PSA PSA Fluid and Electrolyte Prescribing 1 — Questions and Answers
Question 1: A patient is admitted with hypovolemic shock following gastrointestinal bleeding. Which intravenous fluid is most appropriate for initial resuscitation?
- 5% Dextrose in water (D5W)
- 0.9% Normal saline (isotonic saline) (Correct answer)
- 0.45% Half-normal saline
- 5% Dextrose in 0.45% saline
Correct answer: 0.9% Normal saline (isotonic saline)
Isotonic saline (0.9% NaCl) is the standard initial fluid for hypovolemic shock because it expands intravascular volume effectively.
Question 2: Which of the following is the most appropriate fluid for replacing isolated free water deficit in a patient with hypernatremia?
- 0.9% Normal saline
- Lactated Ringer's solution
- 5% Dextrose in water (D5W) (Correct answer)
- Hypertonic saline (3%)
Correct answer: 5% Dextrose in water (D5W)
D5W is effectively free water after glucose is metabolized and is the preferred fluid for correcting hypernatremia due to free water deficit.
Question 3: A post-operative patient develops oliguria. What is the first step in assessing fluid status before prescribing additional IV fluids?
- Immediately administer 1 L of normal saline
- Assess clinical signs of hypovolemia and review fluid balance (Correct answer)
- Start dopamine infusion for renal protection
- Order furosemide to increase urine output
Correct answer: Assess clinical signs of hypovolemia and review fluid balance
Clinical assessment of volume status (skin turgor, BP, HR, fluid balance) is essential before prescribing additional fluids to avoid fluid overload.
Question 4: What complication can result from rapid correction of chronic hyponatremia?
- Cerebral edema
- Osmotic demyelination syndrome (Correct answer)
- Acute kidney injury
- Hyperkalemia
Correct answer: Osmotic demyelination syndrome
Correcting chronic hyponatremia too rapidly risks osmotic demyelination syndrome (previously called central pontine myelinolysis).
Question 5: Which IV fluid is most appropriate for a patient with diabetic ketoacidosis (DKA) after initial stabilization?
- 5% Dextrose in water
- 0.9% Normal saline followed by 0.45% saline with dextrose when glucose falls (Correct answer)
- Lactated Ringer's with potassium only
- 3% Hypertonic saline
Correct answer: 0.9% Normal saline followed by 0.45% saline with dextrose when glucose falls
In DKA, isotonic saline is used initially; as serum glucose approaches 200 mg/dL, dextrose-containing fluid is added to prevent hypoglycemia while continuing insulin.
Question 6: A patient is receiving large volumes of 0.9% normal saline for resuscitation. Which electrolyte abnormality is most likely to develop?
- Hyponatremia
- Hypochloremic metabolic alkalosis
- Hyperchloremic metabolic acidosis (Correct answer)
- Hypokalemia
Correct answer: Hyperchloremic metabolic acidosis
Large volumes of normal saline contain high chloride (154 mEq/L), which can cause hyperchloremic (non-anion gap) metabolic acidosis.
PSA PSA Fluid and Electrolyte Prescribing 1
A patient is admitted with hypovolemic shock following gastrointestinal bleeding.
Which intravenous fluid is most appropriate for initial resuscitation?