Chapter 19. Spirometry

• • Assessment of pulmonary function in patients with respiratory complaints.

Absolute

• • Pneumothorax.

  • Hemoptysis.

Relative

• • Age; patients can usually perform maneuver starting between ages 4 and 5 years.

• • Spirometer.

  • Individual mouthpieces.

  • Nose clips.

• • Pneumothorax (rare).

• • Adequate height, as measured with a stadiometer, is crucial to ensure utilization of appropriate predicted values.

  • A positive response to bronchodilator testing is defined as a 12% increase in the forced expiratory volume in 1 second (FEV1).

• • Explain the procedure in a developmentally appropriate manner before and during procedure.

  • Coach the patient for optimal effort to ensure acceptable results.

  • In older patients, it is ideal to recommend no smoking for 24 hours prior to testing.

  • If assessing response to a bronchodilator, any bronchodilator medications should not be used for at least 8 hours before testing.

• • Patient should be sitting upright or standing tall.

• • Place nose clips on patient.

  • Patient makes a seal with lips around mouthpiece.

  • Ensure tongue does not block opening.

  • Have the patient breathe comfortably for 3 breaths (tidal breathing).

  • At end exhalation, have patient take fast breath in to fill lungs completely (to total lung capacity).

  • At top of inspiration, have patient exhale fast and hard and keep exhaling for 6 seconds or until flow plateaus.

  • At end of exhalation, inhale to fill lungs completely (total lung capacity).

  • Maneuver should be repeated to obtain 3 tests that are acceptable and reproducible.

• • A test must first be considered acceptable and reproducible.

  • A test is acceptable if it fulfills the following criteria:

  • • No cough or glottic closure in first second of exhalation.

    • No leaks or obstruction of mouthpiece.

    • Adequate start of test without hesitation.

    • Full exhalation of 6 seconds or until plateau of volume.

    • No early termination of test.

  • Reproducibility in children can be defined as the values of the forced vital capacity (FVC) and FEV1 being within 5% on 3 acceptable maneuvers.

  • Obstructive lung disease is determined by a combination of the following:

  • • Decreased flows (FEV1, FVC, mid-range flows).

    • Scooped appearance to the flow volume curve (Figure 19–1).

• • • Decreased FEV1/FVC ratio.

  • Restrictive lung disease is suggested by a decreased FEV1 and FVC and a normal or decreased FEV1/FVC ratio (see Figure 19–1).

  • In order to adequately determine restrictive lung disease, full pulmonary function tests should be obtained to include lung volumes.

• • Spirometry alone may not give a complete assessment of the ...