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Subsections
Strangulation and Hanging

Trauma

Strangulation and Hanging

Background

  1. Definition(s)
    • Strangulation is the external compression of the neck leading to airway obstruction or vascular occlusion
    • Hanging occurs when pressure is exerted on the neck (i.e., by a rope or noose) and then tightened by the weight of the victim's body
  2. Synopsis
    • Strangulation
      • Ligature compression by rope/cord
      • Manual compression by physical force (i.e., hands)
      • Postural body weight compresses anterior neck against a firm object
        • Seen in infants
        • Occurs when the child's neck is placed over an object, and the weight of the body puts undue pressure on the neck
    • Hanging
      • A subset of strangulation
      • The mechanism of death may differ depending on the method of hanging
      • Complete (judicial)
        • Body is suspended, feet do not touch the ground
        • Ligature around neck
        • Drop
          • Standard drop is 4-6 feet
          • > 10 feet causes decapitation
        • Victim falls at least the height of the body
          • More typical to cause death by fracture of the upper cervical spine (hangman's fracture) and transection of the spinal cord
      • Incomplete (non-judicial)
        • Partial suspension
        • Some part of the body is still in contact with the ground\
        • More common in confined spaces
          • Home, jail
        • Cervical spine is spared
          • Only 1/150 of suicidal hangings experience a cervical fracture
        • Death may occur secondary to carotid sinus stimulation and increased vagal tone
      • Knot location
        • Typical: knot midline, directly under occiput
          • Greater chance of complete arterial occlusion
        • Atypical all other knot placements
          • Knot under chin
          • More likely to cause a Hangman's fracture
            • Fracture of both pedicles or pars interarticularis of C2
            • Mechanism is a hyperextension injury usually with a neck distraction
            • Causes compression/ distraction of the spinal cord
            • Other mechanisms include sports injuries, MVC
            • Ipsilateral Horner's Syndrome
              • Loss of sympathetic innervation to the eye
    • Management
      • Intubation as needed
        • Mechanical ventilation may be required
      • Stabilize medically
      • Consult ENT or trauma surgery as needed
      • Prep for surgery as needed

Pathophysiology

  1. Mechanism
    • Judicial hanging (with fall of adequate distance)
      • Head forcibly distracted from neck / body
      • Causes high cervical fractures, complete cord transection, death
    • Manual strangulation / attempted suicide hangings
      • Height of fall usually inadequate
      • Mimic non-judicial strangulation
      • Fractures of the thyroid cartilage, hyoid bone and larynx are associated with strangulation
        • Traumatic edema of the airway leads to airway compromise
      • Cervical spine fractures are rare
      • Sequence of events is as follows from low neck pressure (takes as little as 2 kg of pressure on the neck) is multifactorial
        • Venous obstruction
          • Compression of neck causes venous congestion and hypoxia
          • Cerebral blood flow becomes static leading to ischemia
          • Unconsciousness occurs (approximately 10 seconds)
          • Increased ICP
          • Limp body allows ligature to further tighten (approximately 1-2 minutes)
          • Complete arterial occlusion occurs to the carotids and then vertebral arteries
          • Brain damage and death ensue (glucose and ATP exhaustion) at approximately 3-5 minutes
          • Cytotoxic and vasogenic edema
        • Pericarotid stimulation
          • Increased sympathetic discharge
          • Dysrhythmic cardiac arrest
        • Direct carotid bulb pressure or Valsalva
          • Increased parasympathetic discharge
          • Bradycardic arrest
        • Airway obstruction plays a much less significant role
          • Upward displacement of the tongue and epiglottis may occur
          • Patients with permanent tracheostomy may still die by hanging
    • Traumatic asphyxia
      • Sudden increased intrathoracic pressure
      • Object falling on chest prolongs compression
      • Increased thoracic venous pressure leads to capillary rupture and ecchymosis
      • Cause of death is chest wall constriction and hypoxia and apnea
      • No animal can survive more than 5 times its body weight for greater than 10 minutes
        • Relevance to search and rescue efforts
  2. Etiology/Risk Factors
    • Extreme sports (i.e., bungy jumping)
    • Homicides or assault
    • Suicide
      • Second most common form of suicide in the U.S.
      • Most common involves firearms in U.S.
      • Most common form of suicide in Great Britain, Canada
      • Materials are readily available
        • i.e. shoelaces, neckties, belts
      • Full suspension is NOT mandatory
  3. Epidemiology
    • Incidence/ Prevalence
      • 2nd most common suicide modality
    • Mortality/Morbidity
      • Initial GCS is NOT predictive of outcome
      • Time to irreversibility
        • < 5 minutes, universally survivable
        • > 30 minutes, universally fatal
      • Delayed mortality can be caused by
        • Neurogenic pulmonary edema
        • Aspiration pneumonia
        • Cerebral anoxia
          • May caused delayed neurologic sequelae
      • Death can occur by one of three mechanisms
        • Injury to the spinal cord/ brainstem
        • Mechanical constriction of the neck structures
        • Cardiac arrest

Diagnostics

  1. History/Symptoms
    • Ask about mechanism of injury
      • EMS, Bystanders, Patient
    • Pain to the neck or voice changes
    • Pain on laryngeal palpation
    • Presence of Cough
    • Respiratory distress
    • Hypoxia, mental status changes
    • Psychiatric evaluation
  2. Physical Exam/Signs
    • General appearance, Vitals
      • Evaluate for external trauma, may not be found
    • HEENT
      • Ligature marks - variable intensity (View image)
      • Findings of impending airway compromise include
        • Muffled or hoarse voice
        • Stridor
      • Fingernail scratches, abrasions, contusions
        • Disc-like fingertip bruises from assailant during manual strangulation
        • Linear fingernail scratches are from the victim trying to remove the hands
        • Tongue congestion and cyanosis
      • Tardieu's spots
        • Petechial hemorrhages above the ligature marks
          • Conjunctiva
          • Mucous membranes
          • Skin
      • Laryngeal injuries (near hanging victims)
        • Thyroid cartilage fractures (50%)
        • Hyoid fractures (20%)
        • Injury to the sternocleidomastoid muscle
      • Vascular injuries
        • May cause delayed neurologic damage
        • Rare
        • Intimal dissection or thrombus formation
        • Late findings have been reported but are rare
      • Pulmonary sequelae are common
        • Neurogenic pulmonary edema
        • Secondary to increased sympathetic discharge
        • Poor prognosis
        • Can lead to ARDS which is difficult to treat
        • Caused by forceful inspiration against an extrathoracic obstruction leading to negative intrapleural pressure
        • When the pressure is removed, rapid edema ensues and leads to ARDS
  3. Labs/Tests
    • Blood type and cross as needed
    • BMP
    • CPK
    • Urinalysis as needed
  4. Imaging
    • Xray
      • Neck soft tissues
        • Subcutaneous emphysema
        • Fracture hyoid bone
        • Tracheal deviation secondary to edema or hematoma
      • Cervical spine
      • Chest
    • CT
      • Neck
        • High sensitivity for soft tissue injury
      • Head
        • When altered mental status
    • MRI
      • Gadolinium MR angiography - for assessment of carotid injuries
      • Can visualize the carotids from the aortic arch to the circle of Willis - helpful if the level of injury is unknown
    • Carotid Doppler ultrasound
    • Direct fiberoptic laryngoscopy
      • If not at risk for airway compromise
      • Can help establish injuries of the vocal cords and trachea
    • Angiogram
  5. Other Tests/Criteria
    • Psychiatric evaluation
  6. Differential Diagnosis
    • Chronic Obstructive Pulmonary Disease
    • Emphysema
    • Asthma
    • Depression
    • Angioedema
    • Epiglottitis
    • Neck Trauma
    • Spinal Cord Injuries
    • Suicide
    • Domestic Violence
    • Sexual Assault

Treatment

  1. Initial/Prep/Goals
    • Focus on airway, respiratory, cardiac and neurologic findings
      • Also consider psychiatric evaluation
    • ABCs, ATLS
      • C-spine precautions
        • Very unlikely except in judicial style hangings
        • Most suicidal and accidental hangings will not cause cervical fractures
      • Assess need for intubation - consider above airway findings / respiratory distress
      • Cardiac monitoring for dysrhythmias
      • Often need ventilatory support
        • Maintain oxygen saturation
        • Hyperventilate for brain injury
        • Often need PEEP
          • ARDS may develop
    • If comatose/AMS
      • Assume cerebral edema / elevated ICP
    • Consult ENT for neck injuries
    • Elevate head of bed to reduce edema
    • Consider ICP monitoring if suspect cerebral injury
      • Help direct hyperventilation, diuretics and fluid restriction
  2. Medical/Pharmaceutical
  3. Surgical/Procedural
    • Tracheal intubation
      • May be emergently needed
      • Consider cricothyrotomy
        • Caution avoid cricothyrotomy if hematoma over the cricothyroid membrane
      • TTJV may be an option
  4. Complications
    • Aspiration pneumonia
    • ARDS
    • Tracheal stenosis
    • Spinal cord injury
    • Mental and psychiatric issues
    • Scarring
  5. Prevention
    • Counseling

Disposition

  1. Admission Criteria
    • All patients with strangulation or hanging injuries
    • Consider 24 hr observation (delayed airway obstruction)
  2. Consults
    • Surgery
    • ENT
    • Psychiatry
      • Often required for survivors
  3. Discharge/Follow-up instructions
    • Hemodynamically stable
    • Mental status at baseline
    • No evidence of vascular injury
    • No evidence of cervical injury
    • Psychiatric clearance if necessary

References

  1. Bean AS. Neck Trauma. In: Tintinalli JE, Ma JO, Yealy DM, et al; (eds). Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9th ed., New York, NY:McGraw-Hill, 2020; Chapter 260
  2. Dunn RJ, Sukhija K, Lopez RA. Strangulation Injuries. StatPearls [Internet]. Available at: https://www.ncbi.nlm.nih.gov/books/NBK459192/. [Accessed October 2022]
  3. Kumar SR. Cervical vascular injuries carotid and jugular venous injuries. Surg Clin North Am. 2001;81(6):1331-1344
  4. Matsuyama T, Okuchi K, Seki T, et al. Prognostic factors in hanging injuries. Am J Emerg Med. 2004;22(3):207-210
  5. McClane GE, et al. A review of 300 attempted strangulation cases, Part II clinical evaluation of the surviving victim. J Emerg Med. 2001;21(3):311-315
  6. Nikolic S, et al. Analysis of neck injuries in hanging. Am J Forensic Med Pathol. 2003;24(2):179-182
  7. Sauvageau A, et al. Agonal sequences in eight filmed hangings analysis of respiratory and movement responses to asphyxia. J Forensic Sci. 2010;55(5):1278-1281

Contributor(s)

  1. Feldman, Natalie, MD

Updated/Reviewed: October 2022