Forced Expiratory Time: A Simple Test for Airways Obstruction

Abstract

Diabetic Retinopathy-Scott et al. JOUM" haziness of the media in a large proportion of diabetics made it difficult to visualize the capillaries in this study. Although, in Fig. 6 B, an arterial injection of fluorescein has shown up zones of capillary closure alongside arteries and scattered small areas of capillary closure (Ashton, 1953), we have been able to discern this phenomenon in only three patients after intravenous Dollery, C. T., Hodge, J. V., and Engel, M. (1962). Brit. med. 7., 2, 1210Brit. med. 7., 2, . (1963. Med. biol. Ill., 13, 4. Friedenwald, J. S. (1950). Amer. 7. Ophthal., 33, 1187. Gartner, S. (1950. Ibid., 33, 727. Goodman, L. S., and Gilman, A. (1955 , 1964, 1, 814-817 This paper describes a study of a simple physical sign of diffuse airway obstruction undertaken to see how accurate it is in comparison with more refined methods. Diffuse airway obstruction is a feature of asthma and of the chronic nonspecific disease which in Great Britain is commonly labelled as chronic bronchitis and emphysema. Clinical examination as usually practised is not a very good method of detecting or

Physical Diagnosis of Chronic Obstructive Pulmonary Disease

“…Three trials with averaging the results are usually recommended. This clinically measured forced expiratory time correlates well with the forced expiratory time measured by spirometry, the latter being almost one second greater on the average (47) . (49)(50)(51).…”

“…As soon as audible expiration is no longer heard, the stopwatch should be turned off. An FET of more than 6 seconds indicates considerable expiratory airflow obstruction with %FEV1 <50% (47). Three trials with averaging the results are usually recommended.…”

Computer Evaluation of Tracheal Forced Expiratory Noise Time for Bronchial Obstruction Diagnostics

“…Lal et al (1964) [12] , having selected FET as cutoff point as 5 s, yielded a sensitivity of 87% and a specificity of 100%.…”

Assessment of changes in airway calibre I. Tests of forced expiration.

“…The theoretical basis for PEF is more precarious than for other measurements of forced expiration, although it shows a good correlation with FEV1 (Lal, Ferguson & Campbell, 1964). After a short period of training, its reproducibility is little worse than that of FEV1 and probably better than for maximum flow rates at smaller lung volumes.…”

“…The technique has been fairly widely applied to asthmatic subjects, some of whom retain helium-responsiveness while others do not (Despas et al, 1972;Benater, Clark & Cochrane, 1975). It has also been used to detect abnormalities in smokers with normal MEFV curves breathing air (Dosman et al, 1975) (Rosenblatt & Stein, 1962;Lal et al, 1964) which in subjects with airway disease is one of the least repeatable aspects of the spirogram.…”