Fig. 1.

Patients A (red line) and B (blue line) pressure curves and average tidal volumes during positive pressure ventilation, using pressure control mode mechanical ventilation at 20 and 30 cmH₂O and PEEP of 8 cmH₂O. One-way valves ensured stable tidal volumes of B while A deteriorated; however, a severe mismatch holds the potential for fatal simultaneous hyper- and hypo-ventilation without triggering alarms