Rapid cerebral dehydration can rupture the blood vessels connecting the brain to the rigid calvarium. As a protective mechanism, the brain appears to generate new intracellular solute (sometimes called "idiogenic osmoles")2. Osmoles (or osmolytes) are volume-regulatory organic solutes that can accumulate to a high concentration within cells, without adverse effects on cellular structure or function. Intracellular osmolality is thereby increased, minimizing the loss of intracellular brain water. A corollary of this process is the clinical observation that overly rapid correction of hyperosmolar states can be fatal. As extracellular fluid is replaced, the increase in intracellular water associated with idiogenic osmoles can lead, it is presumed, to cerebral edema. The rates of accumulation or removal of the idiogenic osmoles are unknown, so that treatment of patients with hyperosmolal and hypo-osmolal states is empirical. In the presence of severe changes in intracellular osmolytes in the brain (as in this infant), a much slower correction of the plasma sodium concentration, possibly over a period of 7 to 10 days, may be indicated. Thus it is advocated to correct serum sodium of not more than 0.5meq/l/hour. Thus is serum sodium is 180, you may have to correct the same over a period of 3 days. You will have to calculate the free water deficit and also percentage of dehydration and correct the same over the number of days and give maintenance fluids for every 24 hours.