What IV fluids can be given to an 80-year-old patient with oliguria and hypernatremia on IV fluids only?

From the Guidelines

For an 80-year-old patient with oliguria and hypernatremia on IV fluids only, hypotonic fluids such as 0.45% sodium chloride (half-normal saline) or 5% dextrose in water (D5W) should be given to help correct hypernatremia. The patient's low PO intake and reliance on IV fluids, combined with a drop in urine output and elevated sodium levels, necessitate careful fluid management. According to the ESPEN guideline on clinical nutrition and hydration in geriatrics 1, offering subcutaneous or intravenous fluids is recommended for older adults with high serum osmolality who appear unwell, which aligns with this patient's presentation. Key considerations include:

• Starting with a conservative fluid rate, typically 50-75 mL/hour, to avoid rapid shifts in serum sodium and potential cerebral edema.
• Close monitoring of fluid status, electrolytes, and urine output to adjust the IV fluid rate as needed.
• Gradual correction of hypernatremia, aiming not to exceed a decrease of 8-10 mEq/L in serum sodium per 24 hours.
• Investigating and addressing the underlying cause of oliguria and hypernatremia, as IV fluid choice is only part of the supportive therapy. Regular monitoring of vital signs, intake/output, daily weights, and electrolytes (every 4-6 hours initially) is crucial for managing this patient's condition effectively.

From the FDA Drug Label

If the physician elects to use high dose parenteral therapy, add the furosemide to either Sodium Chloride Injection USP, Lactated Ringer's Injection USP, or Dextrose (5%) Injection USP after pH has been adjusted to above 5.5, and administer as a controlled intravenous infusion at a rate not greater than 4 mg/min.

The patient has oliguria and hypernatremia, and the goal is to increase urine output.

• 0.9% Sodium Chloride Injection USP may not be the best choice as it has a high sodium content which may worsen hypernatremia.
• Lactated Ringer's Injection USP or Dextrose (5%) Injection USP could be considered, but the patient's hypernatremia should be taken into account when choosing the fluid. Given the patient's age and low PO intake, careful consideration of fluid and electrolyte balance is necessary. It is essential to monitor the patient's urine output, electrolyte levels, and fluid balance closely. The use of furosemide should be considered to increase urine output, but the patient's renal function and electrolyte levels should be closely monitored 2.

From the Research

IV Fluids for Oliguria and Hypernatremia

The patient's condition of oliguria (low urine output) and hypernatremia (elevated serum sodium level) requires careful consideration of IV fluids to manage these conditions.

• The patient's serum sodium level is 148 mmol/L, which is above the normal range, indicating hypernatremia 3.
• For hypernatremia, the goal is to correct the sodium imbalance while ensuring adequate fluid intake.
• 0.9% saline is often used as a maintenance fluid, but its use can be associated with hyperchloremia, metabolic acidosis, and negative effects on renal hemodynamics 4.
• In this case, considering the patient's hypernatremia, using a fluid that does not exacerbate the sodium imbalance is crucial.
• There is limited direct evidence on the best IV fluid for an 80-year-old patient with oliguria and hypernatremia.
• However, it is essential to avoid using hypotonic fluids, which can worsen hyponatremia, as seen in a study comparing 0.45% and 0.9% saline in 5% dextrose in children 5.
• The choice of IV fluid should aim to maintain or correct serum sodium levels while ensuring adequate hydration and urine output.
• It is also important to monitor the patient's fluid intake and urine output closely, as well as their serum electrolyte levels, to adjust the IV fluid therapy as needed.