The American review of respiratory disease
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In 6 seated subjects with small unilateral pleural effusion without other radiographic abnormality, we measured regional lung function using xenon-133, comparing the function of the lung on the side with the effusion to the function on the contralateral side. When both lungs were equilibrated with Xe, count rates were lower at the base with the effusion, indicating either collapse or displacement of lung in these regions. Regional lung expansion was measured as fractions of regional total lung capacity: regional functional residual capacity/regional total lung capacity and regional residual volume/regional total lung capacity. ⋯ These findings were compatible with effective static pleural pressure being the same on both sides and suggest that the reduction in count rate at the base with effusion was due to displacement rather than compression of lung. We also measured regional washout half-times during dynamic breathing and found them prolonged in regions underlying effusion, indicating that dynamic ventilation of these areas was reduced. We postulated that the dynamic pressure swings applied to these regions were decreased by the effusions.
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Am. Rev. Respir. Dis. · Mar 1977
Case ReportsCharacteristics of pulmonary surfactant in adult respiratory distress syndrome associated with trauma and shock.
Broncho-alveolar lavage fluid was obtained from a 24-year-old man who developed the adult respiratory distress syndrome one day after massive trauma and hemorrhagic shock. The lungs were available 3 days later when organ transplantation was performed. ⋯ This suggests that surfactant films in the adult respiratory distress syndrome are less responsive to stress, and that as a result, a loss of film elasticity may contribute to the abnormal pressure-volume relationships observed with the intact lung. Changes in the lipid-to-protein ratios of the purified lipid-protein aggregates were also found, as indicated by the recovery of 3 lipid-protein aggregates with different isopycnic densities from the lung with adult respiratory distress syndrome; only one major aggregate could be recovered from the lavages of normal lungs.
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Am. Rev. Respir. Dis. · Oct 1976
Lung function changes in smokers with normal conventional spirometry.
The comparative ability to detect early abnormalities in smokers by commonly used lung function tests was studied. Sixty-five healthy male nonsmokers served as a reference group and provided standards for 1-sec forced expiratory volume, vital capacity, end-tidal spirometry, spirometric forced mid-and end-expiratory flows, single-breath diffusing capacity, static lung volumes (helium method), and single-breath N2 closing volume measurements, In the present series of 80 male smokers, the measurements of forced mid-expiratory flow and forced end-expiratory flow did not improve the ability of the more conventional indices, 1-sec forced expiratory volume and the ratio of 1-sec forced expiratory volume to vital capacity, to detect obstructive lung disease. ⋯ In young or light smokers, Phase IV/vital capacity was more frequently increased than the slope of Phase III; an incerse trend was observed in older or heavier smokers. The single-breath N2 closing volume test also provided the greatest number of abnormal results when other indices were impaired in the same subjects.