Basics
Description
- Strangulation:
- Ligature: Material used to compress structures of neck
- Manual: Physical force used to compress structures of neck
- Postural: Airway obstruction from body weight (over an object) or position (typically in infants)
- Hanging is a form of strangulation:
- Complete (judicial type): Victims entire body is suspended off the ground
- Incomplete (nonjudicial): Some part of victim's body contacts the ground
- Typical: The point of suspension is placed centrally over the occiput.
- Atypical: The point of suspension is in any position other than over the central occiput.
- Intentional: Suicide, homicide, autoerotic, "the choking game "
- Accidental: Often children or clothing caught in machinery
- Near-hanging: Survival following nonjudicial hanging
Etiology
- Hanging (judicial):
- Victim is dropped a distance at least equal to his or her height
- Forceful distraction of head from torso results in a decapitation type of injury (fracture of cervical spine and transection of spinal cord)
- Hanging (nonjudicial):
- Typically occurs from a lower height
- Injuries mimic nonjudicial strangulation
- Strangulation:
- External neck pressure causes cerebral hypoxia secondary to venous and arterial obstruction.
- Pressure on neck structures may cause airway, soft tissue, and vascular injuries.
- Cervical spine injuries are uncommon except with judicial-type hanging.
- Death:
- Secondary to mechanical closure of blood vessels or airway
- Secondary to cardiac arrest from extreme bradycardia due to increased vagal tone from carotid sinus pressure
- Secondary to direct neurologic injury to the spinal cord
- Secondary to pulmonary complications in near-hanging victims
- Secondary to cerebral hypoxia
Commonly Associated Conditions
- Cervical spine injury
- Hypoxic cerebral injury
- Arterial or venous dissection/thrombosis
- Hyoid bone fracture:
- Typically seen in nonjudicial strangulation
- Cricoid cartilage disruption (rare)
- Thyroid cartilage disruption:
- More common in nonjudicial strangulation deaths
- Phrenic nerve injury
- Airway edema
- Aspiration pneumonitis (may be late)
- Neurogenic pulmonary edema (may be late):
- Due to massive central sympathetic discharge
- Postobstructive pulmonary edema (may be rapid onset):
- Due to negative intrapleural pressure resulting from inspiration against an external airway obstruction
- Air embolism:
- Consider when SC air and vascular injuries are present
Diagnosis
Signs and Symptoms
- Airway disruption:
- SC emphysema
- Dyspnea
- Dysphonia or stridor
- Loss of normal cartilaginous landmarks
- Cervical spine injury:
- Respiratory arrest
- Paralysis
- Neurologic injury:
- Hoarseness
- Dysphagia
- Altered mental status
- Neurologic deficit
- Pulmonary sequelae:
- Respiratory distress
- Pulmonary edema, ARDS, pneumonia
- Soft tissue injury:
- Abrasions, contusions, ecchymoses, ligature, or hand marks
- Vascular injuries:
- Expanding hematoma
- Pulse deficits or bruits
- Evidence of cerebral infarction
- Tardieu spots: Petechial hemorrhages of the skin, mucous membranes, and conjunctiva cephalad to the ligature marks
- Structures of neck are more cartilaginous and mobile than in adults
- More resistant to crush injuries and fractures
- Rapid airway compromise can occur with relatively little edema of soft tissues secondary to smaller airway diameter.
History
- Strangulation method:
- Patient position:
- To determine mechanism of strangulation
- Predict potential injuries
- Higher fall implies greater force:
- Decapitation-type injury more common
- Knot position:
- Arterial occlusion more likely in typical hanging
- Ligature material:
- Elasticity limits force applied
- Venous occlusion may still produce unconsciousness and death
- Circumstance:
- Accidental, suicide/homicide, NAT, sexual, "choking game "
Physical Exam
- ABCs:
- Airway or respiratory compromise
- C-spine precautions
- Disability:
- Coma, AMS, neurologic deficit, paralysis
- Secondary survey:
- Assess for traumatic injury to the neck:
- Soft tissue, aero-digestive, vascular
- Other traumatic injury due to fall, self-inflicted wounds (suicidal), injury sustained in conflict (homicidal/NAT)
Essential Workup
- CT of the cervical spine through T1
- CT scan of the head:
- For cerebral hemorrhage, subarachnoid hemorrhage, hematoma, edema, and evidence of hypoxic injury
- CT angiography of the neck:
- For thrombosis and intimal dissection
- Plain radiography:
- CXR to evaluate for SC emphysema, aspiration pneumonitis, and pulmonary edema
- Pulse oximetry
- Cardiac monitor
Diagnosis Tests & Interpretation
Lab
- ABG (may be considered):
- Evaluate for evidence of hypoxia or respiratory compromise.
- Hematocrit for significant blood loss
- Type and cross-match in anticipation of transfusion for vascular injuries.
- Coagulation profile for significant blood loss or coagulopathy
- Toxicology studies (ASA/APAP/ETOH):
- Consider for suicide-related ingestions
Imaging
- MRI of the neck:
- High sensitivity of MRI for soft tissue injury, bone and cartilaginous injury.
- Superior to CT in diagnosis of soft tissue injury.
- Arteriography:
- Definitive evaluation for potential vascular injuries
Diagnostic Procedures/Surgery
- Fiberoptic endoscopy:
- Allows direct visualization for evaluation of aero-digestive injury
- May aid in intubation
- Surgical exploration
Differential Diagnosis
Etiology of strangulation:
- Accidental, homicidal, suicidal, NAT, auto-erotic, choking game
Treatment
Pre-Hospital
- ABCs
- Early and aggressive airway management: Oxygen, suction, intubation, as indicated:
- Cardiac monitor
- Cervical spine stabilization:
- Patient position, strangulation method, drop involved, knot location, signs of foul play
Initial Stabilization/Therapy
- ABCs
- Aggressive airway management with cervical spine precautions is paramount:
- Early intubation for respiratory compromise
- Supplemental oxygen
- Cricothyrotomy or tracheostomy may be required if severe maxillofacial injuries are present:
- Avoid cricothyrotomy if hematoma over cricothyroid membrane or evidence of cricotracheal disruption is seen.
- Arrange for emergent tracheostomy in above scenario (see Larynx Fracture).
- Control bleeding with application of direct pressure:
Ed Treatment/Procedures
- IV access
- Consult otolaryngologist or trauma surgeon in management of neck soft tissue injuries.
- Consult vascular surgery in management of vascular injuries.
- Consult neurology for suspected cerebral ischemic insults (thrombosis, embolism, dissection).
- Supportive care for suspected elevated intracranial pressure/cerebral edema:
- Elevate head of bed.
- Ensure adequate oxygenation and cerebral perfusion.
- Prevent secondary neurologic injury/insult.
- Consult neurosurgery for intracranial pressure monitoring and surgery as indicated.
- Neck injury with SC emphysema:
- Assume that mucosa of upper airway communicates with deep tissues of neck.
- Administer antibiotics.
- Laryngeal edema:
- Evaluate for associated injuries or harm:
- Consider ingestions in suicidal cases.
- Report suspected nonaccidental injuries in children.
Medication
- Hypoxic brain injury:
- Mannitol: 0.25 " 1 g/kg/dose IV (consider for elevated intracranial pressure; not routinely used in pediatric cases)
- Hypertonic saline: Dosing regimens vary (consider for elevated intracranial pressure)
- Phenytoin: 15 " 20 mg/kg IV (loading dose) as needed for seizures
- Neck injury with SC emphysema:
- Ampicillin/sulbactam: 1.5 " 3 g (peds: 100 " 400 mg/kg/d) IV q6h
- Clindamycin: 600 mg (peds: 25 " 40 mg/kg/d) IV q8h
- Airway edema:
- Dexamethasone: 0.5 " 2 mg/kg/d (peds: 0.25 " 0.5 mg/kg) IV q6h
Follow-Up
Disposition
Admission Criteria
- Admit patients with strangulation or hanging-mechanism injuries to a monitored setting to observe for airway or neurologic compromise (may have delayed onset).
- Surgical correction of laryngeal, esophageal, or vascular neck injuries
- Altered level of consciousness, new neurologic deficit, coma
- Respiratory distress:
- Supportive care for pulmonary edema, ARDS, pneumonia
- All patients with suspected suicidal or homicidal strangulation injury should have psychiatric or social work consultation.
- For pediatric patients:
- Suspected nonaccidental trauma, concern for safety in the home
Discharge Criteria
Only patients without strangulation or hanging injuries may be discharged after appropriate observation in the ED to ensure absence of airway compromise, vascular injury, neurologic deficit, and suicidal/homicidal ideation.
Follow-Up Recommendations
- Neuropsychiatric evaluation:
- Consider in evaluation for hypoxic encephalopathy
- Psychiatry/psychology:
- Suicidal or homicidal patients
- Auto-erotic or "choking game " patients for medical/cognitive/behavioral therapy
- Surgical follow-up:
- As indicated, based on injuries sustained
Pearls and Pitfalls
- Cervical spine injury is uncommon in nonjudicial hanging victims:
- Cerebral hypoxia is the probable cause of death in the majority of victims.
- Aggressive airway management is paramount.
- Thoroughly evaluate for associated injuries.
- Consider admission for observation of all strangulation/hanging victims.
- Prognosis:
- GCS on arrival does not predict prognosis.
- Poor prognosis is suggested by:
- Anoxic brain injury on head CT
- Increased hanging time
- Cardiac arrest at the scene AND on arrival to the ED
Additional Reading
- Christe A, Oesterhelweg L, Ross S, et al. Can MRI of the neck compete with clinical findings in assessing danger to life for survivors of manual strangulation? A statistical analysis. Leg Med (Tokyo). 2010;12(5):228 " 232.
- Christe A, Thoeny H, Ross S, et al. Life-threatening versus non-life-threatening manual strangulation: Are there appropriate criteria for MR imaging of the neck? Eur Radiol. 2009;19(8):1882 " 1889.
- Dundamadappa SK, Cauley KA. MR imaging of acute cervical spinal ligamentous and soft tissue trauma. Emerg Radiol. 2012;19(4):277 " 286.
- McClane GE, Strack GB, Hawley D. A review of 300 attempted strangulation cases Part II: Clinical evaluation of the surviving victim. J Emerg Med. 2001;21:311 " 315.
- Nichols SD, McCarthy MC, Ekeh AP, et al. Outcome of cervical near-hanging injuries. J Trauma. 2009;66:174 " 178.
Codes
ICD9
994.7 Asphyxiation and strangulation
ICD10
- T71.161A Asphyxiation due to hanging, accidental, initial encounter
- T71.162A Asphyxiation due to hanging, intentional self-harm, initial encounter
- T71.163A Asphyxiation due to hanging, assault, initial encounter
- T71.164A Asphyxiation due to hanging, undetermined, initial encounter
SNOMED
- 129674006 Asphyxiation by hanging (event)
- 242017004 Asphyxia by strangulation by ligature (event)
- 219194004 Assault by strangulation (event)
- 242019001 Asphyxia by manual strangulation (event)
- 248107000 Self-asphyxiation during masturbation (event)