294 may be due to embolism, 10-12 25 it may also be a consequence of disease in sitU.23 Potentiation of atheroma in

the

ophthalmic

or

central retinal artery

by hypertension

may account for some of the differences between the two groups in this study, central occlusion being more often a consequence of local disease.

Embolism of atheromatous or thrombotic material. from the internal carotid artery is a frequent cause of ischaemia in the eye or brain.26 Carotid angiography is therefore undertaken to identify patients with localised atheroma who may be suitable for endarterectomy. Although there has been no recent controlled study of the efficacy of carotid surgery, the results of the only controlled study27 and the continuing decline in operative morbidity has encouraged physicians to refer more patients for surgery in the hope of reducing the risk of subsequent stroke. Many of the patients in this study did have evidence of carotid-artery disease at angiography. The prevalence is certainly an underestimate, since many patients were not considered fit for angiography because of hypertension. Complete occlusion was found in 8 patients and was more frequent in those with central-retinal-artery occlusion than in those with branch occlusion. This may be due to propagation of thrombus from the carotid syphon into the ophthalmic artery. Clinical features of value in predicting a potentially operable carotid lesion on angiography included increasing age, a localised carotid bruit, and cholesterol emboli in retinal branches. No operable lesions were found in patients under 50 who did not have either a carotid bruit or cholesterol emboli. These results confirm the importance of a comprehensive medical assessment of patients presenting with retinal arterial disease. In only 6 out of 98 patients was there a normal blood-pressure, no cardiac valvular abnormality, and negative angiographic findings. The remaining 5 patients of the total of 103 had normal blood-pressure and cardiac findings but did not have angiography; 2 of these 5 were found to be diabetic and 2 had evidence of vascular disease elsewhere. In younger patients without evidence of peripheral arterial disease, particular attention should be paid to the heart as a possible source of embolism. Patients with cholesterol emboli in retinal arteries are likely to have a treatable carotid lesion, especially if a carotid bruit is present. Patients with central-retinal-artery occlusions are more often hypertensive and have a relatively lower prevalence of operable carotid lesions. The evidence suggests that the primary lesion causing occlusion is more often in the ophthalmic or central retinal artery. Angiography is not necessarily indicated in this group unless other factors such as a localised bruit are present. More accurate diagnosis of patients with occlusive retinalartery disease is an essential first step in the reduction of the risk of subsequent ischaemic events in the eye or elsewhere. We thank the ophthalmic surgeons of Moorfields Eye Hospital, St. Thomas’ Hospital, and the Oxford Eye Hospital and Prof. W. I. McDonald for referring patients. The following physicians saw our patients for cardiac evaluation and have allowed us to include the results of their investigations: Dr M. Webb-Peploe, Dr J. Coltart, Dr S. Jenkins (St. Thomas’ Hospital), Dr D. de Bono (United Oxford Hospitals), Dr P. Mills (St. George’s Hospital). For the carotid angiograms we thank Prof. G. du Boulay, Dr B. Kendall, Dr I. Moseley (National Hospital), Dr B. Ayers, Dr K. Tonge, Dr M. Lea Thomas (St.

Hospital), and Dr P. W. E. Sheldon (United Oxford Hospitals).). Requests for reprints should be addressed to L.A.W., Department of Neurology, St. Thomas’ Hospital, London SE 1 7EH.

Thomas’

REFERENCES

Hamilton, A. M., Bird, A. C. Br. J. hosp. Med. 1975, 13, 715. D. G. Neurology of the Visual System, Springfield. Springfield, Illinois, 1966. 3. Wilson, L. A., Ross Russell, R. W. Br. med.J. 1977, ii, 435. 4. Liversedge, L. A., Smith, V. H. Trans. Ophthal. Soc. U.K. 1962, 82, 571. 5. Lorentzen, S. E. Acta ophthalmol. 1969, 47, 690. 6. Karjalainen, K. ibid. suppl. 109, 1971. 7. Appen, R. E., Wray, S. H., Cogan, D. G. Am. J. Ophthalmol. 1975, 79, 374. 8. David, N. J., Klintworth, G. K., Friedberg, S. J., Dillon, M. Neurology, 1963,13, 708. 1.

2. Cogan,

9. McDonald, W. I. J. Neurol. Neurosurg. Psychiat. 1967, 30, 489. 10. Gowers, W. R. Lancet, 1875, ii, 794. 11. Coats, G. Roy. London Ophthal. Hosp. Rep. 1905, 16, 262. 12. Albrecht v. Graefes Arch. Ophthal. 1859, 5 (part 1), 136. 13. Penner, R., Font, R. L. Archs Ophthal. 1969, 81, 565. 14. Jampol, L. M., Wong, A. S., Albert, D. M. Am. J. Ophthal. 1973, 75, 242. 15. Zimmerman, L. E. Archs Ophthal. 1965, 73, 822. 16. Wilson, L. A. and others. Br. med. J. 1977, ii, 86. 17. Barnett, H. J. M. and others. Archs Neurol, 1976, 33,777. 18. Mitchell, J. R. A., Schwartz, C. J., Zinger, A. Br. med. J. 1964, i, 205. 19. Robertson, W. B., Strong, J. P. Lab. Invest. 1968, 15, 538. 20. Baker, A. B., Resch, J. A., Lowewnson, R. B. Circulation, 1969, 39, 701. 21. Garner, A. et al. Br. J. Ophthal. 1975, 59, 3. 22. Hollander, W., Madoff, I., Paddock, J., Kirkpatrick, B. Circ. Res. 1976, 38,

suppl. 2, p. 63. 23. Dahrling, B. E. Archs Ophthal. 1965, 73, 506. 24. Harnish, A., Pearce, M. L. Medicine, 1973, 52, 483. 25. Wolter, J. R., Ryan, R. W. Archs Ophthal. 1972, 87, 301. 26. Gunning, A. J. and others. Q.Jl Med. 1964, 33, 155. 27. Fields, W. S. and others. J. Am. med.Assoc. 1970, 211, 1993.

REGIONAL LUNG CLEARANCE OF EXCESSIVE BRONCHIAL SECRETIONS DURING CHEST PHYSIOTHERAPY IN PATIENTS WITH STABLE CHRONIC AIRWAYS OBSTRUCTION

S. P. NEWMAN J. R. M. BATEMAN KATHLEEN M. DAUNT D. PAVIA S. W. CLARKE

Royal Free Hospital, London NW3 Clearance of excessive bronchial secretions labelled with inhaled radioactive polystyrene particles has been directly measured with a gamma-camera linked to a computer. Chest physiotherapy significantly increased clearance from central, intermediate, and peripheral lung regions and sputum yield. These findings confirm the value of this form of treatment, which has hitherto been in doubt, in removing excessive bronchial secretions from all lung regions and in aiding their expectoration.

Summary

Introduction CHEST physiotherapy is widely used to aid the removal of excessive bronchial secretions in patients with lung disease and to prevent postoperative lung atelectasis. Objective evidence for the effectiveness of this treatment is controversial. 1-16 With one exception, these studies have evaluated changes in pulmonary function and/or volumes of collected sputum samples after a period of chest physiotherapy. The conclusions have been equivocal, owing to the indirect methods of measurement and the difficulties inherent in obtaining reliable

295 CHARACTERISTICS, TOBACCO CONSUMPTION, PRODUCTION, AND VENTILATORY FUNCTION FOR

TABLE I-PHYSICAL DAILY SPUTUM

10

PATIENTS WITH STABLE CHRONIC AIRWAYS OBSTRUCTION

F. E.V. 1=forced expiratory volume in one second. -

F.v.c.=forced vital capacity. P.E.F.R.=peak expiratory flow-rate.

sputum collections. The only report on the direct observation of clearance of tracheal secretions has been by Chopra et al." in anaesthetised dogs. In the present study the clearance of bronchial secretions from central, intermediate, and peripheral lung regions has been measured directly in man during chest ’

physiotherapy. Patients and Methods

Ten patients (six men and four women) with stable chronic airways obstruction and regular sputum production took part in the study. Written informed consent from the patients and

approval from the Medical Ethics Committee were obtained. Six patients had chronic obstructive bronchitis and four bron-

chiectasis. Five were current smokers, three ex-smokers, and two non-smokers. Their physical characteristics, tobacco consumption, daily sputum production, and ventilatory function are summarised in table 1. Using the radioaerosol-tracer technique, 17-19 we have measured the clearance of bronchial secretions from central, intermediate, and peripheral lung regions over a 90-min period with a gamma-camera (Nuclear Enterprises Mark III) linked with a computer (P.D.P. 1105). The aerosol contained uniform 5flm polystyrene particles labelled with the radioisotope technetium-99m, a gamma emitter with a half-life of 6 h, generated in an airtight tank by. means of a spinning disc. Each patient, while seated, inspired known volumes (450 ml)

limited by a Krogh spirometer) of radioaerosol from the tank in a series of twelve breaths from functional residual capacity. A breath-holding pause of 3 s, imposed by means of solenoid valves, before exhalation, allowed for sedimentation of the particles upon the conducting airways. Immediately after inhalation the patients rinsed their mouths and swallowed some water to remove any particles in the mouth, pharynx, and oesophagus. Radioactivity-counts were collected over 10-min periods at half-hourly intervals from 30 to 90 min after radioaerosol inhalation with the patients seated facing the gamma-camera. By means of the computer, the counts in three selected lung regions (central, intermediate, and peripheral) related by area in the ratio 2 : 1 :2 were calculated (fig. 1). All counts were corrected for radioactive decay and background. To allow for unavoidable differences in the total radioactive dose to the lungs (approximately 90 mrad) counts were expressed as a percentage of the total combined count for both lungs at 3C min from the time of radioaerosol inhalation.’ Each patient completed a chest-physiotherapy period and a control period in a crossover manner separated by 1 or 2 days. Chest physiotherapy, consisting of postural drainage, vibration (12 to 16 cycles/s), percussion (5 cycles/s), and shaking (2 cycles/s), was administered for 20 min an hour after radioaerosol inhalation. Expectoration was encouraged after each series of manoeuvres, and sputum samples were collected and weighed during both the physiotherapy and the equivalent control periods. Clearance of deposited radioaerosol before and after chest physiotherapy was compared with that cleared during the equivalent periods in the control study. As the number of patients studied is small and the results do not follow a normal distribution, Wilcoxon’s method for paired comparisons has been used in the statistical analysis. 20

Results The initial group mean distribution of deposited radioaerosol across the three selected lung regions 30 min after radioaerosol inhalation is shown in fig. 2. The distribution was similar for both control and physiotherapy studies. ’the effect of chest physiotherapy for one patient is demonstrated by the computer pictures corrected for radioactive decay and background in fig. 3. There was

2-Initial group (10 patients) mean distribution of deposited radioaerosol 30 min after particle inhalation across the three selected regions.

Fig. v

Fig. 1-The selected lung regions: central (C), intermediate (I), and peripheral (P), related by area in the ratio 2 : 1: 2.

The results from right and left lungs have been combined expressed as a percentage of the combined total lung count.

and

296

Fig. 3--Computer pictures of the lungs taken 30, 60, and 90 min after particle inhalation and corrected for radioactive decay and background for one patient. Chest physiotherapy was administered for 20 min between the 60 min and 90 min pictures a striking fall in radioactivity throughout both lung fields after chest physiotherapy. The group mean clearance of deposited radioaerosol from the three selected lung regions (central, intermediate, and peripheral) for both the control and physiotherapy studies is shown in fig. 4. Before the physiotherapy period clearance from each selected lung region was similar for both studies. During chest physiotherapy, however, clearance from all regions was significantly more than during the equivalent control period (P

Regional lung clearance of excessive bronchial secretions during chest physiotherapy in patients with stable chronic airways obstruction.

294 may be due to embolism, 10-12 25 it may also be a consequence of disease in sitU.23 Potentiation of atheroma in the ophthalmic or central reti...
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