Fifteen patients who developed asthma after the age of 60 years are reported. Attention is drawn to apparent difficulties of diagnosis in this age group. A history of chronic bronchitis is common, and a change in symptoms, especially the abrupt onset of increased breathlessness, wheezing, and paroxysmal nocturnal dyspnoea, should arouse suspicion of the development of asthma. A past or family history of allergy is confirmatory evidence, as is the presence of blood or sputum eosinophilia. Retrosternal pain is not uncommon, and angina pectoris or left ventricular failure must be excluded. Chest radiographs showed changes consistent with old quiescent tuberculosis in five patients; careful follow-up is therefore essential as asthma in this age group often requires steroid therapy.
In the diagnosis of pulmonary embolism, perfusion lung scintigraphy offers high sensitivity but low specificity. The specificity can be significantly increased by the use of combined ventilation and perfusion studies. Most aspects of perfusion lung scintigraphy are uniformly accepted but the technique of ventilation imaging varies from centre to centre. This study describes a new technique for the performance of ventilation scintigraphy using a suspension of ultrafine carbon particles labelled with 99Tcm ("Technegas"). The technique combines the ready availability of 99Tcm and its optimal imaging properties with an easily administered radiopharmaceutical of particle size sufficiently small to deposit in the alveoli. Of 63 patients studied by conventional perfusion scintigraphy plus Technegas ventilation scintigraphy, images of diagnostic quality were obtained in all. 31 of these patients also had a ventilation study using 81Krm gas and in only one instance did the two methods of ventilation imaging lead to differing interpretations. We conclude that high quality diagnostic images may be obtained using this new technique, which can be made available on both a routine and an emergency basis, thus improving the service provided for patients suspected of having pulmonary embolism.
A double-blind within-patient investigation was performed to determine whether the interposition of an extension tube (10 cm length x 3 -2 cm diameter) between a metered dose inhaler and the mouth alters the bronchodilator efficacy of terbutaline sulphate. On two consecutive study days 14 adult patients with stable reversible airways obstruction inhaled a cumulative dose of 500 jig of terbutaline which was delivered from a metered dose inhaler with or without the extension tube attached and received placebo in a similar manner. The drug was inhaled in doses of 125, 125, and
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