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Obstructive Sleep Apnea

3 min read

Obstructive Sleep Apnea

Key Points

  • OSA involves relaxation of posterior pharyngeal muscles during sleep, causing airway obstruction and intermittent apneic episodes.
  • Accumulation of CO2 triggers the brain to awaken the individual briefly to restore airflow, fragmenting sleep.
  • Risk factors include obesity, male sex, advancing age, large neck circumference, and craniofacial abnormalities.
  • CPAP is the first-line treatment; nursing assessment includes monitoring daytime sleepiness, oxygen saturation, and CPAP adherence.

Pathophysiology

During sleep, the muscles of the posterior pharynx relax excessively, failing to support the soft palate, tongue, and lateral throat walls. The airway becomes blocked or narrowed, impairing breathing and causing carbon dioxide accumulation. When CO2 reaches a critical level, the brainstem triggers a brief arousal to reopen the airway for deep breathing. These awakenings fragment sleep, often occurring multiple times per hour, though many individuals have no recollection of waking. The result is severe daytime drowsiness, mood disturbance, and impaired concentration.

Clinical Manifestations

  • Loud snoring with witnessed apneic pauses.
  • Excessive daytime sleepiness (Epworth Sleepiness Scale assessment).
  • Morning headaches and dry mouth.
  • Mood changes, irritability, difficulty concentrating.
  • Nocturia.

Nursing Assessment

NCLEX Focus

OSA is associated with increased risk for hypertension, dysrhythmias, stroke, and motor vehicle accidents. Assess for cardiovascular comorbidities in all OSA clients.

  • Obtain a sleep history including snoring, witnessed apneas, and daytime sleepiness.
  • Assess risk factors: BMI, neck circumference (greater than 17 inches in men, 16 inches in women), Mallampati score.
  • Review polysomnography results: apnea-hypopnea index (AHI) defines severity (mild 5 to 15, moderate 15 to 30, severe greater than 30 events per hour).
  • Monitor oxygen saturation during sleep if ordered.
  • Assess for related conditions: hypertension-assessment-and-management, heart-failure, diabetes-mellitus, Dysrhythmias.

Nursing Interventions

  • Promote CPAP adherence: proper mask fitting, humidification, gradual acclimatization.
  • Encourage weight loss in overweight or obese clients (even 10% weight reduction can improve AHI).
  • Advise positional therapy (lateral sleep position to reduce airway collapse).
  • Educate about avoidance of alcohol, sedatives, and opioids before sleep (relax pharyngeal muscles).
  • Promote sleep hygiene: consistent bedtime routine, adequate sleep duration.
  • Refer for surgical evaluation (uvulopalatopharyngoplasty, mandibular advancement) if CPAP intolerant.

Self-Check

  1. What mechanism causes the brain to trigger arousal during an obstructive sleep apnea episode?
  2. Why should OSA clients avoid alcohol and sedatives before sleep?
  3. What AHI value indicates severe obstructive sleep apnea?

Graph View

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