Total duration of apnea and hypopnea events and average desaturation show significant variation in patients with a similar apnea–hypopnea index

Abstract

Obstructive sleep apnea (OSA) is commonly diagnosed based on the apnea-hypopnea index (AHI). Presently, novel indices were introduced for sleep apnea severity: total duration of sleep apnea and hypopnea events (TAHD%) and a combined index including duration and severity of the events (TAHD% × average desaturation). Two hundred and sixty-seven subjects were divided based on their AHI into four categories (normal, mild, moderate, severe OSA). In the most severe cases TAHD% exceeded 70% of the recorded time. This is important as excessive TAHD% may increase mortality and cerebro-vascular complications. Moreover, simultaneous increase in duration and frequency of apnea and hypopnea events leads to a paradoxical situation where AHI cannot increase along severity of the disease. Importantly, the combined index including duration and severity of the events showed significant variation between patients with similar apnea-hypopnea indices. To conclude, the present results suggest that the novel parameters could give supplementary information to AHI when diagnosing the severity of OSA.

Feature Extraction of Upper Airway Dynamics during Sleep Apnea using Electrical Impedance Tomography

“…The significantly larger amounts of upper airway closure during apnea events agree well with the definition of obstructive apnea and hypopnea 25,26 . The average duration was longer in hypopneic events compared with obstructive ones as described in the previous study by Muraja-Murro et al 27 . In addition to this, our results showed that the plateau percent during apneic events is larger compared with hypopneic ones, whereas the fluctuation was larger in hypopneic events.…”

Sleep Study and Oximetry Parameters for Predicting Postoperative Complications in Patients With OSA

“…58 Although obstruction severity tends to increase with a higher AHI, there is much variability and overlap in this parameter within mild, moderate, and severe AHI categories. 59 The heterogeneity in obstruction severity within similar AHI categories could reflect different arousal thresholds, with high arousal thresholds being associated with a diminished compensatory ventilatory response resulting in longer apneas with greater SpO 2 desaturation. 44 These parameters may offer more insight into the severity of OSA and deserve further study in populations undergoing surgery.…”

Breathing Disturbances Without Hypoxia Are Associated With Objective Sleepiness in Sleep Apnea

“…7,8 Even individuals with the same AHI have vast differences in SDB characteristics. 9,10 Recent studies have highlighted that the oxygen-desaturation index (ODI) 11 or event duration 9,12 may be more predictive of cardiovascular outcomes.…”