Registered Nurse (RN) Endocrine Licensure Exam

In preparation for surgery, when should Metformin be held?

1. 48 hours prior to surgery.

2. 24 hours prior to surgery.

3. Immediately before surgery.

4. It should never be held.

The correct answer is: 48 hours prior to surgery.

Metformin should be held 48 hours prior to surgery due to the potential risk of lactic acidosis, especially in patients with renal impairment or those undergoing procedures that may impact kidney function. Metformin is primarily excreted by the kidneys, and during surgery, factors such as anesthesia, altered fluid status, and changes in blood pressure can compromise renal function. Holding Metformin well in advance allows for adequate time to monitor kidney function and avoid any complications associated with the medication. In contrast, holding Metformin just 24 hours or immediately before surgery may not provide sufficient time for the body to clear the drug, thus increasing the risk of developing lactic acidosis. The notion that Metformin should never be held ignores the critical safety considerations involved in surgical procedures, particularly when patient conditions may fluctuate.