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Biomedical subjects

R Stewart

Publications and source records attributed to R Stewart.

At least 127 records · Page 7Linked to original sources
PubMed1994

Use of the thoracic aorta for renal arterial reconstruction.

PURPOSE: Thoracic aortorenal bypass is a new technique for surgical renal revascularization in patients with severe atherosclerosis of the abdominal aorta. In such cases, the thoracic aorta is often free of disease. METHODS: From 1989 to 1992, thoracic aortorenal bypass was performed in 23 patients with hypertension, abdominal aortic atherosclerosis, and celiac artery stenosis; in 21 patients, renal artery stenosis was present bilaterally or in a solitary kidney. RESULTS: There was one operative death. Among the remaining 22 patients, hypertension was cured or improved after operation in 19 (86%), and renal function was improved or stable in 21 (95%). CONCLUSIONS: Thoracic aortorenal bypass has several advantages and is a useful alternative to abdominal aortic replacement in selected older patients who require renal arterial reconstruction.

Aorta, Abdominal↗
PubMed1993

At the cutting edge.

In the second of two articles, Jim Dukes and Rosemary Stewart look at how protocols can be implemented successfully.

Clinical Protocols↗
PubMed1993

Be prepared.

Explore the source record for details and available documents.

Clinical Protocols↗
PubMed1993

Screening for urinary tract infection in children with neurogenic bladders.

Urinary tract infections (UTIs) are a frequent and potentially disabling problem for children with neurogenic bladders. Frequent monitoring for UTIs using bacterial culture is expensive and troublesome; thus an inexpensive, dependable screening method is desirable. Three hundred and twenty-nine urine specimens were obtained from 141 children with neurogenic bladders, 86% of whom had meningomyelocele. During the 11-month study period, 43% of the children had at least one positive culture (> or = 100,000 CFU/ml). The results of bacterial culture were compared with the occurrence of signs and symptoms, the presence of reflux and the results of a dipstick test for nitrite and leukocyte esterase. Analysis of the data revealed that (1) UTIs were significantly more common in children with reflux; (2) the presence of signs and symptoms was neither sensitive nor specific (positive predictive value (PPV) = 0.44, negative predictive value (NPV) = 0.84); (3) urinalysis was an unreliable screening tool (PPV = 0.63, NPV = 0.73); and (4) the combination of nitrite and leukocyte esterase was more sensitive and specific than either by itself (combined PPV = 0.69, NPV = 0.88). Children with neurogenic bladders who have reflux or have signs and symptoms should continue regular bacterial cultures, whereas others can be screened dependably using the combined leukocyte esterase and nitrite test.

Adolescent↗
PubMed1993

Phenytoin and magnesium sulfate effects on fetal heart rate tracings assessed by computer analysis.

OBJECTIVE: To compare the effects of maternally administered phenytoin and magnesium sulfate on the fetal heart rate (FHR) using computer analysis. METHODS: Thirty-six nonlaboring preeclamptic women between 27-41 weeks' gestation were treated with either phenytoin or magnesium sulfate in a nonrandomized fashion. All fetuses were deemed to be well by traditional electronic-biophysical criteria. One-hour FHR recordings were analyzed by computer analysis before treatment. No other medications were administered. Tracings recorded 1 hour after drug administration were analyzed. Therapeutic serum levels were achieved in both groups before FHR tracings were reevaluated. Statistical analysis used paired Student t test, with significance set at P < or = .05. RESULTS: There were no differences in birth weight, gestational age, Apgar scores, or computer-analyzed FHR characteristics between the groups before treatment. Magnesium sulfate reduced significantly the frequency of accelerations of ten and 15 beats per minute; caused a 62% reduction in reactivity, defined as accelerations of 15 beats per minute in 20 minutes of FHR tracing (but no change in reactivity with accelerations of ten beats per minute); and reduced short- and long-term variability. Phenytoin reduced short-term variability only. CONCLUSION: Phenytoin does not confound the computer analysis of FHR tracings and may offer some advantage over magnesium sulfate when used for prophylaxis against eclampsia.

Diagnosis, Computer-Assisted↗
PubMed1992

[Placement in a nursing home does not automatically lead to increased use of drugs].

OBJECTIVE: To determine whether the use of drugs increases during a stay in a nursing home. SETTING: Fifteen nursing homes in Groningen and Haren. DESIGN: Prospective study. METHOD: In 250 persons admitted to a nursing home in the period December 1986-December 1987 the following data were determined: the mean number of different drugs, the total quantity of drugs used expressed in DDDs (Defined Daily Dose), the number of diagnosis and the functioning. RESULTS: The mean number of different drugs used per person per quarter increased significantly (4.5 in the first quarter as against 5.7 in the fourth quarter). The total quantity of drugs expressed in DDDs used per person per quarter, and the mean duration of their being prescribed did not change significantly. An exception were dermatological preparations (0.13 DDDs in the first quarter as against 0.42 DDDs in the fourth quarter), probably in connection with decubitus. CONCLUSION: A stay in a residential home does not necessarily lead to use of larger quantities of drugs (DDDs). However, there are indications that placement may lead to a greater diversity of the drugs used.

Aged↗
PubMed1992

The effects of melanocortins and electrical fields on neuronal growth.

The effects of the neuropeptide molecules, adrenocorticotrophic hormone or alpha-melanocyte stimulating hormone, on various parameters of in vitro nerve growth, have been studied in the presence and absence of a small applied electric field. Striking effects on rates of nerve growth occurred. Selected concentrations of either substance alone, produced a three- to fourfold increase in nerve growth rate; other concentrations were inhibitory. The applied electric field alone increased rates of growth threefold. Further augmented rates of growth were seen when either neuropeptide was present simultaneously with an applied field. Under these latter conditions, galvanotropic (cathodal) orientation persisted, while nerve branching was suppressed. Given the clinical interest in melanocortin-stimulated nerve regeneration, perhaps a combined electrical and neuropeptide approach would be warranted.

Adrenocorticotropic Hormone↗
PubMed1992

Xamoterol in hypertrophic cardiomyopathy: effects on diastolic function and heart rate.

The aims of this study were to determine the effects of the partial beta 1-adrenergic agonist, xamoterol, on diastolic function and ambulatory heart rate in hypertrophic cardiomyopathy. Eleven patients with non-obstructive hypertrophic cardiomyopathy were studied with cross-sectional and Doppler echocardiography and 24-h Holter monitoring before and after a single intravenous dose of xamoterol. Resting heart rate (mean +/- SD) increased from 76 +/- 16 before, to 83 +/- 15 beats/min 15 min after xamoterol, p = 0.03. In the 4-h period after xamoterol, maximum heart rate was reduced (127 +/- 21 to 112 +/- 19, p = 0.01) and minimum heart increased (60 +/- 16 to 67 +/- 17, p = 0.04) compared to the same 4-h period of the previous day. There were no significant changes in cross-sectional or Doppler echocardiographic measurements of left ventricular function following xamoterol. Xamoterol stabilises the heart rate in hypertrophic cardiomyopathy. The absence of a significant effect on Doppler measurements does not preclude a beneficial effect on diastolic function. This initial study suggests that xamoterol should be further investigated as a new medical therapy for hypertrophic cardiomyopathy.

Adolescent↗
PubMed1992

Recalcitrant ingrowing nails. Surgical approaches.

Ingrowing toenails are a very common condition that has a significant associated morbidity. Although treated by practitioners of many specialties, most doctors have minimal training in this area. In this overview, an algorithm will be used to direct in an efficient and pain minimizing way the management of recalcitrant ingrowing nails.

Humans↗
PubMed1992

The reform and redirection of long-term care in Ontario.

In Ontario, the current fragmented health services system cannot respond to projected demands. Several government reports recommend a shift of focus from institutionalization to community-based services--one-stop shopping--to integrate services.

Aged↗
PubMed1992

Keyless data capture: a report of the Automatic Identification Teacher's Institute.

There is tremendous potential in auto ID technologies for increasing productivity and accuracy in the management of health information. We must make a commitment to integrate keyless data capture technologies into medical record administration and medical record technology curricula. Our profession will seize the opportunity if we can educate students and practitioners in the knowledge and skills to unleash this potential. A recent study of medical record administration, and medical record technology, programs by Elaine Patrikas revealed that, at best, some programs devote a maximum of 10 hours of instructional time to the teaching of keyless data capture technologies. HIM professionals can aggressively pursue applications that demonstrate tremendous cost savings, so that upper management will seriously consider them. Improvements in the flow of, and access to, information do directly impact patient care thus helping our profession fulfill its mission and preparing tomorrow's leaders and decision makers.

Curriculum↗
PubMed1991

Adrenergic hypersensitivity after beta-blocker withdrawal in hypertrophic cardiomyopathy.

Withdrawal of beta-blocker therapy has been associated with the development of adrenergic hypersensitivity and adverse clinical effects in patients with coronary artery disease and hypertension. The aim of this study was to establish the occurrence and clinical significance of adrenergic hypersensitivity after abrupt withdrawal of long-term beta blockade in hypertrophic cardiomyopathy. Beta-adrenergic sensitivity was measured using the isoprenaline chronotropic dose25. Symptom assessment chronotropic dose25 calculation, bicycle exercise, echocardiography and Holter monitoring were performed while the patient received beta-blocker therapy and repeated on days 2, 4, 6, 8 (acute withdrawal period) and on day 21 after abrupt withdrawal. The study was terminated after 7 patients had been studied because all patients experienced a marked deterioration in symptoms and several clinical events had occurred. The chronotropic dose25 (mean +/- standard deviation) demonstrated beta 1-adrenergic hypersensitivity with a minimal value of 1.6 +/- 0.8 micrograms during the acute withdrawal period compared with 3.8 +/- 1.7 micrograms on day 21 (p = 0.003). Heart rates during rest and exercise showed an overshoot increase during the acute withdrawal period. The maximal 24-hour ventricular ectopic count was higher during the acute withdrawal period than during day 21 (p = 0.04). Of 3 patients with inducible outflow tract gradients, 2 developed resting gradients greater than 30 mm Hg during the acute withdrawal period. There was an increase in peak late filling velocity of mitral inflow after beta-blocker withdrawal. In conclusion, transient beta-adrenergic hypersensitivity occurs after beta-blocker withdrawal in hypertrophic cardiomyopathy and is associated with significant physiologic changes and adverse clinical consequences.

Adult↗
PubMed1991

Electrocautery does not interfere with the function of the automatic implantable cardioverter defibrillator.

The automatic implantable cardioverter defibrillator (AICD) manufactured by Cardiac Pacemakers, Inc, contains an automatic sensitivity adjustment. We tested whether this feature would prevent sensing of signals generated by electrocautery by implanting three different models of the AICD in 4 mongrel dogs. Unipolar electrocautery was applied at maximum output to a site close to the rate-sensing leads. The devices were monitored with an AICD-check probe and by auditory monitoring of QRS synchronous tones. No sensing of the electrocautery by the device occurred. Three patients with two different AICD models (1550 and 1520) underwent five surgical procedures in which electrocautery was used. No sensing of electrocautery signals, device charging, or other device malfunction occurred.

Animals↗