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PubMed1990

Lymphangiomyomatosis: CT, chest radiographic, and functional correlations.

Eight patients with the diagnosis of lymphangiomyomatosis were evaluated with computed tomography (CT), chest radiography, and pulmonary function tests to determine the relationship between the extent of disease seen on imaging studies and functional status. Chest radiographic assessment included the subjective determination of disease extent and measurements of lung length and the arc of the right hemidiaphragm. Disease extent on CT scans was scored as a percentage of lung that was abnormal on the basis of visual assessment of the degree of cystic replacement of the lung parenchyma. Significant correlations were observed between CT scores and percentages of predicted forced expiratory volume in 1 second/forced vital capacity (r = -.92, P less than .002) and diffusing capacity of the lungs for carbon monoxide (r = -.80, P less than .017). No significant correlations were observed between subjective chest radiographic scores and pulmonary function tests, although measurements of lung length and percentage of predicted total lung capacity were correlated (r = .76, P less than .045). CT was more accurate than chest radiography in defining the presence and extent of parenchymal cysts and provided for greater morphologic-physiologic correlation. CT, particularly high-resolution CT, may be useful in the diagnosis and longitudinal evaluation of patients with this disease and may be more sensitive than pulmonary function tests in the early stages of lung damage.

Adult↗
PubMed2006

[A comparison of respiratory muscle strength, pulmonary function tests and endurance in patients with early and late stage ankylosing spodylitis].

BACKGROUND: Ankylosing spondylitis (AS) is a multisystemic disease in which pulmonary function is altered owing mainly to the restriction of chest wall involvement. A restrictive ventilatory defect has been extensively reported. This has been suggested to be a consequence of reduced mobility of the thoracic cage. Respiratory function in AS shows a typical restrictive pattern but pulmonary compliance, diffusion capacity, and arterial blood gases are normal. OBJECTIVE: The objective of the present study was to compare pulmonary function tests (PFT), respiratory muscle strength (MIP, MEP) and endurance (MVV) in early and late AS. METHODS: A total of 35 patients (30 males, 5 females) took part, all of whom met the New York criteria for AS. Patients were divided into two groups for the comparison of early (disease duration <10 years, 20 patients) and late (disease duration >10 years, 15 patients) manifestations in pulmonary function tests, respiratory muscle strength and endurance, dyspnea score, chest expansion, and BASFI score. In addition, 21 healthy controls were compared with the AS patients. Measurement of chest expansion was performed in all subjects. Pulmonary function tests were performed by spirometry. Respiratory muscle strength was evaluated by a mouth pressure meter (MPM). Functional status was assessed by BASFI in all AS patients. RESULTS: There was no significant difference in body mass index between the groups. The FVC and FEV(1) were significantly lower in late AS (p=0.003, p=0.03, restrictive ventilatory defect ). Chest expansion was significantly lower in late AS (p<0.05). There was no significant difference for MIP or MEP values between late AS, early AS and the controls (p>0.05). Endurance (MVV) was significantly lower in late AS patients (p=0.05). Although the BASFI and dyspnea scores were higher in late AS, they did not reach significant levels. In addition, age was negatively correlated with MIP and MEP in late AS (r=-0.733; p=0.02, r=-0.667; p=0.05). CONCLUSION: This study demonstrates that FVC and FEV(1) (hallmarks of a restrictive pattern), MVV (endurance) and chest expansion are especially involved in long-standing AS. Therefore, improvement of the thoracic cage should be taken into consideration, especially in early AS. These patients should be encouraged to make regular respiratory exercises for preventing the limitation of chest expansion and also improving cardiopulmonary fitness and respiratory endurance.

Adult↗
PubMed1978

Pulmonary vascular changes following air embolism in the dog.

The effect of an intravenous injection of air in a dose of 1 ml/kg body weight was determined in 15 healthy mongrel dogs. In 4 control dogs the mean pulmonary artery pressure rose to 2-3 times the resting values at 30 seconds, and carbon monoxide diffusing capacity and pulmonary capillary blood volume decreased by half. In the animals pretreated either with heparin or with methysergide (antiserotonin group) the results were the same as in the control animals. In the vagotomized dogs, the rise in pulmonary artery pressure was not significant, and the decrease in pulmonary capillary blood volume was of lesser magnitude and shorter duration than in the control and the antiserotonin dogs. It is concluded that the intravenous injection of air in supine dogs causes a transient obstruction of small pulmonary arteries. Evidence is presented to implicate a vagal mechanism in both main aspects of the response, namely the pulmonary artery pressure rise, and the partial obstruction of the pulmonary capillary bed. These studies offer additional explanation of the symptoms of respiratory distress observed in rapid decompression.

Animals↗
PubMedDate not supplied

Prediction equations for fractional CO uptake derived from 50 healthy subjects.

Fractional CO uptake was measured in 50 healthy men and women aged 18 to 65 years in the sitting and supine positions and during the steady state of treadmill exercise at four different workloads. The unwanted influence of respiratory frequency and ventilation on fractional uptake and the indirect effect of workload (via changes in total diffusing capacity) were taken into account, according to previous theoretical analysis, in formulating prediction equations. Correlations for the best equations were between 0.816 and 0.971. The extra precision they afford makes the fractional CO uptake a potentially useful clinical measurement, less prone to spurious results than conventional measurements of diffusing capacity.

Adolescent↗
PubMed1994

Measurement of lung diffusing capacity and functional residual capacity in lambs during the first postnatal month.

The diffusing capacity of the lung for carbon monoxide (DLCO) is an important index of lung function but is not easily measured in spontaneously breathing animals with small lung volumes. Our aim was to devise a simple rebreathing method that would allow us to make serial measurements of DLCO in spontaneously breathing lambs during their first month after birth. By adding He to the rebreathing gas mixture, we were also able to measure functional residual capacity (FRC), enabling us to normalize DLCO with respect to FRC. We have compared FRC measured by the rebreathing technique with that measured by a closed-circuit helium dilution method (FRCcc). Using the rebreathing method we found highly significant positive correlations between DLCO and body weight (r = 0.70, P < 0.001) and between FRC and body weight (r = 0.79, P < 0.001). There was no significant change in DLCO/FRC over the first postnatal month; the mean value was 8.1 +/- 0.6 mL/min/mmHg/mL. Rebreathing FRC was highly correlated with FRCcc (r = 0.88, P < 0.001), but was lower than FRCcc by about 18%. In normal lambs DLCO and FRC, but not DLCO/FRC, increased during the first month after birth, suggesting that the increase in DLCO parallels lung growth. We conclude that the modified rebreathing method is suitable for measuring DLCO in small uncooperative spontaneously breathing animals.

Analysis of Variance↗
PubMed2006

Reduced pulmonary function in children with the Fontan circulation affects their exercise capacity.

Most children with functionally univentricular hearts nowadays are treated surgically by creating a total cavopulmonary connection. In the resulting Fontan circulation, the venous return and the pulmonary arterial bed are coupled in series, bypassing the heart. This gives the potential for interaction between the abnormal circulation and function of the lungs. In this study, we investigated the pattern of impairment of pulmonary function, and its relation to decreased exercise capacity. We performed spirometry in 33 (85 percent) of 39 eligible Norwegian children, aged from 8 to 16, with a total cavopulmonary connection, along with whole body plethysmography, the carbon monoxide single breath test, and a peak treadmill exercise test. The single breath test showed a mean corrected diffusing capacity of 66.5 percent of predicted, giving a z score of minus 2.88. The mean residual volume measured by whole body plethysmography was 146.8 percent, equivalent to a z score of 2.46, whereas the mean residual volume measured by the single breath test was 102.4 percent of predicted, this being the same as a z score of 0.43. The mean peak treadmill exercise test was 70.0 percent of predicted, equivalent with a z score of minus 3.07. Mean forced vital capacity was 85.7 percent of predicted, the equivalent z score being minus 0.92. Lung function correlated with the peak treadmill exercise test. We have shown, therefore, that children with the Fontan circulation have reduced diffusing capacity, possibly caused by the abnormal circulation through the lungs. The difference between residual volume measured by plethysmography and the single breath test implies trapping of air. The correlation of parameters for lung function with peak consumption of oxygen during exercise indicates that the abnormalities of pulmonary function may affect physical capacity.

Adolescent↗
PubMedDate not supplied

[The effect of physical exercise on lung diffusing capacity in patients with chronic obstructive lung disease].

Diffusing lung capacity (DLCO) was determined at various levels of exercise in three groups of subjects: group with normal spirometry, patients with moderate and severe chronic obstructive pulmonary disease (COPD). Subjects were males with similar anthropometric characteristics and age. Positive correlation between progressive exercise and DLCO was obtained only for the first and second group. Resting and exercise DLCO values were statistically different between the groups. COPD attenuated DLCO at all levels of exercise. However, patients with moderate COPD had DLCO in the normal range, while severe COPD patients had reduction in DLCO during rest and exercise. This test is useful in assessing the working capacity in COPD patients and also as a screening test for exercise-induced hypoxemia.

Adult↗
PubMed1993

Pulmonary function in healthy Chinese, Malay and Indian adults in Singapore.

Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), single-breath diffusion capacity measurements (effective alveolar volume (VA), carbon monoxide transfer factor (DLCO) and transfer coefficient (KCO)) were determined in 452 healthy Singaporean adults (277 males and 175 females) aged 20-70 years. The ratio of Chinese, Malay and Indian subjects was 5:2:3 in both sexes. Age, height and weight in the males were all significantly correlated with FEV1, FVC, DLCO, VA and PEFR. However, for females, only age and height were significantly correlated with the studied lung function parameters. Significant ethnic differences were observed for most of the pulmonary functions (except KCO and PEFR) among the Chinese, Malays and Indians for both males and females. The predicted FEV1 and FVC values (specific age and height) for both sexes were highest among the Chinese followed by the Malays than Indians, in that order. Regression equations, with age and height as independent variables, were derived for males and females in each ethnic group to predict normal pulmonary function for the Singapore Chinese, Malay and Indian populations. The predicted values of various pulmonary function measurements obtained from these regression equations for subjects of specified age (30 years) and height (165 cm for men, 155 cm for women) were compared with those reported in other studies. Differences were observed among the different races.

Adult↗
PubMed1979

[Renal failure and carbon monoxide diffusing capacity of the lung (author's transl)].

Reduced carbon monoxide diffusing capacity of the lung (DLCO) is reported in patients with impaired renal function. Since DLCO also depends on the pulmonary capillary blood volume the role of renal anaemia was evaluated. Measurements were carried out in 43 azotaemic patients [serum creatinine (SKr) 1.5 to 14.0 mg/100 ml], without evidence of cardiovascular or pulmonary complications of uraemia, of SKr, haemoglobin concentration (Hb) and steady state DLCO. In the case of DLCO values allowance was made for body surface area and thoracic gas volume. The relation was studied of the corrected DLCO to SKr and to Hb. There was a higher statistical correlation between DLCO and Hb than between DLCO and SKr. After additional correction of DLCO for Hb, no correlation to SKr was found. It is concluded that the reduction in DLCO in uraemia is due largely to a low Hb and, hence, to renal anaemia rather than to uraemic damage of interstitial lung tissue.

Adolescent↗