What type of surgical procedure was the 75-year-old woman undergoing when tranexamic acid is administered?

The administration of tranexamic acid is particularly relevant in the context of surgeries with a high risk of bleeding, especially in patients undergoing cardiac procedures. In this case, the combination of mitral valve repair and aortic valve replacement is indeed a more complex surgery, often associated with significant blood loss, necessitating careful management of bleeding.

Tranexamic acid is an antifibrinolytic agent that helps reduce bleeding by inhibiting the breakdown of fibrin in blood clots, making it especially useful in procedures involving multiple valve repairs or replacements. The combined nature of the surgical procedures indicates a higher complexity and potential for hemostatic complications compared to isolated procedures.

In contrast, while all the other surgical procedures mentioned could potentially use tranexamic acid, the combination of mitral valve repair and aortic valve replacement represents a scenario where the risk of significant bleeding is particularly elevated, justifying the use of this medication to optimize outcomes.