Flow rate and work

Flow and airway pressure (Paw) during assist-control ventilation at an inspiratory flow rate of 60 L/min (panel A) and 30 L/min (panel B). In panel A, the small negative phase, smooth rise, and convex appearance of the Paw waveform indicate that the patient is making a slight inspiratory effort to breathe. In panel B, the more pronounced negative phase and excessive scalloping of the Paw waveform indicate that the patient is making a strenuous effort to breathe due to inadequate flow.