Chest Trauma

CHEST TRAUMA Chest trauma is classified as either blunt or penetrating. Blunt chest trauma results from sudden compression or positive pressure inflicted to the chest wall. Penetrating trauma occurs when a foreign object penetrates the chest wall.

BLUNT TRAUMA Blunt chest trauma is more common, it is often difficult to identify the extent of the damage because the symptoms may be generalized and vague.

PATHOPHYSIOLOGY

Injuries to the chest are often life-threatening and result in one or more of the following pathologic mechanisms: − Hypoxemia from disruption of the airway; injury to the lung Parenchyma, rib cage, and respiratory musculature; massive hemorrhage; collapsed lung; and pneumothorax − Hypovolemia from massive fluid loss from the great vessels, cardiac rupture, or hemothorax − Cardiac failure from cardiac tamponade, cardiac contusion, or Increased intrathoracic pressure These mechanisms frequently result in impaired ventilation and perfusion leading to hypovolemic shock, and death.

ASSESSMENT INITIAL ASSESSMENT OF THORACIC INJURIES: Assessment for airway obstruction, tension pneumothorax, open pneumothorax, massive hemothorax, flail chest, cardiac tamponade. SECONDARY ASSESSMENT: Assessment for simple pneumothorax, hemothorax, pulmonary contusion, traumatic aortic rupture, tracheobronchial disruption, esophageal perforation, traumatic diaphragmatic injury, and penetrating wounds to the mediastinum. PHYSICAL EXAMINATION: Inspection of the airway, neck veins and breathing difficulty. The chest is assessed for symmetric movement, symmetry of breath sounds, open chest wounds, entrance or exit wounds, impaled objects, tracheal shift, distended neck veins, and paradoxical chest wall motion. In addition, chest wall is assessed for bruising, petechiac, lacerations, and burns. The vital signs and skin color are assessed for signs of shock. The thorax is palpated for tenderness and crepitus.

DIAGNOSTIC PROCEDURE 1. Chest X-ray 2. CT Scan 3. Complete blood count 4. Arterial blood gas analysis

5. ECG

MEDICAL MANAGEMENT 1. An airway is immediately establish with oxygen support and, in some cases, intubation and ventilatory support. 2. Re-establishing fluid volume and negative intrapleural pressure and draining intrapleural fluid and blood are essential. 3. Re-establishing chest wall integrity, occluding any opening into the chest, and draining or removing any air or fluid from the thorax to relieve pneumothorax, hemothorax, or cardiac tamponade.

STERNAL AND RIB FRACTURES Sternal fractures are most common in motor vehicle crashes with a direct blow to the via the steering wheel. Most rib fracture are benign and are treated conservatively. Fractures of the first three ribs are rare but can result in high mortality rate because they are associated with laceration of the subclavian artery of the vein. The fifth through ninth ribs are the most common sites of fractures. Fractures of the lower ribs are associated with injury to the spleen and liver, which may be lacerated by fragmented sections of rib.

SIGNS AND SYMPTOMS STERNAL FRACTURE: Anterior chest pain, overlying tenderness, ecchymosis, crepitus, swelling, and possible chest wall deformity. RIB FRACTURE: Severe pain, point tenderness, and muscle spasm over the area of the fracture that are aggravated by coughing, deep breathing and movement.

DIAGNOSTIC PROCEDURES 1. Chest X-ray 2. Rib films of a specific area 3. ECG 4. Continuous pulse oximetry 5. Arterial blood gas analysis

MEDICAL ASSESSMENT 1. Avoiding excessive activity and treating any associated injuries. 2. Surgical fixation is rarely necessary unless fragments are grossly displaced and pose a potential for further injury.

3.

Alternative strategies to relieve the pain include an intercoastal nerve block and ice over the fracture site.

4. A chest binder may be used as supportive treatment to provide stability to the chest wall and may decrease pain. 5. The patient is instructed to apply the binder snugly enough to provide support, but not to impair respiratory excursion.

FLAIL CHEST Flail chest is frequently a complication of blunt chest trauma from a steering wheel injury. It usually occurs when three or more adjacent ribs are fractured at two or more sites, resulting in free-floating rib segments. It may also result as a

PATHOPHYSIOLOGY During inspiration as the chest expands, the detached part of the rib segment moves in a paradoxical manner in that it is pull inward during inspiration, reducing the amount of air that can be drawn into the lungs. On expiration, because the intrathoracic pressure exceeds atmospheric pressure, the flail segment bulges outward, impairing the patients ability to exhale. The mediastinum then shifts back to the affected side. This paradoxical actions results in increased dead space, a reduction in alveolar ventilation and decreased compliance. Retained airway secretions and atelectasis frequently accompany flail chest. Hypotension, inadequate tissue perfusion, and metabolic acidosis often follow as the paradoxical motion of the mediastinum decreases cardiac output.

MEDICAL MANAGEMENT 1. Providing ventilatory support, clearing secretions from the lungs and controlling pain.

2. If only a small segment of the chest is involved, the objectives are to clear the airway through positioning, coughing, deep breathing, and suctioning to aid in the expansion of the lung, and to relieve pain by intercostal nerve blocks, high thoracic epidural blocks. 3. For mild to moderate flail chest injuries, the underlying pulmonary contusion is treated by monitoring fluid intake and appropriate fluid replacement, while at the same time relieving chest pain. 4. When a severe flail chest injury is encountered, endotracheal intubation and mechanical ventilation are required to provide internal pneumatic stabilization of the flail chest and to correct abnormalities in gas exchange. 5. Surgery may be required to more quickly stabilize the flail segment.

PULMONARY CONTUSION Pulmonary contusion is defined as damage to the lung tissues resulting in hemorrhage and localized edema.

PATHOPHYSIOLOGY The primary pathologic defect is an abnormal accumulation of fluid in the interstitial and intraalveolar spaces. It is though that injury to the lung paranohyma and its capillary network results in a leakage of serum protein and plasma. The leaking serum protein exerts an osmotic pressure that enhances loss of fluid from the capillaries. Blood, edema, and cellular debris enter the lung and accumulate in the bronchioles and alveolar surface, where they interfere with gas exchange. As increase in pulmonary vascular resistance and pulmonary artery pressure occurs. The patient has hypoxemia and carbon dioxide retention.

SIGNS AND SYMPTOMS 1. Tachypnea 2. Tacycardia 3. Pleuritic chest pain 4. Hypoxemia 5. Patient has a constant cough but cannot clear secretions.

MEDICAL MANAGEMENT 1. In mild pulmonary, contusion, adequate hydration via IV fluids and oral intake is important to mobilize secretions, fluid intake must be closely monitored to avoid hypervolemia. 2. In moderate pulmonary contusion may require bronchospy to remove secretions; intubation and mechanical ventilation. 3. In severe contusion, who may develop respiratory failure, aggressive treatment with endotracheal intubation and ventilatory support, diuretics, and fluid restriction may be necessary.

PENETRATING TRAUMA: GUNSHOT AND STAB WOUNDS Gunshot and stab wounds are the most common causes of penetrating trauma, stab wounds are generally considered low-velocity trauma because the weapon destroys a small area around the wound. Knives and switchblades cause most stab wounds. Gunshot wounds may be classified as low, medium, or high velocity. The factors that determine the velocity and resulting extent damage include the distance from which the gun was fired, the caliber of the gun and the construction and size of the bullet.

MEDICAL MANAGEMENT 1. Examination for shock and intrathoracic and intra-abdominal injuries is necessary. 2. Shock is treated simultaneously with colloid solutions, crystalloids, or blood, as indicated by the patients condition. 3. A chest tube is inserted into the pleural space in most patients with penetrating wounds of the chest to achieve rapid and continuing reexpansion of the lungs.

DIAGNOSTIC PROCEDURE 1. 2. 3. 4. 5.

Chest X-ray Arterial blood gas analysis ECG CT scans of chest or abdomen Flat plate x-ray of the abdomen

PNEUMOTHORAX Pneumothorax occurs when the parietal or visceral pleura is breached and the pleural space is exposed to positive atmospheric pressure.

TYPES OF PNEUMOTHORAX 1. Simple Pneumothorax – occurs when air enters the pleural space through a breach of either the parietal or visceral pleura, it may occur in an apparently healthy person in the absence of trauma due to rapture of an air-filled bleb, or blister, on the surface of the lung, allowing air from the airways to enter the pleural cavity.

2. Traumatic Pneumothorax – occurs when air escapes from a laceration in the lung itself and enters the pleural space or enters the pleural space through a wound in the chest wall. 3. Tension Pneumothorax – occurs when air is drawn into the pleural space from a lacerated lung or through a small opening or wound in the chest wall.

SIGNS AND SYMPTOMS 1. Pain is usually sudden and may be pleuritic. 2. Minimal respiratory distress with slight chest discomfort. 3. Tachypnea with a small simple or uncomplicated pneumothorax.

MEDICAL MANAGEMENT 1. To evacuate the air or blood from the pleural space a small chest tube is inserted near the second intercostal space because this space is the thinnest part of the chest wall, minimizes the danger of contracting the thoracic nerve and leaves a less visible scar. 2. If a patient also has a hemothorax, a large diameter chest tube is inserted usually in the fourth or fifth intercostal space at the midaxillary line, the tube is directed posteriorly to drain the fluid and air. 3. If an excessive amount of blood enters the chest tube in a relatively short period, an autotransfusion may be needed. 4. In such an emergency, anything may be used that is large enough to fill the chest wound – a towel, a handkerchief or the heel of the hand. 5. The patient with a possible tension pneumothorax should be immediately be given a high concentration of supplemental oxygen to treat the hypoxemia, and pulse oximetry should be used to monitor oxygen saturation.

CARDIAC TAMPONADE Cardiac tamponade is compression of the heart resulting from fluid or blood within the pericardial sac. Usually caused by blunt or penetrating trauma to the chest.

SUBCUTANEOUS EMPHYSEMA Subcutaneous emphysema is of itself usually not a serious complication. The subcutaneous air is spontaneously absorbed if the underlying air leak is treated or stops spontaneously.