Name common causes of postoperative chest tube drainage requiring re-exploration.

• A. Mediastinal or intraoperative bleeding, incomplete hemostasis, injury to great vessels, or coagulopathy
• B. Postoperative fever
• C. Nausea and vomiting
• D. Arrhythmias only

Answer: (A)

After cardiac surgery, chest tube drainage that leads to re-exploration almost always reflects significant bleeding sources from the operation or a tendency to bleed. The best answer points to mediastinal or intraoperative bleeding that wasn’t fully controlled, incomplete hemostasis along the sternotomy or graft sites, injury to great vessels during cannulation or dissection, and coagulopathy that worsens bleeding or prevents clot formation. These factors create ongoing hemorrhage visible as high or continuous chest tube output and can cause hemodynamic instability, prompting urgent return to the OR to evacuate clots and achieve definitive hemostasis.

Postoperative fever, nausea and vomiting, or arrhythmias alone do not directly cause enough chest tube drainage to require re-exploration. They are common postoperative issues but not the primary surgical bleeding scenarios that drive re-exploration.