When is mediastinal re-exploration indicated due to postoperative bleeding after CABG?

• A. When mediastinal drain output is brisk and ongoing despite medical management, with hemodynamic instability or continued hemorrhage requiring surgical control.
• B. When patient complains of chest pain.
• C. If there is minimal drainage.
• D. After 24 hours regardless of bleeding.

Answer: (A)

Mediastinal re-exploration after CABG is indicated when there is brisk, ongoing mediastinal bleeding that cannot be controlled with medical management, and the patient develops hemodynamic instability or continued hemorrhage that requires surgical control. The mediastinal drain provides a direct sign of active bleeding; if bleeding remains heavy despite fluids, transfusions, and correction of coagulopathy, returning to the operating room to locate and stop the source is necessary to prevent tamponade and shock. In contrast, chest pain alone, minimal drainage with stable vitals, or following a fixed time point like 24 hours without regard to ongoing bleeding do not by themselves justify re-exploration.