PubMed Health⌕ Search

Biomedical subjects

F K Port

Publications and source records attributed to F K Port.

At least 19 recordsLinked to original sources
PubMed1992

Patterns of low incidence of treated end-stage renal disease among the elderly.

We present US county-level maps of the 1983 to 1988 incidence of treated end-stage renal disease (ESRD) among white and nonwhite persons 65 years of age and older (N = 66,129). Recent statistical advances permit the investigation of geographical patterns of unusually low disease incidence. Our maps highlight those US counties which have been determined to have rates of ESRD treatment incidence that are low relative to those of all counties, revealing several interesting geographic patterns. For whites, low rates are found in the Northwest, the Midwest, and the South. Nonwhite rates are seen to be low primarily in the South and Alaska. Low treatment incidence could be due to a combination of (1) low true incidence, (2) lack of access to health care services, (3) insufficient diagnosis and referral, and (4) patients' reluctance to accept ESRD therapy, due to cultural or personal concerns. A state-level regression of elderly rates on those aged 40 to 64 years indicates the variation in treatment incidence among the elderly may be due to factors other than variation in true incidence, which the middle-aged rates reflect more closely. Residual analysis corroborates the visual impression of the maps of low ESRD treatment incidence in several southern states, where referral to dialysis may be as much as 40% lower than the national level. Further research on factors contributing to low treatment incidence, including competing risks, regional lags relative to the national trend to dialyze more elderly patients, and lack of access to health care resources, is indicated.

Aged↗
PubMed1992

Risk of peritonitis and technique failure by CAPD connection technique: a national study.

Peritonitis has been a leading complication of long-term therapy with continuous ambulatory peritoneal dialysis (CAPD). This study was designed to evaluate the risk of peritonitis and technique failure according to the initial CAPD connection technique. Patients from all U.S. facilities starting CAPD therapy at home between January 1 and June 30, 1989 were followed for up to 21 months on the initial CAPD connection technique to change in technique or dialytic modality, to transplantation, death or loss to follow-up. Patients were grouped into standard connection techniques (SCT) (N = 1,133), Y-set (N = 1,067), standard UV set (N = 916) and O-set (N = 167). The time to first peritonitis episode was analyzed actuarially and by using the Cox proportional hazards model which adjusted for age, sex, race, cause of ESRD, CAPD program size and ESRD therapy prior to CAPD. Peritonitis occurred on average at 9.0 month intervals with SCT, 15.0 months with Y-set, 13.4 with standard UV and 9.4 with O-set. The relative risk (RR by Cox analysis) of first peritonitis compared to SCT was 0.60 (40% lower) for the Y-set (P less than 0.01), 0.75 for standard UV (P less than 0.01), and similar to SCT (RR = 0.96) for the O-set (NS), all else being equal. Analysis time to second (N = 1,271) peritonitis episode gave similar results as did analysis of time to CAPD technique failure. Significantly higher RR of peritonitis and technique failure was observed for younger and black patients. These findings suggest the utilization of connection techniques with superior results.

Adult↗
PubMed1992

Using USRDS generated mortality tables to compare local ESRD mortality rates to national rates.

Mortality tables of the U.S. Renal Data System allow description of national mortality rates among prevalent dialysis patients in five-year age groups and four major categories of causes of ESRD for Black and White patients. Based on these tables derived from over 50,000 deaths in dialysis patients during 1987 to 1989 a methodology is described that allows comparison of local or regional mortality rates to national rates with determination of a standardized mortality ratio and statistical significance. Since this methodology adjusts for patient age, race and cause of ESRD, it can serve as a useful tool for dialysis research and local quality assurance.

Adolescent↗
PubMed1992

Comparison of continuous ambulatory peritoneal dialysis and hemodialysis patient survival with evaluation of trends during the 1980s.

To evaluate the mortality of continuous ambulatory peritoneal dialysis (CAPD) patients relative to hemodialysis (HD) patients, all Michigan residents 20 to 59 yr of age who initiated therapy for ESRD during the 1980s (N = 4,288) were studied. The study population was stratified by primary renal diagnosis (glomerulonephritis, hypertension, diabetes, other), and analyses were conducted within each group by Cox proportional hazards methods controlling for age, race, sex, and year in which chronic dialysis was initiated. Intent-to-treat (ITT) and treatment history (RxHx) censoring criteria were used. For patients with hypertension or other reported causes of ESRD, there was no significant difference in CAPD and HD patient mortality (relative risk (RR) = 0.99 and 1.05, respectively). In the ITT analysis, both glomerulonephritic (RR = 0.73; P = 0.10) and diabetic patients using CAPD experienced mortality rates lower than their HD counterparts. Among diabetics, this difference ranged from a RR of 0.40 to 0.70, being lowest for younger diabetics and statistically significant (P < or = 0.05) for ages 20 to 52 yr. Evaluation of mortality trends showed a significant (P < 0.01) decrease in diabetic CAPD mortality rates during the decade, whereas diabetic HD mortality rates increased (P = 0.06). Among diabetics, men had higher mortality rates than women (ITT--RxHx; RR = 1.22 to 1.27; P < 0.001) and white patients had higher mortality rates than black patients (ITT--RxHx, RR = 1.34 to 1.44; P < 0.001). Differences in mortality by sex and race were not found among nondiabetics, but mortality did increase significantly with age in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

The dose of hemodialysis according to dialysis prescription in Europe and the United States.

Prior research has shown that, controlling for age and diabetes, patients with end-stage renal disease in Europe generally have better rates of survival than do ESRD patients in the U.S. This analysis compares the dose of hemodialysis prescription in the two regions. Based on the European Dialysis and Transplant Association Registry (EDTA), the U.S. Renal Data System (USRDS), and other sources, European and U.S. ESRD patients were compared by demographic and anthropometric characteristics, dialyzer characteristics, and duration of dialysis treatment times. Average body weight and body mass indices were found to be similar for the ESRD populations of the two societies, suggesting the same overall requirements for dialysis therapy. During 1986 to 1988, dialyzers selected in Europe had a larger surface area by at least 20 percent compared to those selected in the U.S. In addition, duration of hemodialysis treatment times were on average 23.5% longer for EDTA patients. Dialyzer blood flows were not available for EDTA patients, but if EDTA blood flows resemble U.S. practices, total urea clearance per week was at least 29% higher in Europe than in the U.S. Combining similar patient characteristics with substantially greater total urea clearance per week, the hemodialysis prescription in Europe was substantially higher than in the U.S. for the time period of this study.

Europe↗
PubMed1992

The end-stage renal disease program: trends over the past 18 years.

Data from the Michigan Kidney Registry and the US Renal Data System (USRDS) show that the number of patients receiving treatment for end-stage renal disease (ESRD) increased sevenfold following the introduction of Medicare coverage for ESRD in 1973. The number of new patients added per year has also increased dramatically--approximately fourfold. Initial selection criteria for acceptance into the ESRD Program included age less than 65 years and absence of systemic diseases such as diabetes. During the past 18 years, the gradual acceptance of older patients and of diabetic patients has led to an increase in the median age of new patients from 46 to 61 years and a 12-fold increase in the incidence of treatment in patients with ESRD due to diabetes. Given the broad acceptance of sicker and older patients, withdrawal from dialysis has become a consideration when dialysis no longer benefits the patient. Treatment modalities have also changed, and increasing numbers of patients undergo successful renal transplantation or receive continuous ambulatory peritoneal dialysis (CAPD). During the 1980s, hemodialysis treatment times and dialysis staffs decreased; however, several improvements in the care of patients on dialysis occurred during this period.

Aged↗
PubMed1991

The impact of nonidentical ABO cadaveric renal transplantation on waiting times and graft survival.

Blood type O recipients of cadaveric renal transplants have longer pretransplant waiting periods than blood type A, B, and AB recipients. To evaluate reasons for and consequences of this discrepancy, we studied both the frequency of various donor and recipient blood type combinations and their outcomes. Among 37,659 cadaveric renal transplants performed during 1983 through 1989, there were 2,625 transplants (7%) received by patients of compatible but nonidentical blood types. Of 18,575 type O donor organs, 16,784 were received by type O patients for a recipient to donor ratio of 0.9. The corresponding ratios were greater than 1.0 for all other blood types (1.02 for blood type A, 1.14 for type B, and 2.18 for type AB). This causes blood type O patients to have a lower access to transplantation and to have significantly longer waiting times than patients of all other blood types. This inequality of access diminished significantly (P less than 0.001) over the years, but did not resolve by 1989. Analysis of relative risk for first graft loss by multiple regression (Cox) showed that transplantation across compatible blood types had a 9.1% higher risk (P less than 0.1) than that of transplantation among identical blood types. Cadaveric renal transplantation within identical blood types optimizes access to transplantation and avoids further aggravating past disadvantages for blood type O recipients.

ABO Blood-Group System↗
PubMed1991

The use of immobilized protamine in removing heparin and preventing protamine-induced complications during extracorporeal blood circulation.

Heparin, currently used in extracorporeal blood circulation procedures, may lead to hemorrhagic complications. Protamine, used for reversal of heparin-induced anticoagulation at the end of such procedures, can cause adverse hemodynamic responses. To prevent both types of complications, we have developed a reactor device containing immobilized protamine (i.e., a protamine bio-reactor) that can be placed at the distal end of the circuit, thus providing simultaneous extracorporeal heparin removal and protamine treatment. In preliminary in vivo studies involving dogs at a blood flow of 100 ml/min, the bio-reactor removed about 50% of the administered dose of heparin (i.e., 100 units/kg) in 10 min. While rapid injection of protamine in dogs anticoagulated with heparin produced a transient and significant (P less than 0.005) decreases in systemic arterial blood pressure (-39.5 +/- 9.2 mmHg), cardiac output (-1.59 +/- 0.23 L/min), and mixed venous oxygen saturation (-7.5 +/- 1.3%) and increases in pulmonary artery systolic (+12.7 +/- 4.4 mmHg) and diastolic pressures (+10.0 +/- 3.6 mmHg), the use of the protamine bio-reactor did not elicit any statistically significant change in any of the variables measured. Hemolysis was not significant, as reflected by a statistically insignificant change of the animals' red blood cell counts, hematocrits, and total hemoglobin values. In addition, hemolytic complement was found to be reduced only by 10% in animals with the protamine bio-reactor, whereas it was reduced rapidly by 20% in animals receiving intravenous protamine administration and progressively by 20% in control animals with a sham reactor that contained no protamine. Furthermore, the use of the protamine bio-reactor also significantly reduced the protamine-induced transient thrombocytopenic and granulocytopenic responses. The white blood cell counts and platelet counts decreased to 87.7 +/- 7.5 and 83.3 +/- 5.0% of baseline, respectively, in dogs with the protamine bio-reactor compared to 35.5 +/- 14.3 and 32.1 +/- 8.1% of baseline in dogs receiving intravenous protamine. The protamine bio-reactor may provide a unique means to simultaneously control both heparin- and protamine-induced complications.

Animals↗
PubMed1991

Geographic variation in the incidence of treated end-stage renal disease.

To facilitate identification of geographic clusters of areas with high or low incidence of treated end-stage renal disease, the 1983 to 1988 incidence by county was studied among whites and nonwhites less than 60 yr of age in the United States. End-stage renal disease incidence counts for 1983 to 1988 were obtained from the United States Renal Data System data base and linked to the 1985 county population obtained from U.S. Census data. Maps were smoothed by the method adopted by the National Cancer Institute that smooths only according to variability of the local rates, ignoring geographic information on clustering of events. In addition to identifying specific counties with exceptionally high or low incidence, geographic patterns were observed with many similarities across whites and nonwhites: notably high rates of disease in areas of the Southwest, the Southeast and in counties with Native American reservations and low rates in the West and Northwest. On the basis of these findings, several hypotheses are presented to explain the observed variation in treated end-stage renal disease incidence rates.

Adult↗
PubMed1991

Comparison of mortality risk by choice of CAPD versus hemodialysis among elderly patients.

To evaluate patient survival among geriatric patients by dialytic treatment of choice we assigned all patients aged 65 years and older treated in Michigan to either CAPD at home or center hemodialysis (HD) according to the treatment used on day 120 of ESRD therapy. Michigan Kidney Registry files on all 308 CAPD and 1244 HD patients who started ESRD therapy during 1980-1987 were used for this study. The Cox proportional hazards model revealed a significantly increased relative death rate (RR) for patients with diabetes (RR = 1.91, p less than 0.001) and hypertension (RR 1.4, p less than 0.01) as cause of ESRD when adjusting for age, sex, race, treatment and year of incidence. White patients had a 51% higher relative death rate overall when compared to black patients (p less than 0.001) and specifically among hypertensive (RR = 1.65, p less than 0.001) and diabetic patients (RR = 1.59, p less than 0.001). Those differences were still significant when taking higher rates of withdrawal from dialysis among white patients into account. The relative death rates for CAPD patients was essentially the same as for HD patients overall, however, diabetic CAPD patients appeared to have a higher than diabetic HD patients (RR = 1.58, p = 0.1). This statistically not significant difference may be related to selection of patients with cardiovascular risk into CAPD. There was no trend in mortality over time. By modality on day 120, CAPD has similar outcomes as HD in geriatric non diabetic patients.

Age Factors↗
PubMed1990

A comparison of survival among dialytic therapies of choice: in-center hemodialysis versus continuous ambulatory peritoneal dialysis at home.

Analyses were performed on a series of 2,754 dialysis patients between the ages of 20 and 60 years whose end-stage renal disease (ESRD) therapy started in Michigan from 1980 through 1987 with the selection of either center hemodialysis (CH) or continuous ambulatory peritoneal dialysis (CAPD). The dialytic treatment at 6 months after first ESRD therapy was selected as the dialytic "treatment of choice" for each patient. Analyses of subsequent survival showed lower death rates for black patients than for white patients with hypertension (P less than 0.01) and diabetes (P less than 0.01). Death rates increased with patient age more dramatically among glomerulonephritis patients than among the other diagnostic groups (P less than 0.05). Females had significantly lower death rates than did males among diabetic patients (P less than 0.01). While no significant difference was found in average death rates between CH and CAPD (NS), there was a significant difference (P less than 0.05) in the trend in death rates. Death rates among CH patients increased significantly (P less than 0.001) during the study period, whereas death rates among CAPD patients have improved slightly (NS).

Adult↗
PubMed1990

Five-year survival for end-stage renal disease patients in the United States, Europe, and Japan, 1982 to 1987.

We compared the 5-year survival for new end-stage renal disease (ESRD) patients accepted for renal replacement therapy (RRT) between 1982 and 1987 in the United States (n = 150,862), Europe (European Dialysis and Transplant Association [EDTA]) (n = 124,796), and Japan (n = 66,244). Given these large samples that approach a census in each of the three regions, all results are statistically significant. Our analysis showed that the US patients were older and more likely to be diabetic than the patients in either EDTA or Japan. After correction for patient differences in age composition and the percent diabetic, Japan had the highest survival, followed by EDTA, and then the US. Overall, the US 5-year survival was 40%. When comparison is done by age, only the youngest patients in the US (less than 15 years) have longer survival than their counterparts in Europe and Japan. For ages greater than 14 years, the survival differences between the US and EDTA and between the US and Japan grow larger with higher patient age. The comparisons of mortality by diagnosis showed that the differences between the US and EDTA and between the US and Japan were least for diabetes. For non-diabetic patients, the age adjusted relative risk (RR) of mortality for the US compared with EDTA was 1.22, ie, 22% higher in the US; for the US compared with Japan, the RR was 1.40. In contrast, the RR for diabetic patients in the US compared with EDTA was 1.07, and 1.23 for the US compared with Japan.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Recovery from end-stage renal disease.

To evaluate the rate and associated factors for recovery of renal function in patients labeled by their nephrologists as having end-stage renal disease (ESRD), the data base of the Michigan Kidney Registry was used. All patients reported as starting treatment for ESRD between 1976 and 1985 (N = 7,404) were evaluated, excluding patients with acute tubular necrosis (ATN) or transplantation cases. While patients with ESRD due to diabetes and cystic diseases had lower recovery rates than average, patients with glomerulonephritis associated with a systemic illness, vasculopathies, and crescents had threefold to fourfold higher recovery rates. White race, older age, and later year of ESRD were associated with significantly higher recovery rates. Recovery rates did not differ substantially for patients receiving peritoneal dialysis or hemodialysis. Recovery occurred within 6 months of ESRD in approximately 48% of those recovering, 74% within 1 year, and lasted at least 1 year in 75% of the cases. The authors conclude that caution should be applied when the diagnosis of ESRD is made; the possibility of recovery should be sought and assessed, especially when early renal transplantation is considered.

Actuarial Analysis↗
PubMed1990

Mortality and causes of death in patients with end-stage renal failure.

Using data from the Michigan Kidney Registry, the survival of patients with end-stage renal disease (ESRD) was evaluated by multivariate analysis. Black patients had a significantly better outcome overall. A significantly worse outcome was found for older patients and diabetics, among both races and for black females. Causes of death were analyzed for dialysis patients and specific comments address discontinuation of dialysis leading to death.

Adult↗
PubMed1990

A prospective controlled trial of cold-storage versus machine-perfusion preservation in cadaveric renal transplantation.

A prospective controlled study was carried out in 60 consecutive cadaver renal donors comparing cold storage to pulsatile machine-perfusion preservation. Each donor served as its own control, by allocating one of the kidneys to each of the two preservation methods. There were 51 evaluable pairs of kidneys. Recipient age, panel-reactive antibody level, history of prior renal transplant, and immunosuppressive regimen were similar in the two preservation groups. Almost all recipients were treated with cyclosporine, and over 50% received antilymphoblast globulin. Total cold ischemic time was 1262 +/- 387 min in the machine-perfused group and 1309 +/- 426 min in the cold-storage group (P = NS). Prolonged ischemia (greater than 24 hr) occurred in 31% of machine-perfused and 22% of cold-stored kidneys (P = NS). Post-operative serum creatinine levels at 1, 7, and 30 days posttransplant were similar in both groups. Dialysis requirements were also similar, with 21 recipients of machine-perfused kidneys (41%) requiring at least one dialysis treatment compared to 16 patients (31%) in the cold-stored group (P = NS); the mean number of dialysis treatments required was 3.14 +/- 1.46 and 3.06 +/- 1.29, respectively (P = NS). Long ischemic time (greater than 24 hr) was associated with a higher rate of dialysis requirement in both groups, but in neither case did this achieve statistical significance. The distribution of graft losses within the first 30 days was similar in both groups, and the incidence of preservation-related graft failure was not significantly different. These results demonstrate that, in the cyclosporine era, machine perfusion offers no significant advantages over cold storage for cadaver renal preservation. Because machine perfusion is considerably more expensive and cold storage is simpler and facilitates the logistics of organ sharing, we recommend simple hypothermic storage of renal allografts as the preservation method of choice.

Analysis of Variance↗
PubMed1990

Solvent nephrotoxicity in humans and experimental animals.

Evidence from human case reports, epidemiologic studies and animal experiments have suggested that exposure to organic solvents is associated with a wide spectrum of renal disorders, including tubular necrosis, interstitial disease, glomerulonephritis and neoplasia. This review summarizes what is known about solvent-induced renal damage in humans and experimental animals, with emphasis on hypothesized mechanisms by which this broad range of disorders may occur.

Animals↗