Footnotes

• * V˙e/V˙co₂  =  863/Paco₂ × (1−Vd/Vt), where 863 is a constant to standardise volume measurements, Paco₂ is the arterial tension of carbon dioxide and Vd/Vt is dead space as a fraction of tidal volume.

• In compliance with EBAC/EACCME guidelines, all authors participating in Education in Heart have disclosed potential conflicts of interest that might cause a bias in the article