A patient experiences residual effects following an acute attack of Ménière's disease and receives a new prescription for an antihistamine. Which assessment finding indicates that the medication is effective?

Choice A reason: Potassium 4.7 mEq/L (4.70 mmol/L) is within the normal reference range of 3.5 to 5 mEq/L (3.5 to 5 mmol/L). Potassium is an electrolyte that helps regulate the balance of fluids and acids in the body, as well as the function of nerves and muscles. A high potassium level (hyperkalemia) can cause muscle weakness, irregular heartbeat, and cardiac arrest. A low potassium level (hypokalemia) can cause muscle cramps, fatigue, and arrhythmias.

Choice B reason: Magnesium 2.1 mEq/L (0.86 mmol/L) is within the normal reference range of 1.3 to 2.1 mEq/L (0.65 to 1.05 mmol/L). Magnesium is an electrolyte that helps regulate the activity of enzymes, muscles, and nerves, as well as the balance of calcium and potassium in the body. A high magnesium level (hypermagnesemia) can cause nausea, vomiting, flushing, muscle weakness, and respiratory depression. A low magnesium level (hypomagnesemia) can cause muscle twitching, tremors, seizures, and cardiac arrhythmias.

Choice C reason: Calcium 6.5 mg/dL (1.63 mmol/L) is below the normal reference range of 9 to 10.5 mg/dL (2.3 to 2.6 mmol/L). Calcium is an electrolyte that helps regulate the function of muscles, nerves, bones, and blood clotting. A high calcium level (hypercalcemia) can cause nausea, vomiting, constipation, confusion, kidney stones, and bone pain. A low calcium level (hypocalcemia) can cause muscle spasms, cramps, tingling, numbness, and stridor (a high-pitched sound when breathing). **This is a critical value that should be immediately reported to the healthcare provider**, as it can indicate a serious condition such as acute pancreatitis, sepsis, or massive blood transfusion.

Choice D reason: Sodium 135 mEq/L (135 mmol/L) is slightly below the normal reference range of 136 to 145 mEq/L (136 to 145 mmol/L). Sodium is an electrolyte that helps regulate the balance of fluids and acids in the body, as well as the function of nerves and muscles. A high sodium level (hypernatremia) can cause thirst, dry mouth, confusion, seizures, and coma. A low sodium level (hyponatremia) can cause headache, nausea, vomiting, fatigue, muscle weakness, and confusion.

Choice A reason: Measuring capillary glucose level is not a priority action for a client with a rigid abdomen and rebound tenderness. These signs indicate peritonitis, which is a serious complication of IBD that requires immediate attention. Corticosteroids can increase blood glucose levels, but this is not an urgent concern in this situation.

Choice B reason: Encouraging ambulation in the room is not appropriate for a client with a rigid abdomen and rebound tenderness. These signs indicate peritonitis, which is a serious complication of IBD that requires immediate attention. Ambulation can worsen the pain and inflammation, and increase the risk of bowel perforation.

Choice C reason: Monitoring for bloody diarrheal stools is important for a client with IBD, but not a priority action for a client with a rigid abdomen and rebound tenderness. These signs indicate peritonitis, which is a serious complication of IBD that requires immediate attention. Bloody stools can be a sign of ulceration or bleeding in the bowel, but they are not specific to peritonitis.

Choice D reason: Obtaining vital sign measurements is the priority action for a client with a rigid abdomen and rebound tenderness. These signs indicate peritonitis, which is a serious complication of IBD that requires immediate attention. Vital signs can reveal signs of infection, inflammation, shock, and organ failure, which can guide the appropriate interventions and treatments.