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Pulmonary Function Tests

Comprehensive evaluation of lung volumes, flows, and gas exchange with PFT.

A painless group of tests including spirometry, lung volumes, and diffusion capacity (DLCO) that assess all aspects of lung function.

Indication

  • Unexplained shortness of breath or chronic cough
  • Differential diagnosis of obstructive (COPD, asthma) and restrictive (pulmonary fibrosis) diseases
  • Assessment of gas exchange with DLCO in interstitial lung diseases
  • Preoperative risk assessment (especially for lung resection)
  • Monitoring lung involvement in systemic diseases (scleroderma, rheumatoid arthritis)
  • Follow-up of pulmonary toxicity in patients receiving chemotherapy or radiotherapy
  • Evaluation of occupational lung diseases

Preparation

  • No smoking for 1 hour before the test
  • Bronchodilators are temporarily withheld per physician instructions
  • Avoiding intense exercise and large meals
  • If acute infection is present, the test is postponed
  • Avoiding tight clothing; lipstick is not worn

How it's performed

  1. Spirometry measures FEV1, FVC, and FEV1/FVC
  2. Body plethysmography or helium dilution is used for lung volumes
  3. Diffusion capacity (DLCO) is measured with a single-breath technique using a carbon-monoxide gas mixture
  4. Maximum voluntary ventilation (MVV) may also be measured
  5. Reversibility testing is planned after a bronchodilator is given
  6. All values are normalized for age, sex, height, and ethnicity

Post-procedure

  • Results are interpreted holistically by the pulmonologist
  • Obstructive, restrictive, or mixed pattern and severity classification are determined
  • A reduced DLCO may require further evaluation (HRCT)
  • The test is repeated at 6-12 month intervals based on the treatment plan
  • Disease progression or treatment response is tracked numerically

Risks

  • Dizziness or weakness during forced exhalations
  • Triggering of cough or mild bronchospasm
  • Possible feeling of claustrophobia during body plethysmography
  • Inhalation of low-dose CO during the DLCO test is safe
  • The test is postponed in patients with recent heart attack, severe hypertension, or pneumothorax

FAQ

What is the difference between PFT and spirometry?

Spirometry is one part of PFT. A complete PFT panel also measures lung volumes and DLCO, evaluating airflow, volume, and gas exchange together.

How long does the test take?

The full panel test takes 30-60 minutes. There are rest periods between each measurement.

Are results available immediately?

Raw values are obtained during the test, while the pulmonologist reports them together with the clinical information. They are usually shared on the same day or shortly after.

Will I feel claustrophobic during the test?

Body plethysmography is performed inside a transparent cabin. The cabin is not completely closed and the technician maintains continuous communication; please inform the team in advance if you have claustrophobia.