An infant recovering from a pneumothorax has urinary output less than 1 mL/hr, weight gain of 200 g in 24 hours, serum sodium 125, and urine specific gravity 1.020. What is the next step in fluid management?

• A. Increase total fluids
• B. Maintain current fluid volumes
• C. Stop fluids
• D. Decrease total fluids

Answer: (D)

Fluid balance is the key issue. This infant shows signs of positive fluid balance: weight has risen by 200 g in 24 hours, which points to fluid overload, and urine output is very low. The hyponatremia (125 mEq/L) suggests dilution from excess free water, and a urine specific gravity of 1.020 indicates the urine isn’t highly concentrated, consistent with excess fluid intake relative to excretion rather than dehydration. In the context of recovering from a pneumothorax, excess intravascular and interstitial fluid can worsen pulmonary status and hinder healing, so the goal is to shift toward euvolemia.

Decreasing total fluids is the appropriate next step to reduce positive fluid balance, support diuresis if possible, and help correct the hyponatremia by limiting further free-water intake. Monitor urine output, serum sodium, and weight closely as you adjust, ensuring the infant remains adequately hydrated and avoiding dehydration. Increasing fluids or stopping fluids would either worsen the overload or risk hypovolemia, respectively, and maintaining the current volume would perpetuate the problem.