Final answer:
The goal of treating hypernatremia is achieved when the 3) serum sodium concentration returns to normal. This indicates effective intravenous fluid therapy, as the normalization of serum sodium levels signifies restored osmotic balance and proper sodium and water levels in the body.
Step-by-step explanation:
The nurse evaluating the effectiveness of intravenous fluid therapy in a patient with hypernatremia would consider the goal achieved when the serum sodium concentration returns to normal. Hypernatremia is an elevated sodium level in the blood, usually due to dehydration or excessive loss through urine, sweat, vomiting, or diarrhea. The normalization of serum sodium indicates that the osmotic balance is being restored, suggesting that the fluid therapy is effective. While an increase in urine output, changes in blood pressure, and decreases in emesis and diarrhea are important signs to monitor, the key indicator of resolving hypernatremia is the return of serum sodium levels to normal.
Hypernatremia involves the balancing of sodium and water levels in the body, and intravenous fluid therapy aims to address these imbalances. When sodium concentrations are high, water is drawn from the intracellular space, causing cells to shrink and potentially leading to neurological symptoms. Therefore, successful treatment must rehydrate the body and normalize sodium concentrations to prevent these complications.
Fluid therapy replenishes water and often includes sodium management, typically with a hypotonic solution to gradually reduce serum sodium levels safely. This approach avoids the quick shifts in fluid balance, which can result in cerebral edema if serum sodium levels are lowered too rapidly.
Hence, the correct answer is Option 3.