Chest wall injury is a frequent consequence of thoracic trauma and may comprise lesions of the skeleton, the respiratory and cardiovascular system. Presentation, treatment and prognosis largely depend on the severity of the injury.
Clinical presentation varies largely and depends on the extent of CWI and possible damage to intrathoracic organs. It has to be noted that the absence of visible CWI does not rule out life-threatening internal injuries!
Frequent and severe CWI-related pathologies and their symptomatology shall be described exemplarily at this point.
Many CWI patients additionally present symptoms caused by traumatic injury of other areas of the body, e.g., of head, neck or abdomen.
As much anamnestic data as possible should be collected to allow for an estimation of the extent and localization of injuries. Patients need to undergo a complete physical examination. Detection of an intrathoracic hemorrhage does not rule out another, potentially life-threatening intracranial or intraabdominal bleeding. Moreover, partial damage to certain organs may not cause symptoms at the time of initial presentation, but an overlooked esophageal lesion may rupture later and lead to fatal sepsis.
Pulse oximetry, laboratory analysis of blood samples, subsequent evalution of the hemogram (and blood biochemistry), as well as diagnostic imaging are standard procedures applied in CWI patients. Rib fractures are generally visible on plain radiographic images and this also applies to the majority of sternal, vertebral, clavicular or scapular fractures. Moreover, plain radiography may reveal accumulation of air, blood and/or lymph inside the pleural space. The latter may also be visualized sonographically and electrocardiography is the technique of choice to evaluate the heart's condition. Computed tomography scans or magnetic resonance imaging may become necessary to assess the lungs. Of note, computed tomography may be the more sensitive approach to diagnosis of bone fractures, too.
Emergency stabilization measures will have to be carried out simultaneously to the above described diagnostic measures.
Additionally, most patients presenting with moderate to severe CWI should be intubated to maintain patent airways.
Further therapeutic procedures depend on the specific injuries sustained by the individual patient.
Severe complications may develop several hours or even days after the primary survey - respiratory distress syndrome in patients showing signs of lung contusion, for instance - and thus, continued close monitoring is recommended.
Prognosis largely depends on the severity of trauma and ranges from excellent to infaust. The presence of rib fractures has been proposed as a prognostic factor and mortality rates of 1%, 5% and 17% have been observed in patients presenting to the emergency room with up to two rib fractures, more than two rib fractures and flail chest, respectively .
The majority of CWI patients presents with mild lesions, possibly with bruised ribs, but without pulmonary or cardiovascular injury. Their prognosis is very good and sequelae are not to be expected. In contrast, increasing rates of mortality are associated with pneumothorax, tension pneumothorax and thoracic aortic rupture. Any delay of medical attention increments the likelihood of death in these cases, but many patients die within minutes after sustaining CWI. In fact, trauma is the leading cause of death in minors and young adults.
Significant morbidity may result from CWI that comprise nerve injury.
CWI is a common consequence of thoracic trauma. In general, CWI lesions result from the impact of physical forces that exceed the local resistance of those tissues comprising the thoracic wall. Thus, greater forces are usually associated with more severe damage. However, parameters like distribution of forces, type of trauma and previously existing comorbidities also affect the susceptibility of a patient for thoracic lesions.
Most CWI are caused by blunt, non-perforating trauma sustained during falls, sports accidents or motor vehicle accidents, whereby the latter accounts for the vast majority of severe CWI. In rare cases, stab or incisional wounds may be the cause of CWI. Differences observed between patients presenting with blunt thoracic trauma and those who sustained a penetrating lesion clearly illustrate the above described effect of force distribution:
Chest trauma is a very common lesion and patients of any race, both genders and any age may sustain thoracic trauma and present with CWI. However, an adult's thoracic wall is much more resistant than that of a child. Thus, it may absorb significant forces and the adult patient is more likely to sustain fractures of ribs or other bones. In contrast, mechanical forces are more easily transmitted to the intrathoracic organs in pediatric patients. Because CWI-related morbidity and mortality primarily depend on the degree of internal injuries, the outcome may be worse for children .
Pathophysiological events following CWI depend on severity and localization of tissue damage. Common consequences of blunt chest trauma are dyspnea, tachycardia, hypotension and possibly hypovolemic shock. Less often, leakage of esophageal content leads to sepsis.
Respiratory complaints may result from pneumothorax, i.e., of an accumulation of air in the pleural space. This condition causes visceral and parietal pleura to detach from each other. Consequently, the respective lobe of the lung does not follow thoracic expansion during inspiration and atelectasis develops. Fortunately, the pleural space is divided by the mediastinum and patients suffering from an unilateral pneumothorax may still rely on their contralateral lung for oxygen supply.
In case of tension pneumothorax, symptoms aggravate rapidly. Here, the amount of air inside the pleural space continues to increase, possibly due to valve-like effects mediated by CWI or because of positive pressure ventilation. Eventually, the mediastinum may be displaced towards the contralateral hemithorax, thus interfering with lung function on this side of the body.
Pulmonary function impairment may also be provoked by accumulation of blood or lymph within the pleural space. Symptoms associated with hemothorax or chylothorax are similar to those related to pneumothorax, but considerable hemorrhages may also lead to hypovolemic shock and circulatory failure.
Patients diagnosed with presumably minor or moderate CWI and lung contusion may develop severe complications like adult respiratory distress syndrome . This risk is even higher if the patient sustained major CWI, is aged over 65 years, required great amounts of red blood cell transfusions or suffered from hypovolemic shock . Presumably, inflammatory and coagulopathic mechanisms are involved here, but the pathogenesis of respiratory distress syndrome ensuing from blunt chest trauma is incompletely understood.
According to the etiological factors described above, implementation of safety measures in traffic, work, sports activities and leisure time are the most effective form to prevent CWI. Because severe CWI is mostly caused by motor vehicle accidents, the individual risk of such traumatic lesions can be significantly reduced by using seat belts, complying with speed limits, by careful driving in adverse weather conditions and by adhering to the requirement not to drink when driving.
Chest wall injury (CWI) is a rather broad term and virtually any traumatic lesion of the thorax may be considered in this context. The chest wall consists of skin, muscles and bones and protects those organs located in the thoracic cavity. Consequently, the following anatomic structures may be affected in patients presenting with CWI:
Virtually any thoracic trauma may lead to CWI. However, the vast majority of cases is provoked by blunt trauma, usually sustained in motor vehicle accidents. Consequently, most CWI patients present with multiple lesions. Any of the above mentioned tissues may be compromised as well as anatomical structures in other parts of the human body. Thorough anamnesis and physical examination are required to detect all lesions; high morbidity and mortality may result from overlooking certain injuries while focusing on the correct treatment of others .
Chest wall injury (CWI) is a frequent consequence of motor vehicle accidents, but may also result from falls, sports accidents, stab or incisional wounds.
The thoracic wall consists of skin, muscles and bone, and the most frequent types of CWI are rib contusion and rib fracture. Although these may be painful conditions, they are rarely life-threatening and are generally associated with an excellent prognosis.
However, the chest wall protects several vital organs, e.g., lungs, tracheobronchial tree, heart, major blood vessels and esophagus. Severe CWI may interfere with lung function, cause difficulties to breathe, hypotension and hemorrhagic or hypovolemic shock. Such symptoms may be noted even though no major lesion of the thoracic wall is observed. They require immediate medical attention and any delay of treatment may significantly worsen the outcome; the patient may die.
Strict implementation of safety measures in traffic, work, sports activities and leisure time are the most effective form to prevent CWI.