What treatment is recommended for a Respiratory Event Index (REI) of 14.5 in a sleep study?

Treatment Recommendation for REI 14.5

A Respiratory Event Index (REI) of 14.5 events/hour meets diagnostic criteria for moderate obstructive sleep apnea and warrants treatment with positive airway pressure (PAP) therapy if the patient has symptoms (excessive daytime sleepiness, fatigue, insomnia, or neurocognitive symptoms), or consideration of treatment even without symptoms given the moderate severity. 1

Diagnostic Classification

• An REI of 14.5 falls into the moderate OSA category (15-29 events/hour by standard classification, though 14.5 is at the threshold) 2
• According to AASM diagnostic criteria, OSA is diagnosed when there are 5 or more predominantly obstructive respiratory events per hour with symptoms or comorbidities, OR 15 or more events per hour regardless of symptoms 1
• Your REI of 14.5 with symptoms meets treatment criteria; without symptoms, you are just below the automatic treatment threshold but still warrant strong consideration for therapy 1

Critical Limitation of REI vs. AHI/RDI

Important caveat: REI is calculated from home sleep apnea testing (HSAT) based on monitoring time, not actual sleep time, because HSAT devices lack EEG monitoring 1

• REI typically underestimates the true severity compared to in-laboratory polysomnography (PSG) that calculates AHI based on actual sleep time 1
• HSAT cannot detect arousal-based respiratory events (RERAs and arousal-associated hypopneas) because these require EEG monitoring 1
• If you have persistent symptoms despite borderline REI, in-laboratory PSG is recommended to capture arousal-based events that HSAT misses 1, 2

Treatment Algorithm

If Symptomatic (daytime sleepiness, fatigue, cognitive impairment):

• Initiate PAP therapy immediately - the AASM recommends treatment for symptomatic patients with RDI ≥5 events/hour to improve quality of life, limit neurocognitive symptoms, and reduce accident risk 1
• Auto-titrating CPAP is appropriate as first-line therapy 2

If Asymptomatic:

• Consider treatment given proximity to the 15 events/hour threshold 1
• Evaluate for comorbidities (hypertension, cardiovascular disease, diabetes, stroke risk) that would strengthen the treatment indication 1
• Consider in-laboratory PSG to obtain accurate AHI including arousal-based events, which may reveal higher severity 1, 2

Monitoring Treatment Effectiveness

• Target eAHI <6 events/hour on PAP therapy for adequate control 2
• If eAHI remains >6 events/hour or symptoms persist despite PAP, consider in-laboratory PSG on CPAP to assess for residual events, arousals (RERAs), or alternative diagnoses 2
• eAHI >8 events/hour indicates significant residual OSA requiring intervention 2

Common Pitfalls to Avoid

• Do not dismiss borderline REI values - the true AHI on PSG is often higher due to sleep time vs. monitoring time calculation and missed arousal-based events 1
• Do not rely solely on REI if symptoms persist - HSAT negative results in high-risk symptomatic patients require confirmatory in-laboratory PSG 1
• Do not ignore arousal-based events - failure to account for arousals may lead to misclassification of OSA severity or missed diagnosis entirely 1