While a stable pulmonary contusion may not require any specific therapy, patients
are at high risk of deteriorating respiratory status and therefore require an
expedited evaluation. In addition, the presence of such an injury indicates that
sufficient force was applied to the thorax to warrant thorough evaluation for
additional injuries.
Clinical Assessment
Initial assessment should focus on assessing and stabilizing the airway, breathing,
and circulation, as well as the identification of other associated injuries. Vital sign
abnormalities seen with moderate to severe pulmonary contusions may include
tachypnea and hypoxemia due to shunting within the lung. Patients may complain
of chest pain or shortness of breath, and physical examination may reveal chest
wall bruising and tenderness, with focally diminished breath sounds in the
affected lung. These latter findings are nonspecific, however, and their absence
should not be used to rule out pulmonary contusion without imaging.

FIGURE 115.4 Right lower lobe pulmonary contusion in a patient with associated rib fractures.
Subcutaneous air is also noted in the adjacent soft tissue.

Management


When pulmonary contusion is suspected, CXR is the imaging modality of choice
( Fig. 115.4 ). However, the contusion itself may not be visible on CXR for 4 to 6
hours after the injury, and even then, false-negative rates of up to 33% have been
reported.
Although more sensitive than CXR in detecting pulmonary contusion, a chest
CT scan is usually unnecessary unless a significant injury to the vasculature is
suspected, as management will depend on the clinical condition of the patient and
not the radiographic size of the contusion.
Treatment of pulmonary contusion is supportive. If required, supplemental
oxygen should be administered. If the patient cannot maintain oxygenation

despite passive supplemental oxygen delivery, endotracheal intubation and
mechanical ventilation with positive pressure is the treatment of choice. Fluid
restriction is helpful to avoid exacerbation of pulmonary edema, though must be
balanced against the fluid needs arising from concurrent injuries to other organ
systems and shock in the severely injured child. Patients may require high
inflation pressures to maintain adequate oxygenation, which combined with
injury to the lung leads to high risk of barotrauma and pneumothorax.

Disposition
Due to risk of progression of symptoms and need for increasing respiratory
support, all patients with pulmonary contusion should be admitted for
observation. Given the low sensitivity of CXR for pulmonary contusion, children
with significant chest pain or shortness of breath or an unexplained oxygen
requirement after blunt chest trauma should also be admitted even if chest
imaging is normal. Admission to an intensive care unit is appropriate for patients
with concerning vital signs, a significant oxygen requirement, respiratory distress,
or who otherwise appear to be at high risk of progressing to require mechanical
ventilation.

BLUNT CARDIAC INJURIES
CLINICAL PEARLS AND PITFALLS


Pericardial tamponade from blunt cardiac injury is rare but life
threatening, and requires immediate pericardiocentesis to avoid
circulatory collapse.
Any patient with suspected blunt cardiac injury who is hemodynamically
unstable or has arrhythmias should undergo echocardiography and be
admitted to the intensive care unit.
All patients with suspected blunt cardiac injury need close follow-up.


Current Evidence
Cardiac injury in blunt thoracic trauma is rare. In one study of 1,288 patients with
blunt thoracic trauma, only 60 (4.6%) had a blunt cardiac injury, though other
smaller studies reported higher incidence. Myocardial contusion, ventricular or
atrial rupture, and valvular disruption are considered blunt cardiac injuries.
Myocardial contusion is the most common blunt cardiac injury, far
outnumbering lacerations. Contusions are usually self-limited; rare complications
include arrhythmia, congestive heart failure, and shock. Also rare is commotio
cordis: cardiac arrest following a single, isolated, forceful precordial blow.
Prompt cardiopulmonary resuscitation/defibrillation is the only identifiable factor
associated with a favorable outcome after commotio cordis.
Cardiac rupture is the most common cause of death in blunt cardiac trauma.
The majority of these patients never reach a hospital because they die at the
scene. The right ventricle is the chamber most commonly ruptured because of its
location directly beneath the sternum. Septal rupture can also occur, with the
condition of the patient correlating with the size of the rupture. Patients with
cardiac rupture may present with cardiac tamponade, demonstrating one or all the
components of Beck triad (jugular venous distention, low blood pressure, and
muffled heart tones). Patients with valvular injury may present in congestive heart
failure with a new regurgitation murmur. Coronary artery injury is rare but should
be considered in patients with electrocardiogram (EKG) changes consistent with
ischemia following blunt thoracic trauma.
Pericardial tamponade may also occur when there is injury to the myocardium
and blood accumulates in the pericardial sac. Because of the nondistensible
pericardium, pressure is exerted on the heart. Cardiac output decreases secondary
to a decrease in venous return and ventricular stroke volume. The body will
initially compensate with an increase in the pulse rate and peripheral vascular
resistance. As the pressure within the pericardial sac increases, the systolic blood



pressure will decrease, causing a narrowing of the pulse pressure and subsequent
hypotension and cardiogenic shock.

Clinical Considerations
Clinical Recognition
Blunt cardiac injury occurs more commonly with other associated injuries than in
isolation. Unlike adults, pediatric patients with blunt cardiac injury often have
few presenting signs or symptoms. In one pediatric study, less than half of the
awake patients with blunt cardiac injury complained of chest pain, and external
evidence of thoracic injury was present in only 60% of these patients. In the same
study, cardiac examination was abnormal in less than one-quarter of the patients.
Additional findings that should prompt evaluation for cardiac injury include a
cardiac arrhythmia, a new murmur, or evidence of congestive heart failure (e.g.,
an enlarged liver, a gallop heard on cardiac examination, or rales with
auscultation of the lungs).
Myocardial contusion, ventricular or atrial rupture, and valvular disruption may
produce cardiogenic shock. Circulatory compromise results from a decrease in
cardiac output, usually from impaired myocardial contractility.
Pericardial tamponade, due to air or blood inside the pericardium, will also
decrease cardiac output and cause circulatory collapse. If the patient is
decompensating and a pericardial tamponade is suspected, a pericardiocentesis
should be performed emergently and prior to any further diagnostic evaluation,
with the exception of bedside US when available to confirm the diagnosis and
facilitate the procedure ( Fig. 115.5 ).
Triage
Children with blunt trauma to the sternum or left hemithorax from a high-energy
mechanism should be placed on a cardiac monitor and evaluated immediately.
While the stable patient is unlikely to deteriorate, providers should be prepared to
correct any arrhythmias by both pharmacologic and electrical means. Signs of

cardiogenic shock should be addressed immediately by rapid evaluation and
correction of the cause.
Initial Assessment
Patients with cardiac injuries may complain of chest or sternal pain. Physical
examination may reveal tachycardia, an irregular heart rhythm, a new heart
murmur, signs of congestive heart failure, or in the case of cardiac tamponade,
muffled heart tones. As previously noted, however, many children with blunt