Journal of cardiothoracic and vascular anesthesia
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J. Cardiothorac. Vasc. Anesth. · Aug 2004
Effects of hemodilution and phenylephrine on cerebral blood flow and metabolism during cardiopulmonary bypass.
Hypotension resulting from hemodilution on cardiopulmonary bypass is often treated by pressor (eg, phenylephrine) infusion. The effect of phenylephrine on cerebral blood flow (CBF) in this setting is not clear. It was hypothesized that phenylephrine might decrease CBF. ⋯ Phenylephrine redirects blood flow from the bowel and muscle to the brain and liver. Hemodilution increases CBF and pressor administration further increases CBF by elevating perfusion pressure. Maintenance of a higher hematocrit on CPB increases MAP and should decrease the need for vasopressor administration.