A nurse is assessing a client's cranial nerves as part of a neurological examination. Which of the following actions should the nurse take to assess cranial nerve III?

Choice A Reason: This choice is incorrect because laboratory testing of serum potassium upon admission is an appropriate prescription for a client who has acute heart failure following MI. Serum potassium is an electrolyte that affects the cardiac function and rhythm. A normal serum potassium range is 3.5 to 5 mEq/L, and an abnormal level can indicate hypokalemia or hyperkalemia, which can cause arrhythmias, muscle weakness, or paralysis. Therefore, monitoring serum potassium is important to detect and correct any electrolyte imbalance and prevent complications.

Choice B Reason: This choice is incorrect because bumetanide 1 mg IV bolus every 12 hr is an appropriate prescription for a client who has acute heart failure following MI. Bumetanide is a loop diuretic that helps to reduce fluid retention and edema by increasing the urine output and sodium excretion. It may be used for clients who have heart failure, hypertension, or renal impairment, but it can cause hypokalemia, hypotension, or dehydration.

Therefore, administering bumetanide as prescribed can help to improve the cardiac output and reduce the preload and afterload.

Choice C Reason: This choice is correct because 0.9% normal saline IV at 50 mL/hr continuous is an inappropriate prescription for a client who has acute heart failure following MI. 0.9% normal saline is an isotonic solution that contains the same concentration of solutes as blood plasma. It may be used for clients who have fluid loss, dehydration, or shock, but it can worsen fluid overload and pulmonary edema in clients who have acute heart failure. Therefore, clarifying this prescription with the provider is necessary to prevent further deterioration of the client's condition.

Choice D Reason: This choice is incorrect because morphine sulfate 2 mg IV bolus every 2 hr PRN pain is an appropriate prescription for a client who has acute heart failure following MI. Morphine sulfate is an opioid analgesic that helps to relieve pain and anxiety by binding to the opioid receptors in the brain and spinal cord. It may be used for clients who have moderate to severe pain, dyspnea, or chest discomfort, but it can cause respiratory depression, hypotension, or nausea. Therefore, administering morphine sulfate as prescribed can help to reduce the oxygen demand and improve the cardiac function.

Choice A Reason: This choice is incorrect because providing a brightly lit environment may stimulate the client and increase the intracranial pressure. A brightly lit environment is an environment that has a high level of illumination or brightness. It may be used for clients who have depression, seasonal affective disorder, or insomnia, but it does not help to reduce the intracranial pressure.

Choice B Reason: This choice is incorrect because teaching controlled coughing and deep breathing may increase the intrathoracic pressure and increase the intracranial pressure. Controlled coughing and deep breathing are techniques that help to clear the airway and improve lung expansion. They may be used for clients who have respiratory infections, chronic obstructive pulmonary disease, or postoperative complications, but they do not help to reduce the intracranial pressure.

Choice C Reason: This choice is incorrect because encouraging a minimum intake of 2000 mL (67.5 oz) of clear fluids per day may cause fluid overload and increase the intracranial pressure. Fluid overload is a condition in which the body has too much fluid, which can impair the function of the heart, lungs, and kidneys. Therefore, restricting fluid intake and using diuretics may be indicated for clients who have increased intracranial pressure.

Choice D Reason: This choice is correct because elevating the head of the bed 20° may help to improve the venous drainage and decrease the intracranial pressure. As explained above, positioning the client in a semi-Fowler's or high-Fowler's position can facilitate breathing and prevent further complications. However, elevating the head of the bed more than 30° may decrease the cerebral perfusion pressure (CPP), which is the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). A normal CPP range is 70 to 100 mm Hg, and a low CPP (<50 mm Hg) can cause cerebral ischemia, herniation, or death. Therefore, elevating the head of the bed to a moderate angle (20°) may be optimal for clients who have increased ICP.