Dark side of fluids and Fluid overload

Dark side of IV fluids? Septic patients are typically hypotensive and low blood pressure is often associated with an increased blood lactate concentration, a low urinary output, and other signs and symptoms of physiological distress. Clinicians then make an inference that there must be inadequate vital organ blood flow (typically described as poor perfusion) to … Read more

Fluid responsiveness

Fluid responsiveness and Functional hemodynamic monitoring   What is fluid responsiveness? Fluid responsiveness is an increase of stroke volume > 10-15% after the patient receives a bolus of 500 ml of crystalloid (Bolus by definition means that it has to be pressure bagged and given over 5-10 minutes). Fluid responsiveness is also known as “volume … Read more

Advanced hemodynamic monitors

Advanced hemodynamic monitors and fluid responsiveness Cardiac output is used in the ICU as a marker of oxygen delivery to tissues and to guide treatment, primarily for fluid resuscitation and the use of vasopressors, vasodilators and inotropes.   For decades, PA catheter used to be the ‘clinical reference standard’ for cardiac output monitoring, using thermodilution … Read more

Vasopressors and Shock

Shock is a physiologic state characterized by a significant reduction of systemic tissue perfusion, resulting in decreased oxygen delivery to the tissues. This creates an imbalance between oxygen delivery and oxygen consumption.    Mechanism: Systemic tissue perfusion is determined by the cardiac output (CO) and systemic vascular resistance (SVR):  CO is the product of heart rate and … Read more

Basics of Hemodynamics

Static hemodynamic monitoring variables  The utility of each variable as a single absolute value is questionable. Some individual hemodynamic values are useful primarily as threshold monitors. For example, because a primary determinate of organ perfusion is perfusion pressure, systemic hypotension to below a certain threshold is clinically relevant. Furthermore, elevation in central venous pressure (CVP; … Read more