American journal of respiratory and critical care medicine
-
Am. J. Respir. Crit. Care Med. · Feb 1996
Early detection of lung involvement in lysinuric protein intolerance: role of high-resolution computed tomography and radioisotopic methods.
Pulmonary disease of unknown etiology is a potentially fatal complication in patients with lysinuric protein intolerance (LPI), an autosomal recessive disorder caused by the defective transport of cationic amino acids. Lung involvement was investigated in nine Italian LPI patients through pulmonary function tests and lung imaging studies consisting of conventional chest radiography, high-resolution computed tomography (HRCT), and perfusion and ventilation scintigraphy. One 10-yr-old patient died of severe respiratory insufficiency from alveolar proteinosis. ⋯ Radioisotope studies showed an uneven distribution of perfusion and ventilation, and confirmed the presence of segmental and/or diffuse pulmonary functional defects. No abnormalities of pulmonary function were evident, and answers to a questionnaire excluded primary coexisting lung disease. In patients with LPI, including those without clinical and functional impairment, HRCT and radioisotopic studies appear to be the most sensitive methods for the early diagnosis of lung disease and correct assessment of its progression.
-
Am. J. Respir. Crit. Care Med. · Feb 1996
The determinants of pulmonary diffusing capacity in a national sample of U.S. adults.
Racial and gender differences in single-breath pulmonary diffusing capacity for carbon monoxide (DLCO) have previously received little attention. Between 1971 and 1975, the first National Health and Nutrition Examination Survey determined DLCO for 4,439 adults ages 25 to 74 residing in the United States, including 2,345 women and 438 blacks. The large sample permitted an evaluation of interactions and nonlinear relationships with DLCO, and its association with biomarkers of inflammation. ⋯ In current smokers, cigarettes per day and pack-years were predictive of DLCO even after control for FVC and controlling for these variables fully explained the difference in DLCO between never and current smokers. Peripheral neutrophil count, a biomarker of inflammation, was associated with reduced DLCO. Thus, substantial sex and race differences exist for DLCO within the general United States population.
-
Am. J. Respir. Crit. Care Med. · Jan 1996
Review Comparative StudyHealth effects of outdoor air pollution. Committee of the Environmental and Occupational Health Assembly of the American Thoracic Society.
Particles, SOx, and acid aerosols are a complex group of distinct pollutants that have common sources and usually covary in concentration. During the past two decades, the chemical characteristics and the geographic distribution of sulfur oxide and particulate pollution have been altered by control strategies, specifically taller stacks for power plants, put in place in response to air pollution regulations adopted in the early 1970s. While the increasing stack heights have lowered local ambient levels, the residence time of SOx and particles in the air have been increased, thereby promoting transformation to various particulate sulfate compounds, including acidic sulfates. ⋯ This review suggests that the epidemiologic studies of adverse morbidity measures are coherent with the mortality studies showing quantitatively similar adverse effects of acute exposures to particulate pollution. Despite these epidemiologic findings for acute and chronic adverse health effects from air pollution associated with relatively low levels of inhalable particles, there are no complementary data from toxicologic studies or from acute human exposures to similar levels of respirable particles. Thus, controlled human exposures to various particles, including H2SO4, at relevant levels (< 150 micrograms/m3) have not identified significant alterations in respiratory function in healthy individuals.(ABSTRACT TRUNCATED)
-
Am. J. Respir. Crit. Care Med. · Jan 1996
Comparative StudyResource use implications of do not resuscitate orders for intensive care unit patients.
This study describes the use of do not resuscitate (DNR) orders for ICU patients in four northeastern U. S. teaching hospitals and investigates the relationship between DNR orders and length of stay. The use of detailed data from the mortality probability model (MPM II) study on 6,290 consecutive ICU admissions to general adult medical and surgical ICUs during 1989 through 1991 allows us to control for severity of illness and the time during the ICU stay at which the DNR order was entered. ⋯ Nonsurvivors with early (first 24 h) DNR had shorter mean and median ICU and hospital stays than the comparison group of non-DNR patients. The percentage of patients with very long ICU (> 30 d) and hospital (> 60 d) stays was smaller among DNR patients. The use of DNR orders, particularly early in the ICU stay, may be associated with significant resource use reduction for an identifiable group of patients.
-
Am. J. Respir. Crit. Care Med. · Jan 1996
Comparative StudyAirways responsiveness, wheeze onset, and recurrent asthma episodes in young adolescents. The East Boston Childhood Respiratory Disease Cohort.
To describe the role of airways responsiveness in predicting incidence of wheeze in early adolescence and to examine the association between airways responsiveness and active asthma symptoms, children who had been tested for airways hyperresponsiveness were assessed prospectively. Of 770 children in the East Boston Childhood Respiratory Disease Cohort who were between 5 and 9 yr of age at time of entry into the study, 281 children received airways challenges during voluntary follow-up conducted between 1980 and 1986. Each subject presented a sequence of wheeze or asthma diagnosis reports along with a sequence of time-varying covariates, including airways challenge results and symptom and exposure information. ⋯ In the analysis of recurrent asthma episodes, airways responsiveness at a given visit was associated with a greater tendency to have an asthma diagnosis reported at the subsequent visit (OR = 4.2, 95% CI = 1.92, 9.23). For subjects presenting multiple airways responsiveness challenge studies, two successive positive airways responsiveness results were independently associated with a higher likelihood of recurrent asthma episodes. These results confirm the predictive importance of airways responsiveness in the natural history of the development and persistence of asthmatic symptoms.