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Biomedical subjects

E J Macon

Publications and source records attributed to E J Macon.

13 recordsLinked to original sources
PubMed1997

Safety and efficacy of low-dose subcutaneous erythropoietin in hemodialysis patients.

Anemia in hemodialysis patients is effectively treated by intravenous (IV) injections of recombinant human erythropoietin (rHuEPO) at each dialysis session. Because the hormone is effective by subcutaneous (SC) administration, it was decided that this study would evaluate low-dose weekly SC rHuEPO therapy. To determine the safety and efficacy of weekly SC rHuEPO administration to hemodialysis patients, only one third the weekly IV dose was given and the effects were compared with those from an age-, gender-, and nephrologic disease-matched control group treated in the standard fashion. Forty-four patients entered the trial and 27 completed the protocol along with 27 control subjects. During Phase 1, experimental and control subjects received standard IV rHuEPO at dialysis for 6 months. During Phase 2, experimental patients received weekly SC rHuEPO at one third the weekly IV dose for 10 months; control subjects continued to receive IV therapy. In Phase 3, both groups were treated for 6 more months with IV rHuEPO. In Phase 2, there was no significant reduction in hematocrit value, reticulocyte count, transferrin saturation, or ferritin level in the experimental group, even with only one third the weekly rHuEPO IV dose over the 10-month period. There were no significant differences between IV and SC rHuEPO administration or between experimental and control subjects in blood pressure, serum chemistries, or parameters of "dialysis adequacy." It was concluded that low-dose weekly SC rHuEPO administration is a safe and effective method for maintaining the hematocrit level of stable hemodialysis patients. This therapy could enhance the efficacy of rHuEPO and substantially reduce costs while preserving patient care outcomes.

Anemia↗
PubMed1995

Dialysis survival in a large inner-city facility: a comparison to national rates.

Impoverished patients may represent a high-risk population with poor survival. With 1993 U.S. Renal Data System survival tables (to adjust the risk of death for differences in age, race, and ESRD diagnosis), the mortality rates of patients over 3 yr in a large inner-city dialysis facility using high-flux technique were compared with national averages. At least 93.7% of patients were African-American, 50% had incomes below $7,000 per year, and employment was 5% or less. Observed and expected deaths (the latter derived from the U.S. Renal Data System tables) were used to calculate a standardized mortality ratio (observed deaths/expected deaths); the U.S. average is 1.0. The standardized mortality ratio at this facility for each year was < 0.600 and was significantly lower than the U.S. average in 1991, in 1992 (P < 0.05), and for all 3 yr (P < .001). Over all 3 yr, it was lower for females (0.540, P < 0.05), males (0.620, P < 0.05), patients with diabetes (0.593, P < 0.05), and glomerulonephritis (0.318, P < 0.05). For the 3 yr, a Cox regression analysis revealed independent associations between mortality and age (P = 0.004), serum albumin (P = 0.02), Kt/V (P = 0.02), and dialysis for more than 2 yr (P = 0.01). Patients with economic hardship can attain survival significantly better than the national average with the provision of adequate dialysis, nutrition, and support services.

Adult↗
PubMed1992

The effects of calcium carbonate as the sole phosphate binder in combination with low calcium dialysate and calcitriol therapy in chronic hemodialysis patients.

Alternative phosphate binders, such as CaCO3, have been shown to be effective in the control of phosphate (P) retention in hemodialysis patients (HDP). Additionally, both oral (POC) and iv (IVC) calcitriol are purported to be of benefit in the control of secondary hyperparathyroidism. This investigation was undertaken to determine: (1) the effectiveness of CaCO3 as the sole P binder in combination with low (2.5 mEq/L) Ca dialysate; (2) the effects of discontinuing Al(OH)3 binders on both unstimulated and stimulated Al concentrations; and (3) the comparative parathyroid hormone (PTH) response to both POC and IVC in a large group of hemodialysis patients. One hundred ninety-four HDP completed part 1 of the study where CaCO3 was substituted for Al(OH)3 as the sole P binder for 6 months. A cohort of 49 HDP was given desferoximine (40 mg/kg) initially and 10 months after using CaCO3. In part 2, 54 HDP were given POC and 97 HDP were given IVC in dosages of 0.25 to 0.5 micrograms/day and 1.5 to 6.0 micrograms/wk, respectively, for an additional 6 months. In part 1, Ca and P were not different from baseline values observed with Al(OH)3 therapy. Ionized Ca increased (P < 0.05) and PTH decreased (P < 0.001) during CaCO3 therapy without vitamin D. In part 2, PTH declined 23% with IVC and was unchanged with POC in equivalent dosages (P < 0.05) at 3 months. By 6 months, PTH declined a total of 54% with IVC and was unchanged with POC. Ca, ionized Ca, P, and serum calcitriol were greater (P < 0.05) in the IVC group at 6 months. Serum Al concentrations for the entire 194 HDP fell 65% (P < 0.0001) over 12 months. In the 49 HDP cohort, serum Al fell 43.6% (P < 0.001) and stimulated Al concentrations decreased 68.7% (P < 0.0001) after 10 months. We conclude that: (1) CaCO3 is as effective as Al(OH)3 in controlling P, (2) a small decrease in PTH is observed with CaCO3 alone, (3) serologic evidence of Al excess is virtually eliminated, (4) PTH suppression with IVC is superior to that seen with POC in equivalent doses.

Alkaline Phosphatase↗
PubMed1988

Complications with permanent peritoneal dialysis catheters: experience with 154 percutaneously placed catheters.

A prospective study evaluated the complications in 154 patients in whom a permanent peritoneal dialysis catheter was inserted percutaneously from April 1982 to June 1986. Obstruction to flow and fluid leakage occurred in 9.2 and 2.6% of the catheters, respectively. Catheter survival was 64.6 and 48.6% at 1- and 2-year follow-up, respectively. The complication rates and survival of percutaneously placed catheters was comparable to those reported for surgically placed catheters. Percutaneous insertion of Tenckhoff catheters is a viable alternative to using the surgical technique.

Catheters, Indwelling↗
PubMed1986

Prolonged hypotension after initial minoxidil dose.

Severe prolonged hypotension developed in a hypertensive patient several hours after the initial doses of minoxidil therapy. Hemodynamic measurements revealed a markedly low systemic vascular resistance and a markedly high cardiac output. Other causes of hypotension were ruled out. The patient's hemodynamic abnormalities lasted three days after minoxidil therapy was discontinued, and she then reverted to hypertension. Thus, a 10-mg starting dose of minoxidil may produce profound life-threatening hypotension, which can last up to 72 hours.

Cardiac Output↗
PubMed1981

Increasing the supply of cadaveric kidneys for transplantation.

The number of cadaveric kidneys currently available for transplantation is insufficient. Therefore, the Center for Disease Control (CDC) undertook a collaborative project with the two transplant programs in Georgia to increase te retrieval of cadaveric kidneys. We used retrospective analysis to select productive hospitals, hospital-specific surveillance systems to identify potential donors, and procurement and retrieval evaluation to identify preventable deficiencies. During 900 hospital months of prospective surveillance, we identified a total of 555 potential donors by death record review, giving a potential donor rate of 2.3 donors/100 deaths (110 kidneys/million population/year). We observed an increase in the number of referrals, consent obtained from next of kin, and kidneys retrieved. This period of intensive activity demonstrated that additional kidneys can be retrieved by using systematic methods.

Adolescent↗
PubMed1981

Cadaveric kidneys for transplantation. A paradox of shortage in the face of plenty.

The number of cadaveric kidneys currently available for transplantation is insufficient; therefore, the Center for Disease Control (CDC) undertook a collaborative pilot project to increase the number of cadaveric kidneys available for transplantation. In phase one, a retrospective review of medical records of in-hospital deaths was done to determine the potential number of cadaveric kidney donors and to define the characteristics of potential donors. The medical records of 10,420 (43.1%) of the 24,164 patients who died in 67 acute-care hospitals in Georgia, Kansas, and Missouri were retrieved. In addition to determining suitability for donorship, criteria were developed to reflect the broadest range of criteria in use. By center-specific criteria there were 1.7 potential donors/100 in-hospital deaths, which could make available 109 kidneys/million population. By broad intercenter criteria there were 3.5 potential donors/100 in-hospital deaths, which could provide 232 kidneys/million population. During 1975, by center-specific criteria, kidneys from 19.3% of the suitable potential donors were retrieved. The small number of transplantable cadaveric kidneys retrieved was not attributable to lack of suitable organs but rather the failure to identify suitable donors, obtain consent, and retrieve the kidneys.

Adolescent↗
PubMed1978

Ultrasonographic evaluation of vascular access complications.

In 24 patients, sonograms were obtained of 25 vascular accesses, 16 of which were bovine grafts, 7 arteriovenous fistulae, 1 a polytetrafluoroethylene graft, and 1 an external Silastic shunt. On the sonograms, the lumen, course, and insertions of the vascular grafts and fistulae were outlined, anterior and posterior aneurysms demonstrated, hematomas differentiated from aneurysms, and intrinsic distinguished from extrinsic lesions. The authors conclude ultrasonography is a valuable adjunct to clinical evaluation in assessing certain complications of vascular access.

Adult↗
PubMed1976

Hemodialysis-associated hepatitis: report of an epidemic with further evidence on mechanisms of transmission.

In the period January-September 1974, 50 cases of hepatitis B infection occurred among a nephrology center's hemodialysis patients and staff. The in-center patient population had an attack rate of 96%. Epidemiologic analysis of risk factors for patients revealed an association between the receipt of intravenous medication and the subsequent development of hepatitis, suggesting that parenteral inoculation was a mode of spread among patients (p equals .008). Nineteen per cent of the staff contracted hepatitis, and all of these personnel had had close contact with patients (p equals .005). The prevalence of hepatitis B infection in staff was related to the failure to use gloves (p less than .01), and accidental needle puncture was associated with the development of clinical hepatitis. These data suggested that disease was transmitted to staff by contact with contaminated blood or close personal contact with patients. Additional data showed that the presence of endogenous antibody protected both patients and staff from antigenemia (p equals .002). These data support the hypothesis that contact with blood is the primary mechanism of spread of hepatitis B in dialysis units, and suggest that, as preventive measures, gloves should be used and antibody-positive staff should dialyze antigen-positive patients.

Antibodies, Viral↗