A nurse is reviewing the medication list of a client who has diabetes mellitus and is scheduled for surgery. The client takes metformin orally twice a day. Which of the following actions should the nurse take?

A) Correct. The nurse should check the client's apical pulse for one full minute before giving digoxin as this drug can cause bradycardia and heart block. The nurse should withhold the medication and notify the provider if the pulse is less than 60 beats/min or irregular.

B) Incorrect. The nurse should check the client's serum potassium level periodically while taking digoxin as this drug can cause hypokalemia or hyperkalemia, which can affect its therapeutic effect and toxicity. However, this is not a priority action before giving each dose of digoxin.

C) Incorrect. The nurse should check the client's blood pressure in both arms periodically while taking digoxin as this drug can cause hypotension or hypertension, which can affect its efficacy and safety. However, this is not a priority action before giving each dose of digoxin.

D) Incorrect. The nurse should check the client's serum digoxin level periodically while taking digoxin as this drug has a narrow therapeutic range and can cause toxicity if the level is above 2 ng/mL. However, this is not a priority action before giving each dose of digoxin.

B) Correct. The nurse should instruct the client to hold their metformin for 48 hours before and after surgery as this drug can increase the risk of lactic acidosis in clients who are undergoing procedures that involve contrast media or who have impaired renal function due to dehydration or hypotension.

A) Incorrect. The nurse should not instruct the client to take their morning dose of metformin with a sip of water on the day of surgery as this can cause hypoglycemia during anesthesia or interfere with contrast media if used during surgery.

C) Incorrect. The nurse should not instruct the client to resume their metformin as soon as they can tolerate oral intake after surgery as this can cause lactic acidosis if the client's renal function is not fully restored or if they receive contrast media during surgery or postoperatively.

D) Incorrect. The nurse should not instruct the client to switch to insulin injections until they recover from surgery as this can cause hyperglycemia or hypoglycemia depending on the type and dose of insulin used and the client's nutritional status and blood glucose levels.