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Heavy organs include fluid -filled loops of bowel, the blood -filled thoracic aorta, and mobile parenchymal organs such as the liver and spleen. The momentum of these organs is maintained after the motion of the victim has been stopped.

Damage occurs because force is exerted on the tethered portion of the viscus by the mobile portion of the viscus, which continues to move. For example:

The aortic arch shears at the fixed ligamentum arteriosus.

The small bowel tends to pull away from its mesenteric attachments, creating a “bucket - handle” tear with massive bleeding from mesenteric vessels.

Avulsion of the spleen at its hilus or peritoneal reflection is common.

Renal pedicle avulsion

Missile injuries

Low-velocity missile injuries include most civilian gunshot wounds.

Missiles fired from handguns have a velocity in the range of 600–1,100 ft/second.

Wounds from this type of missile are generally restricted to the path and the residual cavity created by the missile as it penetrates tissues, such as blood vessels and organs. However, secondary injuries can occur.

External articles (buttons or keys) may be driven into the wound by the missile.

Bone fragments, produced when the missile strikes a large bone, can also cause secondary injury.

High-velocity missile injuries can be recognized by a small entrance wound and a large exit wound with severe underlying tissue damage. These wounds may cause damage remote from the apparent tract of the missile as a large temporary cavity is created when the tissue recoils from the path of the bullet.

Shotgun injuries

Close-range shotgun injuries can be devastating. Large soft tissue defects are created with widespread damage. In addition, these wounds often introduce nonopaque foreign material, which originates from the wadding used in the manufacture of the shotgun shell.

Long -range shotgun injuries consist of multiple low -velocity pellet injuries. These cause widespread penetration but are generally not severe unless the missile happens to strike a major blood vessel or organ.

TABLE 21-2 Revised Trauma Score

RTS = 0.9368 GCSc + 0.7326 SBPc + 0.2908 RRc, where the subscript c refers to coded value.

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The shocking, “knock-down” effect of a missile depends on factors that influence the energy transferred to the victim by the impact.

Striking energy is directly proportional to the weight of a missile and the square of its velocity.

Missiles that completely penetrate the victim expend much of their energy on the objects beyond the victim. Maximum energy transfer results from the missile that remains in the victim.

Penetration is diminished when a bullet is used that expands or tumbles after impact.

Treatment. All missile tracts should be debrided, but missiles need not be removed unless they cause symptoms or are in proximity to a vital structure where body movements or tissue erosion could cause further injury.

C Management of trauma victims

The initial assessment of the patient's state, performed when the patient arrives in the emergency room, determines the extent of injury and the need for immediate care. Obviously, inebriated patients often have serious injuries, but the presence of alcohol does not diminish the trauma team's responsibility to diagnose all injuries properly. The initial assessment can be performed by an experienced physician within seconds.

Airway

Assessment

The mouth and upper airway should be inspected for obstruction from foreign bodies (teeth, blood) or maxillofacial instability.

Stridor or hoarseness implies laryngeal obstruction or injury.

Examine the neck for asymmetry, cyanosis, subcutaneous emphysema, and fractures.

The chest should be auscultated for bilateral equal breath sounds.

Treatment. Rapid measures are necessary to correct unsatisfactory ventilation.

Supplemental oxygen should be administered to all trauma victims until stable.

Basic manuevers for relieving obstruction and maintaining ventilation include:

Finger sweep

Chin lift/jaw thrust

Oropharyngeal airway

Nasopharyngeal airway

Provide definitive airway.

Early intubation is important in unstable patients due to the propensity for apnea and sudden circulatory collapse. Some indications for rapid intubation include:

Depressed mental status (GCS <8)

Major head, face, or neck injury

Impaired ventilation from paralysis

Oral tracheal intubation is the most common modality used to provide a definitive airway. Patients are preoxygenated with a bag -valve mask and then intubated with in - line cervical stabilization. Rapid -sequence induction with cricoid pressure should be utilized.

Nasotracheal intubation is acceptable only in a spontaneously breathing patient without a suspected basilar skull fracture.

Surgical airway should be performed if standard intubating techniques are unable to be performed or are contraindicated.

Jet ventilation via a 12 - or 14 -gauge catheter in the cricothyroid membrane

Cricothyroidotomy is contraindicated in children less than 12 years of age or in patients with laryngeal fractures.

Tracheostomy

Breathing

Assessment

Ventilation should be assessed by auscultation of the chest, followed by entidal CO2 monitoring

to check for endotracheal tube misplacement. Continuous pulse oximetry and arterial blood gas analysis is also useful.

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Inspect the thorax for sucking chest wounds, subcutaneous emphysema, tracheal deviation, and diminished breath sounds.

Treatment

Pneumothorax is diagnosed by absent breath sounds, tracheal deviation away from the affected side, and hypotension.

Needle decompression in the second intercostal space, midclavicular line

Chest tube placement

Hemothorax (volume replacement and chest tube)

Open chest wound (placement of a semiocclusive dressing and chest tube)

Circulatory support. Once adequate ventilation has been established, the physician should rapidly proceed to the next critical stage of resuscitation, namely, establishment of tissue perfusion or circulatory support.

Assessment of the circulatory status should include appraisal of:

Character of the pulse

A rapid, faint pulse suggests profound hypovolemia in most cases.

A slow, full pulse may be indicative of severe neurologic injury with increasing intracranial pressure or hypercarbia.

Peripheral perfusion, as indicated by level of consciousness, rate of capillary refilling, urine output, and body temperature

Tachycardia may be an early compensatory sign of hypovolemia.

Blood pressure. The presence of a mild hypotension may be associated with inadequate tissue perfusion. A narrowed pulse pressure with diastolic hypertension is one of the earliest signs of hypovolemia.

Stable vital signs with major injury. The condition of patients with major injury and seemingly stable vital signs is dangerous and deceptive.

Previously healthy trauma patients, especially if young, are able to maintain a normal pulse and blood pressure, despite a continuing occult hemorrhage, until vasomotor response fails. When this occurs, the patient “crashes,” which is manifested by a rapid loss of blood pressure and unconsciousness.

These patients maintain stable hemodynamic parameters and may remain quietly pale or become excitable with progressive mental deterioration until overt shock develops, at which point they may not respond to further volume replacement.

Beta-blockers and pacemakers may block tachycardia due to hypovolemia.

Search for obvious external hemorrhage.

Treatment

Venous access

Lines should be inserted by a reliable method with which the physician is comfortable.

Large-bore peripheral catheters (typically 14 - or 16 -gauge in the antecubital position) should be the primary route of access.

Subclavian catheterization should be learned in controlled settings, not on unstable trauma patients.

Subclavian lines and a saphenous cut -down are the quickest for venous access.

The saphenous vein often looks empty and may look pale and tendonlike in a hypovolemic patient. It should be recognized rather than divided.

Two lines are usually inserted simultaneously.

It is best to keep one on each side of the diaphragm so that volume replacement is effective in case of vena caval or subclavian venous trauma.

Shock patients often require between two to four separate lines for volume replacement to increase the blood pressure to more than 100 mm Hg in less than 10 minutes.

The first intravenous insertion should include the withdrawal of 20 mL of blood for crossmatching and for laboratory studies, including a type and cross .

Femoral artery punctures should be performed early for blood gas analyses.

All resuscitation lines should be replaced in 12–24 hours. The urgent insertion of these lines leaves sterility in question, and catheter sepsis can become a serious problem after 24 hours.

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Volume resuscitation

The initial fluid replacement should be isotonic saline or lactated Ringer's solutions. The amount infused is based on the initial judgment of shock and blood loss and is usually given in 500 -cc boluses in adults.

Once 2 L of crystalloid has been infused, blood transfusion should be strongly considered.

Unmatched O -positive blood should be used in emergent situations when time is not available for formal blood typing and crossmatching. O negative blood should be used in female patients of childbearing age.

If time is available, the use of type-specific crossmatched packed red blood cells is optimal.

Fresh frozen plasma, cryoprecipitate and platelets are reserved for known or suspected coagulopathies.

Control of hemorrhage must accompany fluid resuscitation.

External bleeding

Applying direct pressure on bleeding wounds with manually held gauze pads is safe and usually effective.

Proximal and distal digital compression of bleeding superficial vessels may allow visualization of the bleeding point and accurate clamping. Blind clamping is never indicated.

Pressure dressings may be used to control diffuse bleeding from abrasions and avulsions that involve large areas.

Temporary packing of missile tracts and stab wounds can slow the blood flow until surgical exposure is obtained.

Pneumatic splints and medical antishock trousers (MAST) help in tamponading bleeding and increasing peripheral resistance to increase the blood pressure. The antishock trousers provide increased peripheral resistance without the pharmacologic effects of pressor agents. MAST should be reserved for certain cases where long transport times are anticipated or in pelvic fractures when tamponade and relative immobilization may be important.

Tourniquets should be avoided if personnel are available for direct compression.

Internal bleeding requires early diagnosis and prompt treatment by appropriate surgical intervention (see C 7).

Cardiac resuscitation

Closed chest cardiac massage should be performed while fluid resuscitation is begun if the patient is asystolic or demonstrates evidence of poor cardiac function.

Emergency room thorocotomies for open cardiac massage have few indications and should only be performed by trained surgeons.

Indications for emergency room thoracotomy are:

Hypovolemic cardiac arrest despite vigorous blood volume replacement plus closed chest massage and defibrillation

Cardiac arrest with penetrating injury to the chest

Relative contraindications include:

Major obvious injuries to the central nervous system (i.e., decapitation, extruding brain tissue)

Failed external cardiac massage lasting more than 10 minutes

Major blunt trauma

Monitoring circulating blood volume and resuscitative therapy is based on the signs and symptoms of shock. Examination of pulses, skin color, capillary refill, heart rate, blood

pressure, and mental status should occur continuously. Adjuncts to hemodynamic monitoring useful in trauma include urine output and central venous pressure (CVP).

Urine output measured hourly is an important guideline to the accuracy of fluid resuscitation. Output exceeding 30 cc/hour implies adequate perfusion to all vital organs.

CVP can be useful when its trend is observed over time and in patients with significant preexisting cardiac and pulmonary disfunction. Pulmonary artery (Swan -Ganz) catheter monitoring may be more appropriate in these patients.

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Assessment of neurologic injury. After adequate ventilation and tissue perfusion have been restored, immediate attention must be given to the patient's neurologic condition.

Head trauma

Assessment

Loss of consciousness signifies a head injury until such an injury has been ruled out.

Intracranial trauma cannot be adequately assessed while the patient is in shock.

If hypotension is present in a patient with a head injury, it is rarely secondary to the head trauma, and the physician must look for another cause of the hypotension.

The neurologic evaluation should assess the following factors rapidly:

Level of consciousness. Is the patient alert, lethargic and disoriented, comatose but responsive to pain, or unresponsive?

Motor activity and tactile sensation

Obvious head trauma, such as a depressed skull fracture, gunshot wound, or leaking cerebrospinal fluid

Pupil size and response to light

Oculocephalic (“doll's eye”) reflex. Because testing involves rotating the patient's head, it should only be done after spinal cord injury has been ruled out.

Evolving hypertension and bradycardia (Cushing's phenomenon) indicate increasing intracranial pressure and a worsening neurologic problem.

Treatment

Consultation with a neurosurgeon is imperative for proper management of patients with head injuries. However, if one is not available, then a telephone consultation should be obtained and initial treatment begun, followed by transfer of the patient to a center with a neurosurgeon.

Initial management includes the following considerations:

Sterile saline -soaked gauze should be placed over open injuries.

Mannitol and other drugs to lower intracranial pressure should be given after consultation with the neurosurgeon.

Hypotension and hypoventilation seriously injure brain cells. It is, therefore, important to assess adequately fluid requirements and ventilation.

Overhydration increases intracranial pressure and should be avoided once fluid requirements have been met and the patient is stable.

Spinal cord trauma

Assessment

Until proven otherwise, the spine should be considered unstable and the cord, therefore, liable to injury in all patients with major blunt trauma.

The cervical spine should be considered unstable in:

Every unconscious patient

Every patient with face and head contusions or vertebral tenderness

Every patient with decreased mentation, which precludes adequate neurologic examination

Radiographic films showing all seven cervical vertebrae intact should be obtained before allowing the patient's neck to be extended for any reason. At least three views need to be obtained, including cross-table lateral, anterior-posterior, and odontoid views.

Evidence of injury to the spinal cord should be sought.

It should be recognized that the cord may not yet be injured although the spine is unstable. A negative neurologic examination does not prove the absence of injury to the cervical spine.

Appropriate spinal stabilization must be performed until proper studies have been done.

Findings, such as absence of motor or sensory function below the injury, loss of muscle tone, and loss of anal sphincter tone, should be sought.

Hypotension may be present if there is a loss of vascular tone (arterial and venous) within the affected region.

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Treatment . The required stabilization and reduction of the injury must be performed under the supervision of a neurosurgeon or an orthopedic surgeon experienced in treating these injuries.

Exposure