FCCS Fluid and Electrolyte Management Flashcards

Which dynamic parameter is most useful for predicting fluid responsiveness in a mechanically ventilated patient?

Answer: Pulse pressure variation (PPV)

Pulse pressure variation >13% during mechanical ventilation reliably predicts fluid responsiveness, outperforming static pressures like CVP.

A patient with polyuria (>300 mL/hr), hypernatremia, and very dilute urine (specific gravity 1.001) in the ICU most likely has which condition?

Answer: Diabetes insipidus

Diabetes insipidus causes massive free water loss due to absent or ineffective ADH, resulting in dilute urine, hypernatremia, and polyuria.

When is hypertonic saline (3% NaCl) indicated for hyponatremia?

Answer: Symptomatic acute hyponatremia with seizures or severe altered consciousness

Hypertonic saline is reserved for severe symptomatic acute hyponatremia (seizures, coma) where rapid partial correction is necessary to prevent herniation.

A patient with decompensated heart failure and hyponatremia (Na = 128 mEq/L) presents to the ICU. What is the most appropriate initial fluid management?

Answer: Restrict free water intake and consider diuretics

Dilutional hyponatremia in heart failure is treated with free water restriction and diuresis; adding more fluid worsens volume overload without correcting sodium.

Which clinical finding most strongly suggests fluid overload in a mechanically ventilated ICU patient?

Answer: Rising CVP with worsening hypoxemia and bilateral pulmonary infiltrates

Rising filling pressures combined with worsening oxygenation and pulmonary infiltrates indicate fluid overload causing pulmonary edema in the ICU.

Refeeding syndrome in a malnourished ICU patient is primarily characterized by a dangerous drop in which electrolyte?

Answer: Phosphate

Refeeding syndrome causes severe hypophosphatemia as insulin release during refeeding drives phosphate rapidly into cells, leading to cardiac, respiratory, and neurological complications.

A patient is being resuscitated for septic shock. After 30 mL/kg IV fluid bolus, urine output remains low and CVP is 14 mmHg. What is the best next step?

Answer: Reassess fluid responsiveness with a dynamic test before giving more fluids

A high CVP after initial resuscitation suggests the patient may be fluid non-responsive; dynamic assessment (passive leg raise, PPV) should guide further fluid administration to avoid overload.