Penetrating neck trauma

Penetrating neck injuries are potentially life threatening due to the critical structures contained within the neck. Delayed diagnosis of some serious injuries (eg: oesophageal lacerations) is a significant concern as patients can have minimal initial physical and radiological examination findings.

Anatomy

From an anatomical point of view, penetrating trauma to the neck has been classically divided into three “zones”. These give an indication to which underlying structures may have been damaged. Up until recently, the zones injured would dictate the investigation and management approach undertaken.

From: Zones. emDOCS. http://www.emdocs.net/neck-trauma-practice-update/ Licenced under: CC BY 4.0

 

zones of neck

 

More recent studies have noted that injuries can easily extend beyond the zone of the laceration depending on the trajectory and force of the injuring object. One study found a poor correlation between the location of the external injury and the internal structures damaged.¹

A strict approach to zones of the neck and approach to investigations and management has therefore been questioned and an approach based on physical findings and radiological findings advocated.^1,2

Zone anatomy can still be utilised for describing injuries to other clinicians and as a rough guide for predicting underlying injuries so should be in the lexicon of the trauma physician.

 

Investigations and management

Patients with penetrating neck injuries can present in extremis and require immediate resuscitation

 

Resuscitation 

 

Control external haemorrhage

The leading cause of immediate death from neck lacerations is exsanguination.

In the first instance, apply local pressure. Other methods of haemorrhage control have been described eg: placing a foley catheter into the wound and inflating the balloon with a clamp or artery forcep placed across the catheter next to the skin to provide traction.³

There might also be a place for haemostatic dressings if available as well as tranexamic acid administration.

Do not blindly tie of vessels (they might be important!)

If the bleeding continues briskly, the patient needs urgent operative intervention

 

Airway

Emergent control of the airway is indicated if the patient has signs of airway compromise, respiratory distress, severe haemorrhage/shock, or an extensive/sucking neck wound.

 

Be prepared for a difficult airway due to blood and/or distorted anatomy

 

A “double set up” (being prepared for orotracheal and surgical airway) is advocated – orotracheal intubation is preferable but some patients will severe neck trauma have an “inevitable” surgical airway and will require cricothyroidotomy (note that a cric can also be extremely difficult if there is anatomical distortion).

 

If there is appropriate equipment and expertise with some time to spare, fibreoptic intubation with direct vision of the airway would be the safest intubating method, especially if there is an anticipated airway laceration (to avoid creating a false passage).

 

If the trachea is transected (and can be visualised externally) – a towel clamp can be used to grasp the trachea caudally, and the patient intubated through the open trachea.

 

Note: cervical spine injuries are rare in penetrating neck injuries. In one large case series found an incidence of 1.35% with gun shot wounds and 0.12% with stab wounds. The rate of spinal cord injury were even lower.⁴ If a C spine collar has been placed and is hindering resuscitation or evaluation of the injuries, it should be removed.

 

Breathing

Lower neck lacerations can cause lung injuries with subsequent pneumo/haemothoraces.

 

Circulation

The shocked patient should be resuscitated, ideally with blood. Damage control resuscitation with acceptance of a lower SBP might be appropriate.

 

Investigations

 

If the patient is stable, and no hard or soft signs gently explore the wound. Do not blindly probe wounds.

If the wound has not breached the platysma, the wound can be closed and the patient discharged if appropriate.

For patients where the platysma is breached, the physical examination findings will guide their management.

Penetrating neck flow

 

Some patient with so called “hard signs” require immediate operative exploration of their wounds.

 

hard signs

 

Those with “soft signs” should have further diagnostic imaging. Previously a “zone” approach was advocated (ie: different investigation pathways depending on which zone lacerated) but most patient now are investigated with CT angiography in the first instance.

 

soft signs

 

The next step in management will depend on the results of the CTA. Even if the CT is normal, admission for a period of observation (eg: 24h) is recommended as occult injuries can be missed on CT.

If a tracheal or laryngeal injury is suspected, direct vision with flexible nasal endoscopy is indicated (liaise with ORL if proximal or Respiratory if distal)

Note that oesophageal injuries are notoriously missed (even with CT) with subsequent significant morbidity and mortality. Have a high index of suspicion if the wound trajectory and/or injuries to nearby structures might fit with an occult oesophageal injury. If there are concerns regarding oesophageal laceration, the patient should have oesophagoscopy or barium swallow performed (keep the patient NBM and treat with IV antibiotics until this injury is excluded). Delayed management of oesophageal lacerations is the leading cause of late death in patients with neck lacerations.

Signs of oesophageal injury include

• Dysphagia
• Haematemesis or blood stained saliva
• Subcutanous or mediastinal air seen on CXR/CT.

 

Patients with a normal physical exam and no “soft signs” should have a CXR and AP/lateral neck xrays . Based on the literature, they can probably be safely observed without further imaging,^5,6  but this will depend on the admitting team’s experience and preference. In reality, most of these patients will have cross-sectional imaging prior to being cleared for discharge.

 

References

 

1. Low GM, Inaba K, Chouliaras K, Branco B, Lam L, Benjamin E, Menaker J, Demetriades D. The use of the anatomic ‘zones’ of the neck in the assessment of penetrating neck injury. The American Surgeon. 2014 Oct 1;80(10):970-4.
2. Prichayudh S, Choadrachata-anun J, Sriussadaporn S, Pak-art R, Sriussadaporn S, Kritayakirana K, Samorn P. Selective management of penetrating neck injuries using “no zone” approach. Injury. 2015 Sep 30;46(9):1720-5.
3. Navsaria P, Thoma M, Nicol A. Foley catheter balloon tamponade for life-threatening hemorrhage in penetrating neck trauma. World journal of surgery. 2006 Jul 1;30(7):1265-8.
4. Rhee P, Kuncir EJ, Johnson L, Brown C, Velmahos G, Martin M, Wang D, Salim A, Doucet J, Kennedy S, Demetriades D. Cervical spine injury is highly dependent on the mechanism of injury following blunt and penetrating assault. Journal of Trauma and Acute Care Surgery. 2006 Nov 1;61(5):1166-70.
5. Inaba K, Branco BC, Menaker J, Scalea TM, Crane S, DuBose JJ, Tung L, Reddy S, Demetriades D. Evaluation of multidetector computed tomography for penetrating neck injury: a prospective multicenter study. Journal of Trauma and Acute Care Surgery. 2012 Mar 1;72(3):576-84.
6. Azuaje RE, Jacobson LE, Glover J, Gomez GA. Reliability of physical examination as a predictor of vascular injury after penetrating neck trauma. The American surgeon. 2003 Sep 1;69(9):804.