Fluid balance

see Fluid imbalance

The renin angiotensin system (RAS) or the renin–angiotensin–aldosterone system (RAAS) is a hormone system that regulates blood pressure and fluid balance.

The goal of euvolemia rather than dehydration as a therapeutic target in traumatic brain injury is achieved by assessing fluid balance, central venous pressure, urine output, blood urea nitrogen, serum creatinine, and clinical examination. The placement of a Foley catheter is also routinely used to quantify urine output and to avoid potential bladder rupture.