P121 Raised blood eosinophil count as a predictor of severe asthma exacerbation

Introduction and Objectives Asthma is a condition that involves airway inflammation leading to variable bronchial constriction. It is well-established that blood eosinophil counts are often raised in patients with asthma and correlate with increased brochial hyperreactivity.1 However, blood eosinophils are not currently recommended for monitoring asthma in adults.2 Many patients admitted to hospital have undergone a full blood count in the year prior to their index attack and this is an easy opportunity to assess their risk of exacerbation and intervene. Methods We elected to review patients admitted to hospital at the Countess of Chester Hospital NHS Foundation Trust over a 12-month period. We investigated whether a full blood count was available and also, if there was evidence of raised blood eosinophil counts. We also recorded information on treatment and length of stay. Results 197 patients were included, 58 female and 139 male, with a mean age of 50 years (range 12–13). A total of 135 (68.5%) patients had FBC recorded in the 12 months prior to admission. 87 (64.44%) of these had an eosinophil count of ≥0.3 at least once in the 12 month period. 70 (35.5%) patients had an eosinophil count of ≥0.3 on admission. The average eosinophil count over the 12 months prior to admission was 0.36 (range 0–3.1). Patients with an eosinophil count of ≥0.3 were more likely to be using LABA+ICS combination than their counterparts (51.43% vs 44.09%). No significant difference was noted with other therapies. Conclusion A high proportion of patients admitted to hospital had a historical FBC available. Two-thirds had recorded an eosinophil count of ≥0.3 in the 12 months leading up to admission suggesting an increased risk of a severe asthma exacerbation. There is an opportunity to intervene to prevent future exacerbations. An incidental raised blood eosinophil count in asthmatics should be regarded as a red flag for future asthma attacks. References Price DB, Rigazio A, Campbell JD, et al. Blood eosinophil count and prospective annual asthma disease burden: a UK cohort study. Lancet Respir Med. 2015 Nov;3(11):849–58. British guideline on the management of asthma 2019. SIGN; BTS.