Which drug, given together with dextrose, lowers serum potassium by driving potassium into the cells?
Insulin
✓
Furosemide
Calcium gluconate
Spironolactone
Correct Answer
Insulin
Insulin activates the sodium-potassium pump and moves potassium from the blood into cells, so it is given with dextrose to prevent hypoglycemia. Furosemide lowers potassium by increasing its loss in urine, not by shifting it into cells. Calcium gluconate protects the heart in hyperkalemia but does not change the serum potassium level. Spironolactone is potassium sparing and would raise potassium.
Category: Potassium Imbalances
Question 2
A patient with a serum potassium well above normal is placed on a cardiac monitor. Which ECG change is characteristic of this imbalance?
Prominent U waves
Peaked T waves
✓
Inverted T waves
Shortened QRS complex
Correct Answer
Peaked T waves
Hyperkalemia produces tall, peaked T waves and, as it worsens, flattened P waves and a widened QRS that can progress to cardiac arrest. Prominent U waves are a sign of hypokalemia. Inverted T waves are also associated with low potassium. A shortened QRS complex is not a feature of hyperkalemia, which widens the QRS.
Category: Potassium Imbalances
Question 3
How does sodium polystyrene sulfonate lower serum potassium?
It blocks aldosterone receptors in the kidney
It shifts potassium into the cells
It exchanges sodium for potassium in the bowel
✓
It stabilizes the cardiac cell membrane
Correct Answer
It exchanges sodium for potassium in the bowel
Sodium polystyrene sulfonate is a cation exchange resin that trades sodium for potassium in the colon, and the bound potassium leaves the body in the stool. It blocks aldosterone receptors in the kidney describes spironolactone, which raises potassium. It shifts potassium into the cells describes insulin and sodium bicarbonate. It stabilizes the cardiac cell membrane describes calcium gluconate.
Category: Potassium Imbalances
Question 4
A nurse receives an order to give potassium chloride by IV push for a patient with hypokalemia. What should the nurse do?
Give it slowly over one minute
Dilute it in a syringe of sterile water and push it
Give it by push through a central line
Clarify the order with the prescriber
✓
Correct Answer
Clarify the order with the prescriber
IV potassium must never be given by push or bolus because a rapid rise in serum potassium can cause fatal dysrhythmias, so the nurse holds the drug and clarifies the order. Give it slowly over one minute is still an IV push and is unsafe. Dilute it in a syringe of sterile water and push it still delivers a bolus. Give it by push through a central line is just as dangerous, because potassium must always be diluted and infused on a pump.
Category: Potassium Imbalances
Question 5
A patient has a low serum potassium level. Which of the patient's drugs is most likely contributing to it?
Furosemide
✓
Spironolactone
Lisinopril
Losartan
Correct Answer
Furosemide
Furosemide is a loop diuretic that increases urinary loss of potassium and is a common cause of hypokalemia. Spironolactone is a potassium-sparing diuretic that tends to raise potassium. Lisinopril, an ACE inhibitor, reduces aldosterone and can raise potassium. Losartan, an angiotensin receptor blocker, also reduces aldosterone effects and can raise potassium.
Category: Potassium Imbalances
Question 6
In hyponatremia, extracellular fluid has a lower osmolality than the fluid inside cells. What happens to body water as a result?
It moves out of the cells, causing them to shrink
It moves into the cells, causing them to swell
✓
It moves into the bloodstream, causing hypervolemia
It moves into the renal tubules, causing diuresis
Correct Answer
It moves into the cells, causing them to swell
When extracellular fluid has a lower concentration than the inside of cells, water moves by osmosis into the cells and they swell, which is why severe hyponatremia can cause cerebral edema, confusion and seizures. It moves out of the cells, causing them to shrink happens in hypernatremia. It moves into the bloodstream, causing hypervolemia is not the result of a hypotonic extracellular fluid. It moves into the renal tubules, causing diuresis does not describe the osmotic shift in hyponatremia.
Category: Fluid Balance
Question 7
Which drug class lowers serum calcium in hypercalcemia by inhibiting bone resorption by osteoclasts?
Thiazide diuretics
Vitamin D analogs
Bisphosphonates
✓
Calcium channel blockers
Correct Answer
Bisphosphonates
Bisphosphonates slow osteoclast activity, so less calcium is released from bone into the blood. Thiazide diuretics reduce urinary calcium excretion and can cause hypercalcemia. Vitamin D analogs increase calcium absorption and would raise the level. Calcium channel blockers act on vascular and cardiac muscle and are not used to treat hypercalcemia.
Category: Calcium and Magnesium
Question 8
A patient has weakness, hypotension and depressed reflexes from a toxic serum magnesium level. Which drug is given to counteract these effects?
Potassium chloride
Sodium bicarbonate
Magnesium sulfate
Calcium gluconate
✓
Correct Answer
Calcium gluconate
Calcium antagonizes the effects of excess magnesium on nerve, muscle and the heart, so IV calcium gluconate is the antidote for hypermagnesemia. Potassium chloride replaces potassium and does not reverse magnesium toxicity. Sodium bicarbonate treats acidosis and shifts potassium but is not a magnesium antidote. Magnesium sulfate would make the toxicity worse.
Category: Calcium and Magnesium
Question 9
Which condition is a common cause of hypercalcemia?
Hyperparathyroidism
✓
Hypoparathyroidism
Vitamin D deficiency
Chronic diarrhea
Correct Answer
Hyperparathyroidism
Parathyroid hormone releases calcium from bone and increases its reabsorption in the kidney, so overactive parathyroid glands raise serum calcium. Hypoparathyroidism causes hypocalcemia. Vitamin D deficiency reduces calcium absorption and lowers calcium. Chronic diarrhea causes calcium loss and is linked to hypocalcemia.
Category: Calcium and Magnesium
Question 10
Which IV solution is hypertonic?
0.9% sodium chloride
3% sodium chloride
✓
0.45% sodium chloride
Lactated Ringer's solution
Correct Answer
3% sodium chloride
A 3% saline solution has a higher osmolality than plasma, so it draws water out of cells and is reserved for problems such as severe hyponatremia and cerebral edema, given with close monitoring. The 0.9% sodium chloride solution is isotonic. The 0.45% sodium chloride solution is hypotonic. Lactated Ringer's solution is isotonic.
Category: IV Solutions
Question 11
Half-strength saline, 0.45% sodium chloride, belongs to which category of IV fluid?
Isotonic
Hypertonic
Hypotonic
✓
Colloid
Correct Answer
Hypotonic
Half-strength saline has a lower osmolality than plasma, so water moves from the vessels into the cells, which makes it useful for intracellular dehydration. Isotonic describes 0.9% sodium chloride and lactated Ringer's solution. Hypertonic describes solutions such as 3% sodium chloride. Colloid describes large-molecule fluids such as albumin, not a salt solution.
Category: IV Solutions
Question 12
Which IV fluid is a colloid that stays in the vascular space and pulls fluid in from the tissues by raising oncotic pressure?
Lactated Ringer's solution
0.9% sodium chloride
0.45% sodium chloride
Albumin
✓
Correct Answer
Albumin
Albumin is a large plasma protein that cannot easily cross capillary walls, so it raises oncotic pressure and draws interstitial fluid into the bloodstream. Lactated Ringer's solution is a crystalloid that crosses capillary walls. The 0.9% sodium chloride solution is also a crystalloid. The 0.45% sodium chloride solution is a hypotonic crystalloid that moves water into cells.
Category: IV Solutions
Question 13
Why must total parenteral nutrition be given through a central venous catheter?
Its high osmolality irritates peripheral veins
✓
It must bypass the liver to be absorbed
It requires rates a peripheral vein cannot accept
Its proteins are destroyed in peripheral blood
Correct Answer
Its high osmolality irritates peripheral veins
The concentrated dextrose and amino acids in total parenteral nutrition make it very hypertonic, which would damage small peripheral veins and cause phlebitis or thrombosis, while a large central vein dilutes it quickly. It must bypass the liver to be absorbed is incorrect because nutrients given IV do not need to bypass the liver. It requires rates a peripheral vein cannot accept is incorrect because the rate is not the reason. Its proteins are destroyed in peripheral blood is incorrect because amino acids are not destroyed in peripheral blood.
Category: TPN and Blood Products
Question 14
Stopping total parenteral nutrition abruptly places the patient at risk for which complication?
Hyperglycemia
Hypoglycemia
✓
Hyperkalemia
Hypernatremia
Correct Answer
Hypoglycemia
The high dextrose load of total parenteral nutrition raises insulin secretion, so a sudden stop can leave excess insulin and cause rebound hypoglycemia. Hyperglycemia is a risk while the infusion is running, not after it stops. Hyperkalemia is not the typical result of stopping the infusion. Hypernatremia is not the expected complication of an abrupt stop.
Category: TPN and Blood Products
Question 15
Fifteen minutes into a transfusion of packed red blood cells, a patient develops chills, low back pain and hypotension. What is the nurse's first action?
Slow the infusion rate
Give acetaminophen and continue
Stop the transfusion
✓
Flush the line with dextrose solution
Correct Answer
Stop the transfusion
Any suspected transfusion reaction requires stopping the transfusion at once, then keeping the vein open with normal saline through new tubing and notifying the provider and blood bank. Slow the infusion rate still lets incompatible blood enter. Give acetaminophen and continue ignores signs that may mean a hemolytic reaction. Flush the line with dextrose solution is wrong because dextrose can hemolyze red cells and pushes more blood product into the patient.
Category: TPN and Blood Products
Question 16
A patient with long-term heavy alcohol use is at risk for Wernicke encephalopathy from deficiency of which vitamin?
Niacin
Riboflavin
Cobalamin
Thiamine
✓
Correct Answer
Thiamine
Thiamine, vitamin B1, is needed for carbohydrate metabolism and nerve function, and deficiency in heavy alcohol use causes Wernicke encephalopathy and Korsakoff psychosis. Niacin deficiency causes pellagra. Riboflavin deficiency causes cheilosis, glossitis and angular stomatitis. Cobalamin, vitamin B12, deficiency causes megaloblastic anemia and nerve damage, not Wernicke encephalopathy.
Category: Vitamins and Minerals
Question 17
Deficiency of which fat-soluble vitamin prolongs clotting time and can cause hemorrhage?
Vitamin K
✓
Vitamin A
Vitamin D
Vitamin E
Correct Answer
Vitamin K
Vitamin K is needed for the liver to make several clotting factors, so a deficiency causes prolonged clotting and bleeding. Vitamin A deficiency causes night blindness and dry eyes. Vitamin D deficiency causes rickets and osteomalacia. Vitamin E deficiency causes neuropathy, ataxia and retinopathy.
Category: Vitamins and Minerals
Question 18
Which drug is a chelating agent used to treat iron overload?
Penicillamine
Deferoxamine
✓
Succimer
Dimercaprol
Correct Answer
Deferoxamine
Deferoxamine binds excess iron into a complex that is excreted, and it is used for iron overload such as from repeated transfusions or hemochromatosis. Penicillamine chelates copper and is used for Wilson disease. Succimer is a chelator for lead poisoning. Dimercaprol is a chelator for lead and other heavy metals, not iron overload.
Category: Vitamins and Minerals
Question 19
A patient taking an oral hormonal contraceptive says she has started St. John's wort for low mood. The nurse should teach about which risk?
Severe hypoglycemia
Increased serum potassium
Reduced contraceptive effectiveness
✓
Loss of bone density
Correct Answer
Reduced contraceptive effectiveness
St. John's wort induces liver enzymes that speed the breakdown of hormonal contraceptives, which can lead to unintended pregnancy, so a backup method or a different plan is needed. Severe hypoglycemia is not an effect of combining St. John's wort with a hormonal contraceptive. Increased serum potassium is not an effect of this herb. Loss of bone density is not a recognized effect of combining it with a contraceptive.
Category: Herbal Supplements
Question 20
Which assessment finding suggests fluid volume excess?
Postural hypotension
Dry mucous membranes
Flat neck veins
Crackles in the lungs
✓
Correct Answer
Crackles in the lungs
In fluid volume excess, extra fluid can back up into the lungs and produce crackles, along with edema, weight gain and high blood pressure. Postural hypotension is a sign of fluid volume deficit. Dry mucous membranes point to dehydration. Flat neck veins suggest low volume, while overload distends the neck veins.
Category: Fluid Balance