Abstract
The auditory brain-stem response (ABR) and cardiopulmonary function (as determined by the mean blood pressure [MBP], heart rate, arterial blood gases [ABG], and pH were evaluated in 9 preterm lambs ranging in age from 106-125 days gestation (70-85% term). Following epidural anesthesia of the ewe, the uterus was opened, the fetal head exposed, and a saline-filled rubber glove placed over the snout to prevent inspiration of air. Two platinum-alloy needle electrodes were inserted subdermally just posterior and inferior to the pinnae, another at vertex, and one in the snout area for ground. Click stimuli were generated and delivered by a bone conduction vibrator driven by 100 usec pulses of alternating polarity. Even the youngest group of animals revealed clearly defined 8th nerve and brain-stem response components. The latencies of waves 3,4, and 5 and the interpeak latency 1-5 decreased significantly as a function of age. Results of physiologic measures and the ABR data across subjects revealed a significant negative correlation between MBP and the latencies of waves 4 and 5 and the 1-5 interpeak latency and were suggestive of a possible inverse relationship between the wave 1 latency and pH. These findings demonstrate the presence of the ABR as early as 70% gestation as well as the sensitivity of the ABR to MBP and acid-base balance at this stage of development. (Supported by NIH Grant HL/HD 30525).
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wolfson, M., Durrant, J., Shaffer, T. et al. 337 THE RELATIONSHIP BETWEEN ABR AND CARDIOPULMONARY FUNCTION IN PRETERM LAMBS. Pediatr Res 19, 167 (1985). https://doi.org/10.1203/00006450-198504000-00367
Issue Date:
DOI: https://doi.org/10.1203/00006450-198504000-00367