Pulmonary Function Test Final Exam Questions (100) – Spirometry, DLCO, Bronchial Challenge

This document contains 100 exam-style questions with verified answers designed to help students prepare for a Pulmonary Function Testing (PFT) Final Exam. The study material focuses on spirometry interpretation, lung volume measurements, diffusion capacity testing (DLCO), bronchial challenge testing, exercise physiology, respiratory mechanics, and pulmonary diagnostic quality control procedures commonly tested in respiratory therapy and cardiopulmonary science courses. The questions are organized in a structured Q&A format that reinforces clinical reasoning and diagnostic interpretation skills used in pulmonary function laboratories. The study guide begins with spirometry principles and test quality requirements, emphasizing that when a patient performs three spirometry trials, the pulmonary function technologist should perform at least one additional maneuver to ensure acceptable and repeatable results. Spirometry testing is contraindicated in certain conditions such as untreated pneumothorax, where forced breathing maneuvers could worsen the patient’s condition (page 1). Another section reviews key spirometry measurements used to diagnose obstructive lung disease. The FEV1/VC ratio is highlighted as the most important measurement for identifying airway obstruction, while spirometry is considered the gold standard diagnostic test for obstructive lung disease. In contrast, total lung capacity (TLC) measurements are required to confirm restrictive lung disease, which is characterized by reductions in both TLC and vital capacity (VC) below the lower limit of normal (pages 2–3). The material also discusses bronchodilator response testing, which evaluates reversibility of airway obstruction. A response is considered clinically significant when there is an increase of at least 12% in FEV1 or FVC following bronchodilator administration. The guide also notes that post-bronchodilator testing should be performed approximately 15 minutes after administering an inhaled beta-2 agonist (pages 3 and 6). Another important topic covered is diffusing capacity testing (DLCO), which assesses the ability of gases to diffuse across the alveolar-capillary membrane. DLCO values can be affected by numerous factors including lung disease, hemoglobin levels, and patient effort. The document also explains that DLCO is commonly used to monitor drug toxicity and evaluate diseases affecting the alveolar membrane, such as interstitial pulmonary fibrosis, sarcoidosis, and scleroderma (pages 3 and 7). The guide also includes exercise physiology and cardiopulmonary exercise testing concepts. For example, the respiratory exchange ratio (RER) is described as a useful indicator of maximal effort during exercise testing. Blood pressure typically increases during exercise, and arrhythmias such as premature ventricular contractions (PVCs) are noted as the most common rhythm disturbance during cardiopulmonary exercise testing (pages 9–12). Another section reviews dead space ventilation and gas exchange calculations. The document explains that the VD/VT ratio (dead space to tidal volume ratio) can be determined using measurements such as arterial PaCO₂ and mixed expired CO₂, and that an increase in VD/VT during exercise may indicate conditions such as pulmonary hypertension, where ventilation increases disproportionately relative to perfusion (pages 9–14). The study guide also discusses bronchial provocation testing, particularly the methacholine challenge test, which is the most widely used and standardized test for assessing airway hyperresponsiveness. A positive test result occurs when the patient’s FEV1 decreases by approximately 20% or more following methacholine administration, indicating airway hyperreactivity consistent with asthma (pages 7 and 18). Another major topic covered is lung volume measurement techniques, including helium dilution, nitrogen washout, and body plethysmography. These methods are used to measure residual volume (RV) and functional residual capacity (FRC), which cannot be measured by simple spirometry. For example, body plethysmography relies on Boyle’s law to calculate lung volumes based on pressure changes within a sealed chamber (pages 20 and 25). The document also reviews respiratory muscle strength testing, which is performed using maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) measurements. These tests help evaluate respiratory muscle weakness in conditions such as amyotrophic lateral sclerosis (ALS) and myasthenia gravis, where neuromuscular dysfunction affects breathing mechanics (pages 4 and 22). Another section focuses on quality control and equipment calibration procedures used in pulmonary function laboratories. Spirometers should undergo daily volumetric calibration using a 3-liter syringe, and infection control practices include the use of disposable mouthpieces, nose clips, and bacterial filters to prevent cross-contamination between patients (pages 27–28). The document also addresses pulmonary rehabilitation and respiratory care in alternative healthcare settings, including home oxygen therapy and ventilator support. For example, oxygen concentrators are the most common supply method for oxygen therapy in home care settings, while pulmonary rehabilitation programs typically include aerobic exercise training, ventilatory muscle conditioning, and walking exercise programs (pages 26–27). This study material may be relevant for courses such as: Pulmonary Function Testing Respiratory Therapy Clinical Diagnostics Cardiopulmonary Physiology Cardiopulmonary Exercise Testing Respiratory Care Laboratory Students enrolled in the following programs may benefit from this document: Respiratory Therapy (CRT / RRT) Programs Cardiopulmonary Science Programs Clinical Physiology Programs Nursing and Allied Health Programs Pulmonary Diagnostics Training Programs Example course codes commonly associated with these subjects include: RESP 310 – Pulmonary Function Testing RESP 320 – Advanced Pulmonary Diagnostics RSPT 220 – Cardiopulmonary Physiology MLS 315 – Clinical Pulmonary Diagnostics BIOMED 330 – Cardiopulmonary Laboratory Methods The concepts covered in this document align closely with core respiratory therapy textbooks such as Egan’s Fundamentals of Respiratory Care by Robert M. Kacmarek, James K. Stoller, and Albert J. Heuer and Pulmonary Function Testing and Cardiopulmonary Stress Testing by Jack Wanger. These textbooks provide the foundational theory behind spirometry interpretation, lung volume measurement, bronchial challenge testing, and pulmonary diagnostic procedures reflected in this exam preparation guide. Overall, this document serves as a targeted Pulmonary Function Testing final exam preparation resource, helping respiratory therapy students review diagnostic procedures, pulmonary physiology concepts, and clinical interpretation strategies required for academic exams and respiratory care certification preparation. Keywords pulmonary function test final exam questions, spirometry interpretation respiratory therapy, FEV1 FVC ratio obstructive lung disease diagnosis, lung volume measurement helium dilution nitrogen washout, body plethysmography Boyle law lung volumes, DLCO diffusion capacity pulmonary diagnostics, methacholine bronchial challenge airway hyperresponsiveness test, dead space ventilation VD VT calculation respiratory physiology, cardiopulmonary exercise testing RER interpretation, respiratory muscle strength MIP MEP testing, spirometer calibration 3 liter syringe quality control, pulmonary rehabilitation respiratory therapy training, oxygen concentrator home oxygen therapy respiratory care, restrictive vs obstructive lung disease spirometry, respiratory therapy exam preparation