Respiratory - Respiratory Support Flashcards
What is acute respiratory distress syndrome?
Acute onset of :
- Alveoli and lung tissue collapse (atelectasis)
- Pulmonary oedema
- Decreased lung compliance
- Fibrosis of lung tissue
Due to severe inflammatory reaction
What are the signs of acute respiratory distress syndrome?
Acute respiratory distress
Hypoxia with inadequate response to oxygen
Bilateral infiltrates on CXR
What is the management of ARDS?
Supportive
- Respiratory support
- Prone positioning
- Careful fluid management to prevent excess collecting in the lungs
What is lung protective ventilation used for in ARDS?
Low volumes and pressure used to avoid over-inflating small functioning portion of the lungs
What are the benefits of prone positioning?
Reduced compression of the lungs by other organs
Improved blood flow to lungs
Imrpoved clearance of secretions
Improved oxygenation
Reduces assistance from mechanical ventilation
What oxygen flow can you give with a nasal cannula?
1-4 litres
What oxygen flow can be given with a simple face mask?
5-8 litres
What oxygen can be given with a non-rebreather mask?
8-10 litres
What are venturi masks used for?
Deliver exact oxygen concentrations
Used for COPD patients at risk of CO2 retention if FiO2 is too high
What is positive end-expiratory pressure?
PEEP
End-expiratory pressure is the pressure that remains in the airways at the end of exhalation
Additional pressure in the airways at the end of exhalation keeps them inflated
Prevents airways collapsing and improves ventilation
How is positive end-expiratory pressure added?
High-flow nasal cannula
Non-invasive ventilation
Mechanical ventilation
How does a high-flow nasal cannula work?
Reduces amount of room air patient inhales alongside supplementary oxygen
Increased concentration of oxygen inhaled with each breath
Also adds positive end-expiratory pressure
What is a dead space washout?
Physiological dead space that does not contribute to gas exchange as it never reaches alveoli
High-flow oxygen clears the dead space and replaces it with oxygen improving patient oxygenation
What is continuous positive airway pressure?
Constant pressure added to lungs to keep airways expanded
Used to maintain patient’s airways where they are likely to collapse e.g. obstructive sleep apnoea
Why is continuous positive airway pressure (CPAP) non-invasive ventilation?
Provides constant pressure
Ventilation is still dependent on respiratory muscles so classed as NIV
