Sleep apnoea and neuromuscular respiratory disorders Flashcards
Define sleep apnoea.
A temporary (10 seconds) cessation of breathing during sleep. Recurrent episodes of upper airway obstruction lead to apnoea.
Describe sleeping patterns in infants.
Natural apnoea before 36 weeks, after this increased regular respiration. Infants then begin going straight into REM sleep and have 50% REM and 50% NREM. Newborns spend 16-18 hours asleep. Sleep-wake states alternate in 3-4 hour cycles, then they start to adapt to light/dark and social cues. 6 month olds spend 14-15 hours asleep. They have 2 longer sleep periods at night and 1-2 daytime naps. 2 year olds spend 12 hours asleep and have 1 daytime nap. After 2 years naps usually disappear.
What happens to sleep patterns throughout life?
REM decreases and NREM increases. Total time asleep also decrease.
When is sleep most efficient?
In pre-pubescent children.
Describe sleep in adolescence.
Increased wakenings. Need more sleep but obtain less.
How can sleep be assessed?
Polysomnography (records brain waves, O2 levels in blood, HR, RR, leg and eye movements); direct behavioral observation; time-lapse video; movement sensors in cot mattress; O2/CO2 monitoring.
When do napping and enuresis become abnormal?
Age 3-5.
Is a 1 year old sleeping 8 hours per night without a nap normal or abnormal?
Abnormal.
When is REM onset of sleep normal?
First 3 months.
Which factors can cause excessive sleepiness?
Insufficient sleep, OSAS (obstructive sleep apnoae syndrome) or narcolepsy (falling asleep at inappropriate times, can be caused by orexin deficiency).
Define cataplexy.
A condition in which strong emotions such as laughter causes the patient to suddenly collapse although they are still conscious.
What is a hypnagogic hallucination?
A vivid/frightening hallucination experienced during the transition from wakefulness to sleep.
Define primary snoring.
Snoring without apnoea, hypoventilation, hypoxia, hypercarbia ( > blood CO2) and day time symptoms.
What is the morbidity associated with OSAS in children?
Failure to thrive, neurocognative effects/ADHD, systemic hypertension and Cor Pulmonale.
Contrast adult and child OSAS.
ADULT: daytime sleepiness, majority obese, no mouth breathing, more males, no enlarged tonsils, apnoea is obstructive pattern. CHILD: minority experience day time sleepiness or are obese, mouth breathing common, equal males and females, enlarged tonsils common, obstructive pattern is to hyperventilate.
What is the treatment for OSAS in children?
Adenotonsillectomy, CPAP (rarely), weight loss and avoid environmental tobacco smoke.
Which respiratory disorders can cause apnoea?
Chronic neonatal lung disease, CF and asthma.
Which neurological disorders can cause apnoea?
Cerebral palsy, Downs, Prader-Willi syndrome and DMD (death due to respiratory failure).
What symptoms will adult OSAS patients have?
Snoring, unrefreshing sleep, daytime sleepiness (hypersomnolence) and poor daytime concentration.
What are the pathophysiological causes of OSAS?
Muscle relaxation, having a narrow pharynx and obesity. Repeated closure of the upper airway causes snoring and O2 desaturation. Result is frequent microarousals so the brain is not properly rested - causes symptoms.
What is the difference between apnoea and hypoapnoea?
Apnoea is a total obstruction and hypoapnoea is not a total obstruction.
Why is OSAS important?
Impaired QOL, matiral dysharmony, > RTA, associations with hypertension, > stroke risk and > heart disease risk.
What is the prevalence of OSAS in adults?
2% men and 1% women.
How is OSAS diagnosed?
Clinical history, examination, Epworth questionnaire (11-24 score is significant) and overnight sleep study pulse oximetry (2 repetitive desaturations is sleep apnoea).
What is the gold standard for diagnosis of OSAS?
Polysomnography, but in 99% of cases it is not needed to diagnose. Main difference between this and other tests is that it includes EEG (electroencephalogram).
How is severity scored?
0-5 normal, 5-15 mild, 15-30 moderate and > 30 severe.
How is sleep apnoea treated in adults?
Identify exacerbating factors: weight reduction, avoid alcohol, diagnose/treat underlying endocrine disorders, CPAP (keeps +ve pressure in throat, no O2 just air) and mandibular re positioning splint. Patients should not be driving until treated effectively.
What is the prevalence of narcolepsy?
0.05%. Familial and associated with DRB11501 and DQB10602.
What are the symptoms of narcolepsy?
Cataplexy, excessive daytime sleepiness, hypnagogic hallucinations and sleep paralysis. Last 2 as these patients go into REM sleep very quickly.
What is the treatment of adult narcolepsy?
Modafinil, clomipramine (cataplexy) and sometimes sodium oxybate/xyrem.
Define chronic ventilatory failure.
PCO2 > 6 kPa and PO2 bicarbonate. This is a chronic condition and so to stabilise blood pH in long term body takes bicarbonate from the kidneys.
What are the causes of CVF?
Airways disease, chest wall abnormalities, respiratory muscle weakness and central hypoventilation.
What are the symptoms of CVF?
Breathlessness, orthopnea, ankle swelling, morning headache, recurrent chest infections and disturbed sleep. FVC will be significantly less than predicted.
What is the treatment for CVF?
Domiciliary non-invasive ventilation, O2 therapy (need to be careful as patient will probably use hypoxia central drive to breathe) and T-IPPV (tracheostimised intermittent positive pressure ventilation).
