7 INFLUENCE OF pO 2 ON CEREBRAL BLOOD FLOW VELOCITIES IN PRETERMS 32 GESTATIONAL WEEKS (GA)

Abstract

Animal studies show that beside PCO₂, PO₂ influences brain circulation. Since fluctuations of pO₂ occur frequently in ventilated preterms, we investigated whether changes within the therapeutic range of 40-90 mmHg affect blood flow velocity of internal carotid artery or not. Within continuous Doppler studies in preterms < 32 GA over 1 h we looked for accidental fluctuations of pO₂ > 10 mmHg occuring within 10 min. We questioned whether there was a concomitant change of Doppler parameters. Continuous pulsed Doppler measurements were performed with a miniature transducer fixed onto the infants fontanelle in 10 preterms (mean GA 28 w, mean birthweight 1321 g). A connected microcomputer evaluated the Doppler curves. A total of 15 pO₂ changes > 10 mmHg occured. In 12 of 15 events there were no concomitant changes of mean maximum velocity > 8 % (coefficient of variation of method) which was significant by sign-test, p < 0.05. There were no significant changes in the enddiastolic or peak systolic flow velocities outside the normal range. In conclusion there were no significant changes of cerebral Doppler parameters with accidental pO₂ changes.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD