Fluid & Electrolyte Balance Flashcards
7 cards from real MSNCB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fluid & Electrolyte Balance flashcards as text
A patient develops confusion, muscle twitching, and seizures after receiving multiple blood transfusions. Which electrolyte imbalance is most likely responsible?
Answer: Hypocalcemia
Citrate preservatives in stored blood bind free calcium, causing hypocalcemia, which manifests as confusion, muscle twitching, and seizures during massive transfusions.
Which set of findings would most clearly differentiate diabetes insipidus (DI) from SIADH?
Answer: Elevated serum sodium and dilute urine in DI
Diabetes insipidus results from deficient ADH, causing massive dilute urine output, dehydration, and hypernatremia — the opposite of SIADH's profile.
A post-operative patient who underwent bowel resection develops third-spacing with hypotension and decreased urine output. Which IV fluid replacement is most appropriate?
Answer: Isotonic crystalloid such as 0.9% NaCl or lactated Ringer's
Third-spacing shifts fluid into non-functional spaces, depleting intravascular volume; isotonic crystalloids are first-line to restore functional circulating blood volume.
A patient with chronic kidney disease has a serum potassium of 5.8 mEq/L. Which dietary instruction is the most important priority?
Answer: Avoid high-potassium foods such as bananas, oranges, and potatoes
CKD impairs renal potassium excretion; restricting high-potassium foods is essential to prevent hyperkalemia from rising to levels that cause fatal cardiac arrhythmias.
Which arterial blood gas result indicates respiratory alkalosis?
Answer: pH 7.50, PaCO2 28, HCO3 22
Respiratory alkalosis is characterized by an elevated pH (>7.45) and decreased PaCO2 (<35 mmHg) from hyperventilation, with near-normal bicarbonate if uncompensated.
A post-operative patient receiving 0.45% NaCl IV develops sudden confusion and seizures. Which complication has most likely occurred?
Answer: Dilutional hyponatremia
Hypotonic fluids such as 0.45% NaCl can cause dilutional hyponatremia post-operatively when ADH is elevated, allowing water retention that shifts fluid into brain cells, causing neurological symptoms.
A patient presents with severe hyponatremia (sodium 118 mEq/L) and altered mental status. Which nursing intervention is the highest priority?
Answer: Restrict free water and notify the physician for possible hypertonic saline administration
Severe symptomatic hyponatremia requires immediate free water restriction and urgent physician notification for potential hypertonic saline to prevent progressive cerebral edema and brainstem herniation.