Could not write any notes for the past 2 weeks. Uploading an old set of notes from 2014 as a specialist asked us to remember how much fresh gas flow is required with the Mapleson circuits (though on a recent re-search, I've found the various values to be different between different sources, though the principle remains the same; the later the "letter" the less efficient it is for spontaneous ventilation, and generally vice versa for controlled ventilation).