Nasal pressure recordings to detect obstructive sleep apnea

Abstract

Obstructive sleep apnea (OSA) is a common disease. Given the costs of in-laboratory polysomnography (PSG), alternative ambulatory methods for accurate diagnosis are desirable. The objective of this study was to evaluate the performance of a simple device (SleepCheck) to identify patients with sleep apnea. A total of 30 consecutive patients with suspected OSA syndrome referred to the sleep clinic were prospectively evaluated with standard PSG and SleepCheck simultaneously during an in-laboratory, supervised full-night diagnostic study. The PSG apnea and hypopnea index (AHI) was evaluated according to standard criteria, and SleepCheck assessed the respiratory disturbance index (RDI) based on nasal cannula pressure fluctuations. Compared to the full-night PSG, SleepCheck systematically overscored respiratory events (the mean difference between SleepCheck RDI and PSG AHI was 27.4+/-13.3 events per hour). This overscoring was in part related to normal physiologic decreases in flow during rapid eye movement sleep or after an arousal. However, there was reasonable correlation between AHI and RDI (r=0.805). Receiver operating characteristic curves with threshold values of AHI of 10 and 20/h demonstrated areas under the curves (AUCs) of 0.915 and 0.910, respectively. Optimum combinations of sensitivity and specificity for these thresholds were calculated as 86.4/75.0 and 88.9/81.0, respectively. Overall, the SleepCheck substantially overscored apneas and hypopneas in patients with suspected OSA. However, after correction of the bias, the SleepCheck had reasonable accuracy with an AUC, sensitivity, and specificity similar to other ambulatory type 4 devices currently available.

Automatic detection of sleep-disordered breathing from a single-channel airflow record

“…The other is that subjects with relatively low AHI (AHI ,20) are less affected by the bias, resulting in less adverse effects for the diagnostic ability. Other reports [11,13,25,26] on validation of automated analysis do not show such an AHI-dependent systematic bias but rather a random and larger bias.…”

“…Recently, AYAPPA et al [10] reported that manual analysis of the flow signal could provide a result similar to that obtained by full PSG analysis. Furthermore, several single-channel airflow monitors have been developed for automated detection of SDB [11][12][13]. Studies for the accuracy of these monitors have provided conflicting results and it is unclear whether performance depends on the signal acquisition system, including the sensor, or on the analytical algorithm.…”

Screening for obstructive sleep apnoea in obesity and diabetes – potential for future approaches

“…ApneaLink was shown to be useful in screening high-risk patients [66,67]. Nasal pressure recordings in 30 subjects using SleepCheck, an ambulatory device, overscored disordered breathing events in subjects with OSA, but correlation was reported with the apnoea-hypopnoea index and respiratory disturbance index [68]. The Embletta is a portable device that has been shown to produce AHI results that are correlated with AHI results from sleep laboratory polysomnography [69].…”

Obstructive Sleep Apnea Syndrome in Company Workers: Development of a Two-Step Screening Strategy with a New Questionnaire

“…Three different single NFlow devices (SleepCheck, Flow Wizard, RU-sleeping) and one NFlow-oximetry combined device (ApneaLink) have been tested against PSG, all with high agreement for OSAS. 18,39,42,43 In two studies, oximetry and NFlow recording did have equivalent accuracy for diagnosing OSAS in the home setting. 43,44 Chai-Coetzer et al 39 reported less data loss (3%) (with oximetry) compared to NFlow (9%).…”