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Biomedical subjects

F K Port

Publications and source records attributed to F K Port.

At least 109 records · Page 6Linked to original sources
PubMed1994

Causes of death in dialysis patients: racial and gender differences.

The risk of death in the dialysis population is high and has previously been shown to be accentuated in male (versus female) and white (versus black) subgroups. To better understand the difference in mortality among these subgroups, the causes of death between males and females as well as between whites and blacks adjusting for age, cause of ESRD (diabetic versus nondiabetic), dialysis modality, and time on dialysis (< 1 yr versus > 1 yr) were compared, with national data obtained from the U.S. Renal Data System. A total of 42,372 deaths occurring over 170,700 patient years at risk were analyzed. Males had a 22% higher risk of death than females (P < 0.001), attributable to a higher risk of death due to acute myocardial infarction (relative death rate ratio (RR) = 1.48; P = 0.001), all other cardiac causes (RR = 1.3; P = 0.001), and malignancy (RR = 1.59; P < 0.001). Whites had a 29% higher risk of death than blacks (P < 0.001), accounted for by an increased risk of death due to acute myocardial infarction (RR = 1.34), all other cardiac causes (RR = 1.30), withdrawal from dialysis (RR = 2.72) (all P < 0.001), and infection (RR = 1.09; P = 0.005). This analysis expands the knowledge and understanding of the excess mortality seen in male and white subgroups, which is a necessary step in designing strategies to reduce the high mortality in dialysis patients.

Black or African American↗
PubMed1994

Mortality after fracture of the hip in patients who have end-stage renal disease.

Thirteen fractures of the hip in twelve patients who had end-stage renal disease were treated over a ten-year period; these injuries included one intertrochanteric fracture, seven non-displaced fractures of the femoral neck, and five displaced fractures of the femoral neck. Twelve of the thirteen fractures were treated with an operation. Six patients (who had a total of six fractures) died within one year after the fracture. Two patients died as the result of sepsis related to the wound; the other four deaths were not directly related to the operation. Although the mortality rate in this group of patients was higher than that in a group of matched patients who had a fracture of the hip but who did not have end-stage renal disease, we were not able to demonstrate that this difference was significant, perhaps because of the small size of the sample. The mortality rate in these twelve patients was significantly higher, however, than that in matched patients who had end-stage renal disease but who did not have a fracture of the hip (p = 0.01).

Adult↗
PubMed1994

Differences in survival between black and white patients with diabetic end-stage renal disease.

OBJECTIVE: To evaluate whether the longer survival of blacks with diabetic end-stage renal disease (ESRD) relative to whites is due to racial differences in type of diabetes, comorbidity at ESRD onset, and ESRD treatment modality and to examine whether survival differences between blacks and whites occur only in certain population subgroups. RESEARCH DESIGN AND METHODS: The Michigan Kidney Registry was used to ascertain all blacks and whites (n = 594) with diabetic ESRD in southeastern Michigan, with ESRD onset at age < 65 years during 1974-1983. Patients were followed through 1988. Medical records were abstracted for type of diabetes, comorbidity at ESRD onset, and other factors. RESULTS: Median survival among insulin-dependent diabetes mellitus patients was 27 months in blacks and 17 months in whites, and among non-insulin-dependent diabetes mellitus patients was 30 months in blacks and 16 months in whites. After adjustment for confounding factors by Cox proportional hazards analysis, the death rate was 45% lower in blacks than in whites on dialysis (relative death rate [RDR] = 0.55, 95% confidence interval [CI] = 0.44-0.69), but was similar in blacks and whites with a renal transplant (RDR = 0.99, 95% CI = 0.64-1.52). Compared with dialysis, transplantation was associated with lower mortality in both races (white, RDR = 0.50, 95% CI = 0.36-0.70; blacks, RDR = 0.89, 95% CI = 0.60-1.34), although the effect was not statistically significant in blacks. Racial differences in survival did not vary by type of diabetes or any additional factor. CONCLUSIONS: Survival after ESRD onset is longer in blacks than in whites treated with dialysis, even after adjusting for comorbidity and other factors that affect survival. Survival does not differ by race among transplant patients.

Adolescent↗
PubMed1993

Comparison of survival probabilities for dialysis patients vs cadaveric renal transplant recipients.

OBJECTIVE: To compare mortality risk among cadaveric renal transplant recipients vs transplant candidates on dialysis in the cyclosporine era. SETTING: Patient mortality risk was analyzed by treatment modality for a completed statewide patient population. PATIENTS: All Michigan residents younger than age 65 years who started endstage renal disease (ESRD) therapy between January 1, 1984, and December 31, 1989, were included. Patients were followed up from ESRD onset (n = 5020), to wait-listing for renal transplant (n = 1569), to receiving a cadaveric first transplant (n = 799), and to December 31, 1989. MAIN OUTCOME MEASURE: Mortality rates. RESULTS: Using a time-dependent variable based on the waiting time from date of wait-listing to transplantation and adjusting for age, sex, race, and primary cause of ESRD, the relative risk (RR) of dying was increased early after transplantation and then decreased to a beneficial long-term effect, given survival to 365 days after transplantation (RR, 0.36; P < .001). This lower long-term risk was most pronounced (RR, 0.25) among diabetic transplant recipients compared with diabetic wait-listed dialysis patients (P < .001) and not observed among patients with glomerulonephritis as cause of ESRD (P > .05). Overall, the estimated times from transplantation to equal mortality risk was 117 +/- 28 days and to equal cumulative mortality was 325 +/- 91 days. CONCLUSIONS: The overall mortality risk following renal transplantation was initially increased, but there was a long-term survival benefit compared with similar patients on dialysis. These analyses allow improved description of comparative mortality risks for dialysis and transplant patients and allow advising patients regarding comparative survival outcomes.

Cadaver↗
PubMed1993

The impact of comorbid and sociodemographic factors on access to renal transplantation.

OBJECTIVE: To assess the impact of sociodemographic factors and comorbid conditions on access to renal transplantation for adult US dialysis patients with end-stage renal disease (ESRD). DESIGN: Cohort analytic study. Data on comorbid conditions at onset of ESRD were abstracted from patients' medical records and matched to sociodemographic and ESRD data from the United States Renal Data System database. SETTING: United States Medicare dialysis population. PATIENTS: Random, national sample of ESRD patients starting dialysis in 1986 and 1987 (n = 4118). MAIN OUTCOME MEASURE: Time to first renal transplant (living or cadaver donor) since onset of ESRD regressed with two nested Cox proportional hazards models, first against sociodemographic factors alone, and then against sociodemographic factors and comorbid conditions. RESULTS: Cardiovascular diseases are most predictive of who received a transplant; patients with coronary heart disease, congestive heart failure, or left ventricular hypertrophy showed lower transplantation rates relative to patients without the disease (relative rate [RR] = 0.65 to 0.80, P < .05 each). Obese patients and patients with peripheral vascular disease also showed lower transplantation rates (RR = 0.65 to 0.75, P < .05 each). Previously reported sociodemographic effects of lower transplantation rates for older patients, women, nonwhite patients, and lower income patients were confirmed (P < .01). Sociodemographic effects remained essentially unchanged when adjusted for comorbid conditions. CONCLUSIONS: These findings indicate that sociodemographics have strong independent effects on access to transplantation that cannot be explained away as "surrogate" effects related to comorbid factors. Furthermore, the results suggest that lower mortality rates for transplant recipients relative to dialysis patients are due, in part, to a healthier case mix among patients receiving transplants.

Adult↗
PubMed1993

Influence of race and gender on related donor renal transplantation rates.

Racial differences in kidney transplantation have received recent attention both in the medical community and in the general public. Most efforts to improve renal transplantation among minority groups have been directed toward cadaveric donation and transplantation. Since evaluation of the comparative trends by race of living related donor (LRD) kidney transplantation have been lacking, we examined trends of LRD transplantation from 1983 through 1990 using national data from the US Renal Data System. The total number of LRDs in blacks did not change during the 8-year period between 1983 and 1990 (198 in 1983 and 197 in 1990). During this same period, the total number of LRDs in whites increased by 11% (1,390 in 1983 and 1,548 in 1990). Rates of LRD transplantation per nontransplanted dialysis patients were consistently lower in blacks and females compared with whites and males, respectively. White males have a fivefold higher rate of LRD transplantation than black males, whereas white females have a fourfold higher rate then black females. When intraracial gender differences were examined, black males were transplanted with LRD kidneys at a rate 20% higher than black females. This difference was present between 1983 and 1989, but was nonexistent in 1990. Among whites, males also had a higher rate of LRD transplantation than females, which gradually decreased from 34% in 1983 to 20% in 1990. In view of the ever-increasing demand for cadaver organs, additional effort in the medical community and society toward increasing LRD transplantation rates represents a more promising approach to increasing organ donation in all groups than a single focus on cadaveric donation.(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1993

An estimate of the size of the US predialysis population with renal insufficiency and anemia.

With the development of recombinant human erythropoietin, clinicians can now treat the anemia of chronic renal failure patients. Although most attention has focused on patients with end-stage renal disease, erythropoietin is also prescribed to anemic renal patients before the initiation of dialysis therapy. This study presents the first objective estimate of the size of the US population with predialysis renal insufficiency and the fraction of those patients who also have anemia. The study used population-based data from the second National Health Nutrition Examination Survey (NHANES II), conducted between 1976 and 1980. Participants underwent interviews, standardized physical examinations, and blood testing, including hematocrit and serum creatinine (N = 25,286 who were surveyed, 10,453 who underwent laboratory testing). Our estimates were based on the following methodology: (1) selecting predialysis renal insufficiency patients aged 12 to 74 years from the NHANES II survey, (2) adjusting for population changes between 1978 and 1988, (3) adding estimates for pediatric and geriatric populations, (4) projecting results to 1990, and (5) excluding nonanemic patients. The NHANES II survey included 44 patients with serum creatinine values greater than 2.0 mg/dL and less than 8.0 mg/dL. This yielded an estimate of 648,000 to 708,000 persons in 1990 with predialysis renal insufficiency. Data from both the NHANES II survey and the literature demonstrate that the percent of patients with anemia varies by serum creatinine level. All total, the study estimated that in 1990 there were between 68,000 and 75,000 individuals with predialysis renal insufficiency who also had anemia. However, several limitations of the methodology suggest that these values overestimate the true population numbers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

The excess risk of treated end-stage renal disease in blacks in the United States.

Analysis of national data from the United States Renal Data System for 1988 revealed an important joint effect of age and race in determining the higher risk of ESRD for blacks as compared with whites. For adults, both hypertension and diabetes made important contributions to the combined effect of age and race. In contrast, glomerulonephritis was not considered to be an important contributor to this joint effect. The combined effect of gender and race was weaker than that of age and race; however, among blacks, differences in the proportions of ESRD attributed to hypertension and diabetes across gender were observed. The age-race joint effect is consistent with the hypothesis that a combined effect of lack of treatment and aging on the process that leads to ESRD may play an important role in the excess risk for ESRD among blacks.

Adolescent↗
PubMed1993

Worldwide demographics and future trends in end-stage renal disease.

Dialysis market estimates indicate that over 400,000 patients worldwide were treated with maintenance dialysis. The United States, Europe and Japan have nearly 80% of these patients. This overview examines trends in the observed incidence of treated ESRD, describes international comparisons of utilization of treatment modalities and discusses future trends.

Demography↗
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↗