Activity 5 - Increased dead space

In this section we will look at the effects of increased dead space on ventilation. The dead space was increased by 500ml and the recoding of the subjects breathing was taken for several moments. The trace below was obtained after the dead space was increased. This was achieved by asking the subject to breathe through a long wide-bore tube. The spirometer trace shows the changes that increased dead space induces on ventilation.

Note: The simulation runs at × normal speed

Timer: 0:00.00

Use the above trace to compare and calculate the subjects’ respiratory rate and tidal volume for both normal breathing and with increased dead space.

Minute volume will be automatically calculated from your answers.

Quantity Baseline (normal breathing) Increased dead space

Respiratory rate (bpm)

Tidal volume (L)

Minute volume (L)