M S Urschitz1, F Eichler, C Popow, O S Ipsiroglu. 1. Abteilung für Neonatologie, angeborene Störungen und Intensivmedizir, Universitätsklinik für Kinder und Jugendheilkunde, Wien, Osterreich.
Abstract
OBJECTIVES: The SpiroGuard C is a commercially available cardiorespiratory monitor working with field plethysmography, wireless signal transmission and a novel alarm management system. In order to determine the recognition rates for central, mixed and obstructive apneas, a prospective clinical trial was performed comparing frequency and kind of signals from the monitor with those simultaneously registered by polysomnographic studies. DESIGN: Normal respiratory and alarm signals of the monitor under investigation were integrated into a polysomnographic setting. All central, mixed and obstructive apneas lasting more than 10 seconds as well as all alarms obtained from the monitor were evaluated. RESULTS: 47 series of monitor recordings could be evaluated in parallel to polysomnographic studies: the detection rate for central apneas was 298/328 (90.85%), for mixed apneas 9/41 (21.95%) and for obstructive apneas 0/36 (0%). Out of the total of 708 registered alarms 359 (50.71%) were false alarms, 307 (43.36%) were apnea-related and 42/708 (5.93%) were alarms due to technical problems. 177 of the 359 false alarms (49.30%) occurred during apneas that were shorter than 10 seconds, 119 (33.15%) were related to bad signal quality, and 55 (15.32%) were caused by movement artifacts. CONCLUSION: The recognition rate for central apneas was high (> 90%), while sensitivity for mixed and obstructive apneas was not satisfactory. Approximately half of the alarms were false alarms. These could be reduced by setting the apnea detection time to > 15 seconds, by tighter fastening of the respiration belt (improving the signal transmission), and by turning off the instrument when the child is awake and physically active. The wireless system renders the SpiroGuard C an attractive alternative for home monitoring.
OBJECTIVES: The SpiroGuard C is a commercially available cardiorespiratory monitor working with field plethysmography, wireless signal transmission and a novel alarm management system. In order to determine the recognition rates for central, mixed and obstructive apneas, a prospective clinical trial was performed comparing frequency and kind of signals from the monitor with those simultaneously registered by polysomnographic studies. DESIGN: Normal respiratory and alarm signals of the monitor under investigation were integrated into a polysomnographic setting. All central, mixed and obstructive apneas lasting more than 10 seconds as well as all alarms obtained from the monitor were evaluated. RESULTS: 47 series of monitor recordings could be evaluated in parallel to polysomnographic studies: the detection rate for central apneas was 298/328 (90.85%), for mixed apneas 9/41 (21.95%) and for obstructive apneas 0/36 (0%). Out of the total of 708 registered alarms 359 (50.71%) were false alarms, 307 (43.36%) were apnea-related and 42/708 (5.93%) were alarms due to technical problems. 177 of the 359 false alarms (49.30%) occurred during apneas that were shorter than 10 seconds, 119 (33.15%) were related to bad signal quality, and 55 (15.32%) were caused by movement artifacts. CONCLUSION: The recognition rate for central apneas was high (> 90%), while sensitivity for mixed and obstructive apneas was not satisfactory. Approximately half of the alarms were false alarms. These could be reduced by setting the apnea detection time to > 15 seconds, by tighter fastening of the respiration belt (improving the signal transmission), and by turning off the instrument when the child is awake and physically active. The wireless system renders the SpiroGuard C an attractive alternative for home monitoring.