[Diagnostic image (348). A man with peculiar calcifications on an abdominal X-ray]. / Diagnose in beeld (348). Een man met bijzondere verkalkingen op een buikoverzichtsfoto.

An X-ray of the abdomen of a diabetic dialysis patient showed typical signs of extra-skeletal calcification with mediasclerosis and calcification of the vasa deferentia.

[Daily problems involving contact with terminally ill patients with renal failure]. / Alltagsprobleme im Umgang mit terminal niereninsuffizienten Patienten.

Practitioners and physicians working in emergency rooms are often confronted with dialysis patients or patients who have received a kidney transplant. For dialysis patients, the mode of dialysis treatment needs to be assessed and dialysis access should be secured. Furthermore, the indications for the next dialysis treatment need to be determined. Dialysis patients often present themselves because of fluid overload, hypo- or hypertensive episodes, electrolyte disturbances, fever or cardiovascular events. Patients undergoing continuous peritoneal dialysis are at an increased risk of infection of the catheter or of peritonitis. Patients with a renal transplant require continuation of their immunosuppression and the function of the transplant should be monitored. These patients often present with infections in which case the degree of immunosuppression may need to be reduced. Vaccinations as well as an increased risk for malignancies require special attention in these patients.

Sticky platelet syndrome: an underrecognized cause of graft dysfunction and thromboembolic complications in renal transplant recipients.

Sticky platelet syndrome (SPS) leads to hyperaggregabilty of platelets in response to physiologic stimuli. In this report we describe three patients with clinical symptoms of SPS after renal transplantation. The first patient developed an infarction of her transplant kidney with additional, subsequent renal microinfarctions. The second patient suffered multiple strokes and deep vein thrombosis with episodes of pulmonary embolism and ischemic bowel disease due to colonic microinfarctions. The third patient experienced a long episode of unexplained respiratory and graft dysfunction immediately after transplantation until therapy for SPS was initiated, at which point symptoms resolved quickly. Kidney transplant recipients with SPS may be at increased risk of developing thrombosis, given that most immunosuppressive drugs are known to induce either endothelial cell damage or augment platelet aggregation. All patients awaiting renal transplantation should be screened for a history of thrombosis and, if appropriate, tested for SPS. Affected patients should receive dose-adjusted acetylsalicylic acid.

[Success and failure with the Demers catheter in dialysis]. / Erfolge und Fehlschläge mit dem Demers-Katheter in der Dialyse.

Between January 1995 and January 1999 54 Demers atrial catheters were implanted in 48 uraemic patients. Indications for implantation were: urgent need for haemodialysis with missing vascular access (39), fistula occlusion (7), low shunt flow (3) and problems with a previously implanted catheter (5). We observed 7 catheter infections, 5 catheter occlusions, 1 intraoperative air embolism, 3 haematomas and 1 dacron socket dislocation. The average period of use of an atrial catheter was 170 days, the longest period almost 2 years. The majority of catheters were explanted without any dysfunction. The long time of availability makes Demers atrial catheters an alternative to fistula for multimorbid patients on dialysis with poor long-term survival.

Adenylate cyclase of gastric mucosa in patients with chronic renal failure.

It has been shown previously that antisecretory response of famotidine is altered in patients with renal failure. To evaluate the underlying mechanism(s) of this clinical observation we obtained biopsy specimens of fundic mucosa from 3 groups of patients with variable renal function (group 1 normal renal function (n = 16); group 2 chronic renal failure (n = 16), CLCR > or = 5 < 90 ml/min; group 3 hemodialysis therapy (n = 16)) (matched for age, sex, and Helicobacter pylori (Hp) status. In the homogenized samples adenylate cyclase (AC) activity was assessed and the influence of uremia on this second messenger system involved in gastric acid secretion was tested. AC activity was measured as the formation of cAMP, which was determined by RIA. The mean basal AC activity was 150 in group 1, 190 in group 2, and 120 pmol cAMP/mg protein/20 min in group 3. There was a dose-dependent stimulation by histamine (1 microM-1 mM). Emax of cAMP formation ranged between 230 and 403 pmol cAMP/mg protein/20 min and EC50 between 5.9 and 20.1 microM histamine, dependent on Hp status. Histamine-stimulated AC activation was reduced to about 50% by 0.1 mM famotidine. The sensitivity of AC to histamine seems to decrease in patients undergoing hemodialysis. Similarly, the colonization with Hp may result in decreased maximal response of the AC system towards histamine.

Influence of recombinant human erythropoietin on hematological and hemostatic parameters with special reference to microhemolysis.

Twenty chronic hemodialysis patients with renal anemia (hematocrit < 25%) received recombinant human erythropoietin (40 IU/kg body weight 3 x weekly) intravenously after each dialysis. Prior to and at 4, 8 and 12 weeks after commencement of erythropoietin therapy, hematocrit together with hemostasis and microhemolysis parameters were determined. There were significant increases in hematocrit, platelet count and platelet retention, but a significant fall in the initial clearly prolonged bleeding time. Free plasma hemoglobin likewise increased. Conversely, lactate dehydrogenase, prothrombin time, fibrinogen, antithrombin III activity, protein C activity and protein S concentration were all unaltered. The positive effect on bleeding time and platelet retention is most probably caused by an increase in adenosine diphosphate due to the hematocrit-dependent rise in the blood shear stress via physiologic microhemolysis (raised free plasma hemoglobin).

Pharmacokinetics and pharmacodynamics of roxatidine in patients with renal insufficiency.

1. Roxatidine acetate, a new histamine H2-receptor antagonist, was administered in the evening (75 mg p.o.) to eight patients with renal insufficiency (CLCR 8-17 ml min-1) for 12 days and plasma drug concentrations were measured. 2. Ambulatory intragastric pH was monitored following the last dose and values were compared with those on day 1 when all patients received a placebo. 3. The terminal elimination half-life (mean +/- s.d.) of roxatidine was 10.8 +/- 2.4 h and its oral clearance was 178 +/- 43 ml min-1. 4. During roxatidine treatment gastrin levels increased slightly (median 189 vs 289 ng l-1) and the hyperparathyroid status of the patients was almost normalized (parathyroid hormone levels: median 199 vs 132 ng l-1). 5. The mean latency to a gastric pH of at least 4 was 4.3 +/- 1.4 h. The duration of action (intragastric pH > 4) was 10.6 +/- 3.9 h. 6. As in a pilot study with six patients (CLCR < or = 17 ml min-1) the recommended dosage regimen (75 mg 48 h-1) was unable to maintain gastric pH > 4 for more than 6 h, daily nocturnal intake of 75 mg roxatidine acetate appears appropriate to elevate gastric pH > 4 for a sufficient period of time.

Chronic hypokalaemia of adults: Gitelman's syndrome is frequent but classical Bartter's syndrome is rare.

We evaluated 27 adult patients with chronic hypokalaemia (K+ = 2.9 +/- 0.2 mmol/l), documented over at least 5 years, in whom the cause of the hypokalaemia had not been clarified in spite of previous testing. In 15 patients it was possible to establish a diagnosis by a thorough outpatient workup (diuretic abuse (n = 5), surreptitious vomiting (n = 8), laxative abuse (n = 1), renal tubular acidosis (n = 1)). Commonly utilized tests such as measurements of plasma renin activity, plasma aldosterone, and urinary potassium concentration proved not to be useful in the differential diagnosis of these patients. In contrast the following were diagnostically important: in surreptitious vomiting the hypochloraemia, the mild renal insufficiency, and the extremely low urinary chloride concentration; in diuretic abuse the high urinary concentration of chloride together with repeatedly positive toxicology screens for diuretics; in laxative abuse the high stool weight and extremely low urinary sodium concentration. In the remaining 12 patients none of these diagnoses applied and further tests for suspected Bartter's syndrome were done in the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetic optimisation of the treatment of peptic ulcer in patients with renal failure.

The pathogenesis of peptic ulceration is not yet clear. It could be due to an imbalance between acid secretion and mucosal defensive and/or protective mechanisms, but the association between Helicobacter pylori and peptic ulceration has questioned this hypothesis. Therefore, drugs inhibiting acid secretion and/or eradicating H. pylori are of major interest. Peptic ulcer disease is often associated with renal failure. For the selection of the proper dosage of these agents their pharmacokinetic properties and alterations in pharmacokinetics in various disease states, including renal failure, should be known. As histamine H2-receptor antagonists and pirenzepine are mainly eliminated by the renal route their elimination is dependent on creatinine clearance. Consequently, their elimination will be impaired in patients with renal insufficiency, which makes dosage reduction mandatory in these patients. No dosage supplementation is necessary after any type of dialysis because the drugs are removed in insignificant amounts by the various blood purification procedures. Misoprostol and proton pump inhibitors, such as omeprazole, lansoprazole and pantoprazole, are primarily eliminated by nonrenal routes. Therefore no dosage adjustments are necessary in patients with renal insufficiency. Bismuth salts, sucralfate and antacids should be avoided in patients with renal failure because of the accumulation of their cations and the associated risk of toxic reactions. For most agents more long term experience from comparative and double-blinded studies is needed to define better their clinical efficacy and tolerability in patients with renal failure.

Hydrodynamic thrombectomy of hemodialysis fistulas: first clinical results.

PURPOSE: A hydrodynamic thrombectomy system was used for the treatment of recent dialysis shunt thrombosis. PATIENTS AND METHODS: Sixteen shunt thromboses in 14 patients were included in the study. There were seven polytetrafluoroethylene grafts and nine native arteriovenous fistulas. Occlusion time ranged from 6 to 48 hours, and thrombus length ranged from 4 to 40 cm. RESULTS: Thrombectomy was technically successful in 15 of 16 instances. No significant residual thrombus was found in 15 cases. In one case, half of the thrombus remained in the vessel and the procedure failed technically. One embolus to the radial artery occurred after balloon dilation following hydrodynamic thrombectomy and was removed percutaneously. Early rethrombosis within 24 hours occurred in five shunts; four more rethrombosed within 2 weeks to 3 months. Eleven shunts were available for follow-up. Cumulative patency was 41% after 6 months. CONCLUSION: Hydrodynamic thrombectomy is a promising concept for declotting of both hemodialysis grafts and native shunts and may offer an alternative to thrombolysis and surgical thrombectomy.

Which bicarbonate concentration is adequate to lactate-buffered substitution fluids in maintenance hemofiltration?

We investigated the metabolic and hemodynamic effects of a lactate- and a bicarbonate-buffered (bicarbonate concentration 31.4 mmol/l, type I) hemofiltration substitution fluid in a prospective crossover study of 3 weeks each in 11 patients on maintenance hemofiltration. The lactate-buffered hemofiltration (lactate concentration 34-44.5 mmol/l) lead to hyperlactatemia in all patients without signs of overt lactic acidosis but showed a better control of acid-base balance (pH, base excess, standard bicarbonate) than the type I bicarbonate-buffered fluid (p < 0.01). In 6 patients a higher concentration of bicarbonate- (39.7 mmol/l, type II) buffered fluid was tested. The parameters of acid-base balance showed a better control during type II than during type I bicarbonate hemofiltration and were similar to the lactate-buffered phase. Plasma lactate levels between type I and type II bicarbonate hemofiltration were not different. Also in the steady state phase of the treatment (days 7-9 [week 3]) parameters of acid-base balance rose more to normal values during type II than during lactate-buffered hemofiltration. Hemodynamic parameters showed no differences between the three types of buffers used. Furthermore, also the type II bicarbonate fluid was well tolerated. Bicarbonate in a higher concentration (39.7 mmol/l) proved to be a safe and practical alternative to lactate-buffered hemofiltration.

Helicobacter pylori infection and serum pepsinogen A, pepsinogen C, and gastrin in gastritis and peptic ulcer: significance of inflammation and effect of bacterial eradication.

OBJECTIVES: To study the relationship between Helicobacter pylori infection, gastric inflammatory scores, and fasting gastrin and pepsinogen A and C concentrations, and to evaluate the effect of treatment on these parameters. METHODS: Gastrin and pepsinogen A and C concentrations were measured in 36 patients with gastritis, 10 gastric ulcer patients, 12 duodenal ulcer patients, and in 15 subjects with normal gastric mucosa, by standard radioimmunoassay techniques. Fifteen patients with H. pylori infection underwent triple therapy (bismuth subsalicylate, amoxicillin, metronidazole) and were reassessed 1 month later. RESULTS: Fasting gastrin and pepsinogen A and C concentrations were significantly higher in H. pylori-positive gastritis and peptic ulcer patients than in subjects with normal mucosa and in patients with H. pylori-negative gastritis. There was a significant correlation between inflammatory scores and serum gastrin (r = 0.45, p < 0.0001), and pepsinogen A (r = 0.33, p < 0.006) and pepsinogen C (r = 0.55, p < 0.0001) concentrations. Neither sex nor age affected basal gastrin and pepsinogen concentrations. Eradication of H. pylori infection was successful in 12 patients and resulted in a significant fall in serum gastrin and in pepsinogen A and C concentrations, and in a concomitant improvement of the inflammatory scores. Serum peptide levels and gastritis scores were unchanged in those patients in whom H. pylori infection persisted. CONCLUSIONS: These findings suggest that hypergastrinemia and hyperpepsinogenemia are secondary to H. pylori infection and are related to mucosal inflammation.

Diagnostic value of indirect pancreatic function test in serum of anuric patients with chronic renal failure.

Although patients with chronic renal failure have a high incidence of chronic pancreatic disease, the condition is frequently overlooked. We have modified the pancreolauryl test--an indirect pancreatic function test--for anuric patients. The test permitted good discrimination between patients with chronic pancreatic disease and those with a normal pancreas when serum levels of fluorescein were measured 10 h after administration with a standard meal. The sensitivity at this time interval was 80% and the specificity 83%. We conclude that the pancreolauryl test with serum measurements provides a simple, noninvasive, and reliable diagnostic test for chronic pancreatic disease in anuric patients with chronic renal failure.

Diurnal blood-pressure variations in haemodialysis and CAPD patients.

The influence of variations in fluid state on diurnal blood pressure was studied by measuring day-time and night-time blood pressure during a 3-day interdialytic period in 10 normotensive and 10 hypertensive haemodialysis patients using Spacelab 90207 Monitors. Ambulatory blood pressure was also measured during 24 h in 11 normotensive and nine hypertensive CAPD patients, and in nine normotensive and 11 hypertensive control patients with a normal renal function. Antihypertensive drugs had been discontinued for at least 3 weeks before the study period. Optimal dry weight in the haemodialysis patients was estimated by echography of the inferior vena cava and in the CAPD patients on clinical grounds. Although in the dialysis patients and controls a significant nocturnal blood pressure reduction was found, day-night blood pressure difference in the dialysis patients was blunted when compared with the control patients. No significant differences in diurnal blood pressure variation was found between the normotensive and the hypertensive patients. Day-night blood pressure differences in the haemodialysis patients did not change during the 3-day interdialytic period. Also the more stable fluid state of the CAPD patients was not associated with significant different diurnal blood pressure variation compared to the haemodialysis patients. We conclude that factors other than changes in extracellular fluid volume are responsible for a blunted day-night difference in blood pressure in dialysis patients.

Influence of interdialytic weight gain on blood pressure in hemodialysis patients.

The role of fluid overload in the pathogenesis of hypertension in hemodialysis patients is not clear. One problem is the lack of techniques to determine the fluid state. Recent new noninvasive techniques have become available which make it possible to accurately determine the dry weight in these patients. Therefore, we studied the influence of interdialytic weight gain on interdialytic blood pressure in 10 normotensive and 10 hypertensive hemodialysis patients without antihypertensive medication. The dry weight was determined with echography of the vena cava. The blood pressure was measured during 2-day and 3-day interdialytic periods using Spacelabs 90207 ambulatory blood pressure monitors. Mean systolic and diastolic blood pressures of the last day of the interdialytic period were compared with mean systolic and diastolic blood pressures of the 1st day of the interdialytic period. Although the interdialytic weight gain in the normotensive and hypertensive patients was greater during the 3-day than during the 2-day interdialytic period, the interdialytic systolic and diastolic blood pressure changes were not greater during the 3-day period. Also, the interdialytic blood pressure rise did not correlate significantly with weight gain, neither in the normotensive nor in hypertensive patients. No significant interdialytic blood pressure changes were found between the normotensive and the hypertensive patients. We conclude that fluid overload does not seem to play a major role in interdialytic blood pressure control in normotensive and hypertensive hemodialysis patients.

Diagnosis and treatment of a solitary infected hepatic cyst in two patients with adult polycystic kidney disease.

We report on two women (one 52-year-old who underwent kidney transplantation 15 months ago and the other, 71-year-old, undergoing hemodialysis) both with adult polycystic kidney disease who had to be hospitalized because of recurrent fever attacks up to 40 degrees C without any remarkable abdominal symptoms. Staphylococcus hominis and E. coli were recovered respectively from blood cultures of both patients. Evidence for the presence of a solitary infected cyst in the liver could only be obtained by computed tomography (CT) with i.v. administration of a contrast medium. In both cases the infected liver cyst was non-operatively drained with a CT-guided percutaneous catheter and therefore the necessity of laparotomy was avoided.