OSAHS
Definition: It is disorder in which patients experience apnea and hypopnea due to upper airway narrowing, and is associated with excessive daytime somnolence as a consequence of fragmentation of sleep.
Types:
Central: absence of central respiratory drive to breathe resulting in lack of respiratory effort and airflow, despite patent airway.
OSA: comprises most cases of OSHAS. Decreased or absent airflow due to narrowing or collapse of upper airway.
Both
Risk factors:
Obesity
Nasal obstruction
Adenoidal or tonsillar hypertrophy
Micrognathia
Retrognathia
Macroglossia
Acromegaly
Hypothyroidism
Vocal cord dysfunction or paralysis
Bulbar involvement from neuromuscular disease
Associated conditions: HTN, cardiovascular disease, pulmonary HTN, CHF, arrhythmia, MI, CVA, increased risk of DM, MVA, and cardiac arrest.
Symptoms associated with OSHAS:
Excessive daytime sleepiness (Epsworth sleepiness scale >10)
Snoring
Nocturnal arousals
Nocturnal apneas
Nocturnal gasping, grunting, and choking
Nocturia
Enuresis
Awakening unrefreshed
Morning headaches
Impaired memory and concentration
Irritability and depression
Impotence
Physical exam:
HEENT exam to check for upper airway obstruction, nasal septal deviation, polyps, enlarged tonsil, enlarged uvula, Mallampati classification
Epsworth Sleepiness Scale:
How likely are you to doze or fall asleep in the following situations, in contrast to just feeling tired? This refers to your usual way of life in recent times. Even if you have not done some of these things recently, try to work out how they would have affected you. Use the following scale the most appropriate number for each situation.
0 = would never doze
1 = slight chance of dozing
2 = moderate chance of dozing
3 = high chance of dozing
Situation:
Sitting and reading
Watching TV
Sitting, inactive, in a public place
Sitting as a passenger in a car for an hour
Lying down in the afternoon
Sitting and talking to someone
Sitting quietly after a lunch without alcohol
Sitting in a car, while stopped for a few minutes in traffic.
DDX day time sleepiness: sleep deprivation, periodic limb movement disorders, narcolepsy, and medication side effects.
Dxtic:
PSG: Performed as OP procedure.
Indications: snoring with daytime somonolence, titration of optimal positive airway pressure therapy, and objective assessment to therapeutic interventions.
Determines sleep stages using EEG, EOM, EMG, ECG, assessment of respiratory airflow, oxyhemoglobin saturation, and assessment of objective response to therapeutic intervention.
Obstructive: Airflow is absent or reduced despite continuous respiratory efforts
Central: Airflow and respiratory effort are absent.
AHI (apnea-hypopnea index) is used to dx and quantify the severity.
Apnea is defined as airflow <20% of baseline
Hypopnea is defined as >30% reduction in baseline airflow that must be associated with at least 4% decrease in oxygen saturation.
AHI index is the number of apneic and hypopneic episodes per hour of sleep. Each episode should last for at least 10 seconds to qualify.
Mild OSA: AHI of 5 - 15
Moderate OSA: AHI of 16 - 30
Severe OSA: AHI of >30.
Most sleep studies are performed as "split studies," where first few hours are Dxtic, and the rest is used for CPAP titration.
Some patients who have significant events when lying in certain positions (usually supine) or during REM sleep, they are schedule for two separate nights.
Mallampati Airway Classification
Tx:
Treatment is highly individualized.
Modafinil may improve daytime sleepiness in patients who have persistent sx despite CPAP use.
Nasal saline and decongestant use to hep with dryness associated with the use of CPAP.
CPAP (nCPAP) with autotitrating feature - smart CPAP
BiPAP is bilevel PAP used in patients not tolerating CPAP or a poor response.
Surgical treatment: tracheostomy, and UPPP (uvulopalatapharyngoplasty)
Lifestyle behavior modification: Wt. reduction, avoid tobacco, alcohol, and sedatives.