Sodium in biology mEq/liter (135 - 145 mmol/L). A serum sodium level of less than 135 mEq/L qualifies as hyponatremia, which is considered severe when the serum sodium level is below 125 mEq/L. The renin–angiotensin system and the atrial natriuretic peptide indirectly regulate the amount of signal transduction in the human central nervous system, which depends on sodium ion motion across the nerve cell membrane, in all nerves. Sodium is thus important in neuron function and osmoregulation between cells and the extracellular fluid; the distribution of sodium ions are mediated in all animals by sodium–potassium pumps, which are active transporter solute pumps, pumping
Human serum albumin trauma, burns and surgery patients. A Cochrane systematic review of 37 trials found no evidence that albumin, compared with cheaper alternatives such as saline, reduces the risk of dying. Human serum albumin has been used as a component of a frailty index. It has not been shown to give better results than other fluids when used simply to replace volume, but is frequently used in conditions where loss of albumin is a major problem, such as liver disease with ascites. Human serum albumin may be used to potentially reverse drug/chemical toxicity by binding to free drug/agent. (Tatlow, D, Poothencheri, S,