Correct Answer: B

Rationale: Tetany is the most characteristic manifestation of hypocalcemia and hypomagnesemia. Sensations of tingling may occur in the tips of the fingers, around the mouth, and less commonly in the feet. Taking a normal blood pressure could illicit a carpal spasm if it creates slight ischemia of the ulnar nerve.

Correct Answer: D

Rationale: Bananas are high in potassium. Apples, carrots, and asparagus are not high in potassium.

Correct Answer: C

Rationale: Furosemide is a potassium-wasting diuretic. A low potassium level may cause weakness and palpitations. Telling the patient to rest more often won't help the patient if she's hypokalemic. Digoxin isn't causing the patient's symptoms, so she doesn't need to stop taking it. The patient should probably avoid caffeine, but this wouldn't resolve potassium depletion.

Correct Answer: D

Rationale: Renin is released by the juxtaglomerular cells of the kidneys in response to decreased renal perfusion. Angiotensin-converting enzyme converts angiotensin I to angiotensin II. Angiotensin II, with its vasoconstrictor properties, increases arterial perfusion pressure and stimulates thirst. As the sympathetic nervous system is stimulated, aldosterone is released in response to an increased release of renin, which decreases urine production. Based on the nursing assessment and mechanism of injury, this is the most likely cause of the lower urine output.

Correct Answer: B

Rationale: An air emboli is more often associated with central vein access. Usually only relatively large volumes of air administered rapidly are dangerous. It is more often a concern when air enters a central venous access line.