118 INFLUENCE OF BODY POSITION ON APNEA, HYPOXEMIA AND BRADYKARDIA IN PRETERM INFANTS

Abstract

Methods: 20 preterm infants (mean 28wks; range 24-34wks gestational age,GA) with distinct instability during routine monitoring were studied in prone (PP) and supine (SP) sleeping position. In 45 polygraphic recordings (mean 8,9hrsPP/ 7,3hrs SP) we analysed 14829 events with regard to conceptional age at time of acquisition (groupl: ≤37wks) groupII: >37wks), type and duration of event (central, obstructive, mixed apnea(A.), hypopnea, isolated bradycardia), effect on heart rate and arterial oxygen saturation (SaO2). Results: In group I (mean 34wks, range 31-37wks GA) A. density was identical in PP and SP (median: 46,7m). In PP obstructive A. increased (PP 40%/ SP 34% of all events) and central A. decreased (PP48%/SP52%). Duration, mean heart rate and mean SaO2 before an event and associated desaturation defined as fall ≥3% of mean SaO2 were similar. Hypoxemia associated with any type of resp. event was more frequent in SP (SaO2<85%: PP 19,4%/ SP24%; SaO2<80%: PP7,7%/ SP10,8%). In groupII (mean 43 wks; range 38 - 55wks GA) A. density was reduced (PP32,8/h; SP34,9/h). Again obstructive A. was increased in PP (PP45,3%/ SP39,2%), while central A, did not reveal disparity (PP46,6%/ SP 46,4%). Compared to group I the number of bradycardias and desaturation in association. with a respiratory event was lower. However bradycardias mainly ocurred in SP (HR<100bpm: PP1,4% / SP4,0%; HR≤80bpm: PP 0%/SPI%). Desaturation (≥3%: PP26,5%/ SP 46,2%) and hypoxemia were more frequently noted in SP (SaO2≤85%: PP 2,4%/ SP 7,3%; ≤80%: PP1,4%/ SP2,9%). Summary: Positioning influenced the incidence of A., hypoxemia and bradycardia. In PP obstructive A were more common(p=0,06). In contrast to other studies we found that hypoxemia (SaO2≤85%; all events p=0,01;central A. p=0,001) and with increasing conceptional age bradycardias were more frequent in SP. Conclusion: 1. When positioning unstable preterm infants, consider possible effects on cardiorespiratory regulation. 2.Evaluation of pneumogramms must include the position of the infant. NICU and Statistic.Instit.*,Mainz University, Germany.