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Biomedical subjects

R K Ausman

Publications and source records attributed to R K Ausman.

At least 19 recordsLinked to original sources
PubMed1992

The substance abuser and home intravenous therapy: above all else, do no harm.

Home care therapy is being challenged by changes in patient populations and technologic advances. The selection of appropriate candidates for home intravenous therapy is a critical issue faced by health care professionals. This process is more complex when the patient has a history of intravenous drug abuse. The issues concern patient compliance, safety, ethics, and legal responsibilities. Safe care depends on the ability of the patient to demonstrate a predetermined level of competence with catheter use. The potential use of illicit drugs may influence the ability of the patient to be compliant. Ethical principles of the patient's autonomy and free choice are weighed against the health professional's sense of beneficence. Legal guidelines stress informed consent, standards of care, and adequate documentation. An exploration of each of these factors outlines the potential risks and benefits and provides a basis for making clinical judgments.

Ethics, Medical↗
PubMed1991

Effect of individualized pharmacokinetic dosing on patient outcome.

OBJECTIVE: To study the effect of individualized pharmacokinetic dosing of aminoglycosides on patient outcome. DESIGN: Prospective, randomized study. SETTING: Tertiary care hospital. PATIENTS: Ninety-five patients with documented Gram-negative infections received 97 courses of aminoglycoside therapy. INTERVENTIONS: Patients were randomized between pharmacokinetic dose adjustment and monitoring or traditional physician-directed techniques. Patients were stratified by severity of underlying illness before randomization. MEASUREMENT AND MAIN RESULTS: Sixty-two courses of treatment were satisfactorily completed. Patients in the severely ill group (eight kinetic, eight traditional) had significantly (p less than .05) better survival (7 kinetic, 3 traditional) when managed with pharmacokinetic consultation. The kinetic arm received greater doses (156 +/- 59 mg/dose; 2.4 +/- 0.6 mg/kg) than the traditional arm (81 +/- 27 mg/dose; 1.5 +/- 0.6 mg/kg) (p less than .001). In addition, the dose per day (mg/kg) was greater in the kinetic arm (4.1 +/- 1.5) than the traditional arm (3.2 +/- 1.3) (p less than .001). The improved survival was achieved by attaining therapeutic peak serum concentrations earlier in the course of the infection and by administering more total aminoglycoside without increasing toxicity. CONCLUSIONS: We conclude that pharmacokinetic management of aminoglycoside dosing may improve the outcome of severely ill patients.

Adolescent↗
PubMed1990

Gastric secretion pH measurement: what you see is not what you get!

We evaluated the accuracy of gastric secretion pH measurements as performed in three ICUs. The pH of 275 samples was measured with pH paper using established techniques. The pH of 85 additional samples was determined with a hand-held pH meter. All specimens also were measured using a research laboratory pH meter to learn the true pH. Analyses included mean and SD of the difference between the two measurements, the correlation coefficient (r value), and the concordance correlation coefficient. The pH meter values disagreed significantly with pH paper measurements. Measurements of gastric secretion pH with pH indicator paper do not guide therapy reliably. Inaccurate values derived from pH paper measurements could have resulted in inappropriate treatment in 28% of the samples tested. A portable, battery-powered pH meter accurately reproduced laboratory pH meter measurements and is a reasonable device for clinical use.

Gastric Acidity Determination↗
PubMed1989

Per capita income in breast cancer patients.

The Wisconsin Department of Health and Human Services has identified breast cancer as the most common malignant neoplasm among women in Wisconsin. To determine the potential effectiveness of a program of low-cost screening mammography in reducing cancer morbidity and mortality in individuals of low socioeconomic status, the authors conducted a retrospective analysis of data from tumor registries. Using the tumor registries of two hospitals in Milwaukee, Wisconsin, the records of 323 patients with breast cancer were identified and analyzed for size of tumor at first presentation. These data were correlated with per capita income taken from census block information for the residence of each patient. The data indicate that mean income was lower for patients with more advanced disease. Other variables such as race did not influence tumor classification at initial presentation. Economically disadvantaged women present with more advanced breast cancers than affluent patients. This adverse circumstance may be the result of lack of financial resources and poor dissemination of information. Programs that recognize these problems are likely to be more successful in achieving earlier breast cancer detection.

Breast Neoplasms↗
PubMed1988

Prospective comparison of traditional and pharmacokinetic aminoglycoside dosing methods.

Aminoglycoside (gentamicin, tobramycin) dosage regimens and subsequent serum concentrations were compared in 30 patients treated initially using traditional physician-determined methods and then switched to a pharmacokinetic-based treatment program. Patients received more drug during the kinetic phase (median 5 mg/kg) than during the traditional phase (median 3.6 mg/kg) and achieved greater peak serum concentration (5.9 vs. 4.4 micrograms/ml). Seventy-three percent of kinetic peak values but only 27% of traditional peak values exceeded 5.0 micrograms/ml. Trough concentrations were comparable in both phases of study and no nephrotoxicity was observed. This pharmacokinetic-based management program achieved more consistently greater therapeutic peak concentrations and provided more individualized therapy than did physicians. The use of pharmacokinetic consultants may be of benefit in administering safely optimal aminoglycoside therapy.

Gentamicins↗
PubMed1986

Epidural morphine by continuous infusion with an external pump for pain management in oncology patients.

Ten patients with advanced malignancies and severe pain were given epidural morphine (EDM) by continuous infusion. The pain had been treated previously with large doses of oral or parenteral narcotics, without success. The pain was disabling in all the cases. The total dose of morphine administered was 10-90 mg per day; median dose was 25 mg. Treatment lasted from 9 to 400 days. Pain relief was complete in seven patients, near complete in two, and moderate in one. Five patients became fully ambulatory. Two patients were treated as outpatients and resumed work activities. No central nervous system or gastrointestinal adverse effects, respiratory depression, or pruritus were noted. One patient developed urinary retention. EDM by continuous infusion produced constant pain relief for prolonged periods. This technique is safe for analgesia in oncology patients and suited for outpatient management.

Aged↗
PubMed1985

A quality control analysis of aminoglycoside management.

Aminoglycoside administration practices were evaluated in a teaching hospital using three study methods: a chart review of 40 randomly selected patients receiving aminoglycosides was conducted retrospectively; 93 health care personnel involved in ordering and administering aminoglycosides to patients were interviewed regarding their understanding of aminoglycoside utilization practices; and ten patients having serum peak and trough aminoglycoside determinations were closely monitored for accuracy of dose administration and obtaining blood specimens at appropriate times. The chart review showed that during 15 of 32 evaluable therapy courses no determinations of serum aminoglycoside concentration were obtained. The survey demonstrated that only 24% of the residents actually used the results of peak and trough determinations to adjust dosage regimens. Direct observation of health care personnel disclosed only two of ten instances in which doses were administered and serum concentration specimens obtained with no apparent problems. Most personnel in our hospital were unaware of these pervasive suboptimal or inconsistent practices associated with aminoglycoside administration and interpretation of laboratory results.

Aminoglycosides↗
PubMed1985

Long-term, ambulatory, continuous IV infusion of 5-FU for the treatment of advanced adenocarcinomas.

Twenty-three patients with metastatic adenocarcinomas were treated with long-term, continuous, ambulatory iv infusion of 5-FU. Length of infusion ranged from 54 to 324 days. The usual daily dose was 300 mg/m2. Toxicity was primarily stomatitis. Hand/foot syndrome occurred in 11 patients. Nausea, vomiting, myelosuppression, and alopecia were not observed. Thirteen patients had stomatitis. Eighteen patients had evaluable lesions; eight achieved partial response, five had stable disease, and five had progressive disease. Further studies are necessary to confirm the level of tumor response and survival period of patients treated with this method.

Adenocarcinoma↗
PubMed1985

Stability of mitomycin admixtures.

The stability of mitomycin in admixtures for continuous intravenous infusion was studied. Mitomycin was reconstituted and diluted to 50 micrograms/mL in polyvinyl chloride minibags containing 5% dextrose injection 50 mL or 0.9% sodium chloride injection 50 mL. Additional mitomycin admixtures were reconstituted with a buffer solution containing monobasic and dibasic sodium phosphate; these were diluted with 5% dextrose injection only. Admixtures were stored at room temperature (27-30 degrees C) and refrigerated temperature (5 degrees C) for 120 days. Mitomycin concentrations in each admixture were tested by high-performance liquid chromatography (HPLC) immediately after admixture and at intervals during storage. Ultraviolet spectra were determined at the same time as HPLC analysis, and the admixtures were visually inspected and tested for pH. Mitomycin concentrations decreased rapidly in the unbuffered admixtures; after 12 hours at room temperature, less than 26% of the drug remained in the dextrose admixture. When the unbuffered admixtures were refrigerated for 12 hours, the mitomycin concentrations decreased 10% in the sodium chloride admixtures and 33% in the dextrose admixtures; after 24 hours, the percentages of drug loss were 23% and 42%, respectively. Mitomycin concentrations in the buffered admixtures showed no substantial decrease during 120 days at 5 degrees C. At room temperature, concentrations decreased 10% after 15 days. When the admixture is buffered to a pH of approximately 7.8, mitomycin is stable in 5% dextrose injection for up to 15 days at room temperature and at least 120 days at 5 degrees C. Unbuffered mitomycin admixtures should not be stored or administered by prolonged i.v. infusion.

Chromatography, High Pressure Liquid↗
PubMed1984

Stability of fluorouracil in plastic containers used for continuous infusion at home.

The stability of fluorouracil when prepared and stored in plastic containers used for continuous infusion in home therapy was studied. Fluorouracil was diluted with 5% dextrose injection. Samples were stored for 16 weeks at 5 degrees C and room temperature in polyvinyl chloride drug reservoirs and at 5 degrees C in elastomeric balloons used in a disposable drug pump. Periodically, samples were tested by a stability-indicating high-performance liquid chromatography (HPLC) assay. At 5 degrees C, there was no significant degradation. At room temperature, there was a progressive increase in fluorouracil concentration, presumably because of evaporation of water. A 10% change in the fluorouracil concentration over 55 days was predicted. Fluorouracil is stable in 5% dextrose injection for at least 16 weeks when stored at 5 degrees C in the two types of containers studied.

Bromouracil↗
PubMed1983

Insulin binding to plastic bags: a methodologic study.

A radiotracer method to assess insulin binding to commercially available plastic peritoneal dialysis solution containers was developed. A peritoneal dialysis bag (bag 2) was emptied and attached to another full bag (bag 1) of the same kind. In the syringe-to-bag method, bag 1 was symmetrically injected through the bag wall with four syringes containing dialysis solution and radioactive insulin, with or without regular insulin. The radioactivity in each syringe was measured with a gamma counter before injection, and all of the samples were counted afterwards directly in the syringes. Using a bag-to-bag transfer method, bag 1 was agitated, eight samples were taken from different parts through the wall, and then the contents were transferred to bag 2. Bag 2 was then agitated and eight samples were taken and counted. In the bag-pieces method, pieces of bag wall were cut and the radioactivity on the walls was measured to determine the amount of binding. The syringe-to-bag method gave negative results, severely underestimating the amount of insulin binding. The bag-to-bag transfer method yielded positive results in all instances. Increasing the amounts of regular insulin had no demonstrable impact on percent of binding. When the bag-to-bag method was compared with the bag-pieces method, it gave only slightly higher values; however, the bag-to-bag method was considered more reliable because the counting can be controlled more effectively. A 15-minute delay in sampling was not found to influence insulin binding. A reliable method of assessing insulin binding must be based on the following two principles: (1) The transfer of samples to intermediate containers should be avoided, and (2) radiotracer concentrations in the samples should be similar.

Dialysis↗
PubMed1982

Estimating energy requirements in patients receiving parenteral nutrition.

Adequate nutritional support should use a patient's energy expenditure as a guide for administering sufficient but not excessive caloric intake. Sixty-seven patients were evaluated using indirect calorimetry, to determine the applicability of commonly used predictive equations for energy expenditure in patients requiring parenteral nutrition. The frequently used calculation that involves multiplying a constant value of kilocalories per kilogram by the patients weight consistently underestimated the energy requirements of patients of low body weight and overestimated the requirements for heavy body weight. The Harris-Benedict equation was found to be highly dependent on body weight and was not any more accurate than estimations of individual requirements using a simpler weight or surface area regression equation. We recommend that an actual regression equation incorporating body weight or body surface area be used to predict energy requirements and that the oversimplified but common use of the constant value of kilocalories per kilogram be abandoned.

Body Surface Area↗
PubMed1982

A re-evaluation of energy expenditure during parenteral nutrition.

Nutritional support regimens are currently based on estimates of energy expenditure, and these estimates are then increased substantially in patients with severe trauma or sepsis because of a presumed hypermetabolic state. Forty-four patients on parenteral nutrition were evaluated using indirect calorimetry to measure actual energy expenditure, and an attempt was made to correlate metabolic rate with clinical diagnosis. We found no statistical difference in metabolic rates between groups of patients classified as malnourished, stressed, or catabolic, If high levels of nonprotein energy substrates are to be administered to a catabolic or "hypermetabolic" patient group, the justification must be on a basis other than a significant increase in actual rate of energy expenditure.

Calorimetry↗
PubMed1982

Effect of freezing and microwave thawing on the stability of six antibiotic admixtures in plastic bags.

The stability of six antibiotics in intravenous fluids in polyvinyl chloride containers after freezing and microwave-thawing is reported. Tobramycin sulfate 160 mg, amikacin sulfate 1 g, ticarcillin disodium 3 g, clindamycin phosphate 300 mg, nafcillin sodium 1 g, and ampicillin sodium was also diluted in plastic bags of 0.9% sodium chloride injection 50 ml. For each antibiotic except ampicillin sodium, three bags were prepared and assayed immediately for antibiotic content. Two of the bags were frozen at -20 degrees C for 30 days and then thawed, one by exposure to room-temperature air and the other by microwave radiation. Each was assayed immediately and after 8 and 24 hours storage at room temperature. The third bag was not frozen, but was stored at room temperature and assayed at 8 and 24 hours. Five bags of ampicillin sodium were prepared-three in 0.9% sodium chloride, which were frozen at -20, -30, and -70 degrees C, and two in 5% dextrose, which were frozen at -30 and -70 degrees C. All ampicillin solutions were stored 30 days, assayed, microwave-thawed, and assayed again. All antibiotics except ampicillin retained 90% or more potency when microwave-thawed after storage at -20 degrees C for 30 days, and after subsequent storage at room temperature for 24 hours. Ampicillin sodium was stable in 0.9% sodium chloride when stored at -30 or -70 degrees C, microwave-thawed, and stored up to eight hours at room temperature. Ampicillin sodium was stable in 5% dextrose when stored at -70 degrees C and microwaved-thawed, but its potency declined to 70.5% after eight hours storage at room temperature.

Anti-Bacterial Agents↗
PubMed1981

A standardized approach to parenteral nutrition for the geriatric patient.

Parenteral nutrition can be a useful therapeutic and prophylactic tool in managing some geriatric patients who present with nutritional deficiencies that accompany acute and chronic diseases. An outline is given of recommended procedures, e.g., solutions, dosages, indications, and contraindications. The techniques described permit a standardized approach to parenteral nutrition for most patients.

Aged↗