To evaluate pulmonary status and function through a series of spirometric measurements

To assess the effectiveness of a specific therapeutic regimen

Make sure that the consent form is signed by the child’s parents or legal guardians.

Note and report all allergies.

Withhold bronchodilators and intermittent positivepressure breathing therapy before the pulmonary function test (PFT).

Explain the procedure to the child and his parents, stressing that there’s no pain involved.

Have the child practice tasks, such as handling equipment, holding his breath, and inhaling on cue.

Note that results may not be accurate because the young child may have difficulty following the necessary directions.

Instruct the child and his parents that the child should have only a light meal before the test.

If appropriate, tell the child that he shouldn’t smoke for 4 to 6 hours before the test.

Just before the PFT, tell the child to void and loosen tight clothing, and obtain the child’s height and weight.

For tidal volume (V_T), the child breathes normally into the mouthpiece 10 times.

For expiratory reserve volume (ERV), the child breathes normally for several breaths and then exhales as completely as possible.

For vital capacity (VC), the child inhales as deeply as possible and exhales into the mouthpiece as completely as possible. This is repeated three times, and the largest volume is recorded.

For inspiratory capacity (IC), the child breathes normally for several breaths and inhales as deeply as possible.

For functional residual capacity (FRC), the child breathes normally into a spirometer. After a few breaths, the levels of gas in the spirometer and in the lungs reach equilibrium. The FRC is calculated by subtracting the spirometer volume from the original volume.

For forced vital capacity (FVC) and forced expiratory volume (FEV), the child inhales as slowly and deeply as possible and then exhales into the mouthpiece as quickly and completely as possible. This is repeated three times, and the largest volume is recorded. The volume of air expired at 1 second (FEV₁), at 2 seconds (FEV₂), and at 3 seconds (FEV₃) during all three repetitions is recorded.