Spirometry practical

Question 1

Definition of static and dynamic measures

Answer 1

Static- purely volume based

Dynamic- volume and time dependant

Question 2

Examples of static measures

Answer 2

• Expiratory reserve volume (ERV)

Inspiratory reserve volume (IRV)

Residual volume (RV)

Tidal volume (Vt)

Vital capacity (VC)

Question 3

Examples of dynamic measures

Answer 3

• Forced expiratory volume (FEV)

Forced expiratory volume in 1 sec (FEV₁)

Forced vital capacity (FVC)

Question 4

Spirometry equipment setup

Answer 4

1. Connect the Spirometer Pod to Input 1 on the PowerLab.
2. The Spirometer Pod is sensitive to temperature and tends to drift during warm-up. To prevent this, turn on the PowerLab at least 5 minutes before use. Then place the Spirometer Pod on a shelf or beside the PowerLab, away from the PowerLab power supply.
3. Connect the two plastic tubes from the flow head to the short pipes on the back of the Spirometer Pod.
4. Attach clean-bore tubing, a filter, and a mouthpiece to the flow head.
5. Make sure you have extra mouthpieces and disposable air filters for each volunteer.

Question 5

If you’re suffering a respirtory infection can you take part in spirometry?

Answer 5

No

Question 6

Zeroing the spriometer pod

Answer 6

The spirometer is susceptible to the thermal drift of the baseline signal. However, the baseline can be reset by selecting the zero inputs button before making a new recording.

Procedure

1. Leave the flow head apparatus undisturbed on the bench and select Zero Inputs. This will reset the offset of the Flow channel to zero.
2. Ask the volunteer to put on the nose clip. If possible, leave the nose clip on for the entire lab to promote breathing through the mouth. This ensures that all air breathed passes through the mouthpiece, filter, and flow head.

To calculate volume from the flow, start recording before breathing through the flow head.

1. Select Start to record. The mouthpiece can now be put into the volunteer’s mouth.
2. Hold the flow head with two hands with the plastic tubing pointed upwards.
3. Observe the data. Select Auto Scale if required. Expiration should be a downward deflection. If the signal deflects upward stop recording and swap the tubular connections on either the back of the Spirometer Pod or the flow head.
4. When the volunteer has become accustomed to the apparatus, select Stop.

Make sure the volunteer keeps the nose clip on and breathes through the mouthpiece.