Determinants of cerebral perfusion pressure during carotid endarterectomy
J. P. Archie Jr and R. W. Feldtman
To define cerebral perfusion pressure during carotid clamping, carotid back
and jugular venous pressures were measured in 100 consecutive carotid
endarterectomies in 92 patients. The mean +/- 1 SD was 40.5 +/- 16.0 mm Hg
for carotid back pressure, 11.8 +/- 4.8 mm Hg for jugular venous pressure,
and 28.7 15.4 mm Hg for cerebral perfusion pressure. A number of variables
affect jugular venous pressure, including jugular vein compression, patient
position, and the anesthetic type. The lower the carotid back pressure, the
more likely that back pressure alone is poor determinant of cerebral
perfusion pressure and, hence, of the adequacy of collateral cerebral blood
flow. To accurately use the carotid back or stump pressure method. The
jugular venous pressure must also be measured, and the cerebral perfusion
pressure must be calculated. Based on established safe levels of cerebral
blood flow, it is probable that patients who undergo a carotid
endarterectomy with a cerebral perfusion pressure of less than 18 mm Hg
have cerebral ischemia and may require a shunt. Selective shunting, based
on the cerebral perfusion pressure, gave a 1% mortality and 2% permanent
neurologic deficit in this series.
