Injuries; Poisoning

Injury is the number one cause of death for people aged 1 to 44. In the US, there were 231,991 trauma deaths in 2016, about 70% being accidental. Of intentional injury deaths, more than 70% were due to self-harm. In addition to deaths, injury results in about 39 million emergency department visits and 2.8 million hospital admissions annually.

The abdomen can be injured in many types of trauma; injury may be confined to the abdomen or be accompanied by severe, multisystem trauma. The nature and severity of abdominal injuries vary widely depending on the mechanism and forces involved, thus generalizations about mortality and need for operative repair tend to be misleading.

Altitude illness is caused by the decreased availability of oxygen at high altitudes. Acute mountain sickness (AMS), the mildest form, is characterized by headache plus one or more systemic manifestations; it may occur in recreational hikers and skiers and others traveling to high altitude. High-altitude cerebral edema (HACE) is a form of global encephalopathy, while high-altitude pulmonary edema (HAPE) is a form of noncardiogenic pulmonary edema causing severe dyspnea and hypoxemia. Diagnosis of altitude illness is clinical. Treatment of mild AMS is with analgesics and acetazolamide or dexamethasone. Severe AMS may require descent and supplemental oxygen if available. Both HACE and HAPE are potentially life-threatening and require immediate descent. In addition, dexamethasone is useful for HACE, and nifedipine or phosphodiesterase inhibitors are useful for HAPE. Prevention of AMS is by gradual ascent and use of acetazolamide.

Some larger centipedes can inflict a painful bite, causing swelling and redness. Symptoms rarely persist for more than 48 h. Millipedes do not bite but may secrete a toxin that is irritating, particularly when accidentally rubbed into the eye.

Burns are injuries of skin or other tissue caused by thermal, radiation, chemical, or electrical contact. Burns are classified by depth (superficial and deep partial-thickness, and full-thickness) and percentage of total body surface area (TBSA) involved. Complications and associated problems include hypovolemic shock, inhalation injury, infection, scarring, and contractures. Patients with large burns (> 20% TBSA) require fluid resuscitation. Treatments for burn wounds includes topical antibacterials, regular cleaning, elevation, and sometimes skin grafting. Intensive rehabilitation, consisting of range-of-motion exercises and splinting, is often necessary.

Exposure to cold may cause decreased body temperature (hypothermia) and focal soft-tissue injury.

A dislocation is complete separation of the 2 bones that form a joint. Subluxation is partial separation. Often, a dislocated joint remains dislocated until reduced (realigned) by a clinician, but sometimes it reduces spontaneously.

Drowning is respiratory impairment resulting from submersion in a liquid medium. It can be nonfatal (previously called near drowning) or fatal. Drowning results in hypoxia, which can damage multiple organs, including the lungs and brain. Treatment is supportive, including reversal of respiratory arrest and cardiac arrest, hypoxia, hypoventilation, and hypothermia.

Electrical injury is damage caused by generated electrical current passing through the body. Symptoms range from skin burns, damage to internal organs and other soft tissues to cardiac arrhythmias and respiratory arrest. Diagnosis is based on history, clinical criteria, and selective laboratory testing. Treatment is supportive, with aggressive care for severe injuries.

Common causes of eye injury include domestic accidents (eg, during hammering or exposure to household chemicals or cleaners), assault, sporting injuries (including air- or paint pellet-gun injuries), and motor vehicle crashes (including airbag injuries). Injury may be to the eyeball (globe), surrounding soft tissues (including muscles, nerves, and tendons), and/or bones of the orbit.

Trauma to the external ear may result in hematoma, laceration, avulsion, or fracture.

A fracture is a break in a bone. Most fractures result from a single, significant force applied to normal bone.

External bladder injuries are caused by either blunt or penetrating trauma to the lower abdomen, pelvis, or perineum. Blunt trauma is the more common mechanism, usually by a sudden deceleration, such as in a high-speed motor vehicle crash or fall, or from an external blow to the lower abdomen. The most frequently accompanying injury is a pelvic fracture, occurring in > 95% of bladder ruptures caused by blunt trauma. Other concomitant injuries include long bone fractures and central nervous system and chest injuries. Penetrating injuries, most often gunshot wounds, account for < 10% of bladder injuries.

Heat illness encompasses a number of disorders ranging in severity from muscle cramps and heat exhaustion to heatstroke (which is a life-threatening emergency). Heat illness, although preventable, affects thousands of people each year in the US and can be fatal; it is the second leading cause of death in young athletes. When heatstroke is not treated promptly and effectively, mortality approaches 80%.

More than 1000 diving-related injuries occur annually in the US; > 10% are fatal. Similar injuries can befall workers in tunnels or caissons (watertight retaining structures used for construction), in which pressurized air is used to exclude water from work sites.

Care of lacerations

Mass-casualty incidents (MCIs) are events that generate sufficiently high numbers of casualties to overwhelm available medical resources. They include natural disasters (eg, hurricanes) and several types of intentional and unintentional man-made events, including transportation disasters, releases of dangerous substances, explosions, and mass shootings.

Motion sickness is a symptom complex that usually includes nausea, often accompanied by vague abdominal discomfort, vomiting, dizziness, pallor, diaphoresis, and related symptoms. It is induced by specific forms of motion, particularly repetitive angular and linear acceleration and deceleration, or as a result of conflicting vestibular, visual, and proprioceptive inputs. Behavioral change and drug therapy can help prevent or control symptoms.

Poisoning is contact with a substance that results in toxicity. Symptoms vary, but certain common syndromes may suggest particular classes of poisons. Diagnosis is primarily clinical, but for some poisonings, blood and urine tests can help. Treatment is supportive for most poisonings; specific antidotes are necessary for a few. Prevention includes labeling drug containers clearly and keeping poisons out of the reach of children.

Ionizing radiation injures tissues variably, depending on factors such as radiation dose, rate of exposure, type of radiation, and part of the body exposed. Symptoms may be local (eg, burns) or systemic (eg, acute radiation sickness). Diagnosis is by history of exposure, symptoms and signs, and sometimes use of radiation detection equipment to localize and identify radionuclide contamination. Management focuses on associated traumatic injuries, decontamination, supportive measures, and minimizing exposure of health care workers. Patients with severe acute radiation sickness receive reverse isolation and bone marrow support. Patients internally contaminated with certain specific radionuclides may receive uptake inhibitors or chelating agents. Prognosis is initially estimated by the time between exposure and symptom onset, the severity of those symptoms, and by the lymphocyte count during the initial 24 to 72 hours.

Trauma to the spine may cause injuries involving the spinal cord, vertebrae, or both. Occasionally, the spinal nerves are affected. The anatomy of the spinal column is reviewed elsewhere.

Sports participation always has a risk of injury.

Sprains are tears in ligaments; strains are tears in muscles. Tears (ruptures) may also occur in tendons.

Thoracic trauma causes about 25% of traumatic deaths in the US. Many chest injuries cause death during the first minutes or hours after trauma; they can frequently be treated at the bedside with definitive or temporizing measures that do not require advanced surgical training.

Traumatic brain injury (TBI) is physical injury to brain tissue that temporarily or permanently impairs brain function. Diagnosis is suspected clinically and confirmed by imaging (primarily CT). Initial treatment consists of ensuring a reliable airway and maintaining adequate ventilation, oxygenation, and blood pressure. Surgery is often needed in patients with more severe injury to place monitors to track and treat intracranial pressure elevation, decompress the brain if intracranial pressure is increased, or remove intracranial hematomas. In the first few days after the injury, maintaining adequate brain perfusion and oxygenation and preventing complications of altered sensorium are important. Subsequently, many patients require rehabilitation.