Acute NIV in presumed ECOPD without previous spirometry

Introduction: In the UK around 2m people with COPD are undiagnosed.1 1 in 8 patients hospitalised for presumed ECOPD do not have airflow obstruction.2 Some patients are first diagnosed after being hospitalised for ECOPD requiring ventilation. The NIV Outcomes study (NIVO) is a 10-centre prospective study to validate a prognostic tool assessing outcomes in ECOPD patients needing ventilation for respiratory acidaemia. Demographics and outcomes were separately assessed in patients without preadmission spirometry, termed ‘clinical diagnosis’ (CD). Methods: Unique, consecutive patients are included. Patients with spirometry confirmed COPD were compared to CD patients. Comparisons are made with Fishers’ exact, Mann-Whitney-U or Student’s t-test. Interim data is reported. Results: 111 of 844 patients (13.2%) were CDs. CDs had similar levels of comorbidity, blood gas results, time to acidaemia and mortality. CDs had less severe stable state dyspnoea, higher BMI and more confusion. In the year following discharge 45.9% of CDs had spirometry. Of these, 79.4% had an FEV1/FVC ratio <70%. Conclusion: A large number of patients treated with NIV for presumed ECOPD had no formal diagnosis of COPD. CDs had better functional status but similar mortality to confirmed COPD, suggesting worse outcomes. Under half had subsequent spirometry, but of these ~20% did not have airflow obstruction. References: 1. Thorax 2006;61:1043–1047 2. RCP NACAP Audit 2018