INTRODUCTION Pulse pressure variation predicts fluid responsiveness in mechanically ventilated patients passively adapted to the ventilator. Its usefulness in actively breathing ventilated patients was examined only by few studies with potential methodological shortcomings. This study sought to describe the performance of pulse pressure variation as a predictor of fluid responsiveness in hypote...

STARLING (1894, 1896) described the basic forces responsible for producing fluid shifts between the circulating blood and the surrounding tissue spaces. On page 324 of his classical article entitled "On the absorption of fluids from the connective tissue spaces," Starling described how capillary pressure determines transudation into the tissues and the osmotic pressure of the proteins determine...

We recently modeled fluid flow through gap junction channels coupling the pigmented and nonpigmented layers of the ciliary body. The model suggested the channels could transport the secretion of aqueous humor, but flow would be driven by hydrostatic pressure rather than osmosis. The pressure required to drive fluid through a single layer of gap junctions might be just a few mmHg and difficult t...

STARLING (1894, 1896) described the basic forces responsible for producing fluid shifts between the circulating blood and the surrounding tissue spaces. On page 324 of his classical article entitled "On the absorption of fluids from the connective tissue spaces," Starling described how capillary pressure determines transudation into the tissues and the osmotic pressure of the proteins determine...

To investigate the possible role of body fluid volume or the renin-angiotensin system in the maintenance of high blood pressure in chronic one-kidney, one clip (1K1C) hypertension, we studied whether blood pressure remained high after removal of the clip while the body fluid volume was kept constant or when angiotensin II (Ang II) was infused in conscious 1K1C rats. Blood pressure fell 58 +/- 1...

BACKGROUND Predicting whether a fluid challenge will elicit 'fluid responsiveness' in stroke volume (SV) and arterial pressure is crucial for managing hypovolaemia and hypotension. Pulse pressure variation (PPV), SV variation (SVV) and the plethysmographic variability index (PVI) have been shown to predict SV fluid responsiveness, and the PPV/SVV ratio has been shown to predict arterial pressur...

Acute osmolar loading of cerebrospinal fluid within one lateral ventricle of dogs was examined as a cause of water extraction from the bloodstream and an increase in intracranial pressure. We have shown that a certain amount of (3)H₂O from the bloodstream enters osmotically loaded cerebrospinal fluid significantly faster, hence causing a significant increase in intracranial pressure. The noted ...

Oxygen is an essential part of the most important metabolic pathways in aerobic organisms. Oxygen delivery is merely dependent on blood, rendering blood loss a devastating event. Traumatic pre-hospital liver bleeding is a major cause of early trauma deaths in human and animals, with no established therapeutic method yet. Increasing intra-abdominal pressure (IAP) has been shown to reduce liver b...

An accurate description of the fluid flow and heat transfer within a Pressurized Water Reactor (PWR), for the safety analysis and reactor performance is always desirable. In this paper a mathematical model of the fundamental physical phenomena which are associated to a typical PWR is presented. The mathematical model governs the fluid dynamics in the reactor. Using commercial software CFX, a co...