American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Dec 1994
Comparative StudyCardiopulmonary resuscitation by precordial compression but without mechanical ventilation.
It is widely held that mechanical ventilation is essential for cardiopulmonary resuscitation (CPR). However, cardiac output and therefore pulmonary blood flow is reduced to less than one-third of normal during CPR. We therefore reasoned that ventilatory requirements are correspondingly reduced and postulated that gas exchange may be maintained during precordial compression with oxygen passively delivered to the airway in the absence of mechanical ventilation. ⋯ Postresuscitation myocardial contractility, reflected in the maximally generated dP/dt40, was also not adversely affected. In the unventilated group, only resuscitated animals developed spontaneous gaspings at an average frequency of 17 +/- 2/min-1. The current emphasis on mechanical ventilation as the highest priority for cardiopulmonary resuscitation is therefore not fully supported under the experimental conditions of this study.
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Am. J. Respir. Crit. Care Med. · Dec 1994
Multicenter StudyVolume spirometers need automated internal temperature sensors.
Spirometer temperature was measured automatically during all years of the Lung Health Study. Short- and long-term changes in temperature were analyzed for the 23 dry-rolling-seal volume spirometers used at the 10 clinical centers involved in the study. Within-test-session spirometer temperature increased a mean of 0.3 degrees C, and as much as 3.0 degrees C during methacholine challenge testing. ⋯ Month-to-month changes of more than 15 degrees C were not uncommon. If ambient temperature had been assumed to apply to all maneuvers and used for BTPS corrections, FEV1, and FVC measurement errors of up to 6% would have occurred. When using volume spirometers, the temperature of air inside the spirometer should be measured accurately during each breathing maneuver.
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Am. J. Respir. Crit. Care Med. · Nov 1994
Patterns of cigarette consumption and cotinine levels among African American women smokers.
Cigarette smoking intensifies a number of serious health problems, including lung cancer, hypertension, low birth weight, and infant mortality, that disproportionately affect black Americans. Cotinine, a major nicotine metabolite, is one indicator of smoke exposure. It has been reported that black women have higher mean cotinine levels than white women. ⋯ Average cotinine/cigarette values were higher in black women compared with previous reports for Mexican American women smokers. No comparable values are available for white women. Additional study is needed to begin to explain variations in levels of cotinine, as well as perceived nicotine dependence among black women.