Figure 4

Respiratory patterns (II). Representative tracings of RIP voltage (top) and airway opening pressure (bottom) during the experiment. (A) Lamb 7 at 35 min after first attempt at CPAP transition; initial apnoea is followed by prompt return of spontaneous respiratory effort after reinstitution of NIPPV. (B) Lamb 8 at 30 min post-CPAP; NIPPV does not result in mechanically assisted breaths but does interfere with the cadence of spontaneous breathing. (C) Lamb 7 at 150 min; comfortably breathing on CPAP alone, spontaneous respiratory rate 65/min, PaCO₂ 44 mm Hg and FiO₂ 0.21. See Figure 3 legend for abbreviations.