Waveforms
Paw = V/C + R x Flow + PEEP - Pmus
The answer here is to increase minute ventilation. Minute ventilation equals tidal volume times the respiratory rate. So if you increased the tidal volume, you got this right. If you increase the rate, you have to make sure that you are increasing the rate above the patient's actual rate, not above the set rate. In the original scenario, the set rate was 14 bpm but the patient was triggering 20 bpm already, so you should not expect an increase in minute ventilation if you increased the RR from 14 to 20 bpm.
Teaching points: 1. Always pay attention to the measured parameters, because they reflect what is actually happening. Controlled parameters simply reflect what you set. 2. The ventilator uses the set rate as a patient-independent trigger variable. If the rate is set at 20, it means the ventilator will trigger a breath every 3 seconds, provided the patient has not triggered a breath themselves in that period.