Atrial thrombus and central venous dialysis catheters.

A native arteriovenous fistula is the first choice for hemodialysis access. Despite improved catheter designs and the use of internal jugular veins, thrombotic complications still occur when tunneled central venous catheters are used as an alternative. Although right atrial thrombus (RAT) is a well-characterized complication of long-term central venous cannulation, particularly when used for parenteral nutrition and chemotherapy in pediatric practice, only 9 reported cases previously have been associated with the long-term use of central venous catheters for hemodialysis. We report five cases of RAT seen at our unit between 1994 and 1998 in patients who had been dialyzed using tunneled catheters. In four of five cases, the diagnosis was made during the investigation of hemoptysis or dyspnea. In the fifth case, a screening transthoracic echocardiogram revealed the thrombus. Three of five of the patients suffered pulmonary emboli, and a fourth patient had an unexplained electromechanical dissociation cardiac arrest without definite evidence of pulmonary embolus. Our experience suggests that anticoagulated patients with RAT remain at risk of pulmonary embolism. One of our patients successfully underwent atrial thrombectomy. In four of five of our cases and four of nine cases in the literature, the central venous catheter tip was within the right atrium. Positioning of the central venous catheter tip low down in the superior vena cava or in the right atrium has been advocated to improve dialysis adequacy and to reduce the incidence of catheter thrombosis. However, placement of the catheter tip within the right atrium may be associated with an increased risk of RAT.

Clinical, radiological and serum amyloid P component scintigraphic features of beta2-microglobulin amyloidosis associated with continuous ambulatory peritoneal dialysis.

BACKGROUND: Beta2-Microglobulin (beta2M) amyloidosis occurs in patients with end-stage renal failure (ESRF) who undergo long-term continuous ambulatory peritoneal dialysis (CAPD), but its prevalence in patients treated exclusively by CAPD is unknown. In addition, its features may differ from those of haemodialysis-associated beta2M amyloidosis because CAPD is more biocompatible. METHODS: We performed serum amyloid P component (SAP) scintigraphy, a specific technique for imaging amyloid deposits, in 13 consecutive patients with ESRF who had been dialysed for >5 years, at least 80% of the time by CAPD. Clinical and radiological features of beta2M amyloidosis were sought and compared with the results of SAP scintigraphy. RESULTS: SAP scans showed articular amyloid deposits in seven patients, all of whom had evidence of carpal tunnel syndrome and four of whom had arthralgia characteristic of dialysis amyloidosis. Typical radiographic bone cysts were present in only one case who had been dialysed for >17 years. The remaining six patients had no clinical, radiological or scintigraphic evidence of beta2M amyloidosis. CONCLUSIONS: The prevalence of beta2M amyloidosis in this study was comparable with that in reported haemodialysis populations. Many of the amyloid deposits demonstrated by SAP scintigraphy were not associated with symptoms, but larger and longer term studies are required to determine whether CAPD favourably influences their clinical expression.

Home dialysis: lessons in patient education.

The concept of home haemodialysis for the regular treatment of renal failure was first put into practice in 1964, 30 years ago. It proved extremely successful. This paper describes the epidemiology of renal failure, the reasons for home haemodialysis and the educational role necessary to ensure its success. Continuous ambulatory peritoneal dialysis (CAPD), or autonomous dialysis, is a self-care peritoneal treatment which developed after 1978 for a wider age range of patients. Its rapid expansion needed a professional approach to patient education. Also discussed are the problems patients encounter with conceptual skills, as opposed to the easy acquirement of practical skills and the paper demonstrates how persons, without formal medical and nursing education, can master complex treatment skills.

[Mercury emission measurements in a crematorium. The dentistry aspects]. / Quecksilber-Emissionsmessungen in einem Krematorium. Zahnmedizinische Aspekte.

The amount of mercury released during cremation was calculated in a major Swiss city at two crematoria. A total of 60 mercury "output" calculations were carried out by the Swiss Material Testing Institute (Empa). The amount of mercury initially present ("input") in the dentitions of 54 deceased persons was assessed from their post-mortem dental radiographs and by clinical examination. The correlation between the "input" and the "output" was 0.93, irrespective of the age at death. However, the "input" was calculated to be 1.8 times higher than the "output" for the deceased people with amalgam restorations. In the blind study, the difference was 1.3 times. The main source of mercury was undoubtedly the amalgam restorations. The amount of mercury recorded during the cremation of 88% of the deceased people without amalgam restorations was under the accepted level of 200 micrograms/m3. However, in 3 cases, the amount of mercury was slightly more than 200 micrograms/m3. In contrast, the amount of mercury recorded during the cremation of only 18% of the deceased people with amalgam restorations was less than the accepted level of 200 micrograms/m3. The amount of mercury contamination during cremation as a result of amalgam fillings is so low that no additional preventive measures are required at the crematoria.

Studies of aluminium mobilization in renal dialysis patients using the oral chelator 1,2-dimethyl-3-hydroxypyrid-4-one.

The oral chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1, deferiprone, CAS 30652-11-0) has been tested in 11 renal dialysis patients, 10 for aluminium and 1 for iron mobilization. L1 was administered just after the patients were placed on the haemodialyser and blood samples were collected before haemodialysis at 1 h and for some patients at longer intervals. Plasma aluminium levels before treatment ranged from 12 to 264 micrograms/l. A mean increase of 90% was observed within the first hour of oral administration in 6 patients who received a dose of L1 of 40-60 mg/kg. Plasma aluminium levels then progressively decreased after this period. Three patients with plasma aluminium of 30-66 micrograms/l who received a dose of L1 of less than 30 mg/kg had no significant changes in their plasma aluminium. In 2 other cases administration of L1 resulted in an over 30-fold increase of aluminium concentration in the dialysate of a continuous ambulatory peritoneal dialysis patient and of over 3 times the iron concentration in the dialysate of an iron loaded haemodialysis patient. In the last patient HPLC analysis of the dialysate samples obtained from the haemodialyser has shown complete clearance of L1 within 4 h but not of its glucuronide metabolite within 6.5 h of the L1 administration. No toxic side effects were observed in any of the 11 patients who received oral L1. These are the first clinical trials of an oral chelator in renal dialysis patients which suggest that oral L1 and possibly other alpha-ketohydroxypyridine chelators may have a use in the treatment of patients with aluminium overload.

Relationship between pruritus, transepidermal water loss, and biochemical markers of renal itch in haemodialysis patients.

The pathogenesis of pruritus in patients undergoing chronic haemodialysis is unknown. Dryness of the skin is common in uraemic patients, and a correlation between xerosis and pruritus has been reported. Transepidermal water loss (TEWL) is a measure of cutaneous barrier function and also reflects skin water content. In this study the transepidermal water loss was measured at four sites pre- and postdialysis in 20 subjects undergoing chronic haemodialysis and in 16 healthy controls. Patients were weighed before and after dialysis and blood was taken for measurement of urea, creatinine, calcium, magnesium, phosphate and haemoglobin. All patients had parathyroid hormone measured within 3 months of the assessment. There was no significant difference in TEWL between patients and controls, with control values in general being between pre- and postdialysis rates of TEWL, and no correlation between TEWL and the presence or absence of pruritus. There was no significant differences between the pruritic and non-pruritic patients for any of the biochemical markers measured. Finally there was no significant correlation between the percentage water loss and TEWL. These findings indicate that pruritus of chronic haemodialysis is not related to abnormalities of cutaneous permeability.

["Adhesive anterior tooth restorations" with the use of dentin bonding with and without a cavity liner]. / "Adhäsive Frontzahnrestorationen" unter Dentinadhäsivanwendung mit und ohne Unterfüllung.

In this clinical study 60 class III and class IV restorations were placed according to the rules of the "adhesive restoration". 32 were without, 28 with a light-cured glass-ionomer liner. Total bonding was established in the liner-free group using a modern dentinal adhesive (Prisma Universal Bond 3). Immediately after placement and 3, 6 and 12 months later, respectively, all restorations were clinically inspected. In addition, marginal adaptation of 29 fillings was evaluated in the scanning electron microscope using the replica technique. The results of the clinical examination and of the SEM evaluation at 12 months were not statistically different. Clinically, all restorations were rated A or B. Except for one tooth with pulpitis caused by a restoration, that was not directly involved in this study, all restored teeth were vital and free of clinical symptoms after 12 months. The percentage of "continuous margin" was about 90% in both groups initially. At 12 months-recall, more than 95% "continuous margin" were recorded. This increase was due to repeated removal of flashes at the recall intervals. Under the proviso of an efficient recall, by using a modern dentinal adhesive and a fine hybrid composite, "adhesive restorations" can successfully be placed with and without liner.

Calcium set point progressively worsens in hemodialysis patients despite conventional oral 1-alpha hydroxycholecalciferol supplementation.

Calcium set point was measured in 12 patients on chronic hemodialysis. Dialysate calcium concentration was 1.65 mmol/l. Calcium carbonate (CaCO3) was used as the phosphate binder and oral 1-alpha hydroxycholecalciferol (alfacalcidol) was administered in a dose of 0.25-1.0 micrograms/day for 12 months. Comparing base line and post study values, there were no significant changes in ionized calcium (ICa++), intact immunoreactive parathyroid hormone (iPTH), plasma total calcium (TCa++), plasma phosphate (P), alkaline phosphatase (ALP), or aluminum (Al). However, the relative calcium set point significantly worsened (shifted to the right). Three patients developed hypercalcemia (25%) with a total calcium > 2.65 mmol/l. Total bone mineral content (BMC) fell suggesting demineralization. We conclude that this dose of oral alfacalcidol, CaCO3, and a dialysate calcium concentration of 1.65 mmol/l are not sufficient to halt the progression of secondary hyperparathyroidism in chronic hemodialysis patients. Measurement of calcium set point may be the best early measure of failure to prevent worsening of hyperparathyroidism.

Differing prognostic significance of reinfection and relapse in CAPD peritonitis.

All episodes of recurrent infection in a CAPD unit over a 26-month period have been analysed to discover whether relapse and reinfection have different prognostic importance. Relapse and reinfection were distinguished by detailed microbiological investigation. Prognosis was expressed in terms of outcome of treatment and the fate of the Tenckhoff catheter. Twenty-nine patients suffered recurrent infections (i.e. more than one infection during a 12-month period). Nine (6 male, 3 female, age range 42-73 years) had relapses, and 20 (16 male, 4 female, age range 42-74 years) reinfections. The characteristics of the two groups of patients were indistinguishable. Relapse was of graver prognostic consequence: patients who relapsed were significantly less likely to respond to antibiotic treatment (78% versus 20%) and have to have their catheters removed (78% versus 10%) than those with reinfections. Thus it is important to differentiate relapse from reinfection in CAPD peritonitis. In addition to being helpful for the management of individual patients, this is essential if results of therapeutic trials are to be interpreted correctly.

Amyloidosis and other musculoskeletal complications of long-term regular haemodialysis.

Regular haemodialysis for at least five years is associated with musculoskeletal symptoms. Many of these are caused by a newly recognized disease, haemodialysis amyloidosis. Eighty-three patients who have dialysed for at least 10 years have been reviewed and their symptoms and treatment documented. As yet no cure for this crippling complication is available.

Musculoskeletal manifestations of amyloidosis. A review of 83 patients on haemodialysis for at least 10 years.

Long-term regular haemodialysis for chronic renal failure is associated with amyloidosis. In this condition excess amounts of the unexcretable plasma protein beta-microglobulin are laid down in tendons, joints and bones. Amyloidosis presents with various musculoskeletal disorders only after several years of dialysis. We reviewed 83 patients who had been dialysed for at least 10 years. The commonest complaint was severe joint pain in the absence of radiological changes of arthritis (41%), the shoulders usually being the most affected (33%). Carpal tunnel syndrome had developed in 26 patients, and was bilateral in 14 of them; at operation the presence of amyloid was confirmed. Six of these patients had recurrent symptoms after a further two to three years and required another decompression. Other manifestations of amyloidosis included trigger finger, flexor tendon contracture, spontaneous tendon rupture and pathological fracture through amyloid bone cysts. The frequency of symptoms was proportional to the duration of dialysis: all 13 patients on dialysis for over 20 years were affected. Symptoms developed earlier in older patients.

Splenic abscess in patients on hemodialysis.

We describe two patients on hemodialysis who developed staphylococcal splenic abscesses. Both patients previously had staphylococcal septicemia secondary to infection at the dialysis access site. We postulate that access-site infections may predispose hemodialysis patients to splenic abscess, and that these patients should be investigated for a splenic abscess if they should develop unexplained fever.

Detective work in continuous ambulatory peritoneal dialysis.

We report five cases of continuous ambulatory peritoneal dialysis in which the mechanisms and sources of infection were established. We show how diligent enquiry and environmental investigation can explain the pathogenesis of infection and help in prevention by motivation of the patient.

Apolipoprotein B turnover in dialysis patients: its relationship to pathogenesis of hyperlipidemia.

Exogenously labelled Iodine-125-VLDL (very low density lipoprotein) was given intravenously to twelve dialysis patients and four normal controls. Specific activities of I-125-VLDL apoB (apolipoprotein B) and I-125-IDLapoB (intermediate density lipoprotein apolipoprotein B) were measured for forty-eight hours. Synthesis rates (flux) and fractional catabolic rates (FCRs) of VLDLapoB and IDLapoB for hyperlipidemic (n = 8), normolipidemic (n = 4) dialysis patients and controls (n = 4) were calculated. Dialysis patients had lower VLDLapoB FCRs than controls (p less than 0.05); hyperlipidemic dialysis patients had marginally raised VLDLapoB flux over normolipidemics (p = 0.0508), suggesting apoB production might play a greater role in the pathogenesis of hyperlipidemia. Hyperlipidemics had lower IDLapoB FCRs than controls (p = 0.01). IDLapoB flux was similar in all three groups. The discrepancy in VLDLapoB fluxes between hyperlipidemics and normolipidemics with similar IDLapoB fluxes suggested that VLDLapoB could be directly catabolized in hyperlipidemics. ApoB concentration was increased in VLDL, IDL of hyperlipidemics when compared with normolipidemics (p less than 0.05) and controls (p = 0.01). Hyperlipidemic VLDL plasma levels were relatively enriched with cholesterol when compared with controls, p less than 0.01, and normolipidemics, p less than 0.05. These factors might all contribute towards accelerated atherogenesis in hyperlipidemic dialysis patients.