Figure 2.

Relationship between V_t and respiratory rate. Shown is the relationship between V_t and respiratory rate (f) in the patients at different levels of pressure support: 5 cmH₂O (closed circles), 10 cmH₂O (open circles), 15 cmH₂O (closed squares) and 25 cmH₂O (open squares). The straight lines represent isopleths of different values of f/V_t (20, 40, 60, 80 and 100 l^-1·min^-1). The curved line is the fitting of data points by the following equation: f = K/V_t (where K = 7.9385 ± 0.4324). PS, pressure support; Vt, tidal volume.