Internal carotid artery blood flow velocities before, during, and after extracorporeal membrane oxygenation
R. M. Lohrer, R. F. Bejar, A. J. Simko, S. L. Moulton and J. D. Cornish
Department of Neonatology, Free University of Berlin, Federal Republic of Germany.
Blood flow velocities in the internal carotid arteries were studied with
pulsed Doppler in 25 neonatal patients (birth weight range, 2600 to 4100 g)
who had extracorporeal membrane oxygenation (ECMO). Time averaged mean
systolic, mean diastolic, and mean blood flow velocities were calculated.
Five infants had right common carotid artery reconstruction. Blood flow
velocities measured in 15 healthy full-term infants were used as controls.
Findings during ECMO included the following: (1) forward flow in the right
internal carotid artery in 50% of the infants; (2) significant increase in
the mean diastolic and the mean flow velocities (48% and 128%,
respectively) in the left internal carotid artery when compared with
pre-ECMO and control infants' values; (3) the elevation in the mean and the
mean diastolic velocities was associated with changes in the PaCO2 and with
an increase in the diastolic blood pressure; and (4) forward blood
velocities in the right internal carotid artery were comparable with blood
velocities in the left internal carotid artery and with the blood
velocities of control infants. After ECMO, the mean diastolic velocity in
the left internal carotid artery decreased significantly, but it remained
elevated when compared with pre-ECMO values. Infants with right common
carotid reconstruction had blood velocities in the right internal carotid
artery comparable with the simultaneous blood velocities in the left
internal carotid artery and to the blood velocities of control infants.
Twenty-eight percent of the infants had major neuroanatomic lesions. Right
or left preponderance was not noted. No association between blood velocity
values in the internal carotid arteries or flow direction and the presence
or the absence of brain lesions was noted.
