P133 Does spirometry alone capture all respiratory abnormalities associated with abnormal lung function?. (12th November 2019) - Beech, R
Abstract : Introduction and objectives: Respiratory disease is the third biggest cause of death in the UK, 1 and for the first time, NHS England (NHSE) has designated respiratory disease as a clinical priority. The NHSE Long Term Plan highlights earlier and more accurate diagnosis as an objective. To identify respiratory disease earlier, the plan relies on quality performance of spirometry within the primary care setting. However, lung gas exchange abnormalities can be present in lung disease despite normal spirometry. 2 Therefore, some diagnoses may be missed. Our aim was to investigate within a cohort of our patients, the proportion of those with abnormal gas exchange yet normal spirometry, and whose time to first diagnoses may be protracted due to the reliance of spirometry measurement alone. Methods: A retrospective review of all patients attending the lung function laboratory from July 1995–July 2018 was undertaken. Spirometry and Single Breath Gas Transfer were performed to ERS/ATS standards, with ±1.64 standardised residual FEV1%VC Max used to identify normal spirometry and <-1.64 standardised residual used to identify abnormal TLCOc. Results: Of 41, 480 visits, 5759 (13.9%) were identified on first presentation as having normal spirometry, yet abnormal gas transfer, once corrected for Hb. Within the cohort of 5759 patients, 3270 were female and 2489 male, with a median (IQR) age of 63 (24) years. TLCOc median (IQR) standardised residual -2.23 (0.86). FEV1%VC Max median (IQR) standardised residual -0.25 (1.4). Conclusions: We have demonstrated that a large proportion of patients referred to secondary care with symptoms suggestive of respiratory disease have normal spirometry, yet abnormal gas transfer. These results have implications when solely utilising spirometry in order to detect respiratory disease earlier and will ultimately result in a continued protraction of patient diagnosis. References: GOV.UK. ( 2019). Respiratory disease: applying All Our Health . [online]Available at: https://www.gov.uk/government/publications/respiratory-disease-applying-all-our-health/respiratory-disease-applying-all-our-health [Accessed 27 May 2019]. Pellegrino R, Viegi G, Brusasco V, Crapo R, Burgos F, Casaburi R, Coates A, Van Der Grinten C, Gustafsson P, Hankinson J, Jensen R. Interpretative strategies for lung function tests. European Respiratory Journal 2005;26(5):948–968.