Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Although the mechanisms of neurological disorders after cardiac surgery in neonates are still not fully understood, alterations in blood flow after cardiopulmonary bypass (<jats:styled-content style="fixed-case">CPB</jats:styled-content>) may lead to cerebral injury. The aim of the study was the analysis of flow changes in the carotid artery of neonatal piglets after <jats:styled-content style="fixed-case">CPB</jats:styled-content>. Ten neonatal piglets (younger than 7 days) were connected to the <jats:styled-content style="fixed-case">CPB</jats:styled-content> and further management underwent three steps: (i) cooling to 32°<jats:styled-content style="fixed-case">C</jats:styled-content> core temperature within 30 min; (ii) cardiac arrest under cardioplegic myocardial protection for 90 min; and (iii) rewarming to 37°<jats:styled-content style="fixed-case">C</jats:styled-content> after cross‐clamp release (60 min of reperfusion). In summary, piglets were separated from <jats:styled-content style="fixed-case">CPB</jats:styled-content> after a total duration time of 180 min. The blood flow was measured in the left carotid artery by an ultrasonic flow probe before <jats:styled-content style="fixed-case">CPB</jats:styled-content> (baseline), immediately after <jats:styled-content style="fixed-case">CPB</jats:styled-content>, 30 min, and 60 min after <jats:styled-content style="fixed-case">CPB</jats:styled-content>. Additionally, the pulsatility index and the resistance index were calculated and compared. Finally, the relation of the carotid artery flow data with the corresponding pressure data at each time point was compared. After termination of <jats:styled-content style="fixed-case">CPB</jats:styled-content>, the carotid artery mean flow was reduced from 28.34 ± 13.79 m<jats:styled-content style="fixed-case">L</jats:styled-content>/min at baseline to 20.91 ± 10.61 m<jats:styled-content style="fixed-case">L</jats:styled-content>/min and remained reduced 30 and 60 min after <jats:styled-content style="fixed-case">CPB</jats:styled-content> termination (19.71 ± 11.11 and 17.64 ± 15.31 m<jats:styled-content style="fixed-case">L</jats:styled-content>/min, respectively). Both the pulsatility and the resistance index were reduced immediately after <jats:styled-content style="fixed-case">CPB</jats:styled-content> termination and increased thereafter. Nevertheless, values did not reach statistical significance. In conclusion, the carotid <jats:styled-content style="fixed-case">D</jats:styled-content>oppler flow immediately after <jats:styled-content style="fixed-case">CPB</jats:styled-content> and mild hypothermia in neonatal piglets was lower than before <jats:styled-content style="fixed-case">CPB</jats:styled-content> due to reduced vascular resistance. Additionally, the pressure–flow relation revealed that immediately after <jats:styled-content style="fixed-case">CPB</jats:styled-content>, a higher pressure is required to obtain adequate flow.</jats:p>