The nurse is preparing an older client for a magnetic resonance imaging (MRI) with contrast. Which laboratory value should the nurse report to the healthcare provider before the scan is performed?

Reference Range:
Glycosylated hemoglobin (A1C) [4% to 5.9%]
Creatinine [0.5 to 1.1 mg/dL (44 to 97 umol/L)]
Glucose [74 to 106 mg/dL (4.1 to 5.9 mmol/L)]
Blood Urea Nitrogen (BUN) [10 to 20 mg/dL (3.6 to 7.1 mmol/L)]

Choice A reason: Lifting and clearing drainage from the chest tube is not necessary, as the water level fluctuations indicate that the chest tube is functioning properly and allowing air and fluid to escape from the pleural space.

Choice B reason: Inspecting the tube insertion site for leaking is not indicated, as there is no evidence of air leak in the water-seal chamber. An air leak would cause continuous or intermittent bubbling in the water-seal chamber.

Choice C reason: Continuing to monitor the drainage system is the best action for the nurse to implement, as the water level fluctuations are normal and expected in a water-seal drainage system. The water level should rise during inspiration and fall during expiration, reflecting the changes in intrathoracic pressure.

Choice D reason: Auscultating lungs for unequal breath sounds is not relevant, as it does not address the question of what to do with the water level fluctuations. Unequal breath sounds may indicate a pneumothorax or atelectasis, which are complications of chest trauma or chest tube insertion.

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.