Basics of Fluid Physiology

Proper use of fluids requires consideration of the basic physiology of fluids in the body. This includes consideration of the following questions. What does water do? What is the importance of elements such as Na+, Cl−, and K+ in bodily solutions? What determines how water and electrolytes distribute between the plasma space, interstitial space, and intracellular space? What is the role of colloids, and in particular, albumin? What happens when different types of fluids are infused intravenously? This chapter emphasizes the physiological role of fluids, principles behind the movement and distribution of water and it solutes, and the characteristics of different kinds of commonly infused fluids.