Introduction Until recently the ceiling of management for life-threatening asthma exacerbation involved intubation and mechanical ventilation. In many cases these measures were inadequate given the degree of airflow obstruction. The emergence of extracorporeal membrane oxygenation (ECMO) has offered a management strategy for these otherwise fatal events, however there is a dearth of published data regarding ECMO use in asthma. We sought to investigate factors associated with the requirement for and success of using ECMO in near-fatal asthma.
Methods Patients requiring mechanical ventilation (MV) and/or ECMO for acute asthma at our tertiary centre between 2011–2015 were retrospectively identified from an electronic database.
Results Seventy-five patients were identified. 56/75 (75%) received MV and 19/75 (25%) received ECMO. The proportion of females in the ECMO group was significantly greater than in the MV group (68% vs. 29%, P = 0.002). Median age in the ECMO group was lower (24 years old vs. 41, P = 0.003). There was no statistically significant difference in the smoking history or 30- and 90-day survival between ECMO and MV groups. Bronchoscopy was undertaken in all ECMO and in 28/56 MV patients on admission. Respiratory viruses were identified in significantly more patients requiring ECMO than MV (58% vs. 29%, P = 0.04). The proportion of patients with positive bacterial and fungal cultures was not significantly different between groups. In a subgroup analysis there was no difference in duration of ECMO or MV between patients with and without positive virology.
Conclusion In a single regional intensive care unit we demonstrate that requirement for ECMO due to acute asthma is associated with female gender, younger age and positive virology on admission. To our knowledge, this is the first case series analysing factors relating to ECMO use in asthma in the United Kingdom. It highlights the role of respiratory viruses in near-fatal exacerbations and the need for novel anti-viral approaches to reduce morbidity and mortality. Further research is needed in this population to identify whether differences in underlying inflammatory mechanisms exist that may explain the development of such severe events.