4 The breathless patient Flashcards
Define breathlessness or DYSPNOEA
- Dyspnoea, the sensation of feeling breathless, is a symptom experienced under conditions in which there is an inordinately high ventilatory demand relative to the ability to breathe, ‘air hunger’, and a heightened level of awareness of respiratory sensation and often a strong emotional component.
Its major physical sign is tachypnoea (abnormally rapid breathing)
What things to keep in mind when assessing the level of dyspnoea?
An important assessment is whether the dyspnoea is related only to exertion and how far the patient can walk at a normal pace on flat ground
Other clarifications:
- variability in symptoms
- good/bad days?
- importantly; any times of day/night that are worse than others
Discuss how one may encounter shortness of breath (SoB)
Can be caused by anything that reduces PaO2 or increases PaCO2
You can have issues with:
- Ventilation - the amount of air brought into alveoli
- Perfusion - the amount of blood brought to alveoli for gas exhange
- Diffusion - (exchange surface) - defects include interstitial fibrosis, pulmonary oedema
Describe the problems that may occur to an ideal gas exchange unit
- Poor blood flow from the right side of the heart (clot)
- Too much CO2
- Abnormal tissue between alveolus and capillary (barrier to O2 transfer)
- Anaemia (lack of Hb)
- Faulty Hb (barrier to HbO2 complex)
- Poor backflow to heart e.g. failing left ventricle (hence, blockage in pulmonary vein)
How to distinguish between respiratory and cardiovascular causes of SoB?
Can be done using patient history and examination
- It is based on taking full history + full examination, then selecting tests to rule differential diagnoses in or out
Describe the various causes of dyspnoea
- LVF or Mitral Stenosis: slow or sudden (pulmonary oedema); cause: increased pressure in pulmonary capillaries
- Chronic bronchitis: chronic productive cough, with slowly progressive dyspnoea; Cause: excess mucus production
- COPD: overdistention of airspaces distal to terminal bronchioles; slowly progressive with features of bronchitis, asthma, and emphysema leading to progressive dyspnoea
- Asthma: problem with ventilation, (reversible airway disease - difficult to breathe out); acute episodes, separated by symptom-free breaks
Describe congestive heart failure (CHF)
Definition: the heart fails when it is unable to eject blood delivered to it by the venous system
- Blood builds behind the heart
- Most common type is LHF (Left-sided heart failure)
- In LHF, blood backs up in the lungs (pulmonary congestion)
> LHF - pulmonary oedema (to raised hydrostatic forces in pulmonary vasculature)
History taking (for breathlessness)
- Age?
- Onset of symptoms?
- Variability?
- Drug history
- Occupation? Pets?
- Associated symptoms?
Describe orthopnoea
Defined as breathlessness on lying down.
- While it is classically linked to heart failure, it is partly due to the weight of the abdominal contents pushing the diaphragm up into the thorax.
- Such patients may also become breathless on bending over
Describe the signs of breathlessness
Digital clubbing
- (can be due to lung cancer, bronchiectasis, pulmonary fibrosis, cyanotic heart disease)
- Cyanosis
> Central: reduced O2 saturation (>80%), blueish tongue and lips
> Peripheral: bluing of extremities like fingers
Describe a physical examination you would to a patient suspected of breathlessness
- Inspection
- Palpation
- Percussion
- Auscultation
Describe what you may hear upon auscultation of a patient with suspected breathlessness
- Wheeze: expiration, limitations of flow in asthma and COPD
- Crackles: opening of closed bronchioles
> Early inspiration associated with diffuse airflow limitation (e.g. bronchiolitis)
> Late inspiration associated with pulmonary oedema, fibrosis, bronchiectasis - Pleural rub: inflammation of pleural surfaces
- Stridor: high pitched breath sounds resulting from airflow through the obstructed airway
List some respiratory causes of breathlessness
- Asthma (reversible)
- COPD
- Pneumonia
- Lung cancer
- Pneumothorax
- Foreign bodies
- most other respiratory diseases
List some cardiovascular causes of breathlessness
- Heart failure: pulmonary oedema
- Pulmonary embolism
- Valvular disease
List some other causes of breathlessness
- Functional breathlessness (e.g. obesity)
- Anaemia (PaO2 and SaO2 are normal)
- Anxiety
- Thyroid Disease
- Some muscle disorders
