Each respiratory therapist should possess not only the clinical skills but also, the knowledge and the decision-making skills to diagnose a patient or to monitor the progress of a specific respiratory disease. The respiratory therapist should also understand the effect of various respiratory care diagnostic and therapeutic interventions as well as the devices that are needed for various interventions. For example, general assessment of the patient including vital signs monitoring, would give the practitioner a good but general idea about a patient in respiratory distress, but linking the assessment with additional information such as lab data, pulmonary function tests, and chest radiography will lead to more definitive diagnosis and treatment.

Pulmonary function testing is a way to measure lung volumes and airflow. It is used for the purpose of the diagnosis and measurement of lung impairment. For example, patients with obstructive or restrictive lung disease usually undergo PFT to measure their lung volumes and airflow to provide information about the severity of the disease and the appropriate intervention The benefit of performing pulmonary function testing in patients known to have obstructive lung disease, is to evaluate the severity of the disease and the effectiveness of the therapy1. This depends on performing spirometry with pre and post bronchodilator treatment. If the percentage of change in the volume exhaled in the first second (FEV1) of the forced vital capacity (FVC) maneuver is greater than 12%, it indicates that the patient’s airway obstruction is reversible and that the bronchodilator treatment is effective. An ideal example is an asthmatic patient who performs PFT pre and post bronchodilator2. Additionally, PFT performed prior to surgery could give a clear idea about the risk of postoperative pulmonary complications in patients, who will have surgery under general anesthesia.

Thoracic imaging is another tool that supports the diagnosis of lung diseases. Regular chest X-ray provides an instant thoracic image, but computerized tomography (CT) and magnetic resonance imaging (MRI) require additional time with the benefit of more accuracy. Since thoracic imaging reflects the different densities of various substances (air, fat, soft tissue, and bone) contained in the organs within the thoracic cavity, this will aid diagnosis of a specific disease depending on its characteristics. For instance, pleural effusion, atelectasis or infiltrates tend to appear radiopaque while emphysema or pneumothorax will appear radiolucent. In addition, a chest radiograph serves as a good indicator of the position of artificial airways such as the endotracheal tube. This is important since misplacement of the endotracheal tube could lead to several complications.2-3

Given the diagnostic value of PFTs and chest x-rays, the respiratory therapist should have the ability to interpret the results provided by these diagnostic tools and recommend appropriate interventions.

Reference:

  • Koegelenberg, C. F., Swart, F., Irusen, E. M. (2013). Guideline for office spirometry in adults, 2012. SAMJ. South African medical journal, 103(1), 52-62.
  • Clinical Practioner’s Poket Guide To Respiratory Care by .Dana Oakes .
  • -Egan’s Fundamentals of Respiratory Care book