The Aged Lung per se and Chronic Pulmonary Diseases in and around the Aged Lung

Transcription

1 Special Article* The Aged Lung per se and Chronic Pulmonary Diseases in and around the Aged Lung Takashi Nakamura I. Introduction Professor of the First Department of Internal Medicine, School of Medicine, Tohoku University, Sendai The patho-physiological changes of the lungs due to aging are supposed to be brought about by the following factors ; (1) the accumulation of the external irritants with a long duration, because the lungs are the only organ directly exposed to the atmosphere amongseveral internal organs of the body. (2) the morphologic changes of the lung tissue per se (3) the several effects of the other organs an dtissues, which have already been changed by aging, to the lungs. (4) the effects of the organs which are directly related to respiration, such as diaphragm and rib-cage, to the lungs, when they have already been changed by aging. (5) the accumulations of the past intra-pulmonary diseases. Amongthese factors, the first and fourth factors are supposed to be characteristic to the lung and to be the principal causes to establish the patho-physiological characteristics of the aged lungs or so-called " senile lung". In the aged lungs, the decrease in ciliarly action and obstructive impairment in expiration are brought about, and, in turn, they make difficult to expectrate sputum. Retention of sputum with contamination of bacteria and suitable temperature and moisture, are supposed easily to bring about the intra-airway infection. Therefore, it would be said that the aged lung is always exposed to the airway infection, even though its grade could be different for each aged man. In other words, it would be supposed that most of aged men were suffering from chronic bronchitis. II. Chronic Bronchitis Chronic bronchitis has been characterized by hypersecretion of the bronchial glands, and has been diagnosed by the criteria proposed by Fletcher, 1959, But this criteria is only based on the clinical symptoms, such as cough and sputum, and moreover there have been no morphologic basis. Therefore, the author thought * Presented at the 66th Annual Meeting of the Japanese Society of Internal Medicine* April 1, 1969, in Sendai.

2 82 Nakamura Jap. J. Med that it would be the best way for diagnosis of chronic bronchitis to clarify its morphologic characteristics, even though in Report of an Expert Committee for Chronic Cor Pulmonale, in 1961, the committee pointed out that " although it would be desirable to define chronic bronchitis in anatomical terms, the committee do not consider this possible at present ". For this purpose, the author was convinced that our new clinical diagnostic method, Selective Alveolo-Bronchography (SAB), which was developed 3 years ago, could be very useful. This method has already been reported in detail at 17th general meeting of Japan Medical Association and after then reported in several medical journals. Compared with the ordinary bronchography, SABhas the following clinical advantages to clarify in detail, while a patient is alive; (1) the anatomical changes in the airway from segment bronchus to terminal bronchiole, (2) these in terminal bronchiole per se, (3) these in alveolar regions, (4) the correlation between the airway lesion and alveolar lesion, (5) technically physical loads to a patient are quite small. However, SAB has a short coming to deduce the anatomical changes to the all pulmonary regions. But, compared with liver and kidney biopsy, SAB can detect the anatomical changes of about 1/20 of all pulmonary regions and moreover, in chronic pulmonary diseases, such as chronic bronchitis and chronic pulmonary emphysema, the lesions are used to spread out almost all the pulmonary regions, therefore SABis supposed to be muchworthwhile from the clinical diagnostic points of view....,..-...å å å As the first step to clarify the anatomical changes, characteristic to chronic bronchitis, the author carried out tlie theoretical considerations to bring about deformities of the airways system, used to occur in so called "chronic obstructive lung diseases " and then, as next step, å concerning the several important findings obtained by the ordinary bronchography, such as "pool", "spider", "fringe", "spike", appearance like accordion and others, the author investigated to clarify what anatomical basis brings about such deformities from the morphological points of view in the autopsied lungs as well as from bronchoscopical points of view. Based on these fundamental investigations, we concluded, at present, that "fringe", "spike", ectatic change and organic interupting appearance in SABrepresented the useful index for the organic changes of the bronchial wall per se and functional interupting appearance in SABand multiple dotty spots in bronchoscopy represented the active inflammatory changes. Moreover, considering the concept of "chronic", the author proposed the following clinical diagnostic criteria as the fundamental concept of chronic bronchitis; " chronic bronchitis is a recurrent and active inflammation of the bronchial wall, in which the organic changes have been already brought about "'.

3 W.-9, No. 2 -t AGED LUNG PER SE AND CHRONIC PULMONARY DISEASES 83 III. Branchial Asthma The author carried out SAB in 25 cases of bronchial asthma and observed that the narrowing appearance at the location where bronchi branched and spastic appearance in SABwere characteristic for bronchial asthma, compared with ectatic appearance, often seen in cases of chronic bronchitis. XV, Diseases in and around Terminal Bronchioles Simon et al. in 1953 proposed "peripheral poor filling" in the ordinary bronchography as one of the most important features in chronic bronchitis. According to their finding, the author studied the bronchographical appearances in chronic bronchitis over 40 years of age and proved Simon's finding. However, as described in the previous section, SABmade us possible to clarify several lesions in and around terminal bronchioles on the morphological basis. Therefore, the author could establish, at present, not only the morphological basis for " peripheral poor filling" but; also for several diseases in and around terminal bronchioles. The author presented the following case of ; 1) chronic bronchiolitis obliterans, :2) honey-comb lung, 3) subsegment bronchitis. V. Chronic Pulmonary Emphysema 1) New clinical diagnosis by SAB The author presented the standard films of SABestablished in 1967, for the purpose of clinical diagnosis of ^hroniic 'pulmonary emphysemaon ;the.morphological basis. These films were as follows; a) young healthy lung, b) senile lung, c) centrilobular emphysema, d) panacinar emphysema. 2) Criticism to the diagnostic criteria for chronic pulmonary emphysema, proposed by Emphysema-Research-Group in Japan Emphysema-Research-Group in Japan proposed that chronic pulmonary emphysema woulcj be highly suspected on clinical basis, when the ratio of FEY^to Yital Capacity was under 55%. Therefore, the author studied the reliability.of its.proposition from the morphological basis obtained by SAB, and found that, among 54 cases of chronic pulmonary emphysema confirmed by SAB, 41 cases showed under 55% of the value for the ratio of FEV^otoVC. Accordingly as far as chronic pu'u monary emphysema was concerned, it would be said that the diagnostic criteria proposed by Emphysema-Research-Group were highly reliable (about 80% hit);. However, the same study done on 149 cases, selected from all cases in which SAB and pulmonary function tests were carried out with the relation to the theme of this paper (therefore in these case "senile lungs", chronic bronchitis, bronchial asthma, chronic pulmonay emphysema and others were included and pulmonary tuberculosis and silicosis were excluded), showed that, among 74 cases with the value

4 84 Nakamura. Jap. J. Med. 1970* for the ratio of FEV^o to VC under 55%, only 41 cases were confirmed by SABa& chronic pulmonary emphysema.in other words, as far as these 149 cases were concerned, it would belaid that the diagnostic criteria proposed by Emphysema- Research-Group were not so reliable (about 55%hit), but when the cases of bronchialasthma were excluded from these 149 cases, the diagnostic hit increased up to about 70%. 3) Criticism to the diagnostic criteria proposed by Burrows et al. Burrows et al. in 1965 proposed the clinical diagnostic criteria for chronic pulmonary emphysema, based on the exact clinical features of 32 autopsied cases of so-called chronic obstructive lung disease, that is, Type A represented severe emphysema, Type B, absent or mild emphysema. According to their diagnostic criteria, the author classified 54 cases of chronic pulmonary emphysema confirmed by SABinto Type A and B, and found that Type A showed panacinar emphysema and Type B, panacinar as well as centrilobular emphysema, including far advanced emphysema. Therefore, the author came to the following conclusion; as far as Type A was concerned, the author agreed with Burrows's finding, however, concerning Type B, could not obtain the same result. 4) Patho-physiological characteristics of panacinar and centrilobular emphysema For the purpose of establishing the patho-physiological characteristics of panacinar and centrilobular emphysema respectively, the author studied the results of the exact pulmonary function tests in 54 cases of chronic pulmonary emphysema, confirmed by SABand found that both static pulmonary compliance and DLCO/VA showed the different patterns between these two types of emphysema. In panacinar emphysema, the grade of impairments in terms of both static pulmonary complianceand DLCo/VAranged widely from normal to high, on the contrary, in centrilobular emphysemait was somewhatlimited, especially static pulmonarycompliances were within normal limits in respectable cases. Therefore the author supposed that in: centrilobular emphysemathe respectable numbers of alveoli were still normally functioned, even in the far advanced type, compared with panacinar emphysema. VI. The Correlation between Alveolar Lesion and Airway Lesion, Considering Pathogenesis of Chronic Pulmonary Emphysema Basing on the study of the exact clinical features, pulmonary function test and the findings of SABin chronic pulmonary emphysema, the author supposed, at present, that in centrilobular emphysema the airway lesion preceded first, then it brought about the alveolar lesion via and beyond terminal bronchiole, on the contrary, in panacinar emphysema the alveolar lesion preceded first, then the airwaylesion was brought about as a result. However, this pathogenesis of two types of emphysemacould not be applied to all cases of emphysema,because there were some exceptional cases.

5 VoL 9, No. 2 AGED LUNG PER SE AND CHRONIC PULMONARY DISEASES 85 VII. Diagnosis of Chronic Obstructive Lung Diseases, in Conclusion 1) Chronic bronchitis could be diagnosed, when the author's definition described in the previous section was satisfied, when accompanied with no evidence of alveolar destruction. 2) Chronic bronchitis with chronic emphysema could be diagnosed, when the -existence of centrilobular emphysemawas confirmed and at the same time, the airway infection was highly suspected as a pathogenesis of emphysema. 3) Chronic bronchitis and chronic emphysemacould be diagnosed, whenthe correlation between alveolar lesion and the airway lesion was not clearly confirmed 4) -Chronic bronchitis with infective asthma, when wheezing attack was accompanied with chronic bronchitis. VIII. Morphological Changes in Old Healthy Adults The author carried out SAB in 15 cases of old healthy adults over 40 years of.age, selected by the following criteria; 1) No history of respiratory disease, 2) No respiratory symptomsat the time of examination, 3) No abnormality in chest X-ray film. According to the findings of SAB, 3 cases showed the distinct alveolar destruction, including panacinar, centrilobular and mixed type, and other 10 cases showed the appearance of "ductectasis". Moreover, these 13 cases showed several abnormal.appearances in the airway. Therefore, the fact, that only 1 case among 14 cases of old healthy adults showed no abnormality in SAB, would be reflected how old aged were, all the time, exposed to be affected by chronic bronchitis, chronic pulmonary emphysema and other chronic obstructive lung diseases. IX. NewDiagnostic Approach to Cor Pulmonale Cor pulmonale was brought about inevitably by most of chronic pulmonary diseases related to aged lungs as the terminal stage. In 1961, an Expert Committee for Chronic Cor Pulmonale defined cor pulmonale to be hypertrophy of right heart ventricle at autopsy, however it would be very important for clinical chest physicians to diagnose cor pulmonale on the morphological basis, while a patient is alive. For this purpose, the author developed the following radiological new method ; the catheter, arranged by cylinder shaped silver at the tip, was inserted into the outflow tract of right heart ventricle via right saphenous vein, then it was confirmed by the observation of the motion of the tip in accordance with cardiac pulsation, that its tip was fixed at the inner surface of the ventricular free wall. The X-ray film was taken with the following conditions; 1) a patient was declined to the direction where the outer surface of the right ventricle was exposed perpendicularly to X-ray projection. 2) radiological condition : focus of the X-ray tube was 50pt with 110KV, 3raA, 0.06 sec. of exposure time, and 2 times enlarge-

6 8& Nmam^ra Jap. J. Medv 197! ment 3) Time to take X-ray film, was at thepre-systolic phase. In order to calculate the thickness of right heart ventricle, the author took the ratio of enlargement of $Overà"t&fre m X-ray:fc tnto & consideration. ' Basing or* the funxmrnenta-l experiment for phantom #nd d$gr with open chest,, the author obtained the difference between the observed value for the thickness of right heart ventricle and measured value tti be within- 0.7mm. at most.- Applying this new method to 5 cases of right heart ventrkle suspected, and to> normal subjects, the author' obtained the value of over 5mm. of the thickness for 2 of 5 cases, on the contrary, for normal subjects, the values for the thickness were under 5 mmv