Trauma

Michel B. Aboutanos

John Smith is a 30-year-old man brought in by the emergency medical team (EMT) after a high-speed motor vehicle collision (MVC). He is unconscious and does not respond to verbal or physical stimuli.

What information should be elicited from the prehospital EMTs?

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EMT can provide valuable information regarding (a) mechanism of injury, (b) vital signs, and (c) level of consciousness.

Why is mechanism of injury important?

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Mechanism correlates with the type, severity, and patterns of injury. For MVCs, important information includes use of restraints (seat belt, air bags), steering wheel deformation, direction of impact (front, lateral, rear), extent of damage to the vehicle, rollover of the vehicle, and ejection of the passenger. A patient is 25 times more likely to be injured if thrown from a car than from being belted in place.

Why are prehospital vital signs and level of consciousness important?

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Prehospital vital signs and the level of consciousness are the first steps in the triage of the patient. If vital signs are abnormal at the scene, serious injury should be suspected. Evidence of depressed level of consciousness immediately after the accident indicates either a decreased cerebral oxygenation/perfusion or a possible closed head injury (CHI). Patients with a loss of consciousness (LOC) lasting more than 5 minutes have an increased likelihood of significant head injury even if they are mentating normally on admission (1).

At the scene, Mr. Smith’s blood pressure was 170/90 mm Hg and his heart rate was 110 beats per minute. His Glasgow Coma Scale (GCS) score was 3 (Table 30.1). He lost a significant quantity of blood from a head laceration. He had an obvious deformity of the right thigh.

TABLE 30.1. Glasgow Coma Scale

Indicator	Score
Eye opening
Spontaneous	4
To voice	3
To pain	2
None	1
Verbal response
Oriented	5
Confused	4
Inappropriate words	3
Incomprehensible words	2
None	1
Motor response
Obeys command	6
Purposeful movement (pain)	5
Withdraw (pain)	4
Flexion (pain)	3
Extension (pain)	2
None	1
Total GCS points	3-15
From Michael DB, Wilson RF. Head injuries. In: Wilson RF, Walt AJ, eds. Management of Trauma: Pitfalls and Practice. Baltimore, Md: Williams & Wilkins; 1996:173-202, with permission.

What is the GCS, and what is its significance in evaluation of trauma patients?

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GCS is a simple objective neurologic evaluation that has prognostic value at the time of admission (2). It correlates with the severity of the head injury and its predictive outcome. The components of GCS include motor, verbal, and eye-opening responses. Motor response is most predictive of patient outcome. The normal (and maximum) score is 15; the minimum score is 3. A GCS of 8 or less indicates coma. GCS is also used to classify brain injury. A GCS score of 13 to 15 is designated as mild, 9 to 12 as moderate, and 3 to 8 as severe brain injury (3,4).

What initial monitoring procedures are appropriate for all patients with major trauma?

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Baseline monitoring consists of cardiac rate and rhythm measurement, noninvasive blood pressure measurement, pulse oximetry, and capnography if the patient is intubated. The pulse oximeter measures the oxygen saturation and pulse amplitude via the toes, fingers, or earlobes. Capnography measures the carbon dioxide tension in expired air. A sudden decrease in the tension may suggest mechanical problems in the airway or hypoventilation. Note that the blood pressure is a poor measure of actual tissue perfusion.

What initial therapeutic interventions are appropriate for all patients with major trauma?

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All patients with major trauma receive high-flow oxygen, two large-bore intravenous (IV) cannulas placed in peripheral veins, and resuscitation fluid composed of either lactated Ringer’s (LR) solution or normal saline (NS). LR is preferred over NS because of the high chloride content in NS (154 mEq), which can lead to metabolic acidosis. Patients are also immobilized on a backboard with a cervical collar until injuries to the axial skeleton are ruled out. All obvious fractures or deformities of the extremities are immobilized, usually via a splint.

In the trauma bay, Mr. Smith is connected to cardiac and blood pressure monitors. His initial blood pressure is 120/90 mm Hg, with a heart rate of 120 beats per minute. The arterial oxygen saturation is 98% on 100% oxygen via facemask.

How should the initial assessment of this patient be carried out?

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All trauma patients are assessed in a systematic manner, addressing the most life-threatening injuries first. The primary survey follows an ABCDE sequential protocol and addresses the immediate life-threatening problems. The secondary survey is a head-to-toe evaluation that begins after the primary survey is complete and the resuscitative efforts are established (4). The primary survey consists of the following:

Airway is always addressed first regardless of the type or severity of injuries. A common mistake is to be distracted by a grossly deformed, non-life-threatening, peripheral injury such as a mangled extremity. By definition, a patient who can talk has a patent airway. An unconscious patient is presumed incapable of maintaining his or her airway integrity, and a definitive airway via tracheal intubation must be established. Signs of possible airway obstruction include agitation, stridor, decreased breath sounds, and evidence of increased airway resistance such as respiratory retractions and the use of accessory muscles. Continuous protection of the cervical spine via either a cervical collar or an inline manual stabilization is an essential part of the airway assessment and management.
Breathing is assessed by visual inspection, auscultation, palpation, and percussion. The respiratory rate and depth are determined. Pay attention to the presence of bruising, deformity, paradoxical chest wall motion, chest wall tenderness, crepitus, and diminished breath sounds. In a hemodynamically stable patient with oxygen saturation above 98%, it is reasonable to wait for a chest radiograph to verify the presence of a suspected thoracic injury. In unstable and hypotensive patients with diminished breath sounds and low pulse oximeter readings, early intervention before radiograph is life saving. Conditions that may impair breathing include tension pneumothorax, flail chest, pulmonary contusion, and hemothorax.
Circulation is best assessed by level of consciousness, pulse, and skin color. Hypotension in a multitrauma patient is considered hypovolemic in origin until proven otherwise. Decreased cerebral perfusion secondary to decreased circulating blood volume (BV) leads to a depressed level of consciousness. A person with brisk capillary refill and pink skin is rarely critically hypovolemic. An ashen, gray color characterizes hemorrhage. Full, slow, and regular pulses indicate normovolemia. Rapid, thready pulses usually indicate hypovolemia. Normal pulses can be present with severe hypovolemia in the elderly trauma patient on beta-adrenergic-blocking agents. Absent central pulses usually indicate severe BV depletion with impending death. Hemorrhage control is achieved in the primary survey.
Disability is determined by a baseline neurologic evaluation by means of GCS scoring and pupillary response. Patient’s pupillary size and reaction and the ability to move all extremities is quickly assessed. Drugs and alcohol can affect a patient’s level of consciousness. Until proven otherwise, a head injury is suspected in a multitrauma patient who has a depressed level of consciousness and shows no evidence of hypovolemia or hypoxia.
Exposing the entire patient by removing all clothing is important for complete examination and assessment. This is accomplished with minimal movement of the patient by cutting off all garments. The patient is covered with warm blankets or an external warming device is used (e.g., Bair-Hugger) to prevent hypothermia. IV fluid is warmed before infusion.

Mr. Smith’s arterial oxygen saturation is 98%.

How should his airway be managed?

View Answer

Any patient with a GCS of 8 or less is at risk for respiratory failure and should have a definitive airway, regardless of the adequacy of the pulmonary function. A flaccid tongue may obstruct the airway, and progression of intracranial injury may cause the patient to stop breathing. Definitive airways include orotracheal intubation, nasotracheal intubation, and surgical airway (cricothyroidotomy or tracheostomy).

The preferred intubation method is via the orotracheal route following rapid-sequence anesthesia and inline cervical spine immobilization. Nasotracheal intubation is contraindicated in the apneic patient. Other relative contraindications to nasotracheal intubation include facial fractures, frontal sinus fractures, basilar skull fractures, and cribriform plate fracture. All of these fractures may result in a nasotracheal tube being misguided into the cranial vault. Initially, an oral airway is placed and the patient is ventilated with oxygen-enriched air via a bag-valve-mask unit. Jaw-thrust chin-lift maneuver are used to expose the airway and to avoid hyperextension of the neck. If intubation is unsuccessful, surgical cricothyroidotomy through the cricothyroid membrane is indicated (4).

Mr. Smith is successfully intubated with an endotracheal tube and placed on a ventilator. He suddenly becomes tachycardic (heart rate, 120 beats per minute) and hypotensive (blood pressure, 90/40 mm Hg). His oxygen saturation decreases to 89% with increasing airway pressures. Diminished breath sounds are noted upon repeat auscultation of the right chest.

What are the possible causes of hypotension in a patient in the trauma bay? What is the most likely cause of Mr. Smith’s hypotension?

View Answer

The causes of hypotension in a trauma patient should be divided into hypovolemic and non-hypovolemic causes.

Non-hypovolemic causes of hypotension in a trauma patient

Blunt cardiac injury leading to cardiogenic shock
Spinal cord injury leading to neurogenic shock.

Note that septic shock is rarely a cause of hypotension in the trauma bay.

Hypovolemic causes of hypotension in a trauma patient

Cardiac compressive shock resulting from tension pneumothorax and pericardial tamponade
Hemorrhagic shock caused by external or internal blood loss

It is important to note that head trauma is not a cause of hypotension, except in the terminal events of brainstem herniation. Although blood loss is the most common cause of hypotension in trauma patients, the most likely cause of Mr. Smith’s hypotension is tension pneumothorax.

How is tension pneumothorax diagnosed and treated?

View Answer

Tension pneumothorax results from an injury to the lung that causes a one-way valve air leak into the pleural space upon inspiration. This leads to elevated intrapleural pressures that displace the mediastinum to the opposite side and results in decreased venous return and cardiac output, causing hypotension. It is a life-threatening condition that necessitates immediate action.

There is no time and no need for a chest radiograph to confirm the diagnosis. The diagnosis is made clinically by the unilateral absence of breath sounds and the presence of distended neck veins, tracheal deviation, hyperresonance on percussion, respiratory distress, arterial desaturation, and signs of hypoperfusion such as tachycardia and late cyanosis. The sudden decompensation of Mr. Smith shortly after intubation is the result of a sudden increase in positive pressure leading to the conversion of simple pneumothorax into a tension pneumothorax. Not all of these signs may be present.

If tension pneumothorax is suspected, a large-bore (14- or 16-gauge) IV catheter is inserted into the thorax through the second intercostal space in the midclavicular line to decompress the tension and alleviate the cardiac compromise. After needle decompression, a tube thoracostomy is placed in the lateral fifth intercostal space to treat the remaining simple pneumothorax.

What other thoracic etiology has the same pathophysiology as tension pneumothorax with similar clinical manifestation?

View Answer

Cardiac tamponade has the same pathophysiology as tension pneumothorax except that the increased pressure is in the pericardium, rather than the pleural space. It results from the accumulation of blood in the inelastic pericardial sac leading to increased pressure in the pericardium that exceeds the central venous pressure (CVP) and prevents venous return and cardiac filling. Arterial hypotension, muffled heart sounds, and distended neck veins (Beck’s triad) are the classic manifestation of cardiac tamponade (5,6). Beck’s triad may be falsely positive or falsely negative in up to one third of patients (7).

Other clinical manifestations of cardiac tamponade include pulsus paradoxus (a decrease of systolic blood pressure of more than 10 mm Hg on inspiration) and Kussmaul’s sign (an increase in CVP with inspiration during spontaneous breathing). Any of these findings, however, may also be absent and are rarely detected in acute trauma.

Mr. Smith’s tension pneumothorax was treated with needle thoracentesis followed by tube thoracostomy with rapid normalization of his blood pressure. During assessment of the circulation, brisk arterial bleeding is noted from a deep laceration on his right forearm.

How can this bleeding be controlled?

View Answer

External hemorrhage is controlled with direct manual pressure. Tourniquets only impede venous drainage; therefore, they should not be used except in the field in cases in which a traumatic amputation has occurred. Probing deep wounds with a hemostat is also contraindicated. It is unproductive, time-consuming, and may cause injury to adjacent vital structures such as nerves and veins.

What are the different classes of hemorrhage (Table 30.2)?

TABLE 30.2. Estimated Fluid Blood Losses Based on Patient’s Initial Presentation

	Degree of Hemorrhage
Parameter	Class I	Class II	Class III	Class IV
Blood loss (mL)	Up to 750	750-500	1500-2000	>2000
Blood loss (% blood)	Up to 15%	15%-30%	30%-40%	>40% volume)
Pulse rate (beats/min)	<100	>100	>120	>140
Blood pressure	Normal	Normal	Low	Low
Pulse pressure	Normal	Low	Low	Low or high
Respiratory rate (breaths/min)	14-20	20-30	30-40	>35
Urine output (mL/hr)	>30	20-30	5-15	Negligible
CNS, mental status	Slightly anxious	Mildly anxious	Anxious and confused	Confused and lethargic
Fluid replacement (3:1 rule)	Crystalloid and blood	Crystalloid and blood	Crystalloid	Crystalloid
CNS, central nervous system.
From American College of Surgeons (ACS). Advanced Trauma Life Support Program for Physicians: Instructor Manual. Chicago, Ill: American College of Surgeons; 1993:21, with permission.