British journal of anaesthesia
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Observational Study
Pharmacokinetic/pharmacodynamic model for unfractionated heparin dosing during cardiopulmonary bypass.
High-dose heparin is used during cardiopulmonary bypass (CPB) to prevent thrombosis in the circuits used for extracorporeal circulation. The aim of this study was, initially, to develop a population pharmacokinetic/pharmacodynamic (PK/PD) model to assess the variability of PK/PD parameters and their correlation with the results of the routine haemostatic test activated clotting time (ACT) and thereafter to develop a Bayesian estimator enabling an individualized dosing strategy. ⋯ A population PK/PD analysis of heparin during CPB, using a routine haemostatic test, shows that Bayesian estimation might help to predict ACT on the basis of only one or two blood samples.
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Comparative Study
Comparison of preoperative and intraoperative assessment of aortic stenosis severity by echocardiography.
General anaesthesia and surgically induced changes in cardiac loading conditions may alter flow across the aortic valve. This study examined how echocardiographic assessment of the severity of aortic stenosis (AS) changes during surgery. ⋯ Intraoperative TOE peak velocities and mean gradients are often significantly lower than preoperative TTE measurements, leading to underestimation of AS severity in nearly half of our study patients. The DI is a more reliable measurement of AS severity in the intraoperative setting.