Inside alveo Physiology Mode #1

Too Much Support, and the Breathing Stops

This is the first scene of our new series, Inside Physiology Mode: short recordings from alveo, our lung simulator, each with a brief explanation.

At rest, CO₂ is the main signal to breathe. A ventilator with a high rate and high pressures washes CO₂ out, and the drive to breathe fades. The margin is small. In sleep studies with healthy adults, a drop of just 2 to 5 mmHg below the usual level was enough to stop breathing.

What alveo shows in physiology mode:

→ When the virtual patient is hyperventilated, the patient’s own efforts become smaller.

→ A short time later, the patient has stopped breathing. The ventilator does all the work.

→ We then reduced the ventilator’s rate and inspiratory pressure. Soon after, the patient starts to breathe again.

In physiology mode, patient effort is not a setting. The physiology model calculates CO₂ from the ventilation alveo receives and generates the drive from it.

Why this matters: a patient who does not breathe leaves the diaphragm idle, and within days it can become thinner. On alveo, learners can watch cause and effect on one screen.

Next episode: how PEEP influences lung compliance.