الفهرس 
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Abstract
Hyperinflation is clinically relevant for patients with COPD because it contributes to the dyspnea and morbidity associated with the disease. In a significant proportion of patients with COPD, reduced lung elastic recoil combined with expiratory flow limitation eventually leads to lung hyperinflation during the course of the disease. The aim of this study was to:- (1) compare flow parameters with volume parameters in detecting response to bronchodilators in stable COPD, (2) study correlations of the morphologic features of Multislice CT in COPD patients with pulmonary function tests parameters, (3) study the effect of pulmonary rehabilitation on subjective and objective parameters in hyperinflated stable COPD patients, and (4) compare the effect of inhaled long acting anticholinergic (Tiotropium bromide as an example) to that of inhaled long acting ẞ2 agonist (Salmeterol as an example) on hyperinflation in stable COPD patients and also comparing this effect to that of pulmonary rehabilitation.
Exertional dyspnea, pulmonary function tests, 6 minute walking distance, number of rescue puffs needed were the main outcome measures.
In this study we included 110 patients from Chest outpatient clinic, Assiut University Hospital diagnosed as COPD. For all patients thorough medical history was taken, clinical examination, complete resting pulmonary functions (spirometry & whole body plethysmography( before and after bronchodilator were done .The following parameters were measured (FEV1, FVC, IC, FRC, RV, TLC), also dyspnea sore, 6 minute walking distance, number of rescue puffs needed in the different treatment periods were assessed and compared for the different modalities
The study included 2 parts:
Part I: 50 patients who underwent Multislice CT chest to study its clinical and pulmonary functions correlations.
Part II: 60 patients who were randomly allocated to either Control group, Pulmonary rehabilitation group, Salmeterol (50 mcg) inhalation group, or Tiotropium bromide (18 mcg) inhalation group to study the effect of each modality on hyperinflation in COPD patients.
Spirometric bronchodilator responsiveness (reversibility) was assessed for both flow and volume parameters. There was a non significant difference between the mean pre and post bronchodilator values for FEV1 which represents flow (p0.05). A highly significant difference between the mean pre and post bronchodilator values for FVC and IC was found (p0.001 for each). A significant difference between the mean pre and post bronchodilator values for FRC, RV and TLC was found (p0.05 for each). These results indicate that volume parameters are more indicative of response to bronchodilators than flow parameters in COPD patients.
Given the observation that potentially responsive patients experience important improvements in lung volumes without an identifiable correlation with the increase in FEV1, we suggest measuring lung volumes along with the standard spirometric indices when determining bronchodilator responsiveness in patients with baseline hyperinflation. Studies examining the efficacy of new treatments also should pay closer attention to the effect on lung volumes. Further prospective studies examining the behavior of lung volumes after bronchodilator administration in patients with definite clinical and functional diagnoses of COPD and hyperinflation are required.
Multislice CT classification as regard degree of emphysema revealed mild emphysema in 46% 0f cases, moderate emphysema in 30% of cases and severe emphysema in 24% of cases. Degree of emphysema showed a very highly significant correlation with each of pulmonary function tests parameters measured (p0.001) and there was a highly significant difference (p0.01) between the dyspnea scores in different emphysema severity grades (Table 17).
Emphysema distribution was upper zone predominant in 60% of cases, lower zone predominant in 34% of cases, and diffuse in 6% of cases. Classification of degree and homogeneity of emphysema using Multislice CT added to the understanding of nature of hyperinflation and its impact on exertional dyspnea sensation and PFTs parameters.
In this study we found that stable COPD patients who underwent pulmonary rehabilitation for 12 weeks showed a significant increase in mean FEV1, FVC, and IC (p0.05 for each), significant decrease in TLC (p0.05) and a highly significant decrease in FRC and RV (p0.01 for each). There was a significant reduction in the mean dyspnea score (p0.05) and highly significant difference (p0.01) between baseline and final values for the mean 6 minute walking distance and number of daily rescue puffs.
This indicates that pulmonary rehabilitation is effective in improving both clinical and PFTs parameters.
Salmeterol (50 mcg) inhalation when given for12 weeks, the mean values for FEV1and FVC were increased significantly (p0.05 for each). Similarly, there was a highly significant increase in the mean IC in comparison with baseline (p0.01). Wheras there was a significant reduction in the mean RV (p0.05 for each), and a highly significant reduction in the mean FRC and TLC (p0.01 for each) when compared with the baseline values. There was a significant reduction in the mean dyspnea score (p0.05) and highly significant difference (p0.01) between baseline and final values for the mean 6 minute walking distance and number of daily rescue puffs.
Tiotropium bromide (18mcg) inhalation when given for 12 weeks, there was a highly significant increase in mean FEV1and FVC values (p0.01 for each). Similarly, the mean IC increased significantly when compared with baseline (p0.05).The mean value for FRC, RV and RV/TLC actual ratio showed a very highly significant reduction after treatment as compared with baseline (p0.001). There was a very highly significant reduction in the mean dyspnea score (p0.001) and highly significant difference (p0.01) between baseline and final values for the mean 6 minute walking distance and number of daily rescue puffs.
We conclude that pulmonary rehabilitation and the regular use of inhaled long acting bronchodilator reduce hyperinflation and air trapping and improve patient centered outcomes in COPD patients.
Recommendations :
1.measurement of lung volumes in addition to the standard spirometric indices is recommended when determining bronchodilator response in COPD patients with baseline hyperinflation.
2. Including pulmonary rehabilitation as a routine modality in management of COPD patients, and institution of a pulmonary rehabilitation clinic in our department.