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182 Thoracic Trauma

as needed. Most authors recommend cardiac monitoring in an intensive
care unit to identify arrhythmias. Patients with arrhythmias and
obvious thoracic injuries should be monitored with ECG, serum cardiac
enzymes, and echocardiogram as needed.
Myocardial rupture and valve injury
Traumatic rupture of any chamber of the heart usually results in rapid
death. The most common cause of death from thoracic injury is myo-
cardial rupture. The majority of these are due to high-energy impacts
such as motor vehicle collisions or falls from great heights. The major-
ity of these patients die at the scene. The right ventricle is the most
commonly ruptured cardiac chamber. Children with myocardial rupture
present in extremis with pericardial tamponade. Patients with traumatic
atrial or ventricular septal defects may be clinically stable, with the
only finding being that of a new murmur. Early diagnosis and repair is
mandatory for survival from these lethal injuries.
Valvular injuries may occur following severe blunt chest trauma,

Figure 28.2: Chest radiograph of a ruptured left hemidiaphragm, with but these are rare. The atrioventricular valves are most susceptible
displacement of the heart and mediastinum to the right. to injury, and the damage often occurs to the valve apparatus (i.e.,
annulus, ruptured chorda tendinae, or papillary muscle). These injuries
in clinically stable patients may be repaired electively.
the diaphragm (as a blow-out), rupture in children seems to take place
more often along the periphery of the diaphragm (probably due to the Pericardial tamponade
increased elasticity of the chest wall). The accumulation of blood within the pericardial sac from blunt or
Diagnosis is made on an erect radiograph, which typically shows penetrating trauma can produce pericardial tamponade. Although a
the nasogastric tube in the stomach above the diaphragm (Figure 28.2). range of clinical signs may be seen, the most common presentations are
However, herniation can involve nearly any intraabdominal organ, and tachycardia; peripheral vasoconstriction; and the Beck’s triad of jugular
the appearance of the stomach below the diaphragm does not exclude venous distention, persistent hypotension unresponsive to aggressive
a diaphragmatic rupture. fluid resuscitation, and muffled heart sounds. In resource-poor environ-
Penetrating injuries in the lower half of the chest as well as the ments, the tools needed to establish an accurate diagnosis, such as an
upper part of the abdomen can involve the diaphragm. In these cases, ECG or focused abdominal sonography for trauma (FAST), often are
herniation will rarely occur in the acute phase, but an undiagnosed hole not available. Although pericardiocentesis can be life saving, it should
in the diaphragm can lead to complications on the long term. Repair not be done by those without the proper training and skill.
should be performed via a laparotomy, during which the state of the Resuscitative Thoracotomy
intraabdominal organs also can be assessed.
Immediate resuscitative thoracotomy may be life saving when per-
Heart and Pericardium formed in children with penetrating trauma who arrive pulseless, but
Blunt chest trauma can produce several types of cardiac injuries, includ- with myocardial electrical activity. However, even when myocardial
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ing contusions, concussions, and frank rupture of the myocardium, a function is restored, survival ultimately requires additional operative
valve, a septum, and—very rarely—a coronary artery. Pericardial tears procedures and intensive care, which are generally not available in
leading to herniation of the heart often lead to diminished cardiac func- resource-poor African subregions. Under these conditions, resuscita-
tion and a low output state. Occult structural cardiac injuries (i.e., atrial tive thoracotomy becomes a futile exercise. In any case, such heroic
or ventricular septal defects, valvular insufficiency, and ventricular measures are rarely effective following blunt trauma, which is far more
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aneurysm formation) may also occur and present without physiologic common than penetrating trauma in children.
signs of injury. Often, these injuries are identified only after a new Pitfalls in the Management of Paediatric
murmur is noted or a change in the electrocardiogram (ECG) occurs.
Echocardiography, when available, can assist to confirm the diagnosis. Thoracic Trauma
Myocardial contusion Several pitfalls exist in the management of paediatric thoracic trauma,
The most common type of blunt cardiac injury is the myocardial contu- as outlined here.
sion. Unlike myocardial concussions, myocardial contusions produce • Underestimating the degree of chest injury at the initial survey
focal damage to the heart that can be demonstrated histologically. because of little external evidence and performing only a supine
Patients with myocardial contusions often have an associated chest chest radiograph.
wall injury. Many tests have been proposed to diagnose a contusion • Administration of excess intravenous fluid during resuscitation,
(e.g., echocardiography, electrocardiography, enzyme determinations, aggravating pulmonary contusion and oedema.
and nuclear imaging), but still no definitive diagnostic test exists. A
12-lead ECG is the simplest test and may show reversible changes in • Inadequate analgesia and chest physiotherapy, promoting retention
the ST and T waves. Symptomatic myocardial contusions are diagnosed of secretions, which leads to pulmonary infection.
by echocardiography based on finding a reduced ejection fraction, • Iatrogenic damage through emergency (and faulty) procedures such
localised systolic wall motion abnormalities, and an area of increased as endotracheal intubation, chest drain insertion, and central line
end-diastolic wall thickness and echogenicity. insertion.
Myocardial contusions may be silent and asymptomatic, can present
with cardiovascular collapse from reduced cardiac output, or cause Prevention of Thoracic Trauma
arrhythmias that may be life threatening. The top three causes of child mortality from unintentional injury are
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The treatment of myocardial contusions remains supportive, with road traffic collisions (32%), drowning (17%), and burns (9%). All of
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12- to 24-hour electrocardiographic monitoring and inotropic support these causes are highly preventable. Factors that influence injuries are