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Biomedical subjects

P Lozano

Publications and source records attributed to P Lozano.

At least 37 records · Page 2Linked to original sources

Has asthma medication use in children become more frequent, more appropriate, or both?

OBJECTIVE: Despite national initiatives to improve asthma medical treatment, the appropriateness of physician prescribing for children with asthma remains unknown. This study measures trends and recent patterns in the pediatric use of medications approved for reversible obstructive airway disease (asthma medications). DESIGN: Population-based longitudinal and cross-sectional analyses. Setting. A nonprofit staff model health maintenance organization located in the Puget Sound area of Washington state. PARTICIPANTS: Children 0 to 17 years of age enrolled continuously during any one of the years from 1984 to 1993 (N = 83 232 in 1993). PRIMARY OUTCOME MEASURES. Percent of enrollees filling prescriptions for asthma medications and fill rates by medication class and estimated duration of inhaled antiinflammatory medication use. RESULTS: Between 1984 and 1993, the frequency of asthma medication use increased: the percent of children filling any asthma medication prescription increased from 4. 0% to 8.1%, whereas the percent filling an inhaled antiinflammatory inhaler rose from 0.4% to 2.4%. In contrast, the intensity of inhaled antiinflammatory use decreased among users; 37% of users filled more than two inhalers during the year in 1984, and 29% in 1993. In high beta-agonist users (filling more than two beta-agonist inhalers each quarter per year), the estimated duration of inhaled antiinflammatory use increased slightly from a mean of 4.1 months per year in 1984-1986 to 5.0 months in 1991-1993; estimated duration of use in adolescents 10 to 17 years of age was approximately half that of children 5 to 9 years of age. CONCLUSIONS: The proportion of children using asthma medications increased substantially during the study period, but the use of inhaled antiinflammatory medication per patient remained low even for those using large amounts of inhaled beta-agonists. These findings suggest that most asthma medications were used by children with mild lower airway symptoms and that inhaled antiinflammatory medication use in children with more severe disease fell short of national guidelines.

Adolescent↗

Acute ischemia of the lower limb. An unusual complication of Paget's disease of bone.

Paget's disease of bone (osteitis deformans) is one of the most common skeletal diseases, characterised by bone distortion and the loss of interior structure. Asymptomatic evolution is usual, so diagnosis is likely to be made only when complications of the disease appear. This paper describes such a diagnosis made in a patient with acute lower limb ischemia caused by the compression of the superficial femoral artery between the adductor muscles and an exostosis of the femur.

Aged↗

Recurrent embolism caused by floating thrombus in the thoracic aorta.

A case of embolic recurrent episodes resulting in acute lower-limb ischemia from an unusual source is reported. This occurred in a patient on steroids for rheumatoid arthritis. Femoropopliteal thromboembolectomy successfully restored arterial flow. Diagnostic evaluation for identifying the source of embolism revealed a large, pedunculated and mobile thrombus arising from a nonaneurysmatic and nonatherosclerotic descending thoracic aorta. The thrombus was identified by transesophageal echocardiography and was successfully removed by aortic thromboendarterectomy. We emphasize the importance of transesophageal echocardiography as a reliable method for the diagnosis of thoracic aorta diseases and for identification of aortic thrombi. An aggressive surgical approach is recommended in the low-risk patient to prevent further embolic episodes.

Anti-Inflammatory Agents↗

[Iatrogenic vascular lesions after cardiac catheterization].

INTRODUCTION AND PURPOSE: The increase in vascular complications after cardiac catheterizations is rising due to the increase in the total number of these procedures. The purpose of this report is to determine the incidence of this complication and to identify the variables which are related to the presence of vascular complications which required surgical repair. MATERIAL AND METHODS: Retrospective review of the 3,723 cardiac catheterizations made by the interventional cardiology department during a period between June 1992 to August 1996. RESULTS: Thirty two vascular complications were detected (0.9%), which required surgical reparation. There was no statistical difference in age, sex, presence of vascular risk factors, cardiac indication for catheterization and vascular approach between those patients who had a vascular complication and those who did not. The presence of obesity [RR: 2.5, IC 95% (1.2-5)], use of catheter sheath, superior or equal to 8F [RR: 0.3, IC 95% (0.14-0.62)] and use of systemic anticoagulation [RR: 4.8, IC 95% (2.1-10.8)], increase the risk of vascular complications. Two patients died (6.2%) due to cardiac complications and there were minor complications in 23% after surgical repair. CONCLUSION: Vascular complications after cardiac catheterization continue to be a significant problem. There are several variables which influence the presentation of vascular complications. Continued surveillance of cardiac catheterization complications is necessary to minimize problems and improve results.

Adult↗

Use of health services by children of smokers and nonsmokers in a health maintenance organization.

OBJECTIVES: Use of health services by children of smokers and nonsmokers was compared to assess whether exposure to environmental tobacco smoke resulted in greater use of health services among children of smokers. METHODS: Primary care and emergency room visits, asthma-related prescriptions, and inpatient stays over the 42-month study period were compared for children of smokers (n = 498) and nonsmokers (n = 1062) who were enrolled in a health maintenance organization. Parents of children aged 1 through 11 years were identified from participants in 2 randomized smoking cessation trials. RESULTS: After adjustment for parental age, education, and health status and for child's age, there were no differences between children of smokers and children of nonsmokers in use of primary care or emergency room visits, asthma-related prescriptions, or inpatient stays. However, among those with any preventive care visits, children of smokers had significantly fewer visits than children of nonsmokers. CONCLUSIONS: Further study is needed to elucidate whether parents who smoke underutilize health services for their children or use services differently from nonsmoking parents and whether these differences have cost implications.

Ambulatory Care↗

Traumatic pseudoaneurysm of the axillary artery following anterior dislocation of the shoulder. Case report.

Vascular complications are rare in cases of simple anterior dislocation of the shoulder but the axillary artery or its branches may be damaged. Very few cases are found in the literature reporting false aneurysms of axillary artery secondary to blunt trauma to the shoulder. A case of pseudoaneurysm of the axillary artery in a 75-year-old woman is reported. Diagnosis was suspected because large pectoral haematoma with haemodynamic instability appeared a few hours later after manual reduction of the dislocation. The pseudoaneurysm was confirmed with selective angiography of the axillary artery. Arteriography should be performed whenever vascular injury is suspected. Delayed recognition of these lesions may lead to permanent neurologic deficits despite adequate vascular repair of the axillary artery. A coordinated vascular and orthopaedic approach and prompt surgical treatment may assure full upper limb function. Although endovascular treatment of these lesions could seem attractive, we prefer to use open surgical techniques because they allow us to treat frequent concomitant injuries and perform decompression of the axillar fossa because of the large haematoma.

Accidental Falls↗

Dynamic structure/function relationships in the alpha-chymotrypsin deactivation process by heat and pH.

The activity decay of alpha-chymotrypsin due to temperature and pH has been related to the associated structural changes of the protein that could be studied with the help of melting temperature which was determined by using ultraviolet absorption spectroscopy, and fluorescence spectra measurements. The kinetic behaviour in activity loss of alpha-chymotrypsin followed a two-step deactivation model, involving an intermediate state. The increase in temperature and pH showed a clear deactivation effect, reducing exponentially the half-life of the enzyme. At pH 7.0, this two-step deactivation process was also observed with both the maximum fluorescence intensity (I(max)) and emission wavelength (lambda(max)). The series-type kinetic model allowed to establish a clear correlation between the activity and the fluorescence spectral normalized data: the intermediate state of the enzyme occurred at an identical deactivation denaturation level (alpha1), and a proportionality between the decay rate constants was observed. As a function of the incubation temperature, another correlation was observed between the alpha1 profile, initial lambda(max) and thermal unfolding transition, allowing to identify the intermediate state of the kinetic model as that obtained at the melting temperature (43.9 degrees C).

Animals↗

One-year experience with an inpatient asthma clinical pathway.

OBJECTIVE: To study the effects of an inpatient asthma clinical pathway on the processes and outcomes for children who were admitted to a hospital for the treatment of asthma. DESIGN: Before-and-after study. SETTING: A private nonprofit academic children's hospital in Seattle, Wash. PATIENTS AND METHODS: Three hundred forty-two admissions of 297 patients in the first year of the asthma clinical pathway were compared with 353 admissions of 292 similar patients in the previous year. Patients who required intensive care, were younger than 2 years, or had a major chronic disease were excluded. INTERVENTION: Asthma was chosen for the development of a clinical pathway because of its large number of admissions, involvement of multiple health care providers (nurses, physicians, and respiratory therapists), predictable hospital course, and variable lengths of hospital stay. The pathway was a consensus-based guideline for patient management that was intended to be adapted to the care of an individual patient. Prior to the implementation of the clinical pathway, nurses, attending physicians, house staff, and respiratory therapists were trained in its use. The main hospital chart of each patient who was admitted to the pathway had a flowchart that outlined day-to-day guidelines for monitoring and care. Nursing staff were responsible for documenting when a patient's care varied from the pathway, and these variances were entered into a computer database. OUTCOME MEASURES: Use of peak flowmeters, steroids, laboratory studies, radiological studies, and respiratory therapy was assessed by analyzing the patients' electronic billing records. For patients enrolled in the pathway, additional data on process of care were obtained by analyzing the variance database. For both groups, the total charges, length of stay, and rate of readmission to the hospital were measured by use of the billing records. RESULTS: There were no significant differences in the use of steroids or peak flowmeters, average lengths of stay, or total charges between the 2 groups. However, patients in the "pathway group" had significantly lower average charges for laboratory ($26 vs $39; P < .05) and radiology ($32 vs $55; P < .001) services. Variances from the pathway guidelines were most often related to the patients' responses to therapy. CONCLUSIONS: The asthma clinical pathway had no effect on clinical outcomes and small effects on the use of resources. Further development, including physician and nurse training, computer and administrative support, and clinical severity scales, are needed to develop the potential utility of the clinical pathway as a research and quality assurance tool.

Adolescent↗

Predictors of hemolytic uremic syndrome in children during a large outbreak of Escherichia coli O157:H7 infections.

OBJECTIVE: To evaluate risk factors for progression of Escherichia coli O157:H7 infection to the hemolytic uremic syndrome (HUS). STUDY DESIGN: We conducted a retrospective cohort study among 278 Washington State children <16 years old who developed symptomatic culture-confirmed E coli O157:H7 infection during a large 1993 outbreak. The purpose of the study was to determine the relative risk (RR) of developing HUS according to demographic characteristics, symptoms, laboratory test results, and medication use in the first 3 days of illness. RESULTS: Thirty-seven (14%) children developed HUS. In univariate analysis, no associations were observed between HUS risk and any demographic characteristic, the presence of bloody diarrhea or of fever, or medication use. In multivariate analysis, HUS risk was associated with, in the first 3 days of illness, use of antimotility agents (odds ratio [OR] = 2.9; 95% confidence interval [CI] 1.2-7.5) and, among children <5.5 years old, vomiting (OR = 4. 2; 95% CI 1.4-12.7). Among the 128 children tested, those whose white blood cell (WBC) count was >/=13 000/microL in the first 3 days of illness had a 7-fold increased risk of developing HUS (RR 7. 2; 95% CI 2.8-18.5). Thirteen (38%) of the 34 patients with a WBC count >/=13 000/microL developed HUS, but only 5 (5%) of the 94 children whose initial WBC count was <13 000/microL progressed to HUS. Among children who did not develop HUS, use of antimotility agents in the first 3 days of illness was associated with longer duration of bloody diarrhea. CONCLUSIONS: Prospective studies are needed to further evaluate measures to prevent the progression of E coli O157:H7 infection to HUS and to assess further clinical and laboratory risk factors. These data argue against the use of antimotility agents in acute childhood diarrhea. Our finding that no intervention decreased HUS risk underscores the importance of preventing E coli O157:H7 infections.

Adolescent↗

Health care utilization and cost among children with asthma who were enrolled in a health maintenance organization.

OBJECTIVE: To measure the impact of asthma on the use and cost of health care by children in a managed care organization. DESIGN: Population-based historical cohort study. SETTING: A medium-sized staff model health maintenance organization in western Washington state. SUBJECTS: All 71 818 children, between age 1 to 17 years, who were enrolled and used services during 1992. OUTCOME MEASURES: Children were identified with one or more asthma diagnoses during 1992 using automated encounter data. Nonurgent outpatient visits, pharmacy fills, urgent care visits, and hospital days, as well as associated costs were measured. All services were categorized as asthma care or nonasthma care. Multivariate regression analysis was used to compute marginal cost for asthma (difference in total cost between children with asthma and other children using services, adjusted for covariates). RESULTS: Treated prevalence of asthma was 4.9%. Children with asthma incurred 88% more costs ($1060.32 vs $563. 81/yr), filled 2.77 times as many prescriptions (11.59 vs 4.19/yr), made 65% more nonurgent outpatient visits (5.75 vs 3.48/yr), and had twice as many inpatient days (.23 vs .11/yr) compared with the general population of children using services. Asthma care represented 37% of all health care received by children with asthma, while the remaining 63% were for nonasthma services. Almost two-thirds of asthma-related costs were attributable to nonurgent outpatient care and prescriptions; only one third was attributable to urgent care and hospitalizations. Controlling for age, sex, and comorbidities, the marginal cost of asthma was $615.17/yr (95% confidence interval $502.73, $727.61), which includes asthma as well as nonasthma services. This marginal cost represents 58% of all health care costs for children with asthma. CONCLUSIONS: Children with asthma use significantly more health services (and incur significantly more costs) than other children using services, attributable largely to asthma care. The majority of all health care costs for children with asthma were for nonasthma services. Urgent care visits and hospitalizations are less important components of asthma costs in this managed care organization than has been found in other national studies.

Adolescent↗

Mechanism of the systemic, left ventricular, and coronary vascular tolerance to a binge of cocaine in conscious dogs.

BACKGROUND: Prior experimental studies have emphasized the cardiovascular effects of acute, single doses of cocaine. However, cardiovascular complications are most often reported in chronic users, who have been exposed to repetitive doses of cocaine. It remains unclear whether there is tolerance or sensitization to the systemic, left ventricular, and coronary hemodynamic effects of a binge of cocaine. METHODS AND RESULTS: We studied 11 conscious, chronically instrumented dogs to determine the systemic pressor, inotropic, chronotropic, and coronary vascular resistance responses to cocaine (1 mg/kg IV) administered every 25 minutes for five doses. There was progressive tolerance to the systemic pressor (mean arterial pressure: first dose, +42 +/- 4% from 97 +/- 2 mm Hg; fifth dose, +8 +/- 3% from 116 +/- 7 mm Hg; P < .01) and heart rate (first dose, +45 +/- 8% from 93 +/- 5 bpm; fifth dose, +8 +/- 2% from 109 +/- 9 bpm; P < .01) responses and abolition of the positive inotropic (left ventricular dP/dt: first dose, +19 +/- 4% from 2824 +/- 75 mm Hg/s; fifth dose, -3 +/- 5% from 2531 +/- 436 mm Hg/s; P < .01) and coronary vasoconstrictor (coronary vascular resistance: first dose, +38 +/- 9% from 1.9 mm Hg.mL-1.min-1; fifth dose, -7 +/- 2% from 2.6 +/- 0.2 mm Hg. mL-1.min-1; P < .01) responses to a binge of cocaine despite progressive increases in peak plasma cocaine concentrations. In contrast, both the plasma norepinephrine and epinephrine responses were attenuated with repetitive exposure to cocaine, whereas myocardial alpha and beta-adrenergic responsiveness was maintained. CONCLUSIONS: Repetitive cocaine administration is associated with the development of early and progressive tolerance to systemic, left ventricular, and coronary vascular effects of cocaine. The mechanism of the tolerance involves neither impaired myocardial nor coronary vascular responsiveness to adrenergic stimulation but, rather, attenuated catecholamine responses to repetitive cocaine administration.

Animals↗

Measurement of free glycerol in biofuels.

A method has been developed to determine the free glycerol content in esters derived from vegetable oils. After extraction of glycerol, its measurement in small quantities in biofuels (methyl or ethyl esters) is possible by high-pressure liquid chromatography combined with pulsed amperometric detection, HPLC-PAD. The method has proved to be simple, rapid and accurate. The limit of detection is 1 microg/g.

Journal Article↗

Use of health services by African-American children with asthma on Medicaid.

OBJECTIVE: To determine whether African-American children with asthma use more emergency department (ED) and inpatient medical services and fewer preventive services than white children with similar insurance coverage and family income. DESIGN: Historical cohort study during Medicaid claims data. SETTING: Aid to Families With Dependent Children enrollees aged 3 through 17 years in Seattle-Tacoma, Wash, metropolitan area. PATIENTS: All 576 African-American children and 1369 white children receiving services for asthma between June 1988 and December 1992. MAIN OUTCOME MEASURES: Utilization of asthma services (ED, impatient, office visits, and pharmacy) and well-child services and associated Medicaid reimbursements. RESULTS: African-American children were more likely than white children to make ED visits or to be hospitalized for asthma; adjusted odds ratios (ORs) were 1.70 (95% confidence interval [Cl], 1.34 to 2.15) and 1.42 (95% Cl, 1.03 to 1.96), respectively. African-American children were less likely to have made an office visit for asthma; the adjusted OR was 0.48 (95% Cl, 0.26 to 0.85). The two groups were similarly likely to have filled a prescription for an asthma medication and to have made a well-child visit. Per capita payments for asthma services were 24% higher for African-American children: $436 vs $350 per child-year. CONCLUSIONS: Higher use of ED and inpatient services for asthma among African-American children using Medicaid (compared with white children) cannot be fully explained by poverty or inadequate health insurance. Furthermore, these children appear to make disproportionately few office visits for asthma, suggesting suboptimal use of preventive services for asthma. In contrast, the comparable use of well-child visits in the two groups suggests the problem may not be in access to care in general, but there may be specific problems in the successful management of chronic diseases such as asthma among African-American children.

Adolescent↗

[An aneurysm of the inferior mesenteric artery associated with obstruction of the superior mesenteric artery and the celiac trunk].

The exact prevalence of visceral arteries aneurysms is not well documented and its is mainly known from necropsies. Inferior mesenteric artery aneurysms are the rarest of visceral aneurysms. The authors report a case of an aneurysm of the inferior mesenteric artery in a 52-year-old man with obstructive disease of superior mesenteric artery and celiac axis. The diagnosis was made by angiography. The aneurysm was resected with superior and inferior mesenteric arteries revascularization. Surgical approach is needed in these aneurysms and when they are associated with obstructive disease of other intestinal artery, revascularization is mandatory.

Aneurysm↗