Acute Dyspnea

Overview

Dyspnea (Greek dys, meaning “painful,” “difficult,” and pneuma, meaning “breath. Dyspnea is the medical term for subjective experience of breathlessness or shortness of breath. Dyspnea can be acute when it develops over hours to days and chronic when it has been for more than four to eight weeks.

CAUSES OF DYSPNOEA
Acute	Chronic
Pulmonary edema	COPD
Asthma	Left cardiac failure
Injury to chest wall and intrathoracic structures	Asthma
Spontaneous pneumothorax	Pulmonary vascular disease
Pulmonary embolism	Psychogenic dyspnea
Pneumonia	Anemia (severe)
Acute respiratory distress syndrome	Hypersensitivity disorders
Pleural effusion	Pleural effusion
Pulmonary Haemorrhage
Foreign body aspiration
Anxiety

Dyspnea may be due to diseases in virtually any organ system, whether caused by interference with breathing, increased demand for breathing, or weakening of the respiratory pump. In most cases, however, patients with dyspnea can be categorized into one of two groups: respiratory related dyspnea or cardiovascular related dyspnea.

COMMON CAUSES OF ACUTE DYSPNOEA
Respiratory Disease	Cardiovascular Disease
Pulmonary Embolism	Acute left ventricular failure (heart failure)
Pulmonary Infection (Pneumonia, bronchitis)	Acute Coronary Syndrome
Pneumothorax
Upper airway obstruction (Aspiration, anaphylaxis)
COPD/Asthma exacerbation

 

LIFE-THREATENING DYSPNOEA
Acute onset Dyspnea	Associated signs/symptoms
Foreign object	Sign of choking, Inspiratory and expiratory stridor
Anaphylaxis	Angioedema, stridor, rash, pruritus
Pulmonary Haemorrhage
Pulmonary Embolism	Acute dyspnea, fever, haemopytsis, pleuritic chest pain, signs of DVT
Pneumothorax	Acute dyspnea, one sided-pleuritic chest pain
Cardiac Tamponade	Cardinal Quatrad: hypotension,↑JVP, tachycardia, pulsus paradoxus
Acute Coronary Syndrome	Retrosternal chest pain, radiates to jaw/neck, diaphoresis and feeling of impending doom
Gradual onset Dyspnea	Associated signs/symptoms
Asthma exacerbation	Pallor/Cyanosis, ↑resp rate, accessory muscle use, wheezing, silent chest, muscle exhaustion
COPD exacerbation
Anaemia	From Haemorrhage: Shock
Epiglottitis	“Barking cough”
Diabetic ketoacidosis	History of polyuria, polydipsia, polyphagia, and progressive weakness; signs of severe disease include hyperventilation, altered mental status, and abdominal pain

Approach

• History
  • Drugs history
    • Amiodarone
    • Methotrexate

• Examination
  • Smoker signs
  • BMI

NYHA classification of dyspnea (For Heart Failure)
I	nil at rest, some on vigorous activity
II	nil at rest, dyspnea on moderate exertion
III	mild dyspnea at rest, worse on mild exertion
IV	significant dyspnea at rest and worse on slight exertion

 

MRC Dyspnea score
1	Not troubled by breathlessness except on strenuous exercise
2	Dyspnea when hurrying or walking up a slight hill
3	Walks slower than contemporaries on level ground due to dyspnea, or has to stop for breath when talking at own pace
4	Stops for breath after walking 100m or less on ground level
5	Too breathless to leave house, or when getting dressed

Investigation

• Pulse oximetry
• Full Blood Count
• EUC
• Electrolytes
• Cardiac troponin
• Brain natriuretic peptide (BNP) or N-terminal pro-BNP
• D-dimer
• Chest X-ray
• Electrocardiogram (ECG)

Specific Dyspnea

• Orthopnea – dyspnea when lying flat. patient usually sleeps with multiple pillows
• Paroxysmal nocturnal dyspnea – episodes of breathlessness at night. It is associated with pulmonary oedema
• Cheyne–Stokes breathing is characterized by alternating periods of hypoventilation and hyperventilation
• Kussmaul breathing – Diabetic ketoacidosis who manifests with “air hunger”: rapid breathing
• Hyperventilation – dysfunctional breathing, breathing off CO2 causes ↓CO2 and so increases pH