lecture 6 (respiratory) Flashcards
(29 cards)
what is polysomnography?
- sleep study taken to test for sleep disorders
- measures brain waves, oxygen levels in blood, heart rate and breathing
what is REM sleep?
- rapidly movement sleep
- where memory consolidation occurs
- hypotonia of skeletal muscles
- only diaphragm working
what occurs in slow wave sleep?
- voluntary muscle paralysis
what occurs to sleep as you age?
- need less sleep
- decreased slow wave sleep
- increased awakenings
- decreased melatonin
what two processes govern sleep and wakefulness?
- homeostatic sleep drive
- intrinsic circadian rhythm
what is homeostatic sleep drive?
- messages from brain increase desire to sleep as awake longer
what is intrinsic circadian rhythm?
- biological clocks
- alert in the day, less alert at night
what occurs in obstructive sleep apnoea?
- airway is partially or completely blocked
- cessation of airflow but continuing effort
- ribcage moving but no airflow
what occurs as a result of obstructive sleep apnoea?
- decreased saturation of haemoglobin
- haematological changes
- oxygen saturation decreases
what is central sleep apnoea?
- no effort to breathe
- neurological
- ribcage isn’t moving
what are the causes of central sleep apnoea?
- periodic breathing
- cheyne stokes respiration
- LVF
- neuromuscular disease
- altitude
what is the pathophysiology of obstructive sleep apnoae?
- periods of cessation of breathing despite efforts to breathe
- decreased pharyngeal tone
- pharyngeal collapse
- causes daytime sleepiness, snoring, oxygen desaturation
where is the main area of airway collapse in obstructive sleep apnoea?
- pharyngeal muscles
what MRI images are shown during apnoea?
- awake = air column fully open
- asleep = air column collapsed behind tongue
- asleep = ar column collapsed from uvular to larynx
- awake = air column fully open again
what occurs to oxygen saturation levels throughout the night in OSA?
- decreases
what occurs to pulse rate in the night in OSA?
- episodic rise in pulse rate with each arousal from sleep
what are the predisposing factors of OSA?
- obesity
- weight loss
- large neck size
how is sleep apnoea measured?
- apnea-hypopnea index
- number of apnea events divided by number of hours of sleep
how does retrognathia cause OSA?
- smaller retroglossal airway
- usually have smaller jaws
- teeth removed to maximise airflow inside
what features develop likelihood of OSA?
- enlarged tonsils
- small jaw
- elongated soft palate
what are the symptoms of OSA?
- loud snoring
- gasping
- chocking
- stopping breathing
- daytime sleepiness
what is the treatment fr OSA?
- weight loss
- improved diet, excersize, medications
- sleep hygiene (positional changes, avoidance of sedatives)
what is CPAP?
- nasal continuous postiive airway pressure
- mask used overnight to help breathing
what does CPAP do?
- forces airway open
- supports airflow
