Patients in the intensive care unit (ICU) and in the peri-operative phase are dependent on physicians and nurses for their fluid intake. Volume status optimization is required to maximize oxygen delivery to vital organs. Unnecessary fluid administration can, however, lead to general and pulmonary oedema, cardiac failure, infections, prolonged hospitalization and death. Besides signs like skin turgor, diuresis and skin colour, hemodynamic measurements like central venous pressure (CVP) and mean arterial pressure (MAP) are most often used for hemodynamic management. These parameters, however, often fail to accurately predict the response of a patient to fluid loading. Cardiac output (CO) is the amount of blood pumped through the circulation by the heart per minute. The general conception is that an increase in cardiac output will improve perfusion of vital organs. Increased flow might also imply improved oxygen delivery to the tissues. This is the basis of the fluid loading responsiveness strategy (FLR). This strategy aims to prevent fluid overloading by an accurate prediction of the response in cardiac output to fluid loading. Arthur Guyton__s work provided an important step forward to the determination of volume status directly. Together with the shape of cardiac output function curve, dimensions of the vascular system, blood viscosity and mean systemic filling pressure (MSFP) can be considered as a primary determinant of venous return and thus cardiac output. Ultimately, MSFP can be used to calculate stressed volume and, hence, quantify effective volume status in a specific patient. In this thesis, we review literature on fluid loading responsiveness research, we try to assess the impact of literature on hemodynamic management in Dutch ICU__s, we discuss a novel method to assess mean systemic filling pressure and last we discuss studies performed to assess the reliability of several challenges to predict FLR; +10 cmH2O PEEP, the fluid challenge, passive leg raising, the respiratory ventilator manoeuvre and the measurement of baseline MSFP. The manoeuvres are aimed at determining the working point of the circulation on the Frank- Starling curve. It is assumed that when the patient is on the ascending portion of the Frank- Starling curve an (auto)transfusion will increase cardiac output.Centre for Human Drug Research, Dept. Anaesthesiology LUMCUBL - phd migration 201
