84 +/- 2 per minute, not significant. Heparin dosage averaged 274 +/- 26 IU/hr during the SCUF. We conclude that SCUF is beneficial to diuretic resistant patients with cardiac failure and fluid overload in whom dialysis treatment is not required.

Adult↗