Traumatic brain injury

The Glasgow Coma Scale (GCS) is the traditional means of quickly assessing neurologic function when traumatic brain injury is suspected. The GCS is a coarse screening tool that encompasses eye-opening, verbal, and motor responses ( Table 77-2 ). GCS scores range from 3–15. A score of 3 represents a completely nonresponsive patient with a predicted mortality rate of 65%–90%. A GCS score of 13 predicts mortality rates of <10%. Although the GCS score on admission correlates with survival outcomes, more importantly, the specific details of neurologic function should be accurately noted. Often, loss of consciousness is reported from the field, yet when patients arrive at the hospital, they are awake with normal GCS scores. This finding does not exclude neurologic injury; the “lucid interval” of a potentially fatal epidural hematoma follows precisely this pattern. The presence of seizures has a high correlation with positive findings on CT scans of the brain (80%). Headache, amnesia, and vomiting are each associated with structural brain injury in 40%–45% of cases. Brief loss of consciousness predicts positive CT scan findings in only 29% of cases.

Spinal injury

In a patient who has sustained blunt injury, the default approach is to presume that the spinal column is unstable until proved otherwise. Consequently, neck immobilization must be maintained, and logrolling must be carefully performed when examining or transferring the patient. In a patient who is hemodynamically unstable, clearance of the cervical spine is not a priority, even if the airway must be managed. For the cervical spine to be clinically cleared, the patient must be able to do the following:

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  Focus fully on the examination (no distractions)

  
  
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  Localize and discriminate mildly noxious stimuli

  
  
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  Move and feel all extremities

For this patient, full spinal immobilization would be maintained until detailed imaging and clinical clearance could be possible. Imaging would be obtained nonurgently. Provided that no radiographic abnormalities were noted, a clinical evaluation for clearance could be performed at a later time.

Long bone fractures

Obvious deformities should be noted and the involved limb maintained splinted so as to minimize fat embolism syndrome and disruption of formed blood clots. For each closed fracture, 1–3 units of blood loss should be anticipated.

Pelvic fractures

If a pelvic fracture is suspected, the pelvis must be immobilized as soon as possible with a tied sheet or binder. A rich venous plexus resides on the anterior surface of the pelvis. Pelvic fractures disrupt these veins, and neither embolization nor suturing can be performed. A tremendous amount of bleeding can occur, eventually filling the retroperitoneum and providing venous tamponade. Until that occurs, a blood loss of several liters should be anticipated.

Rib fractures

Even small rib fractures can be excruciatingly painful leading to respiratory splinting, hypoventilation, and hypoxia. Larger, multiple (flail chest), and comminuted rib fractures are associated with hemothorax or pneumothorax and are markers for significant pulmonary contusion.

Hemothorax or pneumothorax

If hemothorax or pneumothorax is suspected from the physical examination (i.e., absent breath sounds, tracheal shift, distended jugular veins, hypotension, or hypoxia), chest tube insertion should not be delayed for a chest radiograph.

Pulmonary contusion

Pulmonary contusion may not manifest initially. However, hypoxia, decreased lung compliance, and infiltrates develop within hours. Care is supportive.

Diaphragmatic rupture

Diaphragmatic rupture can occur when high pressure develops acutely in the abdomen. Depending on the object hit and the patient’s position at impact, abdominal contents may eviscerate into the thoracic cavity.

Blunt cardiac injury

Most cases of blunt cardiac injury manifest as impaired ventricular function. Death, when it occurs, is usually due to malignant arrhythmias. Consequently, when blunt cardiac injury is suspected, the patient must have continuous electrocardiogram monitoring. If no arrhythmias are noted in 24 hours, monitoring may be discontinued. In extreme cases, blunt cardiac injury can lead to cardiac rupture, valvular dysfunction, or coronary occlusion.

Aortic injury

During rapid deceleration, the aorta can be avulsed at the ligamentum arteriosum, where the arch is tethered. Aortic rupture is catastrophic and usually results in death before arrival at the hospital. However, aortic tears and dissections can be occult initially and manifest later with hypotension, stroke, aortic valve insufficiency, or myocardial infarction.

Bowel injury

Bowel injury is generally less common following blunt trauma compared with penetrating trauma. When bowel injury occurs after blunt force trauma, it is often associated with vascular injury and ischemia. A late mechanism of bowel and renal injury is abdominal compartment syndrome.

Solid organ injuries

The liver and spleen are the most commonly injured intraperitoneal abdominal organs from blunt trauma. If the patient is hemodynamically stable, nonoperative management may be appropriate in select cases of hepatic and splenic trauma. The kidney is occasionally injured following blunt trauma, and the pancreas is injured less frequently. Both the kidneys and the pancreas reside in the retroperitoneal space.

Shock

A reliable marker for a shock state does not exist. In this patient, hemorrhagic shock is presumed because he has hypotension, tachycardia, altered mental status, and distended abdomen. Lactic acidosis develops as a consequence of hypoperfusion. The degree of metabolic acidosis present on admission correlates with mortality.

Hypothermia

Although the patient was in the field for only 20 minutes, he is shivering. The largest contributor to hypothermia is depressed metabolism that accompanies shock. Additional factors contributing to this patient’s hypothermia include exposure to cold temperatures in the field and in the emergency department when fully disrobed and treatment with room temperature IV fluids.

Coagulopathy

The development of coagulopathy is inexorably linked to the patient’s shock, acidosis, and hypothermia. Patients surviving massive blunt trauma arrive at the hospital with a measurable coagulopathy. This coagulopathy is exacerbated further by consumption and dilution by EMS-administered crystalloid solutions of coagulation factors.

Airway maintenance with cervical spine protection

The initial focus is on airway patency. The ability to phonate and converse is usually sufficient proof of an adequate airway. Many of the criteria for immediate tracheal intubation of trauma patients are similar to criteria typically used for other patients (i.e., hypoxemia, hypoventilation, lack of airway reflexes). The presence of oropharyngeal bleeding or stridor is always cause for concern. Other times, the threshold for tracheal intubation of the trauma patient is lowered. For example, if victims are intoxicated, combative, and actively bleeding, they may need tracheal intubation expeditiously despite the presence of adequate cough, gag and swallow reflexes. By default and until proved otherwise, trauma patients are presumed to have a full stomach and cervical spine instability.

Cervical spine protection begins with immobilization in the field using minimally padded extrication collars made of stiff, thin plastic. Cervical spine clearance is usually deferred until after the primary and secondary surveys have been completed. If the airway needs to be secured, the risk of exacerbating a cervical spine injury is negligible provided that adequate precautions are maintained. These precautions include manual in-line stabilization, minimizing neck extension, and management of the airway by an experienced laryngoscopist.

Extrication cervical spine collars and backboards can quickly lead to decubitus ulcer formation, sometimes in <1 hour. As soon as possible, backboards should be removed, and the extrication collar should be changed to one that is padded and designed for longer term use.

Breathing and ventilation

In a spontaneously breathing patient, auscultation of both lung fields is performed to establish the presence of bilateral breath sounds. In a hypotensive tracheally intubated patient, unilateral right-sided breath sounds (later discovered to be from a right main-stem intubation) occasionally lead to the avoidable placement of an emergent left thoracostomy tube for suspected pneumothorax.

Trauma patients generally arrive at the emergency department on supplemental oxygen. If the only monitor of ventilatory adequacy is oxygen saturation, significant hypoventilation could be missed because oxygen saturation can be maintained with a fraction of inspired oxygen (FiO ₂ ) of 100% oxygen despite very low tidal volumes.

Circulation with hemorrhage control

Blood pressure is the initial vital sign used to establish adequacy of circulation. However, in severe hypovolemia, especially in young, healthy victims, compensatory mechanisms can maintain blood pressure until precipitous circulatory collapse occurs. Active hemorrhage is controlled with applied pressure or tourniquets. If it has not been done so already, large-bore peripheral IV access is established. Fluids administered from this point forward should be warmed.

Disability (neurologic evaluation)

This stage of the primary survey encompasses a quick assessment of both central and neuraxial integrity. The GCS score ( Table 77-2 ) is correlated with survival in traumatic brain injury and is commonly used as a shorthand method of communicating mental status. Patients with a GCS score <8 are unlikely to be able to protect their airway and may require tracheal intubation.

Beyond the GCS score, it is crucial to assess and document specific findings of an immediate baseline neurologic examination, including cranial nerve function, pupillary size, movement of extremities, lateralizing signs, sensation (if the patient is able to cooperate), and higher functions. Any deterioration from baseline requires immediate investigation.

Exposure and environmental control

The patient should be fully undressed (exposure) while maintaining cervical spine immobilization and kept warm with blankets (environmental control); this facilitates the head-to-toe examination, which is part of the secondary survey.