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
What are the main causes of central cyanosis?
Major causes of hypoxia/ hypo-perfusion, blood leaving heart is insufficient of oxygen
Generalised discolouration of he body and visible mucous membranes
Resp - COPD, pneumonia, PE
Cardio - HF, Cong HD
CNS - Drug overdose, ICH
What are the main causes of peripheral cyanosis?
Any causes of central cyanosis and when blood ‘can’t reach edges’ or is insufficient of oxygen in the periphery
Mucous membranes are not affected.
Reduced cardiac output - shock (septic or hypovolemic)
Hypothermia - peripheral vessels constrict (common in elderly)
Arterial/venous obstruction
What are the different types of masks/methods that can be used to administer oxygen?
Nasal cannula
Venturi mask
Simple Mask
Non- rebreathe mask
How much oxygen can a nasal canula deliver?
Connected to oxygen at the wall - due to nature of mask and likelihood to be not be in correct position is considered a variable performance device
1L = 24%
2L = 28%
3L = 32%
4L = 36%
4L is the max
What is the basic idea of how a venturi mask works?
Coloured clip at the bottom of the mask - controls how much additional air is entrained into the mask. Links to how many litres should be administered from the wall.
Can be connected to other devices such as a neb
Provides accurate levels of oxygen - high control.
What are the different colours of a venturi mask related to how much oxygen they adminster?
Blue = 24%
White = 28%
Yellow = 35%
Red = 40%
Green = 60%
(Boy wants your rosy girl)
What is the basic idea of how a simple mask works and how much oxygen can you deliver?
Connect to any flow of oxygen from the wall
Uncertain amount of additional air breathed in by the patient
Can connect to other devices such as nebs
Highly variable between 1-15L or 24%-60% oxygen
What are the basic principles of how a nonbreathe mask works and how much oxygen can it deliver?
Delivers an accurate and high percentage of oxygen
Between 10L or 60% and 15L 90%
Has an oxygen reservoir back at the bottom to maximise how much oxygen goes into the patient.
What is the normal target oxygen saturation?
94-98%