A postoperative patient who had surgery for a perforated gastric ulcer has been receiving nasogastric suction for 3 days. The patient now has a serum sodium level of 127 mEq/L (127 mmol/L). Which prescribed therapy should the nurse question?

Choice A reason: This statement is false. A serum potassium level of 5.6 mEq/L is not a common side effect of furosemide. This value indicates hyperkalemia, or high blood potassium level, which can cause cardiac arrhythmias and muscle weakness. Furosemide is a loop diuretic that causes potassium loss, not retention.

Choice B reason: This statement is false. A serum sodium level of 142 mEq/L is not a common side effect of furosemide. This value is within the normal range of 135-145 mEq/L and does not indicate any problem with sodium balance. Furosemide is a loop diuretic that causes sodium loss, but it is usually compensated by the renin-angiotensin-aldosterone system.

Choice C reason: This statement is false. A serum sodium level of 138 mEq/L is not a common side effect of furosemide. This value is within the normal range of 135-145 mEq/L and does not indicate any problem with sodium balance. Furosemide is a loop diuretic that causes sodium loss, but it is usually compensated by the renin-angiotensin-aldosterone system.

Choice D reason: This statement is true. A serum potassium level of 2.8 mEq/L is a common side effect of furosemide. This value indicates hypokalemia, or low blood potassium level, which can cause cardiac arrhythmias, muscle weakness, and metabolic alkalosis. Furosemide is a loop diuretic that inhibits the reabsorption of sodium and potassium in the ascending loop of Henle, leading to potassium loss in the urine.

Choice A reason: 1:00 PM is not the correct time to monitor the patient for signs of hypoglycemia related to the insulin's peak action. Humalog is a rapid acting insulin that starts to work within 15 minutes, peaks in about an hour, and lasts for 2 to 4 hours. Therefore, the peak action of Humalog given at 8:00 AM would be around 9:00 AM, not 1:00 PM.

Choice B reason: 8:00 PM is also not the correct time to monitor the patient for signs of hypoglycemia related to the insulin's peak action. As explained in choice A, Humalog peaks in about an hour and lasts for 2 to 4 hours. Therefore, the effect of Humalog given at 8:00 AM would wear off by 12:00 PM, not 8:00 PM.

Choice C reason: There is no peak action for this insulin is an incorrect statement. Humalog does have a peak action, as described in choice A. The peak action of an insulin is the time when the insulin is most effective in lowering the blood glucose level. The peak action of an insulin can vary depending on the type, dose, and individual response of the patient.

Choice D reason: 9:00 AM is the correct time to monitor the patient for signs of hypoglycemia related to the insulin's peak action. Hypoglycemia is a condition of low blood glucose level, which can cause symptoms such as sweating, shaking, hunger, headache, dizziness, confusion, and loss of consciousness. Hypoglycemia can occur when the insulin dose is too high, the food intake is too low, or the physical activity is too high. The nurse should monitor the patient for signs of hypoglycemia around the peak action of the insulin, as this is when the blood glucose level is most likely to drop. The nurse should also teach the patient how to prevent, recognize, and treat hypoglycemia.