Guyton at the Bedside

This chapter describes the classic model of the circulation developed by Arthur Guyton and his team. The model envisions the circulation comprised of discrete components. The cardiac output is largely determined by the interactions of the venous return and the cardiac performance. The venous return is a function of the gradient between the mean systemic filling pressure and the right atrial pressure. The distribution of blood flow is largely controlled by autoregulation, thus matching oxygen demand and subsequently generating the venous return. Thus, cardiac output is a function of oxygen demand when cardiac function is not compromised. Caring for critically ill patient requires an understanding of Guytonian hemodynamics.