The breathless Patient Flashcards
What are the different categories of causes of breathlessness?
The following four are classified as respiratory:
Airways
Tissue
Perfusion
Other
Non-respiratory
What are some airway related causes of breathlessness?
COPD
Asthma
Bronchiectasis
Anaphylaxis
What are some tissue related causes of breathlessness?
Interstitial Lung disease
What are some perfusion related causes of breathlessness?
V/Q mismatch
PE
PA Hypertension
What are some general respiratroy related causes of breathlessness?
Pleural effusion
Pneumonia
Lung Cancer
What are some non-respiratory causes of breathlessness?
Anaemia
Acidosis
Diaphragm splinting e.g in pregnancy
Cardiac tamponade
Arrhythmia
Anxiety
Heart Failure
MI
Acidosis
Define breathlessness
A subjective, distressing sensation of awareness of difficulty with breathing.
At what point can oxygen delivery go wrong?
- From outside world to the alveolar capillaries
- Taken up by Hb in RBCs
- Transported to areas of oxygen demand
- Used by cells in respiration
What is the main cause of breathlessness?
Hypoxia
What are the four different types of hypoxia?
Hypoxic hypoxia
Anaemic hypoxia
Stagnant hypoxia
Histotoxic Hypoxia
What is hypoxic hypoxia?
Not enough oxygen getting into the blood from the environment
Either problem with environment or problems getting into lungs (grossly)
Examples = high altitude, hypoventilation, V/Q mismatch
Pathology = COPD, PE, etc
What is anaemic hypoxia?
Insufficient Hb to collect oxygen to carry in the blood.
Examples - carbon monoxide poisoning, iron deficiency anaemia, haemorrhage
What is stagnant hypoxia?
Oxygen in blood is ineffectively circulated to areas of demand
For example - heart failure, Raynauds syndrome, Buergers disease
What is histotoxic hypoxia?
Sufficient oxygenation to tissues however cells cannot use it.
Main example is cyanide poisoning also alcohol, acetone some narcotics
Define cyanosis
The blue or purplish discolouration fo the skin or mucous membrane due to the tissues near the skin having loss oxygen saturation.
Can be central or peripheral