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.
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J. Cardiothorac. Vasc. Anesth. · Aug 2004
Determination of preload-recruitable stroke work and elastance by the relationship of arterial blood flow velocity to left ventricular area.
The authors investigated the feasibility of an online sampling and display of LV flow-area loops for the determination of LV elastance and preload-recruitable stroke work (PRSW). Automated LV area measurements by echocardiography may be combined with flow velocity measurements in the internal carotid artery to construct LV flow-area loops as estimates of the systolic pressure-volume relationship. ⋯ Indices of the LV pressure-area relationship can be derived from real-time loops constructed from arterial flow velocity and LV area.