Abstract Mkid 73

To compare the reliability of two techniques (thoracic impedance and inductive plethysmography) commonly used to assess respiratory move-ments in infancy. Whole night polysomnographic studies were performed in 52 infants (30 females, 22 males, median postnatal age 15.1 weeks) with simultaneous recordings of respiratory movements by thoracic impedance (TI) and inductive plethysmography (IP), of oxygen saturation, transcutaneous and endexpiratory CO2, ECG, EEG, EMG, EOG, and actimetry. Each test was divided into 10-minute intervals for statistical evaluation. After manual evaluation of all respiratory events shown, occurrence rates of false positive and false negative apnea detection by each system were compared. Median apnea frequency was 19.1 per hour of total sleep time (predominantly central apnea with a significant drop after the first trimenon). The 99.5% of all apneas were correctly detected by IP, 98.9% by TI (difference not significant). There were considerably more false positive results of IP than of TI recordings (in 7.9 % vs. 4.4% of all 10-minute time periods). Both thoracic impedance and inductive plethysmography are suitable for monitoring of respiratory movement in infancy. We recommend TI for surveillance of high-risk patients, while IP remains a suitable screening method. Simultaneous use of both methods may assist to solve differential diagnostic problems in the pediatric sleep laboratory.