The American review of respiratory disease
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Am. Rev. Respir. Dis. · Nov 1984
Comparative StudyTracheal mucus clearance in high-frequency oscillation. II: Chest wall versus mouth oscillation.
We compared the tracheal mucus clearance rate (TMCR) in anesthetized dogs during spontaneous breathing (SB), ventilation by high-frequency oscillation at the airway opening (HFO/AO), and ventilation by high-frequency oscillation of the chest wall (HFO/CW). The HFO/AO was carried out by using a piston pump with a high impedance transverse flow at the proximal end of the endotracheal tube; HFO/CW was effected by creating rapid pressure oscillations in an air-filled cuff wrapped around the lower thorax of the animal, causing small tidal volumes at the mouth. The TMCR was measured by observing the rate of displacement of a charcoal marker in the lower trachea; a fiberoptic bronchoscope was used to deposit the marker before each experiment and to relocate it after a 5-min run. ⋯ At 13 Hz with an oscillatory tidal volume (VTO) of 1.5 ml/kg, mean TMCR was 240% of control with HFO/CW (p less than 0.001) and 76% of control with HFO/AO (NS). During HFO/AO at 20 Hz and a VTO of 3 ml/kg, mean TMCR was 97% of control. We conclude that high-frequency ventilation by rapid chest wall compression enhances tracheal mucus clearance when compared with spontaneous breathing, whereas high-frequency oscillation at the mouth does not.
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A resurgence of interest in clinical auscultation is in progress. Recent technical advances permit more objective observations than were previously possible. ⋯ The complex sonic signals arising in the lung during respiration reflect its mechanical state. More precise understanding of pulmonary sounds and their clinical correlations could lead to powerful diagnostic tools, which have particular appeal because of their noninvasive nature.
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Am. Rev. Respir. Dis. · Oct 1984
Randomized Controlled Trial Comparative Study Clinical TrialEarly lung cancer detection: results of the initial (prevalence) radiologic and cytologic screening in the Johns Hopkins study.
The Johns Hopkins Lung Project was designed to determine whether the addition of cytologic screening to the radiographic screening of high-risk volunteers could enhance the early detection of asymptomatic lung cancer and whether early therapeutic intervention in detected cases could significantly reduce the mortality from this disease. Male volunteers, 45 yr of age and older, who smoked at least 1 pack of cigarettes per day were recruited from the Baltimore metropolitan area. All of the 10,387 acceptable high-risk volunteers received annual chest radiographic screening. ⋯ There was no corresponding decrease in prevalence. Lung cancers detected by cytology alone were found at very early stages. Although there has been an increase in average survival, much of this increase, if not all, may have resulted from lead-time and sampling bias.
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Am. Rev. Respir. Dis. · Oct 1984
Comparative StudyEarly lung cancer detection: results of the initial (prevalence) radiologic and cytologic screening in the Memorial Sloan-Kettering study.
This is a report of the initial (prevalence) screening for lung cancer in a population of 10.040 cigarette-smoking men 45 yr of age and older, recruited from metropolitan New York. All had posteroanterior and lateral chest roentgenograms, and approximately half the men, randomly chosen, also had sputum cytology (dual screen). ⋯ In the dual screen group, in which the 2 detection techniques could be compared, 6 Stage I lung cancers were detected by radiology alone, 7 by cytology alone, and only 1 by both techniques. All of the cases detected by cytology alone were squamous carcinomas, whereas two thirds of those detected by radiology alone were adenocarcinoma.
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Oxygen therapy is one of the most frequently ordered therapies for patients with chronic obstructive pulmonary disease (COPD). In a large percentage of these cases, oxygen therapy is supplied via nasal cannula. With the rising cost of medical care and the search for more effective means of oxygen delivery, a new oxygen-conserving nasal cannula (CNC) that incorporates a closely coupled 20-ml reservoir was developed. ⋯ Results indicate that when the CNC was compared with the SNC, arterial oxygen saturation levels were significantly different (p less than 0.001) at flow rates of 0.5, 1.0, and 2.0 L/min. Oxygen saturation were 2.9% higher at 0.5 L/min, 2.9% higher at 1 L/min, and 2.6% higher at 2 L/min for the CNC than for the SNC. In summary, the CNC offers a more efficient oxygen delivery system for those patients requiring supplemental oxygen administration by nasal cannula.