Major trauma
Major trauma is any injury that has the potential to cause prolonged disability or death. There are many causes of major trauma, blunt and penetrating, including falls, motor vehicle collisions, stabbing wounds, and gunshot wounds. Depending on the severity of injury, quickness of management, and transportation to an appropriate medical facility may be necessary to prevent loss of life or limb. The initial assessment is critical, and involves a physical evaluation and also may include the use of imaging tools to determine the types of injuries accurately and to formulate a course of treatment.
In 2002, unintentional and intentional injuries were the fifth and seventh leading causes of deaths worldwide, accounting for 6.23% and 2.84% of all deaths. For research purposes the definition often is based on an Injury Severity Score of greater than 15.
Classification
Injuries generally are classified by either severity, the location of damage, or a combination of both. Trauma also may be classified by demographic group, such as age or gender. It also may be classified by the type of force applied to the body, such as blunt trauma or penetrating trauma. For research purposes injury may be classified using the Barell matrix, which is based on ICD-9-CM. The purpose of the matrix is for international standardization of the classification of trauma. Major trauma sometimes is classified by body area; injuries affecting 40% are polytrauma, 30% head injuries, 20% chest trauma, 10%, abdominal trauma, and 2%, extremity trauma.Various scales exist to provide a quantifiable metric to measure the severity of injuries. The value may be used for triaging a patient or for statistical analysis. Injury scales measure damage to anatomical parts, physiological values, comorbidities, or a combination of those. The Abbreviated Injury Scale and the Glasgow Coma Scale are used commonly to quantify injuries for the purpose of triaging and allow a system to monitor or "trend" a patient's condition in a clinical setting. The data also may be used in epidemiological investigations and for research purposes.
Approximately 2% of those who have experienced significant trauma have a spinal cord injury.
Causes
Injuries may be caused by any combination of external forces that act physically against the body. The leading causes of traumatic death are blunt trauma, motor vehicle collisions, and falls, followed by penetrating trauma such as stab wounds or impaled objects. Subsets of blunt trauma are both the number one and two causes of traumatic death.For statistical purposes, injuries are classified as either intentional such as suicide, or unintentional, such as a motor vehicle collision. Intentional injury is a common cause of traumas. Penetrating trauma is caused when a foreign body such as a bullet or a knife enters the body tissue, creating an open wound. In the United States, most deaths caused by penetrating trauma occur in urban areas and 80% of these deaths are caused by firearms. Blast injury is a complex cause of trauma because it commonly includes both blunt and penetrating trauma, and also may be accompanied by a burn injury. Trauma also may be associated with a particular activity, such as an occupational or sports injury.
Pathophysiology
The body responds to traumatic injury both systemically and at the injury site. This response attempts to protect vital organs such as the liver, to allow further cell duplication and to heal the damage. The healing time of an injury depends on various factors including sex, age, and the severity of injury.The symptoms of injury may manifest in many different ways, including:
- Altered mental status
- Fever
- Increased heart rate
- Generalized edema
- Increased cardiac output
- Increased rate of metabolism
Diagnosis
The initial assessment is critical in determining the extent of injuries and what will be needed to manage an injury, and for treating immediate life threats.Physical examination
Primary physical examination is undertaken to identify any life-threatening problems, after which the secondary examination is carried out. This may occur during transportation or upon arrival at the hospital. The secondary examination consists of a systematic assessment of the abdominal, pelvic, and thoracic areas, a complete inspection of the body surface to find all injuries, and a neurological examination. Injuries that may manifest themselves later may be missed during the initial assessment, such as when a patient is brought into a hospital's emergency department. Generally, the physical examination is performed in a systematic way that first checks for any immediate life threats, and then taking a more in-depth examination.Imaging
Persons with major trauma commonly have chest and pelvic x-rays taken, and, depending on the mechanism of injury and presentation, a focused assessment with sonography for trauma exam to check for internal bleeding. For those with relatively stable blood pressure, heart rate, and sufficient oxygenation, CT scans are useful. Full-body CT scans, known as pan-scans, improve the survival rate of those who have suffered major trauma. These scans use intravenous injections for the radiocontrast agent, but not oral administration. There are concerns that intravenous contrast administration in trauma situations without confirming adequate renal function may cause damage to kidneys, but this does not appear to be significant.In the U.S., CT or MRI scans are performed on 15% of those with trauma in emergency departments. Where blood pressure is low or the heart rate is increasedlikely from bleeding in the abdomenimmediate surgery bypassing a CT scan is recommended. Modern 64-slice CT scans are able to rule out, with a high degree of accuracy, significant injuries to the neck following blunt trauma.
Surgical techniques
Surgical techniques, using a tube or catheter to drain fluid from the peritoneum, chest, or the pericardium around the heart, often are used in cases of severe blunt trauma to the chest or abdomen, especially when a person is experiencing early signs of shock. In those with low blood-pressure, likely because of bleeding in the abdominal cavity, cutting through the abdominal wall surgically is indicated.Prevention
By identifying risk factors present within a community and creating solutions to decrease the incidence of injury, trauma referral systems may help to enhance the overall health of a population. Injury prevention strategies are commonly used to prevent injuries in children, who are a high risk population. Injury prevention strategies generally involve educating the general public about specific risk factors and developing strategies to avoid or reduce injuries. Legislation intended to prevent injury typically involves seatbelts, child car-seats, helmets, alcohol control, and increased enforcement of the legislation. Other controllable factors, such as the use of drugs including alcohol or cocaine, increases the risk of trauma by increasing the likelihood of traffic collisions, violence, and abuse occurring. Prescription drugs such as benzodiazepines may increase the risk of trauma in elderly people.The care of acutely injured people in a public health system requires the involvement of bystanders, community members, health care professionals, and health care systems. It encompasses pre-hospital trauma assessment and care by emergency medical services personnel, emergency department assessment, treatment, stabilization, and in-hospital care among all age groups. An established trauma system network is also an important component of community disaster preparedness, facilitating the care of people who have been involved in disasters that cause large numbers of casualties, such as earthquakes.
Management
Pre-hospital
The pre-hospital use of stabilization techniques improves the chances of a person surviving the journey to the nearest trauma-equipped hospital. Emergency medicine services determines which people need treatment at a trauma center as well as provide primary stabilization by checking and treating airway, breathing, and circulation as well as assessing for disability and gaining exposure to check for other injuries.Spinal motion restriction by securing the neck with a cervical collar and placing the person on a long spine board was of high importance in the pre-hospital setting, but due to lack of evidence to support its use, the practice is losing favor. Instead, it is recommended that more exclusive criteria be met such as age and neurological deficits to indicate the need of these adjuncts. This may be accomplished with other medical transport devices, such as a Kendrick extrication device, before moving the person. It is important to quickly control severe bleeding with direct pressure to the wound and consider the use of hemostatic agents or tourniquets if the bleeding continues. Conditions such as impending airway obstruction, enlargening neck hematoma, or unconsciousness require intubation. It is unclear, however, if this is best performed before reaching hospital or in the hospital.
Rapid transportation of severely injured patients improves the outcome in trauma. Helicopter EMS transport reduces mortality compared to ground-based transport in adult trauma patients. Before arrival at the hospital, the availability of advanced life support does not greatly improve the outcome for major trauma when compared to the administration of basic life support. Evidence is inconclusive in determining support for pre-hospital intravenous fluid resuscitation while some evidence has found it may be harmful. Hospitals with designated trauma centers have improved outcomes when compared to hospitals without them, and outcomes may improve when persons who have experienced trauma are transferred directly to a trauma center.
Improvements in pre-hospital care have led to "unexpected survivors", where patients survive trauma when they would have previously been expected to die. However these patients may struggle to rehabilitate.