Sleep apnea syndrome: improved detection of respiratory events and cortical arousals using oxymetry pulse wave amplitude during polysomnography

Abstract

Respiratory events (RE) during sleep induce cortical arousals (A) and marked changes in autonomic markers in sleep apnea syndrome (SAS). The aims of the study were double. First, we assessed whether pulse wave amplitude (PWA) added to polysomnography (PSG) could improve RE and A detection; second, we wanted to know whether the quality of detection of these two parameters could be improved using PWA. Respiratory disturbance index (RDI) and A were randomly scored twice by the same observer in 12 male patients with SAS. The first scoring was done using conventional PSG signals, the second scoring adding PWA to PSG. We also measured interobserver agreement by randomly selecting and reading 100 PSG sequences of 5 min with and without PWA by two observers. Adding PWA to PSG parameters allowed to detect significantly more RDI (53.9 +/- 21.6 h(-1) versus 48.3 +/- 22.3 h(-1), p < 0.001) and more A (68.0 +/- 14.4 versus 59.4 +/- 16.5, p < 0.001). Moreover, after using PWA, there was no significant disagreement between two observers for detecting RE, showing better quality of RE detection. PWA is a simple and cheap parameter that improves the diagnostic value of conventional PSG in sleep apnea syndrome by better detecting respiratory events and A.

Arousal responses to respiratory events during sleep: the role of pulse wave amplitude

“…An increased detection of HP associated with PWA drops was also described by Zacharia et al . (). Compared with previous data, our study provided even stronger evidence of powerful sensitivity for both AP (93%) and HP (89%).…”

“…Although collected from a clinical setting, the present study is a physiological investigation on the relationship between autonomic and cortical responses to respiratory events throughout sleep and in the different sleep states (NREM versus REM). Previous studies (Adler et al ., ; Zacharia et al ., ) described a strong association between PWA and AASM arousals in obstructive events, but with analytic description limited to AP and HP, irrespective of the NREM/REM background. Our data show that, at the recovery of airway patency, a dual response, characterized by both cortical and autonomic activation, is the most frequent feature in the investigated patients with OSAS.…”

“…The authors describe a sensitivity of 89.1%, a PPV of 87%, a specificity of 40.7%, and a NPV of 45.8%. An increased detection of HP associated with PWA drops was also described by Zacharia et al (2008). Compared with previous data, our study provided even stronger evidence of powerful sensitivity for both AP (93%) and HP (89%).…”

“…In recent years the use of portable monitoring (PM) has becoming an increasingly accepted cost-effective alternative approach (Blackman et al, 2010;Collop, 2008;Collop et al, 2007;Kuna, 2010;Masa et al, 2011;McNicholas and L evy, 2011), but suffers from a major drawback: the lack of a reliable sign of arousals, resulting in underestimation of respiratory events (Adler et al, 2013). To overcome this weakness, a number of studies have focused on the identification of surrogate markers of cortical arousals (Adler et al, 2013;Argod et al, 2000;Azarbarzin et al, 2014;Catcheside et al, 2002;Contal et al, 2013;Delessert et al, 2010;Haba-Rubio et al, 2005a;Pitson et al, 1994;Sforza et al, 2007;Tauman et al, 2004;Zacharia et al, 2008).…”

Scoring criteria for portable monitor recordings: a comparison of four hypopnoea definitions in a population-based cohort

“…Moreover the magnitude of PWA drops is associated with the EEG arousal intensity and the use of PWA drops as surrogate for EEG arousal was shown to improve inter-scorer reliability for PSG 17 18…”