اختبارات وظائف الرئة

Pulmonary function tests (PFTs) use a spirometer to measure lung volumes and airflow, recording the amount and rate of air a patient can inhale and exhale. These tests comprehensively evaluate ventilatory function, breathing mechanics, diffusion, and gas exchange. Results are interpreted based on deviation from average values, accounting for the patient's height, weight, age, gender, and ethnicity.

PFTs are performed preoperatively for thoracic and upper abdominal procedures to assess respiratory status and evaluate preoperative respiratory function. Patients with high-risk factors such as obesity or symptomatic conditions are often screened using these tests to determine readiness for surgery and identify potential complications.

Nurses explain the PFT procedure to patients and assess for respiratory distress before testing. They schedule tests preferably not immediately after mealtime and avoid administering inhaled bronchodilators 6 hours before the procedure. After testing, nurses provide rest and monitor patients for adverse reactions.

PFTs help diagnose chronic respiratory disorders like asthma and determine the extent of lung dysfunction. They also evaluate the effectiveness of treatments such as bronchodilators and monitor response to therapy. Additionally, PFTs serve as screening tools in industries with respiratory hazards, such as coal mining and exposure to toxic irritants.

During a PFT, the patient sits on a chair with a nasal clip applied to prevent air escape through the nostrils. The patient then takes a deep breath, maximizing inhalation, and exhales forcefully, rapidly, and extensively into a mouthpiece attached to the spirometer. A respiratory therapist provides verbal instructions to ensure the patient continues exhaling until the test is completed.

After initial spirometry, bronchodilators may be administered to assess improvement or response to the medication. The computer then calculates the patient's percentage of predicted values, comparing performance with an average based on age, gender, race, and height to determine therapeutic effectiveness.

While PFTs measure airflow and lung volumes, complementary respiratory diagnostic studies include radiological investigations and endoscopic procedures. Imaging studies like radiological investigation i x ray and ct provide structural information, while endoscopic studies bronchoscopy and thoracoscopy allow direct visualization of airways and lung tissue for comprehensive respiratory assessment.