American journal of respiratory and critical care medicine
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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.
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Am. J. Respir. Crit. Care Med. · Feb 1996
Occupational disease trends in black South African gold miners. An autopsy-based study.
The change in prevalence in silicosis and pulmonary tuberculosis in black South African gold miners dying from unnatural causes from 1975 to 1991 was studied. Data were analyzed for 16,454 black gold miners. Information on age at death, duration of service, year of autopsy examination, and the prevalence of silicosis and tuberculosis was collected. ⋯ A significant trend for tuberculosis, for year of autopsy, remained after adjustment for the other variables in the model, such as age and duration of service (p = 0.0046). In view of current labor stabilization in the South African mines, one can expect further increases in the prevalence of tuberculosis and silicosis. Lowering of dust levels in the mines is urgently required to prevent the increase of disease burden.
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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)
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Am. J. Respir. Crit. Care Med. · Jan 1996
Comparative Study Clinical Trial Controlled Clinical TrialSkeletal muscle microvascular blood flow and oxygen transport in patients with severe sepsis.
To compare skeletal muscle microvascular blood flow at rest and during reactive hyperemia in septic patients, a prospective, controlled trial was conducted on 16 patients with severe sepsis and a control group of 10 patients free of infection in the intensive care unit of a university hospital. Systemic hemodynamics, whole-body oxygen transport, and skeletal muscle microvascular blood flow at rest and during reactive hyperemia were measured. Reactive hyperemia was produced by arrest of leg blood flow with a pneumatic cuff; on completion of the 3 min ischemic phase the occluding cuff was rapidly deflated to 0. ⋯ Cyclic variation in blood flow (vasomotion) was observed in control subjects but not in septic patients. Skeletal muscle microvascular perfusion is altered in patients with severe sepsis despite normal or elevated whole-body oxygen delivery. These microvascular abnormalities may further compromise tissue nutrient flow and may contribute to the development of organ failure in septic patients.
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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.