An Evaluation of Indexes as Support Tools in the Diagnosis of Sleep Apnea

Abstract

This article evaluates several indexes as support tools to diagnose patients with Sleep Apnea-Hypopnea Syndrome (SAHS). Some of these indexes, such as the Apnea-Hypopnea Index, have been standardized and studied in depth in the literature. Other indexes are used extensively in the reports that commercial polysomnographs generate. However, they have not been studied in detail and clinicians have no standardized guidelines for interpreting them. Examples are the mean and maximum duration of apneas and hypopneas. Finally, several novel indexes proposed by the authors are also evaluated. To evaluate the indexes, we have used a database of 274 patients who have undergone a polysomnographic test. Several feature selection techniques were used to assess the capability of each index to discriminate between healthy and SAHS patients. The capability of the indexes for diagnosing the patients was analyzed by using decision trees which were trained using each index individually, and all the indexes together. Our results suggest that some indexes which are often present in the reports of commercial polysomnographs provide little or no information. On the other hand, other indexes that are usually not considered have a great capability to discern between SAHS and control patients.

Phenotyping the pathophysiology of obstructive sleep apnea using polygraphy/polysomnography: a review of the literature

“…REM OSA and nocturnal time course of respiratory events Otero et al [52] reported that the duration of apneas, hypopneas, and desaturations (AHDI) related to the total sleep time (TST) represents a better OSA diagnostic index than AHI alone. Also, the total duration of apnea-hypopnea events related to the TST (TAHD%) represents another OSA severity index, interesting and easy to determine, which can exceed the 70% of all time analyzed in severe grade of OSA patients; the breathing cessation for many hours per night can cause an increase of the physiopathologic load and, mainly, of the cardiovascular risk [53].…”

Novel parameters for evaluating severity of sleep disordered breathing and for supporting diagnosis of sleep apnea-hypopnea syndrome

“…It was shown that the combined percentage of apnea, hypopnea and desaturation duration from total sleep time (AHDI) was able to differentiate SAHS patients with increased accuracy compared to AHI [10]. The findings of the present paper suggest that the novel parameters could bring additional more detailed information to the evaluation of the severity and the need for treatment of the sleep disordered breathing, as also supported by the findings of Otero et al [10]. The great variation in the values of the novel parameters between individuals having similar AHI suggests that the physiological stress experienced by the patients may be different and that AHI might not contain all the necessary information needed to diagnose the severity of SAHS and to evaluate the need for treatment.…”

“…However, significant variation in the values of the novel severity parameters between patients having similar AHI were seen (c, d). several respiratory-related parameters and their capability to support the diagnostics of SAHS were evaluated [10]. It was shown that the combined percentage of apnea, hypopnea and desaturation duration from total sleep time (AHDI) was able to differentiate SAHS patients with increased accuracy compared to AHI [10].…”

“…several respiratory-related parameters and their capability to support the diagnostics of SAHS were evaluated [10]. It was shown that the combined percentage of apnea, hypopnea and desaturation duration from total sleep time (AHDI) was able to differentiate SAHS patients with increased accuracy compared to AHI [10]. The findings of the present paper suggest that the novel parameters could bring additional more detailed information to the evaluation of the severity and the need for treatment of the sleep disordered breathing, as also supported by the findings of Otero et al [10].…”

“…There are recommendations that suggest that parameters such as number of hypopnea and apnea events and minimum oxygen saturation value should also be reported [6]. In a recent study duration and morphology parameters related to respiration, e.g., combined percentage of apnea, hypopnea and desaturation duration from total sleep time (AHDI) during sleep were investigated and they showed capability to support the diagnostics of SAHS [10]. However, e.g.…”