A2- Sleep Breathing Disorders Flashcards
Why is sleep disorders important?
- It is very common. 1 in 8 have sleep apnoea
- affects other medical conditions eg risk of stroke, MI, AF, asthma,DM, HF, depression
What is sleep apnoeas?
A group of conditions that are characterised by abnormal breathing during sleep.
Sleep apnoea can be classed into two main classes? What are they?
Obstructive
Central
What is the difference bwteen obstructive and central sleep apnoea?
Obstructive: (airway is partially or completely blocked)
Failure of thr upper airwya to maintain adequate patency when the upper airway dilator muscles relax with sleep.
Central: (patient fails to make any effort to breathe) IT is to do with your brain
What can cause central sleep apnoea?
HF, Morphine,
What does the term obstructive sleep apnoea syndrome suggest?
is used to describe the occurence of obstructive abnormalities on a sleep study combined with symptoms, usually excessive daytime sleepiness.
ANother word for sleep apnoea?
Hypopnoea syndrome
What are these examples of?
Overnight (8hr) Oximetry Tracings
Cheyne Stokes ventilation is a type of______
Central apnoea
Ix for OSA
Oximetry- fails/falls off finger sometimes
Respiratory polygraphy- more channels so more information =. Detects breathing and efforts as well as heart rate and sats. Can look at legs as well.
Polysomnography- should only be for non respiratory sleep problems such as narcolepsy or leg movements.
Management for OSA other than CPAP
Treating underlying disorder (acromegaly, hypothyroidism (if they are snoring and not changing weight check TFTs))
Stop evening alcohol and sedatives (depress/relax upper airway muscles)
Stop smoking- because it causes swelling and narrowes the airway
Lost weight-
Posture training- (avoid supine position)
Dental Devies/mandibular advancement devices
Surgery
Nasal continuous postive airway pressure.
Mandibular Advancement Devices
Device that can be placed in your mouth- pulling the lower jaw forward so it increases phargeal space
Increasing rates of obesity is causing hyperventilation
TRUE OR FALSE
FALSE
hypoventilation
How does obesity affect hypoventilation?
Inability of the respiratory muscles to cope with added load of fat on chest wall and abdmonial contents whilst supine.
Often misdiagnosed as OSA
Patients often describe increasng discomforti with breathin whilst supine and adopt other positons eg
- lots of pillows
- recliner chair
- hospital bed at home
Other signs and symptoms of OHS (obesity hypoventilation syndrome)
morning headache
Swollen ankles
Signs of cor pulmonale- heart failure fue to respiratory problems with central cyanosis and increasing peripheral oedema
CXR- Enlarged heart
Echo- Dilated RV
ABG- Raised BE or bicarbonate
What is CPAP
It is continuous air pressure.
It improves hypoxia.
Recuits underventilated or collapsed lung units
Increase FiO2 (oxygenation in the blood)
Splints the upper airway
Offloads work of breathing
What is NIV/BIPAP
Non-invasive ventilation
Bilevel positive airway pressure.
reduces hypercapnia.
Will also improve hypoxia and may be better tolerated than CPAP
Offloads work of breathing and resets chemoreceptors and therefore the response to rising Pco2.
What does NIV do?
Reduces pCO2 and resets chemoreceptors and therefore restores the ventilatory response to CO2 rises.
Rest the inspiratory muscles and recruits atelecatic (partial collapse) lung
EPAP- overcomes PEEP, delaying airway collapse
IPAP- reduces work of breathing and assists inspiration.
What does NIV do?
Reduces pCO2 and resets chemoreceptors and therefore restores the ventilatory response to CO2 rises.
Rest the inspiratory muscles and recruits atelecatic (partial collapse) lung
EPAP- overcomes PEEP, delaying airway collapse
IPAP- reduces work of breathing and assists inspiration.
Narcolepsy is not a respiratory sleep problem
TRUE OR FALSE
TRUE
What is Narcolepsy?
Excessive sleepiness during day/night due to a nuerological condiion caused by failure of neurotransmission in a tiny subset of brain neruoens (orexin/hypocretin). (damage)
genetic susceptibility-HLA DQB1
form of autoimmune disease
FUnction of orexin/hypocretin (brain neurones)
Keeps you awake
maintance balance and posture while you are awake
What can cause narcolepsy
it is autoimmune
it can also be triggered by head injury/disease or even infection (influenza)- this can cause further damage to the orexin/hypocreatin neurones
Consequences
Loss of orexin/hypocreatin causes…
- excessive daytime sleepiness
- Loss of control of REM sleep which is associated with loss of muscle tone
- That can causes sleep onset dreaming/hypnagogic hallucinations
- sleep paralysis
- cataplexy- suddent onset loss of muscle tone during wakefulness in response to intese emotions such as a good laugh, great antcipation etc varies from a slight droopng of the face and neck to apparently passing out and fallin on the floor.
Diagnosis of Narcolepsy?
History- cataplexy virtually diagnostic
HLA typing- DQB1
MSLT-
Sleep Study
CSF orexin levels
Tx for narcolepsy
Sleepiness- Non Pharmacological: scheduled naps, regular sleep/wake cycle. Pharmacological- amohetamines, modafanil, trycylics.
Cataplexy- Tricyclics (clomipramine, voloxazine, imipramine, fluoxetine
Latest drugs fro narcolepsy?
Also pitolisant
H3 receptor antagonist/iverse agonist
other management for narcolepsy
