Trauma (medicine)

Trauma (from Greek τραῦμα, "wound" ) also known as injury is a physiological wound caused by an external source. It can also be described as "a physical wound or injury, such as a fracture or blow." Trauma is the sixth leading cause of death worldwide, accounting for 10% of all mortalities, and is therefore a serious public health problem with significant social and economic costs.

Classification
Trauma can be classified by the affected area of the body. Trauma may also be classified by the affected demographic group. For example, trauma involving a pregnant woman, pediatric, or geriatric patient. It may also be classified by the type of force applied to the body, such as blunt trauma or penetrating trauma.
 * Polytrauma (40%)
 * Head injury (30%)
 * Chest trauma (20%)
 * Abdominal trauma (10%)
 * Extremity trauma (2%)
 * Facial trauma
 * Spinal cord injury
 * Genitourinary system trauma
 * Pelvic trauma
 * Soft tissue injury

Injury severity scales
Various scales exist for the purpose of having a quantifiable metric in which to measure the severity of an injury. The value can be used for triaging a patient or for statistical analysis. Injury scales measure damage to anatomical parts, physiological values (such as blood pressure), comorbidities, or of combination of those. Some examples of common scales used are the abbreviated injury scale or the Glasgow coma scale.

Causes
The leading cause of traumatic death is blunt trauma, motor vehicle accidents and falling accidents, subsets of blunt trauma, are the number one and two causes of traumatic death. The use of drugs such as alcohol or illicit drugs such as cocaine increases the risk of trauma, by making traffic collisions, violence, and abuse more likely. Other drugs such as benzodiazepines increase the risk of trauma in elderly people. In addition, 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 tissue of the body, 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 may also be accompanied by a burn injury.

Prevention
By identifying risk factors present within a community and creating solutions to decrease the incidence of injury, trauma referral systems can help to enhance the overall health of a population. Commonly injury prevention strageties are utilized to prevent injuries in children as they are a high risk population. Generally, injury prevention strageties involve education of the general public to specific risk factors and developing strageties to mitigate injury. Some common forms of legislation regarding injury prevention typically involve seatbelts, child car seats, helmets, alcohol control, and increased enforcement.

The care of acutely injured people is a public health system is an issue which involves bystanders, community members, health care professionals, and health care systems. It encompasses prehospital assessment and care by emergency medical services personnel, emergency department assessment, treatment, and 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 experienced natural disasters and terrorist attacks.

Pathophysiology
The body responds to traumatic injury both systemically and locally 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. Healing time depends on sex, age and severity of injury.

Inflammation, common after injury, protects against further injury and starts the healing process. Runaway inflammation can, however, cause organ failure. Immediately after injury, the body produces more glucose through gluconeogenesis, and burns more fat via lipolysis. Next, the body tries to replenish its energy stores of glucose and protein via anabolism. In this state the body will temporarily increase its maximum expenditure for the purpose of healing injured cells.

Physical examination
The purpose of the primary physical examination is to identify any life-threatening problems. Upon completion of the primary examination, the secondary examination is begun. This may occur during transport or upon arrival at the hospital. The secondary examination consists of a systematic assessment of the abdominal, pelvic and thoracic area, complete inspection of the body surface to find all injuries, and a neurological examination. The purpose of the secondary examination is to identify all injuries so that they may be treated. A missed injury is one which is not found during the initial assessment, such as when a patient is brought into a hospital's emergency department, but manifests itself at a later point in time.

Imaging
Persons with major trauma commonly have chest and pelvic X-rays taken, and, depending on the mechanism of injury and presentation, are subject to a Focused assessment with sonography for trauma (FAST) exam to check for internal bleeding. For those with relatively stable blood pressure, heart rate, and sufficient oxygenation, CT scans are considered effective. Full-body CT scans, known as pan-scans, improve the survival rate in those who have suffered major trauma. These scans use intravenous injections for the radiocontrast agent, but not oral administration. There are concerns of radiation exposure from CT scans on the kidneys. However routine CT scans on the kidneys have shown no associated harm. A complete scan takes around ten minutes. In the U.S., CTs or MRIs are performed on fifteen percent of trauma victims in emergency rooms. Where blood pressure is low or the heart rate is increased, likely from bleeding in the abdomen, immediate surgery bypassing a CT scan is recommended.

Surgical techniques
Surgical techniques, using a tube or catheter to drain fluid from the peritoneum, chest, or the pericardium around the heart, are often 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.

Stabilization and transportation


Before arriving at a hospital, the use of stabilization techniques improve the chances of a person surviving the transport to the nearest trauma-equipped hospital. A healthcare provider should ensure their own safety and take appropriate isolation precautions. A primary survey is then performed, consisting of checking and treating airway, breathing, and circulation followed by an assessment on the level of consciousness. To prevent further injury, unnecessary movement of the spine is minimized by securing the neck with a cervical collar, and the back with a long spine board with head supports. This can be accomplished with other medical transport devices such as a Kendrick extrication device, before moving the person.

Rapid transportation of those who are severely injured is improves the outcome in trauma. If a person is in imminent danger of death, first responders will typically "load and go," meaning they will minimize time between arriving to nearest appropriate facility by performing important interventions in the back of an ambulance, rather than on scene. Helicopter EMS transport reduces mortality when compared to ground based transport in adult trauma patients. Before arrival to 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 prehospital intravenous fluid resuscitation while some evidence has found it may be harmful.

People who have suffered trauma may require specialized care, including surgery and blood transfusion with successful outcomes occurring if this occurs as quickly as possible during the golden hour of trauma. This is not a strict deadline, but recognizes the many deaths which can would be prevented by appropriate care occurring in the short time following injury. Hospitals with designated trauma centers have improved outcomes when compared to hospitals without them., and if people who have experienced trauma are transferred directly to a trauma center it can improve the outcome. In certain traumas, such as maxillofacial trauma, it can be beneficial to have a highly trained health care provider available to maintain airway, breathing, and circulation.

Intravenous fluids
Traditionally, high volume intravenous fluids were given in people who are unable to provide adequate perfusion to tissues (hemodynamically unstable) due to trauma. This is still appropriate in those cases with isolated extremity trauma, thermal trauma, or head injuries. The current evidence supports limiting the use of fluids for penetrating thorax and abdominal injuries allowing mild hypotension to persist. Targets include a mean arterial pressure of 60 mmHg, a systolic blood pressure of 70–90 mmHg, or until adequate mentation and peripheral pulses are observed.

As no intravenous fluids used for initial resuscitation has been shown to be superior to warmed Lactated Ringer's solution, it continues to be the solution of choice for the treatment of trauma victims. If blood products are needed, a greater relative use of fresh frozen plasma and platelets to packed red blood cells has been found to result in improved survival and less overall blood product usage, with a ratio of 1:1:1 being recommended. The success of platelets has been attributed to the fact that they can prevent coagulopathy from developing. Cell salvage and autotransfusion can also be used as treatment.

Blood substitutes such as hemoglobin-based oxygen carriers are in development. As of 2011 however, there are none available for commercial use in North America or Europe. The only countries where these products are available for general use is South Africa and Russia.

Medications
In people who are bleeding due to trauma, tranexamic acid decreases the mortality rate. For severe bleeding, say from bleeding disorders, a protein that assists blood clotting, recombinant factor VIIa, may be appropriate, While it decreases blood use it does not appear to decrease the mortality rate. In those without previous factor VII deficiency it use is thus not recommended outside of trial situations. Various other medications may be used in conjunction with other procedures in order to stabilize a person who sustained a significant injury.

Surgery
Whether or not surgery is preformed is determined by the extent of the damage and the anatomical location of the injury. Before definitive repair can occur, active hemorrhaging must be controlled first. Damage control surgery is employed in the management of severe trauma in which there is a cycle of metabolic acidosis, hypothermia, and hypotension. It involves performing the least number of procedures to save life and limb, with less critical procedures being left until the victim is more stable.

Prognosis
Trauma used to lead to death in one of three stages: immediate, early, or late. Immediate deaths were usually due to apnea, severe brain or high spinal cord injury, or rupture of the heart or of large blood vessels. The early deaths occurred within minutes to hours and were often due to hemorrhages in the brain's outer meningeal layer, tears in arteries, blood around the lungs, air around the lungs, ruptured spleen, liver laceration, or pelvic fracture. This period was known as the golden hour, often deciding whether a patient lived. Late deaths occurred days or weeks after the injury. These stages may no longer be relevant in the United States due to improved care.

Long-term prognosis is frequently complicated by pain, with over half of people having moderate to severe pain one year after injury. Many victims also experience a reduced quality of life years following an injury, with twenty percent of victims sustaining some form of disability. Physical trauma can lead to development of post-traumatic stress disorder, or PTSD. That being said, one study has found no correlation between the severity of trauma and the development of PTSD.

Epidemiology
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Trauma is the sixth leading cause of death worldwide resulting in five million or 10% of all deaths. It is the fifth leading cause of significant disability. About half of deaths due to trauma are in people aged 15–45 years and in this age it is the leading cause of death. Death from injury is twice as common in males as females. The primary causes of traumatic death are central nervous system injury, followed by substantial blood loss.

Research
For the most part, major research on trauma occurs during war and similar conflicts. Some research is being done on patients who were admitted into an intensive care unit or trauma center and received a trauma diagnosis caused a negative change in their health related quality of life outlook, with a potential to create anxiety and symptoms of depression. New preserved blood products are also being researched for use in prehospital emergent care as currently it is not practical to use the current blood products in a timely fashion it an out-of-hospital rural setting or in a war time situation.

Economics
The average cost for the treatment of traumatic injury in the United States is around $334,000 per person, making it costlier than the treatment of cancer and cardiovascular diseases. One reason of the high cost of injury is the increased possibility of complications which leads to the need for more interventions. Costs to maintain a trauma center are substantial as they are open continuously and maintain their readiness. In 2009 around 693.5 billion USD was lost due to traumatic injury in the United States.

Low and middle income countries
Citizens of low and middle income countries (LMICs) often have higher mortality rates due to various reasons. Many of these countries do not have access to proper surgical care to deal with injury as many do not have a trauma system. In addition, most LMICs do not have a prehospital care system to initially deal and transport injured persons to appropriate facilities in a timely manor. Hospitals also lack the appropriate physical resources (equipment), organizational resources (improvement efforts), or human resources (trained staff). By 2020 the amount of trauma related deaths is expected to decline in high-income countries while in low to middle-income countries it is expected to increase.

In children
Accidents are the leading cause of death in children 1–14 years of age. In the United States approximatively sixteen million children go to an emergency department due to some form of injury every year. Boys are more frequently injured then girls by a ratio of two to one. The top five worldwide unintentional injuries in children are as follows:

An important part of managing trauma in children is weight estimation as the accurate dosing of medicine may be critical for resuscitative efforts. A number of methods to estimate weight exist including the: Broselow tape, Leffler formula, and Theron formula.

In pregnancy
Trauma occurs in about 5% of all pregnancies, and is the leading cause of maternal death. Pregnant women may additionally experience placental abruption, preterm labor, and uterine rupture. There are diagnostic issues during pregnancy as ionizing radiation has been shown to cause birth defects although the doses used for typical exams are generally considered "safe". Due to normal physiological changes of pregnancy shock can be more difficult to diagnosis. In those cases in which the woman is more than 23 weeks pregnant it is recommended that the fetus be monitored for at least four to six hours by cardiotocography.

A number of treatments beyond typical trauma care may be needed in the care of a pregnant woman. As the weight of the uterus on the inferior vena cava can decease blood return to the heart, it is important to lay the women in late pregnancy on her left side or tilt the spine board. Other measures that are recommended include: rho(D) immune globulin in those who are rh negative, corticosteroids in those who are 24 to 34 weeks who may need delivery, or a caesarian section in the event of cardiac arrest.