Sleep Apnoea Flashcards
Apnoea definition
“Cessation of Airflow” for 10 seconds or longer
Risk factors
Male sex
Obesity
Neck circumference greater than 43 cm (41cm women)
Family history of OSAS
Smoking
Alcohol/sedative use
Craniofacial abnormalities (e.g retrognathia)
Pharyngeal abnormalities (e.g. tonsillar enlargement)
Some medical conditions (hypothryroidism, acromegaly, pregnancy)
Sleeping supine
Abnormal china
micrognathia & retrognathia
Nasal pathology
polyps, deviated septum
Clinical features
Snoring (Hx often from partner) Nocturnal choking/waking with a “start” Unrefreshing/restless sleep Morning dry mouth Morning headaches Excessive daytime sleepiness Difficulty concentrating Irritability/Mood changes Sleeping at inappropriate times Nocturia
Complications
Cor pulmonale
Right heart failure 2ndry respiratory disease
Secondary Polycythaemia
Excess of red blood cells
Investigations
Sleep Studies
Nocturnal oximetry
Video studies
Polysomnography
Diagnosis
AHI = apnoeas + hypopnoeas / total sleep time in hours
Mild: AHI 5–14per hour (+ symptoms/signs).
Moderate: AHI 15–30per hour.
Severe: AHI more than 30per hour.
OSA consequences
Hypertension Type 2 diabetes Ischaemic heart disease Heart failure Cerebrovascular disease/stroke Cardiac arrhythmias Death
Management goals
Resolve signs and symptoms of OSA
Improve sleep quality
Normalise:
apnoea-hypopnoea index (AHI)
oxyhaemoglobin saturation levels
Management
Patient education – driving Behavioural change: Weight loss Avoid sleeping supine Avoid alcohol Treat contributing problems (e.g hypothyroidism) Review medications Sedating drugs, drugs causing weight gain
Continuous Positive Airway Pressure (CPAP)
Device generates airflow => positive pressure delivered to airway via mask
Intraluminal pharyngeal pressure > surrounding pressure
Pharynx stays open
