DEFINITION OF DYSPNOEA
Dyspnoea is a subjective experience of
breathing discomfort that is comprised of
qualitatively distinct sensations that vary in
intensity. The experience derives from
interaction among multiple physiological,
psychological, social, and environmental
factors, and it may induce secondary
physiological and behavioral responses.
Receptors involved in mechanism of dyspnea
1) J receptors – alveolo-capillary junction
• Stimulated by pulmonary congestion ,oedema, micro emboli.
• Responsible for rapid shallow breathing
2) Stretch receptors – thoracic cage & lung
3) Chemoreceptors - carotid arteries, aorta & reticular substance of
Stimulated by hypoxia, excess of CO2, decrease in PH
4) Receptors in the respiratory muscle – immediate cause of
appreciation of dyspnea
Thorax is in hyperinflated position/Diaphragm
Work of breathing is high, O2 cost of breathing high
Derangement of dead space ventilation & alveolar capillary gas
Afferent stimuli to sensorymotor cortex
INTERSTITIAL LUNG DISEASE
Work of breathing & O2 cost of ventilation
Effort of respiratory muscles in ventilation stimulate
Pleural effusion & Pneumothorax
collapse of the normal lung hypoxia
muscles at mechanical disadvantage
Inadequate O2 delivery to respiratory muscles
increased respiratory drive
DYSPNOEA GRADING SCALES
Visual analogue scale
Sherwood jones grading
American thoracic society scaling
MMRC dyspnoea scale
EXAMPLE OF A VISUAL ANALOG SCORE. THESE CAN BE ADAPTED TO ANY
SYMPTOM AND CAN BE SUPPLEMENTED WITH ANCHORING VERBAL
OR VISUAL DESCRIPTORS AS SHOWN HERE.
SHERWOOD JONES GRADING
Grade 1a : housework/job with moderate difficulty
1b : with great difficulty
Grade 2a : confined to chair/bed but able to get
up with moderate difficulty.
2b : with great difficulty
Grade 3 : totally confined to chair/bed
Grade 4 : moribund
GRADE 1 –Dyspnoea only with unusual exertion.
GRADE 2 –Dyspnoea on doing ordinary activity
GRADE 3 –Dyspnoea on doing less than ordinary
GRADE 4 –Dyspnoea at rest.
I. Not troubled by breathlessness with
II. Shortness of breath when hurrying or walking up a slight
III. Walks slower than contemporaries on level ground
because of breathlessness or has to stop for breath when
walking at own pace.
IV. Stops for breath after walking about 100m or after a few
min. or level ground.
V. Too breathless to leave the house or breathless when
dressing or undressing.
0. Not troubled by breathlessness with strenuous exercise.
1. Shortness of breath when hurrying or walking up a slight hill.
2. Walks slower than contemporaries on level ground because
of breathlessness or has to stop for breath when walking at
3. Stops for breath after walking about 100m or after a few
min. or level ground.
4. Too breathless to leave the house or breathless when
dressing or undressing.
The trachea may deviate away from the lesion-
tension pneumothorax or a large pleural effusion.
Unilateral dullness to percussion - pleural effusion,
atelectasis, foreign body aspiration, pleural
tumours, or pneumonia.
Hyper-resonance - pneumothorax or severe
Subcutaneous emphysema -
Cranial nerve palsies associated with
Ptosis -myasthenia gravis, myotonic
dystrophy, or botulism.
Sudden-onset dyspnoea associated with unilateral chest pain may
indicate acute pneumothorax.
On examination, breath sounds are unilaterally absent, and
percussion of the ipsilateral chest may reveal tympany.
The trachea may also be deviated away from the lesion.
Acute-onset dyspnoea associated with wheezing and cough,
especially in a person with prior history of asthma
Asthma is diagnosed based on the history and demonstration of
airflow obstruction reversibility.
Exposed to a medication, food product, or insect bite.
Sudden-onset dyspnoea is accompanied by cutaneous
manifestations , voice changes, a choking sensation, tongue and
facial oedema, wheezing, tachycardia, and hypotension.
Nausea, vomiting, and diarrhoea
History of trauma
may present with dyspnoea, circulatory collapse, and shock.
Acute pulmonary embolism
Sudden dyspnoea and chest pain, associated
with tachycardia, tachypnoea, hypotension,
hypoxaemia, hemoptysis and calf tenderness.
Foreign body aspiration
History of epilepsy, syncope, altered mental status (e.g.,
intoxication, hypoglycaemia), or choking and coughing
after ingesting food (particularly nuts) may suggest
foreign body aspiration.
Cyanosis and stridor followed by hypotension and
circulatory collapse .
Upper airway obstruction
Significant dyspnoea, inspiratory stridor, and
occasionally expiratory wheezing, exacerbated
Acute myocardial infarction
Presents with central chest pain radiating to the shoulders and
neck frequently accompanied by dyspnoea.
► O/E patient may be clammy and hypotensive.
S3 or S4 gallop rhythm
characteristic ECG changes,
elevated cardiac enzymes
Acute valvular insufficiency
systolic murmur and signs of acute cardiovascular collapse with
hypotension, tachycardia, and pulmonary rales.
An echocardiogram is typically required to establish the diagnosis.
severe chest pain that may radiate to the back.
hypotension and absent peripheral pulses.
Emergency echocardiogram or a CT chest is used for diagnosis.
Congestive heart failure
Presents with dyspnoea worsened by exertion, orthopnoea and
paroxysmal nocturnal dyspnoea, elevated neck veins, peripheral
fluid retention, an S3 gallop rhythm, and pulmonary congestion
(fine bibasal rales) .
The CXR shows characteristic signs of pulmonary venous
congestion with cardiomegaly.
B-type natriuretic peptide >100 pg/ml
Complete heart block
Dyspnoea with weakness, light-headedness, or syncope.
Dyspnoea accompanied by neck vein and facial engorgement,
shock, peripheral cyanosis, and tachycardia.
An enlarged cardiac silhouette on CXR and a low-voltage ECG,