A2- Sleep Breathing Disorders

Question 1

Why is sleep disorders important?

Answer 1

• It is very common. 1 in 8 have sleep apnoea
• affects other medical conditions eg risk of stroke, MI, AF, asthma,DM, HF, depression

Question 2

What is sleep apnoeas?

Answer 2

A group of conditions that are characterised by abnormal breathing during sleep.

Question 3

Sleep apnoea can be classed into two main classes? What are they?

Answer 3

Obstructive

Central

Question 4

What is the difference bwteen obstructive and central sleep apnoea?

Answer 4

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

Question 5

What can cause central sleep apnoea?

Answer 5

HF, Morphine,

Question 6

What does the term obstructive sleep apnoea syndrome suggest?

Answer 6

is used to describe the occurence of obstructive abnormalities on a sleep study combined with symptoms, usually excessive daytime sleepiness.

Question 7

ANother word for sleep apnoea?

Answer 7

Hypopnoea syndrome

Question 8

What are these examples of?

Answer 8

Overnight (8hr) Oximetry Tracings

Question 9

Cheyne Stokes ventilation is a type of______

Answer 9

Central apnoea

Question 10

Ix for OSA

Answer 10

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.

Question 11

Management for OSA other than CPAP

Answer 11

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.

Question 12

Mandibular Advancement Devices

Answer 12

Device that can be placed in your mouth- pulling the lower jaw forward so it increases phargeal space

Question 13

Increasing rates of obesity is causing hyperventilation

TRUE OR FALSE

Answer 13

FALSE

hypoventilation

Question 14

How does obesity affect hypoventilation?

Answer 14

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

Question 15

Other signs and symptoms of OHS (obesity hypoventilation syndrome)

Answer 15

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

Question 16

What is CPAP

Answer 16

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

Question 17

What is NIV/BIPAP

Answer 17

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.

Question 18

What does NIV do?

Answer 18

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.

Question 19

What does NIV do?

Answer 19

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.

Question 20

Narcolepsy is not a respiratory sleep problem

TRUE OR FALSE

Answer 20

TRUE

Question 21

What is Narcolepsy?

Answer 21

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

Question 22

FUnction of orexin/hypocretin (brain neurones)

Answer 22

Keeps you awake

maintance balance and posture while you are awake

Question 23

What can cause narcolepsy

Answer 23

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

Question 24

Consequences

Loss of orexin/hypocreatin causes…

Answer 24

1. excessive daytime sleepiness
2. Loss of control of REM sleep which is associated with loss of muscle tone
3. That can causes sleep onset dreaming/hypnagogic hallucinations
4. sleep paralysis
5. 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.

Question 25

Diagnosis of Narcolepsy?

Answer 25

History- cataplexy virtually diagnostic

HLA typing- DQB1

MSLT-

Sleep Study

CSF orexin levels

Question 26

Tx for narcolepsy

Answer 26

Sleepiness- Non Pharmacological: scheduled naps, regular sleep/wake cycle. Pharmacological- amohetamines, modafanil, trycylics.

Cataplexy- Tricyclics (clomipramine, voloxazine, imipramine, fluoxetine

Question 27

Latest drugs fro narcolepsy?

Answer 27

Also pitolisant

H3 receptor antagonist/iverse agonist

Question 28

other management for narcolepsy

Answer 28