Crystalloids

Crystalloids are fluids that contain water and electrolytes. They are grouped as balanced, hypertonic, and hypotonic salt solutions. Crystalloid solutions are used to provide maintenance water and electrolytes and expand intravascular fluid. The replacement requirement is threefold or fourfold the volume of blood lost because administered crystalloid is distributed in a ratio 1:4 like ECF, which is composed of about 3 L intravascularly (plasma) and about 12 L extravascularly (i.e., about 20% should remain in the intravascular space).