Does the sheer prevalence of lung diseases such as asthma and COPD lead to the overlooking of restrictive pulmonary defects?

Mehreen Tahir, L. A. O'Byrne, Elizabeth S. Starren, Nicola J. Roberts, I. S. Patel, Rachel Haffenden, Martyn R. Partridge

    Research output: Contribution to conferencePosterpeer-review


    Introduction: Use of spirometry enhances diagnostic accuracy. This report concerns one aspect of evaluation of the first 3.5 years of a community respiratory assessment unit. Methods Referral forms, nurses’ records and results of investigations of patients referred between 2005 and 2008 were examined. Where relevant, hospital and GP records were reviewed. Results: 84% (857/1024) of referrals attended. 6% (51/857) had spirometric evidence of a restrictive pulmonary defect (22M, 29F, age 63±15 years) (referral diagnoses: 26/51 suspected/definite COPD, 14/51 suspected/definite asthma, 11/51 unexplained breathless). 24/51 were obese (body mass index (BMI) >30) and a further 15/51 were overweight (BMI 25–30). In 10/51 cases no chest radiograph (CXR) was available. 5/10 of these had a BMI >30 and this was the likely cause of restriction. 41/51 patients had an available CXR. BMI >30 was the likely cause of restriction in 13/41, and the combination of BMI >30 with another cause in 6/41 (significant cardiac enlargement (n¿=¿3), pulmonary atelectasis (n¿=¿2), gastric pull-up surgery (n¿=¿1)). Overall, BMI >30 was the probable sole or a major contributory cause of restriction in 24/51(47%). Where BMI was <30 (n¿=¿22) the CXR provided a likely explanation for the restriction in 11/22 (post-tuberculous pulmonary fibrosis (n¿=¿2), unilateral diaphragm elevation (n¿=¿2), infective shadowing and pneumonia (n¿=¿3), and one each of significant cardiac enlargement, atelectasis, interstitial lung disease and asbestos-related pleural disease). After review of CXR and BMI, the 16 patients with no cause for restriction had their data reassessed. GP records were also consulted. In 4/16 BMI was 25–30, providing a plausible explanation for their mild restrictive defect. In 1/16, myotonic dystrophy explained the restrictive defect. In a further 4/16 the accuracy of the diagnosis of the restrictive disorder could be debated, leaving 7/16 patients with a definite restrictive defect for which no explanation could be identified. Conclusions: Restrictive pulmonary defects were identified in a significant minority of patients being referred to a community respiratory assessment unit. The referral diagnoses of these patients included definite or suspected asthma or COPD or, in a smaller number, unexplained breathlessness. The causes of the restrictive defect were diverse and not always explained, but obesity as a cause of breathlessness may be being overlooked in primary care.
    Original languageEnglish
    Publication statusPublished - Dec 2009


    • asthma
    • COPD
    • pulmonary defects
    • spirometry
    • respiratory assessment


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