Sleep Apnoea and Neuromuscular Respiratory Failure Flashcards
What is obstructive sleep apnoea syndrome ?
Recurrent episodes of upper airway obstruction leading to apnoea during sleep
What is the presentation of OSAS ?
Usually associated with heavy snoring
Typically unrefreshing sleep
Daytime somnolence/ sleepiness
Poor daytime concentration
What is primary snoring ?
Snoring without apnoea, hypoventilation, hypoxia, hypercapnea, daytime symptoms
What is OSAS associated with ?
Impaired QoL
Marital disharmony
Increased risk of RTAs
Associated with hypertension, increased risk of stroke and increased risk of heart disease
What is the prevalence of OSAS ?
2% adult men
1% adult women
How is OSAS diagnosed ?
Clinical history and examination
Epworth questionnaire
Overnight sleep study:
What is involved in an overnight sleep study ?
Pulse oximetry
Limited sleep studies
Full polysomnography
What is the Epworth sleepiness scale ?
0- would never dose
1- slight chance of dozing
2- moderate chance of dozing
3- high chance of dozing
When is the Epworth scale abnormal ?
a score >/= 11
What is overnight oximetry ?
Probe on end of finger
Records saturation of O2
What is polysomnography ?
Oronasal airflow Thoracoabdominal movement Oximetry Body position EEG EOG EMG (peripheral muscle) ECG
What is the OSA severity ?
Desaturation rate/ AHI:
- 0-5 normal - 5-15 mild - 15-30 moderate - >30 severe
What is the treatment for OSAS
Identify exacerbating factors:
- weight reduction
- avoidance of alcohol
- diagnose and treat endocrine disorders e.g. Hypothyroidism acromegaly
Continuous positive airways pressure (CPAP)
Mandibular repositioning splint
What is the regulations for driving with someone with OSAS ?
Advise pateints with sleep apnoea and excessive daytime somnolence not to drive or restrict driving and to inform DVLA of condition
Once satisfactory treated should be allowed to drive
What is narcolepsy ?
a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep.
What is the prevalence of narcolepsy ?
0.05%
What is narcolepsy associated with ?
HLA-DRB1*1051
HLA DQB1*0602
What are the clinical features of narcolepsy ?
Cataplexy
Excessive daytime sleepiness
Hypnagogic/ hypnopompic hallucinations
Sleep paralysis
What are the investigations of narcolepsy ?
Polysomnography
MSLT (multiple sleep latency test)
Low CSF orexin
What is the treatment for narcolepsy ?
Modafinil
Dexamphetamine
Venlafaxine
Sodium oxybate (xyrem)
What is chronic ventilatory failure ?
Condition that results in the inability to effectively exchange carbon dioxide and oxygen
What are the features of CVF ?
Elevated pCO2 (>6kPa)
pO2 <8kPa
Normal blood pH
Elevated bicarbonate
What are the causes of CVF ?
Airways disease:
- COPD
- bronchiectasis
Chest wall abnormalities:
- kyphoscoliosis
Respiratory muscle weakness:
- motor neurones disease (ALS)
- muscular dystrophy
- glycogen storage disease (pompe's disease)
Central hypoventilation:
- obesity hypoventilation syndrome
- congenital central hypoventilation syndrome (Ondine's curse)What are the typical symptoms of CVF ?
Breathlessness Orthopnoea Ankle swelling Morning headache Recurrent chest infections Disturbed sleep
What are the typical examinations findings for CVF ?
Paradoxical abdominal wall motion in suspected neuromuscular disease Ankle oedema (hypoxic cor pulmonale)
What are the investigations for CVF ?
Lung function:
- lying and standing VC
- mouth pressures. SNIP
Assessment of hypoventilation:
- early morning ABG
- overnight oximetry
- transcutaneous CO2 monitoring
(fluoroscopic screening of diaphragms)What is the treatment for CVF ?
Non-invasive ventilation
O2 therapy
