The McGill Physiology Virtual Lab

Respiration Laboratory

  MVV test
  In this test, the subject is asked to breathe as quickly and as deeply as possible. This does not mean that the subject should pant (i.e. moving air back and forth in the dead space of the upper airways at a very high rate.) Rather, the subject must consciously attempt to breathe in as far as possible, breathe out as far as possible, and try to execute these movements as quickly as possible. Periods longer than 15 seconds should not be allowed because prolonged hyperventilation leads to fainting due to excessive lowering of arterial PCO2 and H+.

Turn the spirometer on, choosing a chart speed of 5 mm/second, and move the piston so the pen is at the center of the chart paper.

The subject should put on the noseclip and place the mouthpiece attached to the hose in the mouth.

Press the handswitch to start recording. The subject should be instructed to breathe in and out at maximal rate and depth for no longer than 5 breaths. Press the handswitch to stop recording. This is the Maximum Voluntary Ventilation Manoeuvre.