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Biomedical subjects

R Vanholder

Publications and source records attributed to R Vanholder.

At least 217 records · Page 12Linked to original sources
PubMed1987

Adequacy studies of fistula single-needle dialysis.

The preferred method of vascular access for routine hemodialysis is via an arteriovenous fistula into which two needles are inserted. Single-needle access is an alternative to this method. Thorough evaluations of the efficiency of the single-needle method are lacking. The present study evaluates the weekly time-averaged urea concentrations (TACUrea) and protein intake (PI) in 76 patients routinely treated with single-needle dialysis on a chronic basis. Furthermore, other clinical parameters of dialysis adequacy, such as hematocrit, nerve conduction velocity, hospitalization rate, and cumulative survival also were evaluated, as well as fistula survival. TACUrea appeared to be 53.2 +/- 6.0 mg/100 mL, a value corresponding to adequate two-needle dialysis with low morbidity, as outlined by the American National Cooperative Study Group. PI was evaluated from urea generation rates (G) and from outpatient dietary records. G was 6.07 +/- 2.42 mg/min, and the corresponding PI was calculated to be 1.07 +/- 0.28 g/kg body weight/24 h. PI estimated from dietary records was 1.14 +/- 0.43 g/kg body weight/24 h. The relation of total clearance over distribution volume (KT/V) averaged 0.98 +/- 0.23. Mean hematocrit and nerve conduction velocity during 2 years of follow-up ranged between 24% and 26% and 38 and 40 m/s, respectively. Hospitalization rate during 1 year was 18%. Five years' cumulative survival was 64% for the period 1975 to 1985, and 79% for the period 1980 to 1985. Five years' fistula survival was 74%, a value higher than in four studies on two-needle dialysis of comparable extent. It is concluded that urea kinetic data and other parameters of dialysis adequacy indicate that the efficiency of the single-needle technique is at least as good as that obtained in the more currently used two-needle technique. Subsequently, the current reluctance towards single-needle dialysis as a routine procedure in chronic renal failure, appears to be unjustified.

Adult↗
PubMed1987

Influence of reuse and of reuse sterilants on the first-use syndrome.

Over a 4 year period, five of 98 patients at our dialysis unit developed signs and symptoms consistent with first-use syndrome (FUS). Marked improvement was noted after subjecting new dialyzers to automated processing using either formaldehyde or peracetic acid. No episodes of FUS occurred in patients being treated with reused dialyzers. Use of formaldehyde sterilization was associated with development of anti-N-like antibodies in the blood of four (8%) of 50 patients over a follow-up period of 14 months. In two patients on the reuse program, itching during dialysis resolved after changing from formaldehyde-sterilization to a method using peracetic acid. Our results confirm the beneficial effects of reuse with regard to first-use syndrome. However, our data also suggest that use of formaldehyde, the most common reuse sterilant, continues to be associated with undesirable clinical and laboratory side effects.

Antibodies, Anti-Idiotypic↗
PubMed1987

Pseudo-Kaposi's sarcoma as a complication of Cimino-Brescia arteriovenous fistulas in hemodialysis patients.

Pseudo-Kaposi's sarcoma is a skin lesion that is associated with chronic venous insufficiency and/or congenital arteriovenous fistulas. Theoretically, this lesion could also be expected in connection with hemodialysis vascular accesses. Nevertheless, this disease has been reported only once in conjunction with a Cimino-Brescia arteriovenous fistula, and no attention has been paid to the potential complications of this disease. In the present paper 3 cases are reported. In 1 patient pseudo-Kaposi's sarcoma was complicated by an infected open wound as a consequence of a trauma. In the 2 other patients, a skin biopsy was followed by local infection and retarded healing of the wound. Evaluation by fistulagraphy and/or Doppler revealed venous outflow stenosis in only 1 case. After reconstruction or ligation of the fistula, correction of the lesions was observed. It is concluded that pseudo-Kaposi's sarcoma can occur as a complication of Cimino-Brescia arteriovenous fistulas, necessitating early correction of the fistula. The performance of a skin biopsy might be associated with infection and delayed wound healing, so that this diagnostic procedure should only be performed in cases where the clinical diagnosis is not obvious.

Adult↗
PubMed1987

[Technical and economic aspects of bicarbonate hemodialysis].

The bicarbonate haemodialysis which is better tolerated by the patient is accompanied by a series of technical and economical problems. The insolubility of bicarbonate in the usual dialysis concentrates demands the production of an additional concentrate which is added to the irrigation solution. Furthermore, the evaporation of CO2 may lead to the change of the composition of the solution. The special production of the concentrates, particular criteria of storage as well as the necessity of additional monitors for the control of the irrigation solution for dialysis leads to an increase of the cost. The devices for the bicarbonate dialysis being sold now are judged and classified in their efficiency.

Bicarbonates↗
PubMed1987

Causes and prognosis of acute renal failure in elderly patients.

In this retrospective study, 287 patients with acute renal failure observed between 1980 and 1985 were divided into 2 groups, according to age: group 1 of 65 years or more (n = 100) and group 2 between 17 and 64 years (n = 187). In both age groups the whole spectrum of causes of acute renal failure was found, but within that spectrum a higher incidence of post-renal failure, acute renal vascular disease and of hypovolaemic acute renal failure was noted in group 1 versus group 2. On the other hand, pigment-induced acute renal failure was lower in group 1 (4%) versus group 2 (13%). The overall survival was 54% in the elderly versus 56% in the younger patients (NS). A close relationship between survival and the number of postadmission complications was found in both groups. Interestingly, the presence of severe hypokalaemia (less than 3.5 mmol/l) and metabolic alkalosis (plasma HCO3 greater than 30 mmol/l) was associated with a very high mortality of 73% and 86% respectively in the elderly patients. Complete or incomplete recovery of renal function was the same in both age groups. It is concluded that age alone should not be used as a discriminating factor in therapeutic decisions concerning acute renal failure in an older patient.

Acute Kidney Injury↗
PubMed1987

Influence of vasoactive substances on early toxic acute renal failure in the dog.

The influence of different vasoactive substances on the evolution of HgCl2-induced acute renal failure (ARF) was evaluated in the dog. HgCl2 alone caused a progressive fall in both glomerular filtration (GFR) and renal blood flow (RBF) during the first 3 h of the mercury administration (delta after 3 h: -44% and -39%) and provoked a concomitant stimulation of the renin-angiotensin (RAS) and thromboxane systems. The administration of the thromboxane inhibitor dazoxiben (2 mg/kg i.v. every 2 h) adequately inhibited the activation of the thromboxane system after HgCl2, but could not prevent the fall in GFR and RBF. The continuous intrarenal administration of the Ca2+ entry blocker verapamil (0.005 mg/kg per min) into the left kidney resulted in the prevention of the postmercurial fall in GFR and RBF at the perfusion site. This beneficial effect was immediately lost when the verapamil administration was stopped. Finally, the administration of the converting enzyme inhibitor captopril (300 micrograms/kg every 2 h) resulted in an effective inhibition of the renin-angiotensin system, the prevention of the postmercurial fall in RBF, and the partial attenuation of the fall in GFR. This beneficial effect was immediately lost after the intravenous administration of indomethacin (2 mg/kg). These results indicate that the fall in GFR after HgCl2 can be prevented by vasoactive agents such as captopril and verapamil and point at least in part to a pathophysiological role of the renin-angiotensin system or of an alteration in the equilibrium between renin-angiotensin and prostaglandins. The thromboxane system is seemingly of no major importance.

Acute Kidney Injury↗
PubMed1987

Renal function in burns.

The present study evaluates the evolution of renal function parameters and serum electrolytes in 34 severely burned patients. The population was arbitrarily subdivided in a group with normal renal function (n = 24) and a group with acute renal failure (n = 10), defined by the fact that serum creatinine rose above 2.5 mg/dl at least once. The patient group with normal renal function was characterized by a normal to high creatinine clearance, reaching a consistent peak at day 2 of follow-up. Serum sodium and fractional sodium excretion were low. Further disturbances were a low serum protein, an early hypocalcemia and hypophosphatemia, and a discrete metabolic alkalosis. The patients developing acute renal failure maintained a low fractional sodium excretion. They were in general of older age and had more severe burns than the patients with normal renal function. The survival rate in the patients with acute renal failure was 30%, compared to 75% in the patients, who maintained normal renal function.

Acute Kidney Injury↗
PubMed1987

[Hemodynamic aspects of bicarbonate dialysis].

About the comparison of the acetate haemodialysis with the bicarbonate haemodialysis different and partly contradictory data are found in literature. In general the bicarbonate haemodialysis is regarded as that variant of therapy which has a less negative influence on the haemodynamics during the dialysis treatment. On 21 patients comparative examinations were performed with the two variants of therapy. The acute complications during the treatment were registered, the circulatory parameters blood pressure, pulse rate and cardiac output (1/min) were measured and the oxygen partial pressure was established. Comparing the two methods of therapy, no essential differences could be found. Patients with evident acetate incompatibility showed significantly more frequently clinical complications under the acetate dialysis. In the acetate dialysis the oxygen partial pressure clearly decreased which is to be discussed as cause for the circulatory instability in this therapeutic method.

Bicarbonates↗
PubMed1986

[Single needle hemodiafiltration].

The haemodiafiltration is a valuable alternative to the conventional dialysis in the cases of both clinical and/or allergic intolerance in conventional dialysis. Moreover, it is suitable for the treatment of therapy-resistant hypertension as well as in all situations, where an insufficient elimination of solved substances is supposed. Up to now the higher expenses prevent the routine use of haemodiafiltration in all dialysis patients.

Blood↗
PubMed1986

Effect of premercurial resetting of intrarenal vascular resistance on HgCl2-induced acute renal failure.

The role of renal hemodynamics in the first hours of HgCl2-induced acute renal failure was examined by studying the influence of resetting the total renal vascular resistance (RT) within the limits of autoregulation before and after the mercury administration. Intravenous HgCl2 alone (3 mg/kg) caused an early fall of glomerular filtration rate (GFR) from 69 +/- 3 to 38 +/- 4 ml/min/100 gm kidney weight (KW) and of renal blood flow (RBF) from 535 +/- 42 to 276 +/- 27 ml/min/100 gm KW, 3 hours after HgCl2 (P less than 0.01). In a second series, the RT was decreased by clamping the aorta before and after HgCl2 so that the mean renal perfusion pressure (MRPP) was lowered to a mean of 87 +/- 5 mm Hg). This maneuver did not prevent the fall in GFR (from 81 +/- 5 to 36 +/- 6 ml/min/100 gm KW) or in RBF (from 510 +/- 79 to 197 +/- 20 ml/min/100 gm KW) after HgCl2 (P less than 0.01). In a third group, the RT was increased by a rise of MRPP to 158 +/- 8 mm Hg by bilateral carotid clamping. Subsequently, 3 hours after HgCl2, the GFR decreased not significantly from 72 +/- 6 to 61 +/- 7 ml/min/100 gm KW, and RBF increased from 405 +/- 66 to 431 +/- 71 ml/min/100 gm KW. Three hours of continued carotid clamping alone caused a rise of GFR from 64 +/- 7 to 83 +/- 7 ml/min/100 gm KW (P less than 0.05) and of RBF from 425 +/- 16 to 581 +/- 28 ml/min/100 gm KW (P less than 0.01). Autoregulation of RBF was studied in a control period and after 3 hours of carotid clamping and found to be lost during prolonged carotid clamping. The autoregulatory capacity remained intact after HgCl2 alone. The renal vasoconstrictive response to norepinephrine was not affected 3 hours after carotid clamping. It is concluded that the fall of GFR and RBF after HgCl2 can be prevented by prolonged carotid clamping. This is related to a loss of the capacity to maintain renal vasoconstriction after carotid clamping because of a concomitant loss of autoregulation of RBF and points at least in part to a pathogenetic role of changes in renal hemodynamics in the first hours after HgCl2. The tubular effects of HgCl2 were, however, maintained, despite the protection of GFR.

Acute Kidney Injury↗
PubMed1985

Long-term experience with the combination of clonidine and beta-adrenoceptor blocking agents in hypertension.

The risk of cardiovascular and fatal complications and the antihypertensive effect of a clonidine-beta-blocker combination was studied in 98 patients and was compared with the results for a group of patients treated with other antihypertensive regimens. The profile of complications was similar in the two groups for a total follow-up period of more than 2000 treatment-months. Clonidine in combination either with propranolol or atenolol had a distinct antihypertensive effect. However, clonidine plus atenolol resulted in a more immediate and pronounced fall in blood pressure. It is concluded that the combination of clonidine and a beta-blocker is an effective antihypertensive medication, and that patients treated with it are apparently at no greater risk of serious cardiovascular incidents than are those treated with other regimens.

Adrenergic beta-Antagonists↗
PubMed1985

Absence of a beneficial haemodynamic effect of bicarbonate versus acetate haemodialysis.

The present study compares data on blood pressure and clinical tolerance, obtained consecutively in the same patients during acetate and bicarbonate haemodialysis. Twenty-one patients were followed over an equal period of acetate and bicarbonate dialysis, averaging more than 30 months per patient. Absolute and relative blood pressure changes were noted. Contrary to what often has been claimed previously, it is concluded from the present long-term study that, bicarbonate haemodialysis has no specific beneficial effect on blood pressure in stabilised chronic patients. As far as vomiting and nausea are concerned, clinical tolerance is, however, significantly better than for acetate haemodialysis.

Acetates↗