Objectives:To determine whether a starch solution for volume resuscitation in a flow-based protocol improves circulatory status better than a crystalloid solution, as defined by the need for catecholamines in patients the morning after cardiac surgery, and whether this can be performed without incre

Fluids after cardiac surgery: a pilot study of the use of colloids versus crystalloids.

In patients with septic shock, hypovolemia is a major factor contributing to circulatory instability. In the early phase, cardiac filling pressures are often lowered, due to a decrease in venous return, compromising cardiac output and tissue perfusion [1, 2]. A decline in effective circulating volume can be induced by a variety of sepsis-related mechanisms. First, generalized vasodilation increases total vascular capacitance with subsequent relative hypovolemia. A decline in systemic vascular resistance, mainly due to arteriolar vasodilation, is a constant feature in human septic shock [3]. Alterations in the venous capacitance system, by far the largest part of the intravascular compartment, are however difficult to assess. The concept of venous pooling as a major factor limiting effective venous return stems from animal experiments [4, 5]. Experimental studies in endotoxin and sepsis models have indicated that in several body areas venous capacitance increases. Although significant increases in venous capacitance in the forearm could not be demonstrated in the clinical study [6], it is likely that also in human septic shock venous pooling in vascular beds other than skeletal muscle (e.g. the splanchnic area) is an important mechanism. The evidence for this is, however, only circumstantial. The observation that large amounts of fluids are usually required for initial resuscitation supports such a concept. Secondly, absolute hypovolemia may contribute to a defect in effective circulating volume. This could be due to fever with perspiration and increased insensible loss, vomiting, diarrhea, volume loss by drains or sequestration (e.g. in the gut), and inadequate oral intake.

Fluid Therapy in Septic Shock

Pulmonary and Extrapulmonary Effects of Increased Colloid Osmotic Pressure During Endotoxemia in Rats

Sepsis is a systemic illness characterized by an uncontrolled host inflammatory response, usually to severe bacterial infection [1]. Morbidity in sepsis relates to the development of multiple organ dysfunction (MODS), a Syndrome of simultaneous dysfunction of the lungs and the majority of extrapulmonary Organs [2]. Estimated to affect greater than 500,000 patients in North America annually [3], the prevalence of sepsis is increasing as it is a complication of applying new medical and surgical technologies to our aging population.

Ronald E. Bowers

Papers

Saline compared to plasma volume replacement after volume depletion in sheep: Lung fluid balance