resonance with angiography (MRA): MRA is used to evaluate the carotid and vertebral arteries for a possible dissection after strangulation. MRA is equally as sensitive as CTA for arterial dissection and does not involve ionizing radiation (Appendix 7).
—Magnetic resonance imaging (MRI): MRI is a technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within the body. An MRI machine also produces 3D images that can be viewed from many different angles.16
—Odynophagia: Pain when swallowing.9
—OLDCARTS: Acronym (Onset, Location, Duration, Character, Aggravating/relieving, Radiation, Timing, Severity) used by health care providers when completing a comprehensive symptom history in the great subjective history provided by the patient.
—Petechial hemorrhages: Small, pinhead-sized hemorrhages caused by increased venous pressure in the capillary bed. Capillaries may be singular or multiple in appearance and may occur in any part of the body. The development of petechial hemorrhages in strangulation requires venous obstruction without obstruction of arterial flow. May be found under the eyelids (conjunctive), around the eyes, scalp, or anywhere on the face and neck in and above the area of constriction. Petechial hemorrhages can also result from nontraumatic causes, including forceful vomiting, coughing, childbirth, infection, and bleeding disorders.5
—Positional asphyxia (postural asphyxia): A form of asphyxia occurring when the position of a person’s body or external pressure prevents the person from breathing adequately.17 External pressure on the chest, neck, or abdomen restricts respiration and the exchange of oxygen and carbon dioxide resulting in hypoxia and elevated levels of carbon dioxide.
—Pulse oximetry: A device that measures the oxygen saturation of arterial blood in a subject. A sensor is usually attached to a finger, toe, or ear to determine the percentage of oxyhemoglobin in the blood pulsating through a network of capillaries.18
—Sexual assault forensic examiner (SAFE): Advanced practice providers, including nurse practitioners, physician assistants, and physicians with specialized education in the forensic aspects of health care for sexual assault patients.1,15
—Sexual assault nurse examiner (SANE): A registered nurse who has specialized education in the forensic aspects of health care for sexual assault patients.1,15
—Sexual assault response or resource team (SART): Coalitions of agencies that serve sexual assault victims. Core membership for SARTs typically includes victim advocates, law enforcement officers, medical forensic providers, forensic scientists, and prosecutors. Multidisciplinary SARTs work together to formalize interagency guidelines that prioritize victims’ needs, hold offenders accountable, and promote public safety.19,20
—Strangulation: A form of asphyxiation characterized by closure of the air passage and/or blood vessels of the neck from the application of external pressure to the neck.
—Subconjunctival hemorrhage: Capillary rupture and bleeding into the white portion of the eye (ie, sclera).
—Suffocation: Obstruction or restriction of breathing by external mechanical forces. Suffocation does not require blunt force.9
—Swelling (edema) of the neck: Notable puffiness or tight appearance of the neck caused by tissue trauma, bleeding, or subcutaneous emphysema; may also be slight visible puffiness with more significant swelling inside, compromising the airway. Patient may complain of feeling tightness or fullness in the neck. Examiner may see jewelry impressions on the neck.
—Victim advocate: Someone who provides immediate crisis intervention, confidential emotional support, and information and advocacy to victims and their loved ones. The advocate is part of a coordinated response team and facilitates medical and legal services while providing trauma-informed, victim-centered care.
METHODS OF STRANGULATION
—Complete hanging: Suspension from a ligature around the neck holding the full body weight.
—Incomplete hanging: Suspension from a ligature around the neck holding partial body weight (ie, the feet, legs, pelvis, or torso is in contact with the ground).
—Ligature strangulation: Strangulation without suspension using some form of flexible linear object (eg, cord-like item).
—Manual strangulation: Strangulation using the hands, fingers, arms, or legs.
MECHANISMS OF STRANGULATION
—Compression of the laryngopharynx, larynx, or trachea: Inhibits inhalation and exhalation causing hypoxia and eventually anoxia.
—Compression over the carotid artery ganglion: May stimulate the carotid sinus reflex; produces bradycardia and hypotension; however, it does not cause cardiac arrest.21,22
—Sustained compression of the carotid arteries: Prevents 80% to 85% of oxygenated blood flow to the brain, which leads to cerebral anoxia and unconsciousness within 10 seconds.
—Sustained compression of the carotid and vertebral arteries: Prevents 100% of oxygenated blood flow to the brain. Without any arterial inflow to the head, no petechial hemorrhages develop, leading to “pale strangulation” or “pale hanging.”
—Sustained compression of the jugular veins: Prevents outflow of venous blood from the brain. Leads to a gradual backup of venous blood into the face and brain causing “venous congestion” and eventually petechial hemorrhages. However, the jugular vein and the carotid artery are anatomically side-by-side, and the difference between the collapse of the jugular vein and the carotid artery is only 7 pounds of pressure.
ANATOMY OF THE NECK
To best understand the clinical features associated with strangulation, one must understand the basic anatomy and functions of the neck (Figure 1). The neck is comprised of subcutaneous fat, muscle, cartilage, bone, vessels, nerves, lymph nodes, and salivary glands. The underlying neck structures that are especially vulnerable to the intentional external pressure from strangulation are located in the anterior and anterolateral neck. These structures include the hyoid bone, larynx, trachea, jugular veins, and carotid arteries. The vertebral arteries are located on the side of the neck (Figure 2-a and b). To grasp the importance of these structures, it is important to understand the role of the individual structure in the cardiovascular and respiratory system.
Life-sustaining oxygenation depends on the combination of air and blood flow. Respiration starts with the free movement of oxygenated air through the upper air passages (ie, the nose and mouth). Then, the air must flow freely through the larynx, to the trachea, and finally, to the lungs. Oxygenation occurs when the lungs shift oxygen from inhaled air into the blood. Then, the cardiovascular system pumps oxygenated blood through the heart and up into
