Sleep apnoea and narcolepsy

what is obstructive sleep apnoea syndrome

recurrent episodes of upper airway obstruction leading to apnoea during sleep

associated with heavy snoring, unrefreshing sleep, daytime sleepiness, poor daytime concentration

pathophysiology of sleep apnoea

muscle relaxation, narrow pharynx and obesity all causing repeated closure of airways

• this causes snoring and oxygen desaturation

apnoea and hypoapnoea

• causes frequent microarousals causing daytime sleepiness and poor concentration

why is sleep apnoea important

impaired QoL

marital disharmony due to heavy snoring causing lack of sleep

increased risk of RTA's

associated with hypertension increasing risk of stroke and heart disease

classifying sleep apnoea severity

desaturation rate/AHI

• 0-5 normal

• 5-15 mild

• 15-30 moderate

• >30 severe

diagnosis of sleep apnoea

clinical history and examination

epsworth questionnaire

overnight sleep study

pulse ox

limited sleep studied

full polysomnograph

treatment for sleep apnoea

identify exacerbating factors

• weight reduction

• avoidance of alcohol

• diagnose and treat endocrine disorders

continuous positive airways pressure (CPAP)

mandibular repositioning splint

driving and sleep apnoea

advise patients not to drive and inform DVLA

• once satisfactory should be allowed to drive

what is narcolepsy

a familial condition associated with HLA-DRB11501 and HLA DQB10602

clinical features of narcolepsy

cataplexy

excessive daytime somnolence

hypnagogic/hypnopompic hallucinations

sleep paralysis

narcolepsy investigations

PSG

MSLT (>1 SOREM and mean sleep latency <8mins)

low CSF orexin

narcolepsy treatment

modafinil

dexamphetamine

venlafaxine

sodium oxybate

chronic ventilator failure ABG

elevated pCO2 (>6.0 kPA)

pO2 <8 kPA

normal blood pH

elevated bicarbonate

aetiology of chronic ventilatory failure

airways disease

• COPD

• bronchiectasis

chest wall abnormalities

• kyphoscoliosis

resp muscle weakness

• MND

• muscular dystrophy

• glycogen storage disease

central hypoventilation

• obesity hypoventilation syndrome

• congenital central hypoventilation syndrome

symptoms of chronic ventilatory failure

SOB

orthopnoea

ankle oedema

morning headache

recurrent chest infections

disturbed sleep

treatment of chronic ventilatory failure

non-invasive ventilation (NIV)

oxygen therapy

t-IPPV

investigation - neuromuscular disease

lung function

• lying and standing VC

• mouth pressures/SNIP

assessment of hypoventilation

• early morning ABG

• overnight oximetry

• transcutaneous CO2 monitoring

fluoroscopic screening of diaphragms

fluoroscopic screening of diaphragms