Final answer:
Metformin is held before surgery or procedures using contrast to prevent the accumulation of the drug due to potential decreased kidney function, which could lead to lactic acidosis. It is typically stopped 48 hours prior to the procedure and resumed once kidney function is verified post-procedure. Prophylactic antibiotics are also given before surgery to nearly halve the risk of hospital-acquired infections.
Step-by-step explanation:
The reason metformin must be held before surgery or imaging procedures that use contrast is related to the risk of a rare but serious condition called lactic acidosis. When a patient undergoes a procedure that involves contrast dye, there is a potential for decreased kidney function. Metformin is excreted by the kidneys, and if kidney function is compromised, metformin can build up in the body and increase the risk of lactic acidosis. This risk is particularly concerning in the context of surgery or procedures where contrast is used because the stress on the body can further affect kidney function.
It is standard practice to stop metformin before certain surgical procedures or imaging tests to prevent this potential complication. Typically, metformin is held for about 48 hours before a procedure and may be held after the procedure until kidney function is confirmed to be normal. This precaution helps to ensure patient safety by minimizing the risk of drug-induced complications during and after surgery. The temporary discontinuation of metformin must be managed alongside other glucose-controlling measures to maintain blood sugar levels.
Additionally, prophylactic antibiotics are administered typically 60 minutes before incision to significantly reduce the risk of hospital-acquired infections (HAIs), almost cutting the risk in half. This is a separate precaution that is taken to ensure a sterile environment and to prevent postoperative complications. While insulin may be used to manage glucose levels, it functions distinctly from metformin by facilitating transport and storage of glucose.