Sleep And Breathing Flashcards
What are the two types of respiratory failure
Type 1 - hypoxaemic
Type 2 - hypoxaemia and hypercapnia.
What is type 2 respiratory failure and what does it mean
Influence of respiratory system to inadequately ventilate
It can be caused by restrictive diseases
Load on respiratory muscles eg obesity
How is breathing controlled during sleep?
Voluntary control - motor cortex
Automatic control - brain stem
Emotional control - limbic system
What has to be controlled during sleep in relation to breathing
Respiratory centre sensitivity
Chemoreceptor and mechanoreceptor sensitivity
Respiratory muscle contractility
Lung mechanisms
What happens to breathing during sleep
Reduction in tidal volume
Frequency stays the same
Breathing becomes less
CO2 increases
What happens if you have obstructive disease and go to sleep
Leas breathing, can be dangerous
Reduces O2 concentration in body
Why is Co2 so important in sleep
PaCO2 has to rise above apnoeic threshold during sleep
If not breathing will stop
Why is the upper airway not well designed for breathing
No cartilage, soft
During sleep, tounge falls back into tube
Can cause tube to close shut when breathe in
= obstructive sleep apnoea
What is the effect of obstructive sleep apnoea
Sleep Airway collapse Arousal caused Increased ventilation Sleep
Each arousal accompanied by surge in blood pressure : lead to hypertension
What is the differences in airflow in obstructive and central apnoea
Obstructive: airflow stops but breathing continues
Central: breathing is absent, no respiratory movement to initiate breathing due to insufficient CO2
How can we measure nocturnal respiratory disorders
Measurement of O2 saturation
Does not tell you if ventilating sufficiently
Can take arterial blood gas reading upon waking
How can central apnoea be caused
Drug therapies eg. Opioids
Heart failure
Injury or disease to brain
How can obesity affect ventilatory drive
Leptin resistance
Less sensitive to central hypercapnia
Increased load onto airways
Obstruction
How are type 1 respiratory failures treated
Oxygen therapy- long term oxygen therapy LTOT
How are type 2 respiratory failures treated
Ventilation - application of positive pressure
Continuous positive airway pressure CPAP
Removes reliance on internal negative pressure
