A comparison of sleep disordered breathing events detected by CPAP devices with in-lab polysomnography

Background: The evaluation of residual sleep disordered breathing (SDB) is important to verify the therapeutic success of continuous positive airway pressure (CPAP) devices. Modern therapy devices continuously record and analyse the flow signal. Sufficient comparative measurements between the devices and polysomnography (PSG) are missing. Method: in 13 severe OSA patients (female: 2; age: 51.8±14.2; BMI: 31.4±4.9 kg/m²; baseline AHI: 58.7±26.9), the detected events of a manual scored polysomnography (PSG) in the sleep laboratory were compared with the simultaneously recorded events of a CPAP device (PrismaLine, Löwenstein Medical Technology). Results: When comparing the PSG indices with the device indices based on the total sleep time (TST) determined in the PSG, the evaluation of the PSG resulted in a residual AHI of 8.3±7.0 (AASM criterion 1A) respectively 4.8±4.7 (1B), versus a device index of 6.8±4.8 (correlation coefficient device to PSG: 0.904 (1A) und 0.845 (1B). The mean absolute AHI deviation from the device to the PSG was 2.7±2.4 (1A), respectively 2.5±2.1 (1B). When comparing the events without limiting the device to the PSG TST, a mean device AHI of 6.4±4.1 was detected (correlation coefficient device to PSG: 0.786 (1A); 0.735 (1B). The mean absolute AHI deviation from the device to the PSG was 3.4±3.5 (1A), respectively 2.9±2.2 (1B). Conclusion: The results show that the averaged AHIs determined by the device deviate only slightly from the PSG indices despite the lack of information about sleep, SpO2, or arousal. Larger numbers of patients are needed for a further statistical evaluation of the differentiation between apnea types.