OBSTRUCTIVE SLEEP APNOEA Flashcards
Pathophysiology of OSA?
During sleep, airway muscles relax narrowing airway.
OSA patients have already narrow airways.
Increased inspiratory effort and lower airway pressure
Airway collapse
Pt wakes to maintain patency
What is OSA?
Repeated pauses in breathing while asleep > 10seconds due to upper airway obstruction.
Associated with 02 desats and cerebral arousal
Predisposing factors for OSA?
Obesity Male - dt increased neck torso mass Family history Smoking alcohol Age > 65 Facial abnormalities and large neck
What are the causes of OSA in children?
Due to tonsil or adenoid enlargement.
Symptoms of OSA?
Daytime - somnolence, fatigue, lack of energy, headaches, irritability, rapid weight gain.
Nocturnal - snoring, episodes of gasping, nocturia (ANP)
Examination of OSA?
BMI raised, CVS (hypoxia pulm. HTN)/RESP
Examine oral cavity, neck (MALAMPATI score) and do Muller’s manoeuvre.
What is Muller’s maneovre?
Force expiration, then block nose and close mouth while attempting to inspire.
Looking for airway collapsed can use fibre optic scope.
Ix for OSA?
CBE EUC TFT (hypothyroidism) GH (acromegaly)
Epworth sleepiness scale >12/24
GOLD STANDARD : sleep study (ECG EOG OXIMETRY EEG) - lowest 02sat, number of desats, respiratory disturbance index (RDI)
Anaesthetic complications of OSA?
Difficulty intubating due to narrow airway
Increased propensity for airway to collapse with opioids
Therefore sensitive to respiratory depression.
Diagnosis of OSA?
RDI > 5
SATS < 90%
Management of OSA?
Non-surg
Wt loss
CPAP (GOLD STANDARD but social stigma)
Mandibular advancement splint - moves jaw forward
Surg
Uvulopalatopharngoplasty?(not evidence)
Complications of OSA?
Psychosocial, marital
CVD - hypoxia -> pulm HTN -> RHF (ANP release causes diuresis).
Somnolence - car accidents, QOL issues
