ABSTRACT
Mortality from severe respiratory failure, especially acute respiratory distress syndrome, remains frustratingly high, prompting searches for alternative ways to oxygenate and remove carbon dioxide from patients. Although some of these options bypass the lungs, this chapter uses "alternative ventilation" as a convenient, if technically inaccurate, means of encompassing these "rescue therapies". Extracorporeal membrane oxygenation (ECMO), initially developed as "bypass" for open-heart surgery, can replace or augment conventional ventilation. One of the earliest ECMO variants, extracorporeal carbon dioxide removal, improves carbon dioxide clearance, enabling lower tidal volumes, so potentially reducing ventilator-induced lung injury. Tempting as it is to seek alternatives when conventional ventilations fails, the safety and complications of extracorporeal lung support remain largely speculative. Heliox is inert, colourless, odourless and tasteless. It disperses quickly, so should not significantly affect anyone nearby. Delivering vasodilators either as a gas or nebuliser has attracted intermittent interest, partly because delivery is to ventilated parts of the lungs, optimising V/Q match.
