Final answer:
A nurse should administer IV fluids containing sodium to correct a client's low sodium level of 119 mEq/L, while monitoring vitals and symptoms closely.
Step-by-step explanation:
A nurse caring for a client with a sodium level of 119 mEq/L should recognize this as a sign of hyponatremia, which is a lower-than-normal sodium level in the blood. The most appropriate nursing action would be to administer IV fluids to correct the electrolyte imbalance. Specifically, a solution containing sodium, such as ordinary NaCl solution or a mixture of 2/3 isotonic saline and 1/3 Na lactate, could be given intravenously to repair the losses depending on the underlying cause. Meanwhile, vital signs and symptoms should be monitored closely, as severe hyponatremia can lead to complications like cerebral edema. Close collaboration with the treating physician is also essential for ongoing assessment and management of the patient's condition.