Final answer:
3% saline IV is used for severe symptomatic hyponatremia where rapid elevation of sodium levels is required, such as risk of brain swelling. It is not common and typically used in critical care. The choice of IV fluid is based on the patient's specific needs.
Step-by-step explanation:
When a patient has low sodium, 3% saline IV is an intensive treatment that's generally used in situations where there's a need for rapid elevation of sodium levels, such as in the case of severe symptomatic hyponatremia where there's a risk of brain swelling. It is not a common treatment and is often reserved for emergency or critical care settings. In the scenario described, a physician orders an intravenous (IV) delivery of 100 mL of 0.5% KCl for a patient with hypokalemia (low potassium levels), which suggests that the patient is having a different electrolyte imbalance than low sodium. Here, the aide would indeed get an IV bag containing the specific concentration of KCI as ordered by the physician.
It's important to remember that the choice of IV fluid and the concentration of the electrolytes administered is a critical decision based on the patient's specific condition. For instance, a normal saline IV solution, with a mass/volume percent of 0.9% NaCl, is often used for hydration and to provide sodium to patients, but it is not as concentrated as 3% saline and is used in different clinical situations. The correction of dehydration sometimes requires specific mixtures of fluids to replenish electrolytes accurately and safely. In case of a hypertensive crisis, IV drips can also be used to manage high blood pressure and reduce the risk of heart failure.