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
Relationship between peripheral and central venous pressures in different patient positions, catheter sizes, and insertion sites.
To investigate the relationship between peripheral and central venous pressures in different patient positions (supine, prone, lithotomy, Trendelenburg, and Fowler), different catheter diameters (18 G and 20 G), and catheterization sites (dorsal hand and forearm) during surgical procedures. ⋯ It has been assumed that replacing central venous pressure by peripheral venous pressure would cause problems in clinical interpretation. If the validity of this data is confirmed by further studies, the authors suggest that central venous pressure could be estimated by using regression equations to compare the 2 methods.
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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.