Breathlessness

Synonym: dyspnoea

Subjective sensation of difficult, laboured or uncomfortable breathing.

Physiologically, we are all aware of breathlessness when we exercise beyond our normal tolerance but pathologically it can occur with little or no exertion. Afferent sources for the sensation of breathlessness arise from receptors in the upper airway, lungs and chest wall as well as autonomic centres in the brain stem and motor cortex. It is almost always associated with fear and when chronic, can be disabling and severely diminish quality of life.¹

Approximately two thirds of cases of dyspnoea in adults are due to a pulmonary or cardiac disorder. In about a third of cases, diagnosis will be multifactorial.²

Next to pain, breathlessness is the most common symptom for which patients seek help and relief from their doctor. Peak incidence of chronic dyspnoea occurs in the 55 to 69 year old age bracket.²
Seventy percent of all terminal cancer patients suffer breathlessness in their last six weeks.⁴

Given the multiplicity of causes, investigation of breathlessness should begin with a full history and examination.

History

• Duration of breathlessness and speed of onset i.e. acute, chronic
• Timing of breathlessness e.g. diurnal variation with asthma
• Any known precipitating events e.g. trauma, palpitations, chest pain, exercise
• Try to quantify exercise tolerance (e.g. breathlessness at rest, with talking, dressing, distance walked or number of stairs climbed).

  MRC dyspnoea score5
  Grade	Impact
  1	Not troubled by breathlessness except on vigorous exertion.
  2	Short of breath when hurrying or walking up inclines.
  3	Walks slower than contemporaries because of breathlessness, or has to stop for breath when walking at own pace.
  4	Stops for breath after walking about 100 metres or stops after a few minutes' walking on the level.
  5	Too breathless to leave the house or breathless on dressing or undressing.

• Smoking history
• Occupation
• Past history of chest or cardiac disease
• History of atopy
• History of anxiety-related disorder
• Family history
• Pets ± contact with birds
• Drug exposure (β-blockers, amiodarone, nitrofurantoin,methotrexate, heroin)

Examination

Should include:

• General e.g. patient distress, colour of skin and lips, cyanosis, clubbing, lymphadenopathy, tremor, flap
• Trachea-central, deviated to one side
• Shape of chest e.g. kyphosis
• Movement of chest - symmetrical, asymmetrical
• Respiratory rate
• Pulse - rate, rhythm
• Percussion note e.g. stoney dull over a pleural effusion, hyperresonant over a pneumothorax
• Auscultation of chest

Further investigations ²

Dependant on the findings of the history and examination but may include:

• Lung function tests e.g. Peak flow measurement, FEV1, FVC, ±reversibility after short acting beta agonist inhalation
• Pulse oximetry
• CXR
• FBC
• Arterial blood gases
• Natriuretic peptides (BNP)
• ECG
• Pulse oximetry
• Echocardiogram
• High-resolution CT scan
• V/Q scan
• RAST measurement or skin prick testing to common aero-allergens

Dependant on the underlying cause.

• In an acute situation, breathless individuals should be assessed rapidly and treated with high flow oxygen(>60%) unless there is a known history of COPD, in addition to any specific therapy for the underlying condition. If unstable, transfer to hospital should be arranged as an emergency.
• In the chronic situation, the underlying cause should be addressed and treated. Frequently breathlessness is a common end point of non-reversible disease and symptomatic relief should be sought instead.

Strategies for relieving breathlessness (of respiratory origin)

• Reassure and educate patient and care-givers to increase confidence at their ability to control and interpret symptoms.
• Controlled breathing technique counteracts the fast, shallow, inefficient breathing associated with dyspnoea (sit upright, control respiratory rate, use diaphragmatic breathing, relax shoulders and upper chest).
• Cognitive Behavioural Therapy (CBT) seeks to modify the patient's response to the symptom. Anxiety and panic can be reduced often by using techniques such as distraction or relaxation.
• Drug treatment can be used to reduce the sensation of breathlessness. Opiates,such as morphine and codeine, are effective and used in palliative care settings^6,7but may further depress breathing so care is required. Similarly, benzodiazepines such as diazepam are used to reduce anxiety associated with breathlessness but also carry the side-effect of respiratory depression.
  

  Drugs for symptom control in end stage COPD5: Oral morphine prn (e.g. Oramorph® or Sevredol® 2.5-5 mg) Can be converted to regular longer acting opiate if helpful Benzodiazepines used when anxiety an integral part of breathlessness, alone or alongside opiates e.g lorazepam sublingual 0.5-1 mg prn or diazepam 2-5 mg tds where persistent symptoms.

• Pulmonary rehabilitation - individuals with severe breathlessness become less active and their general fitness levels diminish, causing a cycle of worsening breathlessness with less and less physical exertion. Supervised programmes of exercise training has been shown to be beneficial in COPD.⁸
• Nutrition - patients with severe respiratory disease may be cachexic and have such generalised muscle weakness that the work of breathing is extremely demanding. Addressing nutritional needs with a dietician may be helpful.
• On-going or intermittent oxygen therapy via facemask or nasal prongs may be of benefit in some cases. In chronic heart and lung disease, benefit is only evident where there is confirmed hypoxia or pulmonary hypertension. Benefit in advanced lung cancer patients has been shown in small, double-blind cross over studies but this should be balanced against the risk of psychological dependence, where patients become 'glued' to their facemasks.^4,9
• Partial ventilation support - CPAP (continuous positive airway pressure) can be used for several hours a day to rest chest muscles but is intrusive and of temporary benefit only.
• Positioning- leaning forward when standing or nursing a bedbound patient as upright as possible can help to relieve breathlessness.
• Stream of air - fan, open window
• Modifying activities of daily living, lifestyle and expectations in line with disability.