Insensible Fluid Loss

Excerpt

Water is essential for the maintenance of life. As the major element of fluid compartments in the body, water makes up approximately 60% of body weight. Gender, age, physical activity, and adiposity are pertinent factors that may alter this percentage. In the body, water subdivides between extracellular (33%) and intracellular (67%) spaces. Thirst and hormonal mechanisms are both responsible for maintaining total body water within a tight range. A decrease in plasma volume, increase in plasma osmolality, or decrease in blood pressure all stimulate a patient’s thirst drive. The hormone vasopressin is responsible for controlling daily water balance, and hyperosmolality stimulates its release.