Definitive management of acute cardiac tamponade secondary to blunt trauma

Abstract

Blunt cardiac injuries are a leading cause of fatalities following motor-vehicle accidents. Injury to the heart is involved in 20% of road traffic deaths. Structural cardiac injuries (i.e. chamber rupture or perforation) carry a high mortality rate and patients rarely survive long enough to reach hospital. Chamber rupture is present at autopsy in 36-65% of death from blunt cardiac trauma, whereas in clinical series it is present in 0.3-0.9% of cases and is an uncommon clinical finding. Patients with large ruptures or perforations usually die at the scene or in transit--the rupture of a cardiac cavity, coronary artery or intrapericardial portion of a major vein or artery is usually instantly fatal because of acute tamponade. The small, rare, remaining group of patients who survive to hospital presentation usually have tears in a cavity under low pressure and prompt diagnosis and surgery can now lead to a survival rate of 70-80% in experienced trauma centres. As regional trauma systems evolve, patients with severe, but potentially survivable cardiac injury are surviving to ED. Two distinct syndromes are apparent--haemorrhagic shock and cardiac tamponade. Any patient with severe chest trauma, hypotension disproportionate to estimated loss of blood or with an inadequate response to fluid administration should be suspected of having a cardiac cause of shock. For patients with severe hypotension or in extremis, the treatment of choice is resuscitative thoracotomy with pericardotomy. Closed chest cardiopulmonary resuscitation is ineffective in these circumstances. Blunt traumatic cardiac injury presenting with shock is associated with a poor prognosis. The majority of survivors of blunt or penetrating cardiac injury present to the ED/trauma centre with vital signs. The main pathophysiologic determinant for most survivors is acute pericardial tamponade. The presence of normal clinical signs or normal ECG studies does not exclude tamponade. In recent years the widespread availability and use of ultrasound for the initial assessment of severely injured patients has facilitated the early diagnosis of cardiac tamponade and associated cardiac injuries. Two cases of survival from blunt traumatic cardiac trauma are described in the present paper to demonstrate survivability in the context of rapid assessment and intervention.