What is the initial workup for a patient with suspected sleep apnea?

Initial Workup for Suspected Sleep Apnea

The initial workup for suspected sleep apnea must include a comprehensive sleep evaluation followed by polysomnography (PSG) or home sleep apnea testing (HSAT) with a technically adequate device for definitive diagnosis. 1

Comprehensive Sleep Evaluation

A thorough initial evaluation should include:

• Assessment of risk factors and symptoms suggestive of OSA:

  • Snoring (a key symptom that warrants further investigation) 2
  • Witnessed apneas or gasping during sleep 3
  • Daytime sleepiness or fatigue 3
  • Non-restorative sleep 3
  • Morning headaches 3
  • Irritability or cognitive impairment 3

• Physical examination focusing on:

  • Body mass index (BMI) - obesity is a significant risk factor 2
  • Neck circumference (increased neck circumference is associated with higher risk) 1
  • Upper airway assessment for potential obstruction 1
  • Evaluation of craniofacial abnormalities that may predispose to OSA 1

• Screening tools may be used as part of the initial evaluation but should not replace diagnostic testing:

  • Epworth Sleepiness Scale (ESS) to assess daytime sleepiness 4, 5
  • Berlin Questionnaire (BQ) to assess risk factors 6

Important Caution on Screening Tools

• Clinical tools, questionnaires, and prediction algorithms should not be used alone to diagnose OSA in the absence of proper sleep testing 1
• The Epworth Sleepiness Scale has limited predictive value (only explaining 7-10% of the variation in OSA probability) 5
• Even subjective clinical impression alone correctly identifies only 52% of patients with sleep apnea 2

Diagnostic Testing

After the comprehensive sleep evaluation, diagnostic testing is required:

• For uncomplicated adult patients with signs and symptoms suggesting moderate to severe OSA:

  • Either polysomnography OR home sleep apnea testing with a technically adequate device is recommended 1

• Polysomnography is specifically recommended (rather than home sleep testing) for patients with:

  • Significant cardiorespiratory disease 1
  • Potential respiratory muscle weakness due to neuromuscular conditions 1
  • Awake hypoventilation or suspected sleep-related hypoventilation 1
  • Chronic opioid medication use 1
  • History of stroke 1
  • Severe insomnia 1

Follow-up Testing

• If a single home sleep apnea test is negative, inconclusive, or technically inadequate, polysomnography should be performed 1
• If the initial polysomnogram is negative but clinical suspicion remains high, a second polysomnogram should be considered 1

Practical Considerations

• A split-night diagnostic protocol (diagnostic portion followed by CPAP titration in the same night) may be used when clinically appropriate 1
• OSA severity is classified based on the Apnea-Hypopnea Index (AHI):
  • Mild: AHI 5-14/h with no or mild symptoms 3
  • Moderate: AHI 15-30/h with occasional daytime sleepiness 3
  • Severe: AHI >30/h with frequent daytime sleepiness that interferes with daily activities 3

Common Pitfalls to Avoid

• Relying solely on screening questionnaires for diagnosis - they have poor specificity and cannot replace objective testing 1, 5
• Overlooking OSA in non-obese patients or those without classic symptoms 3
• Failing to proceed to polysomnography when home sleep testing is negative but clinical suspicion remains high 1
• Not considering OSA in patients with comorbidities like resistant hypertension, atrial fibrillation, or heart failure where OSA prevalence is particularly high 3