Collapse therapy (medical) in pulmonary tuberculosis.

Whatever the exact mechanism involved in the various measures embraced by the term ' collapse therapy' for pulmonary tuberculosis, a feature common to them all is the reduction in volume of the diseased portion of lung. There is ample evidence that the resultant relaxation is beneficial and conducive to healing. Yet, even before the advent of chemotherapy and the progress in thoracic surgery which the past decade has witnessed, the mainstay of minor collapse therapy, the pneumothorax, was receiving its full share of criticism. Unfavourable general conclusions, however, were too often drawn from what we should now regard as its misuse. Many past failures can today be understood as a result of our greater knowledge of the pathology of the disease, especially as regards the important role played by the bronchi. The essential factors for success of any treatment are a proper selection of cases and a clear recognition of the limitations of the particular method employed. All are agreed that cavitated disease is the main indication for some form of collapse therapy. In such cases the risk of further spread of the disease by bronchial aspiration to the opposite lung or to other parts of the same lung is ever present, and the ultimate prognosis of patients with persistent cavitation is very poor indeed. Bed rest alone, if strict and prolonged, will cause some cavities to close. If, at the same time, a position in bed is adopted which places the cavity in the most dependent position, as suggested by Dilwyn Thomas (1950), even large cavities can sometimes be persuaded to close or shrink considerably in size. Without additional mechanical control, however, the tendency for them to re-open when the patient becomes ambulant is very great. Effective antibacterial treatment of recent years raised hopes that collapse procedures might soon become unnecessary. Such hopes, however, have not yet been realized. Recent pulmonary cavities will often appear to close on chemotherapy, but if no additional measures are adopted, the relapse rate is high when the treatment is stopped. For disease which has progressed to cavitation, therefore, chemotherapy must be integrated with other forms of treatment and not replace them. It has done much to make them safer by rendering the disease quiescent before collapse therapy, and has also reduced the incidence of the more serious complications; to a lesser extent it has brought unsuitable cases within reach of collapse therapy. Whether to apply collapse measures for uncavitated tuberculous infiltration remains a difficult problem, the solution of which depends largely on personal judgment and experience. Assuming there is evidence of activity, antibacterial treatment should be started without delay together with bed rest, preferably under close observation in hospital. If considerable radiological clearing does not result after six weeks of such a regime, or should there be deterioration, some form of collapse should be considered. Many factors other than the X-ray appearance and clinical condition weigh in this decision, e.g. the young woman with dependent family, a bad family history of tuberculosis, racial predisposition-such features would rightly influence the decision for active treatiflent in cases of doubt.