B: Breathing
Give high-flow oxygen. If there is bronchospasm remember that adrenaline will treat this most effectively. The Resus Council UK [1] state that there may be a role for salbutamol (nebuliser or IV) in persistent bronchospasm and this forms part of their Refractory Anaphylaxis guideline. Similarly, ipratropium bromide and aminophylline may be considered. However, be aware that IV magnesium may lead to vasodilatation and further drop in blood pressure so should be avoided.