Is it appropriate to use 0.225% sodium chloride?
Crytalloid solutions are the most common parenteral solutions used for maintenance and replacement of fluid requirements in hospitalized patients. There are many crystalloid products available including sodium chloride, dextrose, and Lactated Ringer’s. Normal saline (0.9%) contains 308 mOsm/L, which effectively mimics the osmolarity of body fluids (280-300 mOsm/L); therefore it is considered an isotonic solution. In contrast, 0.45% and 0.225% sodium chloride contain 154 and 77 mOsm/L, respectively and are considered hypotonic compared to body fluids. Hypotonic solutions are used in patients with high serum osmolarity such as those with hypernatremia or hyperglycemic nonketotic coma. These fluids lower serum osmolarity by causing body water to shift out of the blood and into cells and interstitial spaces. In critically ill adult patients, hypotonic solutions are recommended to correct free water deficits in patients with hyperosmolar states after extracellular fluid los ses have been co
