1497 COMPARISON OF SCREENING OF HIGH RISK INFANTS BY AUDITORY BRAINSTEM RESPONSES (ABRs) AND BY PNEUMOGRAMS

ABRs assess function of the brainstem auditory pathway. Interwave distances reflect brainstem conduction time and wave V latency is an index of maturation. Pneumograms are recordings of respiratory activity which allow quantitation of breathing pauses during sleep. Pneumogram abnormalities reflect dysfunction or immaturity of brainstem respiratory control mechanisms. We compared screening results for 15 high risk infants (GA 30.7 ± 4 wks), BW 1300 ± 600 gm) who had pneumograms and reproducible ABRs and were not receiving theophylline at the time of either screen. All had identifiable waves I and V and 12 (80%) also had wave III. Sleep portions of 12 hr pneumograms were scored for density of short (≥6 sec) apneas (A6/D), % time spent in periodic breathing (% PB) and number episodes PB/100 min (#PB/100). Relationship of ABR and pneumogram measurements was analyzed by linear regression. Postconceptual age at the time of screening was 38.5 ± 5.9 wks for ABRs and 38.4 ± 5.7 wks for pneumograms. Wave V latency showed significant correlation with all pneumogram measurements: for A6/D, r=0.73, p=0.002; for % PB, r=0.67, p=0.007; for #PB/100, r=0.61, p=0.015. Interwave distances (I-III, I-V) showed no significant correlation with pneumograms. Thus assessment of the brainstem auditory pathway by ABR wave V latency correlates well with assessment of brainstem respiratory control mechanisms by pneumograms. These findings strengthen the validity of both the ABR and the pneumogram as tests of brainstem maturation and function.