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Bronchial narrowing is the major side effect of inhaled nebulised pentamidine isethionate, used for the prophylaxis and treatment of Pneumocystis carinii pneumonia. Several agents and delivery systems were assessed for prophylaxis of bronchial narrowing in HIV-positive males receiving regular nebulised pentamidine isethionate. In a previous study we found the mean maximum fall in FEV1 with nebulised pentamidine alone to be 21%. FEV1 was measured before and after inhaling nebulised pentamidine, preceded by one of the following bronchodilator/immunoregulatory agents: Terbutaline metered dose inhaler (500 micrograms), nebulised salbutamol (5 mg), nebulised ipratropium bromide (500 micrograms), nebulised sodium cromoglycate (20 mg), and nedocromil sodium metered dose inhaler (4 mg). Each agent was administered once only to ten different subjects. Nebulised salbutamol gave most effective prophylaxis against bronchial narrowing induced by nebulised pentamidine (mean maximum fall in FEV1 = 5% vs. 21%, P less than 0.001). Terbutaline given by metered dose inhaler was significantly less effective than high dose terbutaline (10 mg) given by nebuliser, demonstrated in the previous study (mean maximum fall in FEV1 = 14% vs. 6%, P less than 0.05). Mean maximum falls in FEV1 for ipratropium bromide, sodium cromoglycate and nedocromil sodium were 16, 17 and 16%, respectively. High dose beta 2-agonists administered by nebuliser give more effective prophylaxis against nebulised pentamidine-induced bronchial narrowing than either lower doses given by metered dose inhaler, anticholinergics or immunoregulatory drugs.

To evaluate how steroid trials are currently used in the assessment of reversibility of air flow limitation, a postal questionnaire was sent to 355 consultant members of the British Thoracic Society working in England and Wales; 253 questionnaires were returned (71% response rate). Two respondents did not undertake steroid trials; of the remaining 251, 75% prescribed 30-40 mg oral prednisolone, with the commonest treatment period being 2 weeks. A high dose steroid inhaler was sometimes used as an alternative by 31% of respondents. Although 71% of respondents made lung function measurements on several occasions before starting steroids and 76% made measurements during treatment, 78% assessed patients on only one occasion at the end of the trials to ascertain its outcome. Weight, blood pressure and glycosuria were measured less frequently after the steroid treatment compared to the pre-trial period. Blood glucose and serum electrolytes were infrequently measured both before and after treatment. Wide variations exist in steroid trial regimens and current practice may neither provide definitive evidence of treatment benefit nor an adequate safeguard for patients against potential side-effects.

Simple tests of lung function may be misleading in the assessment of patients with interstitial lung disease. Eight patients are described with cryptogenic fibrosing alveolitis (histologically proven in four) with severe breathlessness and low gas transfer (median DLCO 32.4%, range 9.2 to 35.3%, % predicted) in whom lung volumes were preserved [median VC 98.7, range 67.5-131.1%; median TLC 92.5, range 88.1 to 121.2, (% predicted)], and in whom there was no evidence of airflow obstruction [median FEV1/FVC 84.6, range 68-116 (% predicted)]. All were current or ex-heavy smokers. Thoracic high resolution computed tomography revealed upper zone emphysema, the extent of which was not appreciated using conventional chest radiography. The atypical physiological and radiological features can be explained by coincidental cryptogenic fibrosing alveolitis and emphysema and high resolution computed tomography was valuable in the assessment of these patients.

Sixteen cases of tuberculosis (14 in inmates, only one of whom was female) occurred in a mental handicap hospital of some 400 inmates during the period 1973-85. This represents an annual incidence of 269 per 100,000, substantially higher than that in the surrounding community. In 1980, 29% of inmates had Grade 3 or 4 positive Heaf tests. Widespread chemoprophylaxis was successfully undertaken in 1980/81, the only problem encountered being interaction of isoniazid with carbamazepine. One Down's syndrome patient had recurrent disease, and a second developed disease despite chemoprophylaxis. Immunological investigation of a small number of Down's syndrome patients with tuberculosis showed no consistent defect.