The impact of the AIRWAYS-2 randomised controlled trial on clinical practice in out-of-hospital cardiac arrest in England: a registry-based cohort study

Introduction:
The AIRWAYS-2 randomised control trial, published in August 2018, showed that the use of a supraglottic airway was not superior to tracheal intubation in adult out-of-hospital cardiac arrest. We aimed to explore the impact of the AIRWAYS-2 trial and its findings on clinical practice in adult out-of-hospital cardiac arrest in England.

Methods:
We used data from the English Out-of-Hospital Cardiac Arrest Outcomes registry. We included adult out-of-hospital cardiac arrest patients treated between 2014 and 2020 and who received treatment from an English emergency medical service that submitted advanced airway management data to the registry. In our primary analysis, we used segmented regression to explore the association between the publication of the AIRWAYS-2 trial and the use of tracheal intubation.

Results:
We included 73,764 patients treated by seven emergency medical service systems between January 2014 and December 2020. The median age was 71.8 years; 64% were male, and 23% presented in a shockable rhythm. Between 2014 and 2020, the proportion of patients receiving tracheal intubation decreased from 44% in 2014 to 14% in 2020. The odds of receiving tracheal intubation decreased per quarter over the 7-year study period (adjusted odds ratio 0.93, 95% confidence interval 0 .93-0.94). In our segmented regression model, the estimated percentage decrease in the use of tracheal intubation per quarter was lower before the publication of AIRWAYS-2 (-0.02, 95% CI -0.02 to -0.01) than following the publication of AIRWAYS-2 (-2.01, 95% CI -2.04 to -1.99).

Conclusion:
In England, the proportion of adult OHCA patients receiving tracheal intubation decreased between 2014 and 2020. This decrease accelerated following August 2018, which may be partly attributable to the AIRWAYS-2 trial results.