**2.3 Traumatic**

For trauma-induced pericardial effusion, most surgeons would suggest surgical exploration rather than conservative approach. This is because in the acute setting, most patients are unstable with multiple injuries, and they would require urgent surgery to exclude ongoing bleeding into the pericardial cavity. The resultant tamponade is rapidly fatal unless drainage and hemostasis are quickly established. Any blunt or penetrating injury in the cardiac box (bounded by both nipple lines laterally, the clavicles superiorly and the costal margin inferiorly) must be viewed with a high index of suspicion that there is myocardial injury. Opinion is divided between the left anterior thoracotomy incision and the sternotomy incision. The sternotomy approach is safer as it allows rapid access to the ascending aorta and vena cava if cardiopulmonary bypass is urgently required for repair of a heart chamber perforation. Left anterior thoracotomy avoids a bigger incision and the risk of sternal wound infection; however, if cardiopulmonary bypass is required, it may still require conversion to a sternotomy for better control. Another reason why traumatic pericardial effusion cannot be usually treated conservatively is the fact that most commonly the right ventricle is involved and this usually requires surgical repair.
