• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.374-379
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• 2005

Background : The single-breath carbon monoxide diffusion capacity (DLCO) and the per unit alveolar volume (KCO; $D_LCO/VA$) gave discordant values when there was an abnormal alveolar volume (VA). However, the clinical significance of the discordant values in patients with airflow limitation has not been examined. This study investigated the $D_LCO$ and KCO changes after improving the airflow limitation. Methods : The baseline $D_LCO$ and KCO with lung volume were measured in patients with an airflow obstruction. The effective alveolar volume was measured using the single-breath $CH_4$ dilution method. The patients divided into two groups according to the baseline values: (1) increased KCO in comparison with the $D_LCO$ (high discordance) (2) decreased or not increased KCO in comparison with the $D_LCO$ (low discordance). The diffusion capacity and lung volume were measured after treatment. Results : There was no significant difference in the baseline lung volumes including the $FEV_1$ and FVC between the two groups. The $FEV_1$ and FVC were significantly increased in the high discordance group compared with the low discordance group after treating the airflow limitation. The $D_LCO$ and alveolar volume were significant higher in the high discordance group compared with the low discordance group while the TLC was not. Conclusion : The discordance between the $D_LCO$ and KCO could be translated into an airflow reversibility in patients with an airflow limitation.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.555-568
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• 1995

Background: It is most physiologic to measure the diffusing capacity of the lung by using oxygen, but it is so difficult to measure partial pressure of oxygen in the capillary blood of the lung that in clinical practice it is measured by using carbon monoxide, and single-breath diffusing capacity method is used most widely. However, since the process of withholding the breath for 10 seconds after inspiration to the total lung capacity is very hard to practice for patients who suffer from cough, dyspnea, etc, the intra-breath lung diffusing capacity method which requires a single exhalation of low-flow rate without such process was devised. In this study, we want to know whether or not there is any significant difference in the diffusing capacity of the lung measured by the single-breath and intra-breath methods, and if any, which factors have any influence. Methods: We chose randomly 73 persons without regarding specific disease, and after conducting 3 times the flow-volume curve test, we selected forced vital capacity(FVC), percent of predicted forced vital capacity, forced expiratory volume within 1 second($FEV_1$), percent of forced expiratory volume within 1 second, the ratio of forced expiratory volume within 1 second against forced vital capacity($FEV_1$/FVC) in test which the sum of FVC and $FEV_1$ is biggest. We measured the diffusing capacity of the lung 3 times in each of the single-breath and intra-breath methods at intervals of 5 minutes, and we evaluated which factors have any influence on the difference of the diffusing capacity of the lung between two methods[the mean values(ml/min/mmHg) of difference between two diffusing capacity measured by two methods] by means of the linear regression method, and obtained the following results: Results: 1) Intra-test reproducibility in the single-breath and intra-breath methods was excellent. 2) There was in general a good correlation between the diffusing capacity of the lung measured by a single-breath method and that measured by the intra-breath method, but there was a significant difference between values measured by both methods($1.01{\pm}0.35ml/min/mmHg$, p<0.01) 3) The difference between the diffusing capacity of the lung measured by both methods was not correlated to FVC, but was correlated to $FEV_1$, percent of $FEV_1$, $FEV_1$/FVC and the gradient of methane concentration which is an indicator of distribution of ventilation, and it was found as a result of the multiple regression test, that the effect of $FEV_1$/FVC was most strong(r=-0.4725, p<0.01) 4) In a graphic view of the difference of diffusing capacity measured by single-breath and intra-breath method and $FEV_1$/FVC, it was found that the former was divided into two groups in section where $FEV_1$/FVC is 50~60%, and that there was no significant difference between two methods in the section where $FEV_1$/FVC is equal or more than 60% ($0.05{\pm}0.24ml/min/mmHg$, p>0.1), but there was significant difference in the section, less than 60%($-4.5{\pm}0.34ml/min/mmHg$, p<0.01). 5. The diffusing capacity of the lung measured by the single-breath and intra-breath method was the same in value($24.3{\pm}0.68ml/min/mmHg$) within the normal range(2%/L) of the methane gas gradient, and there was no difference depending on the measuring method, but if the methane concentration gradients exceed 2%/L, the diffusing capacity of the lung measured by single-breath method became $15.0{\pm}0.44ml/min/mmHg$, and that measured by intra-breath method, $11.9{\pm}0.51ml/min/mmHg$, and there was a significant difference between them(p<0.01). Conclusion: Therefore, in case where $FEV_1$/FVC was less than 60%, the diffusing capacity of the lung measured by intra-breath method represented significantly lower value than that by single-breath method, and it was presumed to be caused largely by a defect of ventilation-distribution, but the possibility could not be excluded that the diffusing capacity of the lung might be overestimated in the single-breath method, or the actual reduction of the diffusing capacity of the lung appeared more sensitively in the intra-breath method.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.549-555
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• 1999

Background: Patients who are considered for major pulmonary resection are generally evaluated by spirometry and clinical assessment to predict morbidity and mortality. Despite this, none has yet proved to be a convenient and reliable estimate of risk. Material and Method: A retrospective analysis was performed in 167 patients who were diagnosed for lung cancer, bronchiectasis, pulmonary tuberculosis, and other benign pulmonary disease, and who underwent major lung resections. The relationship of 25 preoperative or postoperative variables to 19 postoperative events were classified into categories as operative mortality, pulmonary or cardiovascular morbidity, and other morbidity was assessed. Logistic regression analysis and $\chi$2 analysis were used to identify the relationship of the operative risk factors to the grouped postoperative complications. Result: The best single predictor of complications was the percent predicted postoperative diffusing capacity (pulmonary morbidity, p<0.009; cardiovascular morbidity, p<0.003: overall morbidity, p<0.004). Conclusion: The diffusing capacity of the lung for carbon monoxide was an important predictor of postoperative complications than the spirometry, and it usually should be a part of the evaluation of patients being considered for pulmonary resection.

• Tuberculosis and Respiratory Diseases
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• v.64 no.2
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• pp.80-86
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• 2008

Background: Park et al. developed the Korean reference equation for the measurement of diffusing capacity in 1985. However, the equation has not been widely used in Korea and foreign reference equations have been popularly used. We intended to compare the clinical usefulness and the accuracy of the the Korean reference equation (Park's equation) with that of the foreign equation (Burrows' equation) that is commonly used in Korea. Methods: 1. Evaluation of clinical usefulness; Among 1,584 patients who underwent diffusing capacity ($D_LCO$) at the Asan Medical Center from July to December 2006, group A subjects included 276 patients who had different interpretations of $D_LCO$ in trials employing Burrows' equation and Park's equation. Clinical assessment was decided by consensus of two respiratory physicians. In order to evaluate the clinical usefulness of Burrows' equation and Park's equation, agreement of clinical assessment and $D_LCO$ interpretation were measured. 2. Evaluation of accuracy; Group B subjects were 81 patients with interstitial lung disease (ILD) and 39 normal subjects. The 81 ILD patients were diagnosed following a surgical lung biopsy. The accuracy of diagnosing ILD as well as sensitivity and specificity were evaluated according to the use of the reference equations (Burrows' equation and Park's equation) for $D_LCO$. Results: Agreement between clinical assessment and interpretation of $D_LCO$ was 22% for the use of Burrows' equation and 78% for the use of Park's equation. The sensitivity and specificity of the Burrows' equation for diagnosing ILD were 64.2% and 100%. The sensitivity and specificity of the Park's equation for diagnosing ILD were 90.1% and 100%. The sensitivity of the Park's equation for diagnosing ILD was significantly higher than that of Burrows' equation (p<0.001). Conclusion: The Korean reference equation (Park's equation) was more clinically useful and had higher sensitivity for diagnosing ILD than the foreign reference equation (Burrows' equation).

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.597-603
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• 1994

Background: Because of the power of HRCT to detect the minute changes in lung parenchyme and the advantage of noninvasiveness, it may be the ideal method of follow-up evaluation of the patients with diffuse interstitial pulmonary fibrosis. So the aim of the study is to find out whether the change of HRCT during the course of the disease can represent the change in symptom and pulmonary function test. Method: Thirteen patients with diagnosis of diffuse interstitial pulmonary fibrosis who had more than two times of HRCT during the course of disease were studied. The extent of the disease in HRCT was measured at three levels using image analyzer. The ralationship between the percent change in the disease extent in HRCT, symptom score, and pulmonary function tests were analysed. Results: The change of disease extent in HRCT has good correlation with the change in dyspnea and diffusion capacity(r=0.716, p=0.0012). But there was no correlation between the change of HRCT and FVC or TLC. Also significant inverse correlation was noted between the change in dyspnea and diffusion capacity(r=-0.707, p=0.0047). Conclusion: These data suggest that HRCT may be a good method of follow-up in diffuse interstitial pulmonary fibrosis.

• Tuberculosis and Respiratory Diseases
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• v.61 no.3
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• pp.218-226
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• 2006

Background: The lung volume and diffusing capacity are influenced by ethnicity. However, there are no equations for predicting the normal lung volume in the adult Korean population, and there is only one equation for diffusing capacity. The aim of this study is to select the most suitable reference equation for the Korean population. Method: 30 men and 33 women at Hanyang University Guri Hospital, and 27 men and 34 women at Asan Medical Center in healthy nonsmoking adults were enrolled in this study. The subject's age, gender, height, weight, lung volume by plethysmography, and diffusing capacity by a single breathing method were obtained. The most suitable equation with the lowest sum of residuals between the observed and predicted values for lung volume and diffusing capacity was selected. Result: At Hanyang University Guri Hospital, the equations with the lowest sum of residuals in the total lung capacity were ECSC's equation in males (sum of residual: 0.04 L) and Crapo/Morris's equation (-1.04) in women. At the Asan Medical Center, the equations with the lowest sum of residuals in the total lung capacity were Goldman/Becklake's equation in males (sum of residual: -2.35) and the ECSC's equation -4.49) in women. The equations with the lowest sum of residuals in the Diffusing capacity were Roca's equation in males (sum of residual: -13.66 ml/min/mmHg) and Park's in women (25.08) in Hanyang University Guri hospital and Park's equation in all cases in the Asan Medical Center (male: -1.65, female: -6.46). Conclusions: Until a reference equstion can be made for healthy Koreans by sampling, ECSC's equation can be used for estimating the lung volume and Park's can be used for estimating the diffusing capacity.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.471-479
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• 2015

In this study, we measured lung function and lung diffusing capacity of Jeju women divers who were gathering activities in the sea waters of the low temperature. The results Compared with ordinary women of the same age group were as follows: First, FVC and FVC% of Jeju women divers were significantly higher than the general population. Second, $FEV_1/FVC$ had no significant difference the difference between the general population and Jeju women divers. Third, $FEF_{25{\sim}75%}$ in both groups was in the normal level, especially Jeju women divers groups showed significantly higher FEF results than normal women. Fourth, DLCO is no significant difference between the Jeju divers and the general female group. Despite the advanced age of Jeju women divers These results indicated that adaptation and development of state institutions while performing long-term lung apnea immersion activities. Despite the advanced age of Jeju women divers These results indicated that adaptation and development of state institutions while performing long-term lung apnea immersion activities.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.489-499
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• 1999

Background: The patient with bronchiectasis may have obstructive ventilatory impairment combined with mild restrictive ventilatory impairment due to fibrosis of surrounding lung parenchyme and pleural adhesions caused by chronic recurrent pulmonary infections. Since hyperinflation or emphysematous change can be occured in bronchiectasis, pulmonary functions such as lung volumes and diffusing capacity may also vary with associated emphysema. Methods: For the evaluation of lung volumes and diffusing capacity in bronchiectasis with respect to the anatomic types and severity of bronchiectasis, a total of 40 cases comprising 24 cases of tubular, and 16 cystic type of bronchiectasis were analyzed retrospectively. Correlation between lung functions and extent of bronchiectasis or associated emphysema detected in HRCT were also evaluated. Results: Vital capacity(VC) tended to decrease in cystic type than in tubular type. As the severity of bronchiectasis became serious, the VC were significantly reduced, whereas the total lung capacity(TLC), residual volume(RV) and its ratio to the total lung capacity(RV/TLC) had no significant difference. Lung clearance index(LCI) was significantly increased in cystic type than in tubular type, whereas the slope of phase III in single breath nitrogen curve($\triangle$N2/L) was not significantly changed regard to the type and severity of bronchiectasis. DLCO and DLCO/VA reflecting diffusing capacity were significantly decreased in cystic type and also as the severity of bronchiectasis became serious. The correlation coefficient of VC, DLCO and LCI with the extent of bronchiectasis were -0.322, -0.339 and 0.487, respectively, whereas other parameters were not significantly correlated with the extent of bronchiectasis. VC and DLCO correlated negatively with the extent of emphysema while RV, RV/TLC, LCI and $\triangle$N2/L correlated positively. Conclusion: These findings suggest that the reduction of VC and diffusing capacity or uneven distribution of inspired gas in bronchiectasis are related to both the extent of bronchiectasis and associated emphysema while increased residual volume be related to the extent of associated emphysema alone.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.992-999
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• 1998

Background: To correlate the emphysema score for quantification of the overall extent of emphysema in both lungs by CT with physiologic fingings and to get more objective and simple method to assess the extent of emphysema. Method: Thin-section CT and pulmonary function test(PFT) were performed in 17 patients with emphysema (all males, mean age, 62 years). Emphysema score was obtained as percentage of emphysematous lung area, dividing the total area of the emphysema(voxels with attenuation value less than -880, -900, -920HU, respectively) by the overall area of both lungs(voxels with attenuation value less than -400HU) with highlighting voxels using "Density mask" program. Emphysema score was calculated from whole lung(ESV) and 5 representative scans(ESR) using "Density mask", Visual emphysema score(ESV) was obtained by visual assessment from 5 representative scans. Correlation of these emphysema scores(ESW, ESR, ESV) and physiologic findings were performed, comparing the ESW with ESR and ESV. Results: ESW had correlation with DLCO(r=0.53-0.64) and $FEV_1/FVC$(r=0.42-0.57) among PFT parameters. ESR had good correlation with ESW and with PFT parameters as well. ESV did not correlate with PFT parameters except DLCO. Conclusion: CT quantification of emphysema using "density mask" correlated well with physiologic findings. To assess the severity of emphysema, both ESW and ESR are more reliable than ESV, and ESR is recommended in routine practice as it is objective, simple and reliable.

• Tuberculosis and Respiratory Diseases
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• v.65 no.5
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• pp.385-389
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• 2008

Background: There are reports that food deprivation causes emphysematous changes in the lungs of rats and humans. However, the meaning of this phenomenon in patients with chronic obstructive pulmonary disease has not been evaluated. The aim of this study was to determine the correlations between the caloric intake and parameters of the lung function in patients with chronic obstructive pulmonary disease. Methods: Patients with chronic obstructive pulmonary disease who had visited the respiratory clinic from March, 2006 for one year were enrolled in this study. The patients underwent pulmonary function tests, and a dietitian evaluated their nutritional intake using a food record method. Results: There was no correlation between the total caloric intake and forced vital capacity (FVC, %predicted) or forced expiratory volume in one second ($FEV_1$, %predicted). The total caloric intake showed a positive correlation with the diffusing capacity of carbon monoxide (DLCO %predicted, DLCO/VA %predicted), and a negative correlation with the total lung capacity (TLC, %predicted). Of the calories taken, only calories from protein intake correlated with the diffusing capacity of carbon monoxide (DLCO %predicted, DLCO/VA %predicted). Conclusion: The total caloric intake of patients with chronic obstructive pulmonary disease showed a positive correlation with the diffusing capacity of the lung, and a negative correlation with the total lung capacity. Further study on the linkage between the caloric intake and severity of emphysema is needed.