Transcutaneous oxygen tension in patients with calciphylaxis.

Calciphylaxis is a severe complication of chronic renal failure, confined almost exclusively to patients on dialysis therapy. Histological characteristics of calciphylaxis include small-vessel calcifications of skin, subcutaneous tissue, and visceral organs. These vascular changes promote tissue ischemia that often results in tissue necrosis. In this study, we investigated the extent of skin ischemia in patients with calciphylaxis by means of transcutaneous oxygen tension (TCPO(2)) measurement, a noninvasive test that accurately assesses skin oxygenation. TCPO(2) levels were measured in 21 patients with calciphylaxis and 21 age- and sex-matched patients without evidence of calciphylaxis (controls). TCPO(2) levels were measured bilaterally at the chest, anterior abdomen, and upper thigh while patients breathed room air and after a 30-minute exposure to 100% fraction of inspired oxygen (FIO(2)). Compared with controls, patients with calciphylaxis showed significantly lower TCPO(2) levels at each body region. In both controls and patients with calciphylaxis, lower TCPO(2) levels correlated with increased weight and use of hemodialysis. No correlation with serum parathyroid hormone (PTH), serum calcium, or serum phosphorus values was present, although 39% of the patients with calciphylaxis had markedly elevated PTH values (sixfold greater than normal; >300 pg/dL). Low TCPO(2) levels in patients with calciphylaxis were documented in body regions with and without skin lesions. In patients with calciphylaxis, extremely low TCPO(2) values (

Renal artery dissection causing renal infarction in otherwise healthy men.

Arterial dissection is usually associated with pathological states such as malignant hypertension, severe atherosclerosis, severe trauma, Marfan syndrome, or Ehlers-Danlos syndrome. However, we report three cases in which renal artery dissection occurred in otherwise healthy, normotensive men. In two cases, the onset of symptoms of renal artery dissection was coincident with an unusual degree of physical activity. In the third case, the symptoms occurred while the patient was sitting but during a stressful business meeting. In each case, the patient experienced severe unilateral flank pain. Urolithiasis was suspected, but intravenous pyelography showed only ipsilateral impaired renal cortical perfusion, and the urinalyses showed no hematuria. The diagnosis of renal artery dissection was established by arteriography in two cases and by nephrectomy in one case. The latter case showed fibromuscular dysplasia by arteriography performed after the nephrectomy. The other two cases showed no evidence of fibromuscular dysplasia. We conclude that spontaneous renal artery dissection can occur in otherwise healthy individuals. Our experience and the reports of others indicate that this condition occurs mainly in men, conservative (nonsurgical) management is generally indicated, and the long-term prognosis is generally excellent. In some patients, an unusual degree of physical exertion might be the cause of renal artery dissection.

Relationship between appearance of urinary red blood cell/white blood cell casts and the onset of renal relapse in systemic lupus erythematosus.

The purpose of the study was to determine the extent to which urinary sediment findings (changes in red blood cells [RBCs], white blood cells [WBCs], and the appearance of RBC and WBC casts) predict the onset of renal relapse (defined as a specific increase in proteinuria and/or serum creatinine level) in patients with systemic lupus erythematosus (SLE). Seventeen SLE patients with biopsy-proven diffuse proliferative glomerulonephritis at initial presentation were followed prospectively for 1,129 patient-months under a study protocol. Semiquantitative urinalyses were performed at 2-month intervals during periods with little or no SLE activity and, more frequently, during periods with increased SLE activity. Each urinalysis was accompanied by a clinical evaluation and a panel of screening tests relevant to the evaluation of SLE activity. During this study, 877 semiquantitative urinalyses were performed and 43 renal relapses were observed in 14 patients. No relapse occurred in three patients. Of the renal relapses, 30 were defined as proteinuria relapses (mean baseline proteinuria increased from 0.8 +/- 0.1 g/24 hr to 2.7 +/- 0.3 g/24 hr; P < 0.001) and 13 were defined as serum creatinine relapses (mean baseline serum creatinine increased from 2.7 +/- 0.4 mg/dL to 3.8 +/- 0.5 mg/dL; P < 0.001). Red blood cell and/or WBC casts (cellular casts) were observed before or at the onset of 35 of the 43 renal relapses (sensitivity, 81%). The mean and median intervals between the appearance of cellular casts and the onset of renal relapse was 10 +/- 2 weeks and 8 weeks, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Modification of the percutaneous approach to peritoneal dialysis catheter placement under peritoneoscopic visualization: clinical results in 78 patients.

The placement of percutaneous peritoneal dialysis catheters under direct peritoneoscopic visualization is a relatively new technique for establishing peritoneal dialysis access. In this study, in which a modification of the Seldinger technique was used to facilitate the placement of the peritoneoscope, the experience with 82 consecutive catheterization procedures in 78 patients is reported. In 2 (2.4%) of 82 catheterization procedures, we were unable to enter the peritoneal cavity but experienced no other complications unique to the percutaneous approach. Of the 80 successful catheterization procedures, 76 represented first-time catheter placement and constituted a population subjected to life-table analysis examining catheter survival rates, the time to first cutaneous exit site or s.c. tunnel infection, and the time to first episode of peritonitis. After a follow-up period of 50.1 patient yr, 11 catheters were lost because of catheter dysfunction. Other clinical complications included peritoneal fluid leaks at the cutaneous exit site in 11 instances (0.22/patient yr), cutaneous exit site infection in 7 instances (0.14/patient yr), s.c. tunnel infection in 2 instances (0.04/patient yr), and 34 episodes of peritonitis (0.68/patient yr). The results of this study demonstrate that the suggested modification of the percutaneous placement of peritoneal dialysis catheters, under peritoneoscopic visualization, is a viable method for establishing peritoneal access.

Continuous arteriovenous hemofiltration.

CAVH is a bedside form of dialysis that is used in the treatment of fluid and electrolyte disorders seen in critically ill patients. The major advantages of the procedure include (1) gradual, continuous therapy, which is ideal in hemodynamically unstable patients; (2) control of fluid balance; and (3) ease of administration in the ICU. The major disadvantages of CAVH include (1) a requirement for arterial access, (2) the need for anticoagulation, (3) the risks of infection from long-term indwelling vascular lines, and (4) the potential for significant volume depletion. The effectiveness of CAVH may continue to improve owing to technical developments in filter composition and the application of clinical tactics such as suction-assisted filtration, predilution fluid replacement, or regional heparinization. The next step in bedside dialysis is represented by CAVHD, which offers all of the advantages of CAVH as well as improved urea clearance.

Simple method for monitoring 24-hour urinary urea nitrogen excretion.

The urine urea nitrogen/urine creatinine excretion ratio (UUN/UCr) of a "spot" urine specimen obtained approximately 5 hours after the last meal of the day can be used to accurately calculate the urinary urea excretion for the previous 24-hour period. Because UUN excretion is largely determined by dietary intake of protein nitrogen, this method can be used to estimate dietary protein intake for the previous 24-hour period. Strategies for using this simple method for inexpensively and continuously monitoring dietary protein intake are discussed.

Pancytopenia with mixed cryoglobulinemia: evidence for anti-percursor cell activity of cryoglobulin--effects of plasmapheresis.

The efficacy of plasmapheresis in a patient with mixed cryoglobulinemia and pancytopenia is shown. The cryoglobulin was shown to have percursor cell suppressing activity and its depletion by plasmapheresis resulted in improvement of blood counts, Indications, limitations and guidelines for plasmapheresis in various diseases are discussed.

A rapid bioassay for the comparison of xanthophyll availability from various sources.

A rapid bioassay method for comparing xanthophyll availability from various sources or the pigmenting ability of genetic strains or crosses is proposed. Xanthophyll depleted, fasted birds are intubated with equal amounts of xanthophyll from various sources. Serum xanthophyll is then determined from blood samples obtained 14 to 24 hr following intubation. Results are expressed as the increase in serum xanthophyll (microgram/ml) over the intubated controls per milligram xanthophyll intubated per kilogram body weight. Limitations of the bioassay are discussed.

Variation in the biological availability of xanthophyll within and among generic sources.

Xanthophyll depleted, fasted broilers were intubated with various xanthophyll sources in a series of six experiments. The increase in serum xanthophyll per milligram xanthophyll intubated per kilogram body weight was used to estimate exahtnophyll availability. Statistically significant differences among samples within and among generic sources were obtained. As a result, beta-apo-8'-carotenoic acid ethyl ester (apo-EE) was used as a reference standard in Experiments 4 to 6. When the availability of apo-EE was given a relative value of 100, the availability of xanthophyll from corn gluten meal ranged from 47.7 to 89.1% (four samples), from dehydrated alfalfa, 34.6 to 65.4% (eight samples), and from Coastal Bermudagrass, 18.8 to 27.9% (three samples).