Oxygen Desaturation Index Valuable for Sleep Apnea Diagnosis in Some Instances

by Linda Kossoff •

What is the value of the oxygen desaturation index (ODI) as compared to the apnea-hypopnea index (AHI) in accurately diagnosing adult obstructive sleep apnea (OSA)?

BOTTOM LINE: Consideration for diagnosing adult OSA, or recommending further evaluation for diagnosis, should be given where there’s a 4% ODI of >15 events/hour or >10 events/hour, respectively.

BACKGROUND: Undiagnosed OSA is a public health issue. Its most common diagnostic measurement tool is the AHI, derived from level 1 polysomnography (PSG). The ODI, derived from the nocturnal pulse oximeter (NPO), is another OSA measurement modality. There has been no systematic literature review comparing AHI and ODI as diagnostic tools.

STUDY DESIGN: Literature review.

SETTING: Unit of Otorhinolaryngology, Department of Surgery, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia.

SYNOPSIS: Researchers performed a literature search for studies directly comparing ODI with AHI. The primary outcome measure was degree of diagnostic agreement and accuracy between ODI and AHI cutoffs to diagnose OSA. Eight studies with 1,924 patients met the review criteria. In contextualizing their work, researchers cited the two general hypoxia patterns most characteristic of patients with OSA: intermittent hypoxemia (IH) and sustained or low-frequency hypoxemia. They note that IH in particular is thought to play a significant part in elevating a hypersensitive chemo-reflex feedback loop in ventilation control during sleep and, therefore, that oxygen metrics such as the ODI may prove to be at least as useful in screening, diagnosing, and quantifying OSA as AHI. Researchers proposed that consideration should be given for diagnosing OSA with a 4% ODI of >15 events/hour and for recommending further evaluation for diagnosing OSA with a 4% ODI >10 events/hour. They cited significant heterogeneity in ODI/AHI comparison studies as a major study limitation, however, as well as the exclusion of non-English language studies.

CITATION: Rashid NH, Zaghi S, Scapuccin M, et al. The value of oxygen desaturation index for diagnosing obstructive sleep apnea: a systematic review [published online ahead of print April 25, 2020]. Laryngoscope. doi:10.1002/lary.28663.