A 26-year-old female presents to the emergency department, stating that her husband assaulted her. She complains of headache and sore throat. When directly questioned, she states, “He choked me so bad, I thought I was going to die. I might have blacked out for a minute. It really hurts to swallow.”
Strangulation is a form of asphyxia, characterized by closure of the blood vessels and air passages of the neck as a result of external pressure. There is a distinction between strangulation and choking, which is an internal obstruction of the airway. There is a misperception that strangulation is always fatal, and patients will often describe a “choking” episode following nonfatal strangulation.
Strangulation and Domestic Violence
Strangulation has been identified as one of the most lethal forms of domestic violence. It is one of the best predictors for subsequent homicide. Prior strangulation increases the odds of strangulation homicide by more than seven times.1 For perpetrators, strangulation is the ultimate form of power and control. However, because there are often no visible injuries, patients, physicians, and law enforcement often minimize the possible health consequences of reported strangulation.
The vasculature of the neck is relatively unprotected and vulnerable to injury and vascular occlusion. The application of 4.4 pounds of pressure to the jugular veins causes venous outflow obstruction from the brain and thus stagnant hypoxia. Eleven pounds of pressure to the carotid arteries can cause loss of consciousness in approximately 10 seconds. Compression of the trachea requires significantly more force: 33 pounds of pressure for occlusion and 35 pounds to fracture tracheal cartilage.2
Strangulation can be fatal in as little as four to five minutes. Mechanisms in addition to hypoxia due to vascular occlusion have been proposed. Pressure on the carotid body may cause bradycardia and subsequent cardiac arrest. Delayed mortality may be caused by carotid artery dissection, aspiration, postobstructive pulmonary edema, acute respiratory distress syndrome, or tracheal injury.
In domestic violence and sexual assault cases, manual strangulation (with hands or other body parts such as a knee) is most common. Ligature strangulation is significantly less common but more likely to result in visible injuries.
Frequently, strangulation does not result in visible physical findings.3 The lack of obvious injury, along with the distraught mental state of these patients, often results in underevaluation. It is important to perform a thorough exam, as findings may be subtle and located in difficult to see areas such as the scalp, behind the ears, and inside the mouth.
In the 50 percent of patients who have visible injuries, skin injuries are the most common. Faint bruises caused by the assailant’s fingertips, fingernail marks (sometimes self-inflicted), and petechiae may be seen. Subconjunctival hemorrhage may also occur.
Patients may have dysphagia and odynophagia. Voice changes are present in about half of strangulation cases; ask the patient if their voice sounds normal. Pain with movement of the tongue may indicate injury to the epiglottis. Although uncommon, hyoid fracture or tracheal cartilage fractures may result in crepitus followed by rapid airway obstruction.
Patients who have been strangled may present with pulmonary complaints, which are often mistakenly attributed to hyperventilation. Aspiration or postobstructive pulmonary edema may result in tachypnea and hypoxia.
Occlusion of or injury to one carotid artery may cause neurological deficits on the contralateral side. These include changes in vision, ptosis, facial droop, and unilateral weakness.4 If strangulation results in hypoxia, patients may have mental status changes and incontinence. Death has resulted days after strangulation due to hypoxic encephalopathy.
Miscarriage may also occur due to fetal hypoxia.3