Fig. 2. Representative examples of changes in oxygen consumption (V̇o2) of the body associated to a decrement in pressure support (PS) level. Although in one patient (filled circles ) the V̇o2constantly increased, in two patients (filled and open triangles ) the V̇o2initially decreased to a minimum (resting PS level) and then progressively increased again. Finally, in one patient no systematic changes in V̇o2were observed when PS level was decreased (open circles ).
