Sleep Apnea and Neuromuscular Respiratory Disorders

sleep apnoea syndrome - upper airway obstruction leading to apnoea during sleep

stopping breathing is apnoea

associated with heavily snoring

•Nocturnal polyuria when you wake up a lot in the night to pee

muscle in pharyngeal wall that can activate and open the throat if it closes off

sleep apnoea combination of muscle relaxation, narrow pharynx, obesity

all pharyngeal muscles become relaxed

2% of adult men, 1% adult women

diagnosed by -clinical history and examination

-epworth questionnaire

-overnight sleep study → pulse oximetry (O2 sats and pulse rate overnight)

→limited sleep studies

→full polysomnography

polysomnography most sophisticated study

electroesephonogram (EEG)

includes light sleep, REM sleep, deep sleep

severity of OSA

0-5 normal

5-15 mild

15-30 moderate

>30 severe

desaturation rate/AHI

Treatment

weight reduction, alcohol avoidance, diagnose and treat endocrine disorders (which mostly present in sleep apnoea) e.g. hypothyroidism, acromegaly

continuous positive airways pressure (CPAP) *main treatment - like breathing device in night

mandibular repositioning splint - guard in mouth, brings lower jaw forward, advances jaw as much as you want

positional therapy devices - stops them sleeping on their back, some only get sleep apnoea on their back

Narcolepsy

•Associated with HLA - DRB1*1501 and HLA DQB1* 0602

with a specific haplotype, gene that codes for mite cell antigens?

cataplexy, laughing or crying might induce cataplexic attack, can be confused with fainting, not everyone has cataplexia with narcolepsy

excessive daytime somnolence

hypnagogic- just about to sleep and hallucinate or hear voices, hynopompic hallucinations - just coming around from sleep

sleep paralysis- seeing something in the room and can’t move

Sleep Onset Rem Sleep (SOREM)

rem sleep is the state which we dream, rapid eye movement

narcolepsy go straight into rem sleep, all skeletal muscles paralysed, explains why they get hyponogic and paralysis

PSG -polysonograpahy to diagnose

can also sample CSF, if orexin low in CSF, feature of narcolepsy

Treatment

-modafinil

-dexamphetamine

-venlafaxine (for cataplexy)

-sodium oxybate (xyrem), can be used for sleepiness and cataplexy

Chronic Ventilatory Failure

also called chronic type 2 respiratory failure

elevated pCO2 >6.0 kPa (high)

pO2 <8kPa (low)

normal blood pH

(unlike acute ventilatory failure where body hasn’t compensated, compensation here leads to normal pH)

elevated bicarbonate, how body compensates (HCO3-)

pK a constant

in order to maintain normal pH body compensated by retaining carbonate, leading to rise of bicarbonate in blood, hence turning this ratio back to normal

most people with COPD DON’T have chronic ventilatory failure but a chronic proportion of the spectrum do

symptoms depend on the condition causing the CVF

orthopnoea is breathlessness lying flat, if weakness of diaphragm when you lie flat no gravity to help muscle descend and abdominal organs pushing on it making it difficult for diaphragm to descend causing people to feel breathless lying flat

morning headache because vasodilation of brain vessels? CO2 too much

PI max is maximum inspiratory pressure

PE max is maximum expiratory pressure