Pulmonary fibrosis (PF) is characterized by the lungs’ walls thickening over time, prohibiting the optimal respiratory flow of air into the lungs, preventing the movement of oxygen into the bloodstream and, from there, to the different organs in the body.

The major symptoms of PF include shortness of breath (dyspnea), coughing, fatigue, aching muscles and joints, and clubbing of the fingertips.

PF is a progressive life-threatening disease with a poor prognosis. Even though some patients live much longer, the median survival is about 2.5 years after diagnosis. The most common cause of death is respiratory failure.

Individual predictors of survival include ethnicity, smoking, dyspnea, physical features, and the presence of other disorders. However, the lack of reliable prediction models that can be used in clinical practice makes it difficult to evaluate an individual’s risk of mortality.

Dyspnea and PF prognosis

Dyspnea, or shortness of breath, is a major symptom of pulmonary fibrosis. The higher the dyspnea score assessed by a physician, the shorter the survival rate.

Although the evaluation of dyspnea throughout the progression of the disease is not enough on its own to accurately predict individual survival, research has shown that the clinical assessment of dyspnea is one of the most reliable ways of predicting survival. Along with this evaluation, lung volume is also assessed to help with PF prognosis.

Dyspnea is measured at the time of PF diagnosis and every six months thereafter in order to assess how fast the disease is progressing and to adjust treatment accordingly.

How is dyspnea measured?

Dyspnea is not easily measured using a clinical device. Instead, it is assessed through the perception of patients’ own respiratory disabilities.

There are several scales to analyze dyspnea, but the one with the most widespread use is the Medical Research Council (MRC) chronic dyspnea scale.

This scale grades breathlessness during daily activities and allows patients to indicate the extent to which their shortness of breath affects their mobility. It is composed of a six-point scale from 0 (no dyspnea) to 5 (very severe degree of dyspnea). Category 1 is for patients with shortness of breath when hurrying on a flat surface or while walking up a slight hill. In category 2, the patient walks slower on the surface than most people their age because of breathlessness, while in categories 3 and 4 the patient has to stop for breath while walking at their own pace or after having walked for a few minutes, respectively. In category 5, the patient becomes too breathless to leave the house or to dress and undress.

The dyspnea score can be assessed through the patient’s answers to a specific questionnaire or via a six-minute walk test where the physician accompanies the patient on a walk for six minutes, measures the distance, and registers the difficulties.

Other measures of dyspnea include the BORG scalethe baseline dyspnea index (BDI), and the O2-cost diagram (OCD).

The BORG scale is an 11-point scale where patients answer the question: “How much difficulty is your breathing causing you right now?” with 0 being none at all, and 10 being the maximum level of difficulty.

The BDI is a five-grade scale with three categories including functional impairment, magnitude of a task, and magnitude of the effort. The sum score of the three categories is obtained for a final score. The lower this number, the greater the dyspnea.

Finally, the OCD is a visual analog scale that places activities according to their oxygen cost. Patients are asked to identify the level of activity at which they experience shortness of breath on a scale from 0 to 10, with higher numbers representing better function.

Note: Pulmonary Fibrosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.