Calcium Antagonists in COPD

communications 10 Ihe editOr

~ ~IIII.

Communications for this section will be published as space and priorities permit. The comments should not exceed 350 words in length, with a maximum offive references; onefigure or table can be printed. Exceptions may occur under particular circumstances. Contributions may include comments on articles published in this periodical, or they may be reports of unique educational character. Specific permission to publish should be cited in a covering letter or appended as a postscript.

Cough and Transbronchial Needle

Aspiration To the Editor:

uansbronchial needle aspiration (TBNA) during flexible fiberoptic bronchoscopy, as introduced by Wang in 1978,1-3 is becoming a popular modality for the assessment of malignant involvement of mediastinal lymph nodes in patients with primary lung cancer. At our facility, our experience with this technique includes over 100 patients. We have found that one of the more difficult aspects of this procedure involves penetration of the needle through the trachea or major bronchi, even when the needle is carefully positioned between cartilage rings. Quite by accident, we discovered a technique that greatly facilitates the speed and ease ofpenetration ofthe needle through the tracheobronchial wall. We securely position the needle into the mucosa and simply ask the patient to cough while advancing the needle. This "intentional cough technique" (IClj will nearly always accomplish penetration of the needle through the tracheobronchial wall despite the presence ofcartilage rings. This technique allows pinpoint localization of TBNA into specific regions where adenopathy is believed to be present without the need for frequent repositioning ofthe needle to bypass an interfering ring ofcartilage. Consequently, we are able to complete transbronchial needle aspirations much more rapidly. We have encountered no complications with this technique. We recommend this "intentional cough technique" (IClj in all cases of TBNA to facilitate the performance of this procedure, and where needle penetration of the tracheobronchial wall is difficult or appears impeded by cartilage. John D. Olsen, M.D., Captain; DavidA Thomas, M.D., Major; Michael B. Young, M.D., Colonel; Colonel; Michael E. Perry, M.D., F.C.C.~, Fitzsimons Army Medical Center, Aurora, Colorado The opinions expressed here are those of the authors and do not necessarily represent the opinions of the Army Medical Department, Department of the Army, or Department of Defense. REFERENCES

1 Wang K~ Terry PB, Marsh BR. Bronchoscopic needle aspiration biopsy ofparatracheal tumors. Am Rev Respir Dis 1978; 118:17-21 2 Wang K~ Marsh BR, Summer WR, Terry PB, Erozan YS, Baker RR. Uansbronchial needle aspiration for diagnosis oflung cancer. Chest 1981; 80:48-50 3 Wang K~ Brower R, Haponik EF, Siegelman S. Flexible transbronchial needle aspiration for staging of bronchogenic carcinoma. Chest 1983; 84:571-76

To the Editor: I have read the letter from Dr. John Olsen and Dr. Michael E. Perry with great interest. It is not surprising, with extensive experience (over 100 patients) in TBNA procedures, that they discovered a useful technique. We experienced the same and also use the ICT technique quite often. This technique is not only helpful in getting through the tracheobronchial wall, it is also extremely helpful in cleaning the lens of the scope if secretions interfere with the viewing. Difficulty in penetration can result from multiple factors: 1) inadequate angulation ofthe scope, 2) hitting the cartilage, and/or 3) fiberous nodular tissues. In case ofa difficult patient, we use another technique to facilitate the penetration; position the needle tip between the cartilage ring with the whole length of the needle protruded out ofthe tip ofthe scope and fixing the needle catheter at the proximal end by the index finger and pushing the scope body as a whole unit. By this manuever, the scope tip will be repositioned more horizontally and reinforce the needle catheter. This will usually avoid cartilagenous ring and even able to penetrate into the most fiberous tumor tissue. Of course, Icr can also be used simultaneously. While we are agreeing with the authors discovery, it is important to point out that, if cartilage is not avoided, forceful penetration through the cartilage will result in a cartilagenous plug ofthe needle, markedly reducing the chance of obtaining diagnostic material. Ko Pen Wang, M.D.,

F.C.C.~

The Johns Hopkins University School of Medicine,

Baltimore

Calcium Antagonists in COPD To the Editor: We appreciate the interesting article published on Chest concerning the problem of calcium and calcium-antagonists in airway disease. 1 Calcium entry blockers (CEBs), especially nifedipine, showed significant protective action in both in vitro and in vioo human studies on pharmacologic-, antigen-, and exercise-induced bronchoconstriction. l In a previous study, 2 nifedipine sublingually administered (20 mg) to patients with stable chronic asthma caused a mild bronchodilator response. We underlined the possible therapeutic use of nifedipine in clinical conditions characterized by cardiovascular disease with increase of airway resistance and/or pulmonary hypertension. We have started a double-blind follow-up study in patients with chronic obstructive pulmonary disease (COPD) who are receiving therapy with a combination of nifedipine (slow-release) and theophylline. The aim of this investigation is to confirm the beneficial effects obtained in acute treatments, and to evaluate the synergic action ofnifedipine and theophylline on bronchial smooth muscle, as demonstrated in vitro. 3 Recently, we investigated the effect of various CEBs (nifedipine, Hunarizine, diltiazem, and verapamil) on ethanol-induced changes in bronchomotor tone (inhalation of an isotonic 25 percent ethanol CHEST I 89 I 2 I FEBRUARY, 1986

315

solution). The ethanol-induced effect is probably mediated through release of histamine, followed by HI-receptor activation. 4.5 Nifedipine provided the most evident and significant protective action. s We hypothesize that, in the near future, this class ofdrugs will be used as a minor bronchodilator drug in the treatment of airway diseases, as well as in therapy for cardiopathic subjects with respiratory problems. Furthermore, its desirable to have new dihidropiridine derivatives (we are now testing nitrendipine) with more relaxant action on bronchial smooth muscle and major selectivity on lung tissue, using nifedipine equimolecular doses. Cesare Spedini, M.D.; and Carlo Lombardi, M.D., Department of Internal Medicine, S. Orsola-FateBeneFrateUi H081Jital Brescia, Italy Reprint requests: Dr. Spedini, Via Einaudi 26, Brescia, Italy 25122

we found multiple giant cells and sometimes cobalt in open lung biopsy tissue as well as bronchoalveolar lavage fluid (Demedts et al, Am Rev Respir Dis 1984; 130:130-35). In the lavage fluid, no cobalt was detected some weeks after interruption of the exposure, but giant cells, or at least "loaded" multinuclear macrophages, could still be fOund even several years later in affected patients (in one, even after lung function and chest x-ray film normalized again). Other exposed diamond polishers developed occupational asthma and presented a positive inhalation challenge test to cobalt, with a temporarily increased response to histamine (Gheysens et al, Chest, accepted for publication). In the bronchoalveolar lavage fluid of exposed workers with occupational asthma, or in those without disease, no giant cells or cobalt was detected. Finally, I want to draw attention to the fact that these diamondcobalt disks are now used also for other occupational duties (eg, building construction and tile-pavement) and ~ in affected workers, the exposure hazard may be overlooked, especially because the manufacturers' misleading campaign stress that these tools contain no hard-metals.

M. Demedts, M.D., F.C.C.P.,

REFERENCES

1 Russi 2

3

4

5

6

Ahmed '[ Calcium and calcium antagonists in airway disease. A revievv. Chest 1984; 86:475-82 Lombardi C, Spedini C, Govoni S. Efleet of nifedipine in the treatment ofchronic stable asthma. It J Chest Dis 1984; 38:187-88 Daya S, Joubert Ph. The interaction between nifedipine and theophylline on bronchial smooth muscle. International Symposium on calcium entry blockers and tissue protection, Rome, March 15-16, 1984. Abstract book, 1984: pl56 Gong H Jr, Tashkin D~ Calvarese BM. Alcohol-induced bronchospasm in an asthmatic patient. Chest 1981; 80:167-73 Spedini C, Lombardi C, Thlbucchi M. Bronchoconstriction after ethanol inhalation: hypotetic role of histamine. It J Chest Dis 1983; 36:373-76 Lombardi C, Spedini C, Govoni S. Effect of calcium entry blockade on ethanol-induced changes in bronchomotor tone. Eur J Clin Pharmacol 1985; 28:221-22

To the Editor: We appreciate the interest Spedini and Lombardi have shown in our article. Their preliminary findings are encouraging, and seem consistent with the hypothesis that calcium antagonists may have some role in the therapy of obstructive airway disease, especially in patients with associated angina and atherosclerotic heart disease. Certainly, information with newer calcium antagonists will be of much help. Tahir Ahmed, M.D., F.C.C.P. University of Miami and Mount Sinai Medical Center, Miami Beach, Florida

Cobalt and Hard Metal To the Editor: In the April, 1985 issue of Chest, I read with interest the discussion between Drs. Abraham and Cullen with reference to the editorial in Chest 1984; 86:513-14. It is not my intention to argue whether cobalt is the single pathogenetic factor in hard-metal disease, but I would like to draw attention to an exposure hazard to cobalt not alloyed to tungsten carbide, causing a similar pathology as in hard-metal disease. In recent years, grinding tools with a cutting edge of microdiamonds cemented in a binding substance, over 99 percent of which consists of extra fine cobalt without tungsten carbide, have been marketed for diamond polishing, at least in Belgium. We have observed that some diamond polishers, exposed to the powder abrased from these disks, developed fibrosing alveolitis, and

316

Pulmonary Division, University Hospital, Pellenberg, Belgium

E~

To the Editor: Dr. Demedts makes an important point which I had included in my previous letter, but which had been edited out due to space limitations. I specifically pointed out that the recent work by Dr. Demedts and his colleagues showed the distinctive pathologic reaction and clinical picture ofinterstitial pneumonitis with peculiar giant cells (giant cell interstitial pneumonia) in workers exposed only to cobalt (not to other hard metals). The occupational asthma related to cobalt exposure in the diamond polishers is further support ofthe role ofcobalt in so-called 'nard metal" disease. Dr. Demedts and his colleagues have, in fact, kindly allowed me to review and analyze tissue from three ofthe patients they reported in 1984. In contrast to the results ofmy electron probe analyses oflung tissues from patients with exposure in the tungsten carbide industry, the cases from Dr. Demedts group of diamond polishers showed very little inorganic particulate dust in the lungs. Cobalt was detected in one of the biopsies, but not in the others (cases one and four). Similarly, cobalt was only rarely detected in the lung tissues from patients with exposure in the tungsten carbide industry. The use ofcobalt in potentially respirable form in numerous other industries is an important point also. A recent document from the United States Department of the Interior (Kirk, William S. Cobalt. In: Mineral facts and problems, 1985, Superintendent of Documents, Washington, D.C.) points out that the United States is the largest consumer of cobalt, accounting for about one-third of the total world consumption (U. S. consumption was 15.7 million pounds in 1983). Major uses ofcobalt include transportation, electrical parts, machinery, paints, chemicals, and others. The major point of all this continuing correspondence is that the type of uncertainty presented in Dr. Cullens editorial may lead to unnecessary delay in cleaning up the work place to prevent the development of disease in the future. Appropriate engineering controls have been installed in most European countries once the problems have been recognized, and subsequent development of disease has either been eliminated or greatly reduced (personal communications from Dr. Demedts and from Dr. G. Hillerdal, who reported a similar problem in 1980 [Thorax 1980; 35:653-59]). Jerrold L. Abraham, M.D., Associate Professor and Director of Environmental and Occupational Pathology, State University of New York Upstate Medical Center, Syracuse Communications to the Editor