32. Symptoms, causes and examination of sleep apnea syndrome.

What is sleep apnea- SA

• sleep related breathing disorder

• characterised by abnormal breathing patterns during sleep → breathing repeatedly stops and starts

• measured by apnea/ hypopnea index AHI= number of apnea and hypopnea events per hour of sleep

Define apnea, hypopnea, hyperpnea

• Apnea = absence of breathing for > 10s

• Hypopnea = excessive decrease in rate or depth of breathing

• Hyperpnea = excessive increase in rate or depth of breathing

What is severity of SA

• Normal: AHI <5

• Mild: 5 < AHI < 15

• Mildly severe: 15 < AHI < 30

• Severe: 30 < AHI

What are the types of sleep apnea

• obstructive SA

• central SA

• mixed SA

What is OSA

• Caused by transient, episodic obstruction of the upper airway

• No or decreased airflow despite persistent respiratory effort

• Risk factors: obesity, upper airway abnormality, neuromuscular disease, hypothyroidism, alcohol, nasal congestion

What is CSA

• Caused by transient, episodic decrease in CNS drive to breathe

• No airflow because of no respiratory effort

• Risk factors: LV failure, brainstem lesions, encephalitis, high altitude, encephalopathy

What is mixed sleep apnea

• Features of both OSA and CSA

• Loss of hypoxic and hypercapnic drives to breathe secondary to ‘’resuscitative breathing’’ → overcompensatory hyperventilation upon awakening from OSA-induced hypoxia

What are the predisposing factors for SA

• men, >50 years, central obesity

• anatomical abnormalities of head and neck

• smoking, alcohol

• comorbidity → metabolic syndrome

What are the night timesymptoms of SA

• loud snoring

• waking up not being able to breathe

• not relaxed sleeping

What are the daytime symptoms of SA

• daytime sleepiness

• concentration/ learning problems

• comorbid diseases

How do you diagnose

• ENT examinations

• Drug induced sleep endoscopy

• questionares- Berlin, STOP-BANG

• screening device- at home apnea test

• sleep polysomnography- GOLD STANDARD

Describe the ENT examinations

• mirror examination, anterior rhinoscopy, fibroscopy

• eg. elongate uvula, hyperplasia of palatine tonsils, septal deviation, turbinate hyperplasia

What is drug induced sleep endoscopy

• assessing degree of oropharyngeal obstruction at the level of the soft palate

What is the treatment of SA

• Modifiable factors (weight loss, ↓alcohol, treatment of underlying conditions)

• Position dependent OSA (no supine sleeping)

• Intraoral devices

• BiPAP, CPAP (continuous/bilevel positive airway pressure)

What is the surgical treatment of SA

• Surgeries improving nasal flow:

  • Septoplasty, mucotomy, FESS, adenectomy

• Soft palate surgeries:

  • Uvulopalatopharyngoplasty (UPPP), anterior/lateral pharyngoplasty

• Pharynx volume increasing surgeries:

  • Tonsillectomy/tonsillotomy, reduction of tongue base

• Electrical stimulation of the hypoglossal nerve