Evaluation of the Apnea-Hypopnea Index Determined by the S8 Auto-CPAP, a Continuous Positive Airway Pressure Device, in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

Abstract

Objective: Continuous positive airway pressure (CPAP) has been established as an effective treatment for obstructive sleep apnea-hypopnea syndrome (OSAHS). Recently, several auto-CPAP devices that can detect upper airway obstructive events and provide information about residual events while patients are on CPAP have come into clinical use. The purpose of this study was to compare the apnea-hypopnea index (AHI) determined by the S8 auto-CPAP device with the AHI derived by polysomnography in patients with OSAHS. Method: Consecutive patients with OSAHS titrated on S8 auto-CPAP were included. The correlation between AHI determined by manual scoring (AHI-PSG) and by S8 (AHI-S8) during an overnight in-hospital polysomnogram with the patient on CPAP was assessed. Furthermore, the apnea index (AI) and the hypopnea index (HI) were evaluated separately. Results: Seventy patients with OSAHS (94% men) were enrolled. The mean AHI on the diagnostic study was 51.9 ± 2.4. During the titration, this device markedly suppressed the respi-ratory events (AHI-PSG, 4.2 ± 0.4; AI, 1.9 ± 0.3; HI, 2.3 ± 0.3). On the other hand, the AHI-S8 was 9.9 ± 0.6 (AI-S8, 2.4 ± 0.3; HI-S8, 7.5 ± 0.4). There was a strong correlation between the overall AHI-PSG and the AHI-S8 (r = 0.85, p < 0.001), with a stronger correlation in the apnea component AI-PSG and the AI-S8 (r = 0.93, p < 0.001), whereas there was a weaker correlation between the HI-PSG and the HI-S8 (r = 0.67, p < 0.001). Conclusions: Using the same airflow signals as those of the CPAP device, a strong correlation between the AHI-PSG and the AHI-S8 was observed. However, the correlation was weakened when the analysis was limited to the HI.

Validation of the System One RemStar Auto A-Flex for Obstructive Sleep Apnea Treatment and Detection of Residual Apnea-Hypopnea Index: A European Randomized Trial

“…The latter is especially the case if detected events are apneas. As previously reported 27,28,30,31 we found that the correlation between devicedetected and manually scored breathing events was higher for apneas than for hypopneas. This is not surprising because the polysomnographic definition of hypopnea includes oxygen desaturations and arousals that are not detected by the APAP device.…”

“…11,[25][26][27][28][29][30][31] A review of the more recent studies concluded that the assessment of the residual apnea index was more robust than the hypopnea index, and that the event detection algorithms tended to underestimate the AHI at higher manually scored AHI values (AHI > 10 events/h) and overestimate the AHI at lower manually scored AHI values (AHI < 10 events/h). [25][26][27][28]30,31 From a clinical perspective, the authors concluded that these event detection algorithms can be used if the data are at either end of the spectrum. Treatment of OSA is likely to be effective if AHI < 10 events/h, and is likely to be inadequate if AHI > 20 events/h.…”

Identifying poor compliance with CPAP in obstructive sleep apnoea: A simple prediction equation using data after a two week trial

“…The AHI estimated by Auto-titrating CPAP has been shown to correlate with AHI from polysomnography. 25,26 At this consultation patients were asked whether they wished to continue CPAP long-term. Occasionally patients were offered an extension of the two-week period or a second trial either because they had developed a problem which compromised their ability to use CPAP (for instance upper respiratory tract infection) or if they had severe symptomatic disease, had struggled with CPAP initially and were willing to have another try.…”

Ventilación no invasiva en el tratamiento de la insuficiencia cardíaca

“…En la práctica general, CPAP se utiliza con más frecuencia para el tratamiento de patología respiratoria del sueño. Algunos de estos dispositivos de CPAP están diseñados para detectar diversos grados de obstrucción de las vías respiratorias superiores y luego ajustar el nivel de presión para mantener abierta la vía aérea (Auto CPAP) (Figura 3) 11 . Algunos pacientes que no toleran CPAP manifiestan dificultad al exhalar contra la presión de la vía aérea generada por el dispositivo, especialmente en pacientes cuya presión terapéutica necesaria es alta (p.…”