Is 18 apneas in 7 hours significant on a sleep study?

Significance of 18 Apneas in 7 Hours on Sleep Study

18 apneas in 7 hours corresponds to an Apnea Index of approximately 2.6 events per hour, which is below the diagnostic threshold for obstructive sleep apnea (OSA) and is not clinically significant. 1

Understanding Sleep Apnea Diagnostic Criteria

The diagnosis of sleep apnea is based on the Apnea-Hypopnea Index (AHI), which represents the number of apneas and hypopneas per hour of sleep:

• AHI < 5 events/hour: Normal, no OSA
• AHI ≥ 5 events/hour: Diagnostic threshold for OSA 1
  • 5-15 events/hour: Mild OSA
  • 15-30 events/hour: Moderate OSA

  • 30 events/hour: Severe OSA

Analysis of Your Results

Your result of 18 apneas over 7 hours yields:

• Apnea Index: 18 ÷ 7 = 2.6 events/hour
• This falls below the diagnostic threshold of 5 events/hour

Clinical Implications

1. No OSA Diagnosis: Based on apnea events alone, this result does not meet criteria for OSA diagnosis 1

2. Important Considerations:

   • The full sleep study report should be reviewed for hypopneas, which combined with apneas determine the AHI
   • The type of apneas (obstructive, central, or mixed) may have clinical relevance 2
   • Even if below diagnostic threshold, monitoring is recommended if symptoms are present

3. Symptoms Assessment: Despite the low apnea count, evaluate for:

   • Daytime sleepiness (using tools like Epworth Sleepiness Scale)
   • Morning headaches
   • Unrefreshing sleep
   • Witnessed apneas by bed partner

Common Pitfalls to Avoid

1. Focusing only on apneas: The complete AHI includes both apneas and hypopneas; your full sleep study will provide this information

2. Ignoring apnea types: Central apneas have different clinical implications than obstructive apneas 2

3. Overlooking other sleep disorders: Non-apneic sleep disorders might explain symptoms despite low apnea counts

4. Dismissing borderline results: If symptoms are significant despite borderline results, clinical judgment may warrant treatment trials in select cases 3

Recommendations

1. Review the complete sleep study report for the total AHI (including hypopneas)

2. No treatment is indicated based solely on the apnea count of 18 in 7 hours

3. Follow-up recommended if you have significant sleep-related symptoms despite the low apnea count

4. Consider repeat testing if symptoms worsen or persist despite the negative initial study