Dyspnea MRC Scale

MRC scale explained

This is a five grade clinical scale for patients with COPD that assesses the degree of dyspnea severity based on its impact on different physical daily activities.

The Medical Research Council scale was created by Fletcher in 1952 and starts from no nuisance from breathlessness during normal activities. Along the scale the degree of dyspnea increases.

The following table introduces the two versions of the MRC scale:

Currently, the modified version of the MRC (the MMRC) is most often used, especially alongside the BODE index, in the prognosis of patients diagnosed with chronic obstructive pulmonary disease.

The discriminative capacity of the MRC has been compared to data from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric classification of COPD.

The two assessment methods have proven sufficient sensitivity separately but do not correlate between stages.

About dyspnea in COPD

Chronic obstructive pulmonary disease is a respiratory condition characterized by the following symptoms:

■ Breathlessness;

■ Cough (sometimes chronic);

■ Sputum production;

■ Wheezing;

■ Chest tightness;

■ Airway irritability.

The above are suggestive of chronic COPD whilst COPD exacerbation means a stronger infective episode of COPD when the symptom severity increases and fatigue and weight loss are also experienced.

Dyspnea or breathlessness, is defined as a sensation of difficulty in breathing. This is most often attributed to lack of exercise and low level of fitness but also to pulmonary conditions such as COPD.

On exertion, a certain degree of breathlessness can occur normally but in pathological cases, it occurs at a level of activity that is either generally well tolerated or at a level of activity that the patient used to tolerate.

The symptoms include a clearly audible breathing, gasping, flaring nostrils, cyanosis, distressed facial expression and chest protrusion.

The following introduces major causes of dyspnea:

■ Heart attack, congestive heart failure, arrhythmias;

■ Pneumonia or pulmonary hypertension;

■ Gastroesophageal reflux disease;

■ Presence of allergies;

■ Chest wall trauma or foreign object inhalation.

Paroxysmal nocturnal dyspnea (PND) occurs at night and awakens the patient. PND is only relieved by an upright position.

Dyspnea needs to be differenced from other respiratory frequency or flow variations such as tachypnea, hyperventilation, and hyperpnea.

Original source

Fletcher CM. The clinical diagnosis of pulmonary emphysema; an experimental study. Proc R Soc Med. 1952; 45(9):577-84.

Other references

1. Stenton C. The MRC breathlessness scale. Occup Med (Lond). 2008; 58(3):226-7.

2. Fletcher CM, Elmes PC, Fairbairn AS, Wood CH. The significance of respiratory symptoms and the diagnosis of chronic bronchitis in a working population. Br Med J. 1959; 2(5147):257-66.

3. Bestall JC, Paul EA, Garrod R, Garnham R, Jones PW, Wedzicha JA. Usefulness of the Medical Research Council (MRC) dyspnoea scale as a measure of disability in patients with chronic obstructive pulmonary disease. Thorax. 1999; 54(7):581-6.

4. Rhee CK, Kim JW, Hwang YI, Lee JH, Jung KS, Lee MG, Yoo KH, Lee SH, Shin KC, Yoon HK. Discrepancies between modified Medical Research Council dyspnea score and COPD assessment test score in patients with COPD. Int J Chron Obstruct Pulmon Dis. 2015; 10:1623-31.