Pulmonary Function Tests

Pulmonary Function Tests (PFTs)

Pulmonary Function Tests are crucial diagnostic tools for assessing respiratory function, particularly in patients with chronic respiratory disorders. They comprehensively evaluate lung volumes, ventilatory function, breathing mechanics, diffusion, and gas exchange. These tests help diagnose pulmonary diseases and play a significant role in monitoring disease progression, evaluating disability, and assessing response to therapy.

PFTs involve using a spirometer, a device that measures and records the amount and rate of air a patient can inhale and exhale. It provides detailed information about air movement as the patient performs prescribed respiratory maneuvers. The results of PFTs are interpreted based on the degree of deviation from average values, taking into account the patient's height, weight, age, gender, and ethnicity.

Purpose

PFTs are performed for several reasons. They help diagnose chronic respiratory disorders, determine the extent of lung dysfunction, and identify the need for mechanical ventilation or readiness for weaning from ventilatory support. Additionally, they serve as screening tests in industries with potential respiratory hazards, such as coal mining and exposure to asbestos and other toxic irritants.

PFTs are also utilized before surgeries, especially thoracic and upper abdominal procedures, to evaluate preoperative respiratory status. Patients with a history suggesting high risk, such as obesity and symptomatic patients, are often screened using these tests. Furthermore, PFTs are used to assess the effectiveness of bronchodilators and monitor response to therapy.

Procedure

Performing PFTs entails the following steps:

• The patient inserts a mouthpiece.
• They take a deep breath, maximizing inhalation.
• They exhale forcefully, rapidly, and extensively.

A respiratory therapist usually carries out this procedure under the supervision of trained personnel who provide verbal instructions to ensure the patient continues exhaling until the test is completed. After the initial spirometry, bronchodilators may be administered to assess any improvement or response to the medication. The computer then calculates the patient's percentage of predicted values, comparing the performance with an average based on age, gender, race, and height.

Nursing Responsibilities

Nurses play a pivotal role in conducting PFTs. They are responsible for scheduling the tests, preferably not immediately after mealtime, and avoiding the administration of inhaled bronchodilators 6 hours before the procedure. Nurses should explain the procedure to the patient and assess for respiratory distress before the test. After the process, they should provide rest and monitor the patient for any adverse reactions. Additionally, they are tasked with teaching patients with respiratory disorders how to measure their peak flow rate at home using a spirometer, which allows patients to monitor therapy progress and alter interventions as needed.