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Biomedical subjects

F K Port

Publications and source records attributed to F K Port.

At least 145 records · Page 8Linked to original sources

Air under the diaphragm in patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

To understand the significance of pneumoperitoneum in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), we reviewed 110 upright x-rays of 33 patients. Only 3 x-rays belonging to 2 patients displayed large amounts of air under the diaphragm. One patient had documented colonic perforation and the other patient used a faulty technique that introduced air into the abdomen. Five additional asymptomatic patients showed minute amounts of air. We conclude that large amounts of air, as defined radiographically by an air shadow of more than 5 mm in height, is unusual in CAPD patients and should be taken seriously as suggestive of bowel perforation until proven otherwise.

Aged↗

Outcome of end-stage renal disease in patients with rare causes of renal failure. I. Inherited and metabolic disorders.

This study represents the first national multi-center evaluation of treatment for end-stage renal disease outcome in patients with rare metabolic and inherited disorders in the United States. Because of the small number of such patients at single centers only a co-operative study could provide adequate data on enough patients for meaningful conclusions. By co-ordinating such data, the Network Forum provides a model for the newly organized U.S. Renal Data System and demonstrates the potential for useful special studies in the future. It is clear from these data that despite the systemic nature of these illnesses, treatment for ESRD can be applied to achieve excellent survival rates.

Adult↗

Outcome of end-stage renal disease in patients with rare causes of renal failure. II. Renal or systemic neoplasms.

We describe a large experience with patients with end-stage renal disease (ESRD) whose primary cause was considered multiple myeloma, renal cell carcinoma and amyloidosis. Data were obtained by a collaboration of the majority of the ESRD Networks of the United States. The data presented reflect recent practice in the United States. Even though it is likely that some selection bias plays an important role, the demographic characteristics, choice of early treatment and overall survival data provide some assistance to physicians when advising their patients with these rare conditions. More detailed analyses are needed to assess the outcome by choice of treatment as well as the age- and treatment-adjusted survival for these diagnoses.

Actuarial Analysis↗

A comparison of employment rates of patients treated with continuous ambulatory peritoneal dialysis vs in-center hemodialysis (Michigan End-Stage Renal Disease Study).

This study examines factors associated with employment status in a stratified subsample of the Michigan End-Stage Renal Disease Study population. To reduce the variation in employment potential, the subsample consisted of nondiabetic patients aged 20 to 64 years. The patients were stratified on the basis of their treatment histories as follows: (1) treated by in-center hemodialysis only; (2) primarily treated by continuous ambulatory peritoneal dialysis; and (3) failed continuous ambulatory peritoneal dialysis, substituted by another form of dialysis. A significantly higher percentage of the patients undergoing stable continuous ambulatory peritoneal dialysis were in the labor force than were those undergoing in-center hemodialysis (27.4% vs 9.6%). Using logistic regression, even when adjusted for sex, race, age, education, marital status, primary diagnosis, and duration of end-stage renal disease, the stable continuous ambulatory peritoneal dialysis group was significantly more likely to be employed than the group undergoing either in-center hemodialysis only or the group that failed continuous ambulatory peritoneal dialysis.

Adult↗

Assessment of quality of life in end-stage renal disease.

Ten different multi-item indexes and nine single-item measures were used to assess the quality of life of patients undergoing one of four major modalities of treatment for end-stage renal disease (ESRD). Assessments were made on a population-based sample of Michigan patients with onset of ESRD after November 1, 1981, during the period May 1984 to September 1986. The nature of these measures is described and correlations among them are reported. The correlations suggest that these indexes tend to represent either function or feeling, with moderate relationships within the two clusters but little between them. Findings are also reported in terms of age, race, and sex. Depending on the measure chosen to assess quality of life, different conclusions about the relationship of quality of life to these demographic characteristics will be reached. These conclusions may help readers think more critically about the nature of quality of life in arriving at judgments on the relative validity of these different measures.

Activities of Daily Living↗

Excessive ATP degradation during hemodialysis against sodium acetate.

As the initial step in examining the metabolic basis for acetate intolerance, we have tested the hypothesis that excessive adenosine triphosphate (ATP) degradation occurs during hemodialysis against acetate dialysate (compared with the degree of degradation occurring during dialysis against bicarbonate dialysate). Seven patients undergoing long-term dialysis were infused with carbon 14--labeled 8-adenine, and their response to dialysis against acetate was compared with their response to dialysis against bicarbonate. The following changes were observed. During dialysis against acetate, the mean dialysate uric acid--to-creatinine ratio levels were significantly higher than the mean levels observed after dialysis against bicarbonate (p less than 0.001). The mean dialysate uric acid radioactivity--to-creatinine ratio and inosine, hypoxanthine, and xanthine radioactivity--to-creatinine ratio levels were significantly increased during dialysis against acetate (p less than 0.001). There was no significant change in plasma venous hypoxanthine level, but during dialysis against acetate, the arterial hypoxanthine levels (3.7 +/- 1.6 mumol/L) at 60 minutes were significantly higher than the levels observed after dialysis against bicarbonate (1.4 +/- 0.5 mumol/L) (p less than 0.01). These data provide evidence that excessive ATP degradation occurs during hemodialysis against acetate but not during hemodialysis against bicarbonate dialysate.

Acetates↗

Atrial natriuretic hormone secretion in patients with renal failure.

To study the effects of volume overload and renal failure on plasma levels of immunoreactive atrial natriuretic hormone (IR-ANH), we measured levels of this hormone in normal subjects, in patients with advanced chronic renal failure (CRF) with and without clinically evident volume overload, and in patients with end-stage renal disease (ESRD) treated with chronic hemodialysis. The levels were 13 +/- 2 pmol/l in normal volunteers, 77 +/- 24 pmol/l in patients with CRF without volume overload, and 219 +/- 50 pmol/l in patients with CRF and clinically evident volume overload (analysis of variance, p less than 0.001, alpha = 0.05 compared to normals). In patients with ESRD, the levels of IR-ANH were 145 +/- 46 pmol/l before dialysis and decreased to 87 +/- 31 after dialysis (p less than 0.025). No correlation was found between the decrease in IR-ANH levels and the decrease in weight during dialysis. A significant positive correlation was found between the IR-ANH levels and blood urea nitrogen in patients with CRF (r = 0.658, p less than 0.01). Volume overload appears to be the most important stimulatory factor for ANH secretion in renal failure patients but other mechanisms, especially a decrease in metabolic clearance, may also contribute to elevated plasma levels. The increased secretion of ANH in patients with renal failure may be an important adaptive response to volume overload and hypertension.

Adult↗

Enhanced thermolability in anephric rabbits.

Uremic patients tend to have a lower than normal deep-body temperature. In addition, there is a clinical impression that uremic patients are also more thermolabile than healthy people; that is, in a warm environment, body temperature tends to be higher, and in a cold environment, body temperature tends to be lower than in healthy subjects. To test the hypothesis that uremia results in enhanced thermolability, nonoperated control (NO), nephrectomized (NX), and sham-nephrectomized (SHAM) rabbits were subjected to mild cold (5 degrees C) and heat (30 degrees C) stresses. At 48 hours postsurgery, the core temperature of NX rabbits was significantly lower than that of the NO or SHAM rabbits (P less than .01). Exposure to 5 degrees C resulted in a significant fall in body temperature of the NX (from 39.1 degrees C to 38.3 degrees C; P less than .05) rabbits compared to the NO rabbits. There was a tendency for body temperature of the SHAM rabbits to fall, and as a result, there was no significant difference in the change in body temperature between the SHAM and NX rabbits. Exposure to 30 degrees C resulted in virtually no change in the core temperature of the NO or SHAM rabbits, but did result in a significant rise in core temperature of the NX rabbits (P less than .02 and P less than .01 for respective comparisons), as well as a significant increase in mortality rate (P less than .02). Based on these data, we conclude that anephric animals are more thermolabile, and are less able to tolerate exposure to a warm environment, than are normal animals.

Animals↗

The role of dialysate in the stimulation of interleukin-1 production during clinical hemodialysis.

To evaluate the role of the dialysate in the stimulation of interleukin-1 (IL-1) production during clinical hemodialysis (HD), we studied maintenance HD patients in two experiments. Cellulosic hollow-fiber dialyzers were obtained after 20 minutes of HD using either nonsterile standard dialysate (n = 6) or sterile pyrogen free 0.9% saline as dialysate (n = 6). After rinsing the blood compartment with normal saline, dialyzers were incubated at 37 degrees C for six hours. Aliquots from the blood compartment were analyzed for the presence of IL-1 by (1) rabbit pyrogenic response after intravenous injection or (2) thymocyte co-proliferation assay. The in vivo assay showed a significantly greater febrile response when standard dialysate was used than in the sterile saline group (P less than .001), and this response could be abolished by heat inactivation of aliquots (P less than .001). The in vitro assay confirmed the presence of significantly greater amounts of IL-1 (P less than .05). Studies were repeated using filter sterilized standard dialysate (n = 6) v standard dialysate (n = 6) for 240 minutes of clinical HD. The in vitro assay revealed significantly lower IL-1 levels in the filtered sterilized dialysate group (P less than .05), however, a blank control assay showed yet significantly lower levels (P less than .05). We conclude that IL-1 is produced during clinical HD and that endotoxin or its fragments play a role in the stimulation of IL-1 production, probably through monocytes adhering to the dialysis membrane. In addition to this dialysate factor, IL-1 production appears also to be stimulated by a blood-membrane interaction.

Electrolytes↗

Influence of race of cadaveric kidney donor and recipient on graft survival: a multifactorial analysis.

Actuarial survival analysis of 889 cadaver transplant patients between 1972 and 1981 in Michigan reveals functional graft (P = .0003) and patient (P = .004) survivals are improved when donors and recipients are of the same race (black or white). The Cox regression model for multifactorial analysis confirms the significantly lower graft survival for the mixed racial combination group with a relative risk of 1.27 (P less than .05). By this analysis, other significant factors adversely affecting the graft survival rates include diabetes as a cause of end-stage renal disease, earlier date of transplantation, shorter duration of prior dialysis, and a significant center effect. Patient survival has a significantly greater relative risk for the black to white racial combination, diabetes, earlier calendar year of transplantation, and age of patient. While the mixed racial group was slightly older (delta = 2 years), had more hypertension, less glomerulonephritis, and more HLA mismatches, our analysis by the Cox regression model suggests that these factors played only minor roles (P greater than .05) regarding graft survival rates. Therefore, our data suggest that independent of several other factors, cadaver kidneys have a better functional outcome when they are transplanted into recipients of the same race.

Actuarial Analysis↗

Successful treatment of Pseudomonas peritonitis during continuous ambulatory peritoneal dialysis.

Successful eradication of Pseudomonas peritonitis is described in 12 (57%) of 21 cases from a large continuous ambulatory peritoneal dialysis (CAPD) program at a tertiary care center. In successful cases, cure was achieved within 17 days using therapy which included aminoglycoside started routinely at the onset of symptoms and an antipseudomonal penicillin or cephalosporin derivative added as soon as pseudomonas infection was identified on culture. Of the 9 treatment failures which required catheter removal, 2 had failure of peritoneal drainage, 4 had infection with multiple and/or drug-resistant Pseudomonas strains, and 3 had persistent catheter tunnel infection which resulted in recurrent Pseudomonas peritonitis. Factors such as diabetes mellitus and pediatric age group did not prevent successful medical therapy. Predisposing factors favoring development of Pseudomonas peritonitis included technical failures and in a few cases recent antibiotic therapy. We conclude that Pseudomonas peritonitis complicating CAPD can be successfully cured without catheter removal or discontinuation of CAPD in many cases, particularly when complicating factors are not present.

Adolescent↗

Continuous arteriovenous filtration: an effective treatment for surgical acute renal failure.

Continuous arteriovenous hemofiltration (CAVH) is a new method of renal replacement therapy that has several advantages in the surgical treatment of acute renal failure. We initially learned the technique in laboratory testing and then developed a management protocol. Since 1983 we have used CAVH to treat 61 patients with acute renal failure. This extracorporeal technique consists of arteriovenous cannulation of the femoral vessels, which provides continuous blood flow through a hollow-fiber membrane. Hydrostatic pressure (systole greater than 80 mm Hg) creates an ultrafiltrate at a typical rate of 12 L/day. Volume is replaced with an intravenous solution at a rate to achieve the desired fluid balance, usually a net loss of 1 to 2 L/day. This extracellular fluid exchange typically results in removal of 15 gm of urea nitrogen and 50 mEq of potassium per day. The technique can be used in most intensive care units and has relatively few complications. In addition to being a safe and effective means of renal replacement therapy for acute renal failure, CAVH is particularly advantageous for managing conditions of fluid overload in hemodynamically unstable patients.

Acute Kidney Injury↗

Ectopic prolactinoma in a patient with hyperparathyroidism and abnormal sellar radiography.

In a patient with hyperparathyroidism and chronic renal failure due to polycystic kidney disease, a finding of destroyed sellar and parasellar structures and hyperprolactinemia suggested the diagnosis of invasive pituitary prolactinoma. At surgery no tumor was found, and pathological examination of the sphenoid bone revealed a parathyroid bone lesion (brown tumor) as well as ectopic prolactinoma in the clivus. This patient demonstrates that a tumor may develop in ectopic pituitary tissue. The combination of radiographically abnormal sellar structures with pituitary hormone hypersecretion should not be regarded as absolute proof of a pituitary adenoma.

Choristoma↗

Continuous arteriovenous hemofiltration: improved survival in surgical acute renal failure?

Continuous arteriovenous hemofiltration (CAVH) is an effective method for renal failure management that has the potential to decrease mortality rates. This hypothesis has not been comparatively studied. Fifty six patients with acute oliguric renal failure complicating multiple organ failure had measurements of resting energy expenditure by indirect calorimetry, caloric and protein intake, energy balance, and outcome. Two management protocols included hemodialysis, full calories, and low protein (phase I) or CAVH, full calories, and high protein (phase II). The survival rate in phase I was 12% and 28% in phase II (not a statistically significant difference); CAVH did facilitate parenteral feeding. Patients with positive energy balance had improved survival compared with those with significant energy deficit (37.5% versus 9.4%, p less than 0.025). We conclude that full nutritional support improves survival in acute renal failure. The method of renal replacement therapy is of secondary importance, but CAVH has distinct advantages in the nutritional management of surgical patients.

Acute Kidney Injury↗

Urinary protein binding, kinetics, and dynamics of furosemide in nephrotic patients.

The urinary protein binding, kinetics, and dynamics of furosemide were studied in five nephrotic patients after intravenous dosing. Serial plasma and urine samples containing furosemide were analyzed by HPLC, and drug binding to plasma and urinary proteins was determined using equilibrium dialysis techniques. In comparison to data reported previously in healthy subjects, the steady-state volumes of distribution and nonrenal plasma clearances were significantly increased in nephrotic patients, reflecting the reduced binding of furosemide to plasma proteins. Although there was no significant difference in renal clearance between these two groups, the unbound renal clearance of furosemide was significantly reduced in nephrotic patients even when compensated for by the number of functioning nephrons. Furosemide was extensively bound to urinary protein (19.6-78.4%), and the binding was dependent on the degree of proteinuria. Nevertheless, dose-response analyses, in which the response was represented by sodium excretion rate and the dose by urinary excretion rate of unbound drug, demonstrated that nephrotic patients were less responsive to equivalent amounts of unbound diuretic as compared to healthy subjects.

Adult↗

Fever in uremia: production of leukocytic pyrogen by chronic dialysis patients.

Uremic patients frequently have low baseline temperatures and a blunted febrile response to infection. We investigated the first step in the generation of a febrile response, the production of leukocytic pyrogen (LP) by blood monocytes, in 12 patients on chronic hemodialysis, five patients on continuous ambulatory peritoneal dialysis (CAPD), and 17 control subjects. No significant differences were found in the amount of LP produced by hemodialysis patients, CAPD patients, and control subjects. Uremic serum did not decrease LP production by monocytes from control subjects. Hemodialysis patients who were consistently hypothermic (mean oral predialysis temperature less than or equal to 35.6 degrees F) produced as much LP as those with more normal oral temperatures (mean oral predialysis temperature greater than or equal to 36.8 degrees F). Decreased production of LP does not explain the blunted febrile response noted in patients with chronic renal failure.

Adult↗