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จาก Cumming's Otolaryngology - Head & Neck Surgery, 5th Edition (2010)

Sign & Symptom

• Airway: Respiratory distress, Stridor, Hemoptysis, Hoarseness, Tracheal deviation, Subcutaneous emphysema, Sucking wound
• Vascular: Hematoma, persistent bleeding, neurodeficit, absent pulse, shock, bruit, thrill
• Nervous: Hemiplegia, quadriplegia, coma, CN deficit, hoarseness
• Esophagus/hypopharynx: subcutaneous emphysema, dysphagia, odynophagia, hematemesis, hemoptysis

Handgun

• Impact 50 m/s เข้า skin, 65 m/s fracture bone
• Civilian - Low-muzzle velocity (90 m/s)
• มักเบียด vascular structures มากกว่า
• High velocity bullet: > 610 m/s
• Handgun/pistol (.22, .45) : 210-600 m/s
• Magnum .44 : greater velocity – injury comparable with rifle
• กระสุนที่เบี่ยงวิถี/เด้ง จะสร้างความเสียหายมากกว่า

Rifle

• Mostly 760 m/s
• Created cavity up to 30 times the size of bullet
• High energy missiles not easily deflected, cause significant destruction along path (energy absorbed)
• Mortality is significant, usually not survive to study

Shotgun

• Pellets scatter as they travel
• At close range: act like single missile similar to high-velocity bullet of rifle (blast)
• At further distance: act like multiple bullet (depends on gauge, shot, powder load and choke of gun) – may be hidden in multiple locations
• Low-velocity (300 m/s)

Table 115-2 Classification of Birdshot Shotgun Wounds

	Range
Type	Standard Barrel	Sawed-off Shotgun	Injury	Mortality (%)
0	Long >12 m	>4 m	Superficial—pellets in skin only	0
I	Long >12 m	>4 m	Penetrates only subcutaneous tissue	0-5
II	Close 5-12 m	2-4 m	Penetrates beyond deep fascia	15-20
III	Point blank <5 m	0-2 m	Extensive tissue damage	85-90

• Massive bleeding
• Expanding hematoma
• Nonexpanding hematoma + hemodynamic instability
• Hemomediastinum
• Hemothorax
• Hypovolemic shock

Stable patient: exploration or close monitor

Classification of neck zone

• Zone I: below cricoid: vital vascular structures close to thorax. Mortality 12%. Angiography suggested before exploration. Not recommend mandatory exploration
• Zone III: above angle of mandible: difficult to explore. Abnormal neuro exam suggest need for angiography (CN close to vessels – hypoglossal-carotid, Horner’s syndrome due to injury of sympathethic chain around carotid)
• Zone I & Zone III with stable, without airway obstruction/heavy bleeding/expanding hematoma: angiography +- barium swallow (Zone III beware hematoma in parapharyngeal/retropharyngeal space)
• Zone II: controversy, leading cause of death: hemorrhage

Initial management

• Airway management
• Intubation
• Cricothyroidotomy
• Tracheostomy (safer when OC/pharynx/larynx are traumatized)
• Blood perfusion management
• IV large bore + fluids
• Clarification/classification of severity of wound
• No probing (clot dislodgement and uncontrolled bleeding may occur)
• Film neck AP – lateral
• Film CXR: manage pneumo/hemothorax

Management of vascular penetration

• Zone I: thoracic approach (low cervical not sufficient) – mediastinotomy / lateral thoracotomy
• Zone III: may require mandibulotomy
• All vein in neck can be safely ligated to control hemorrhage (if 2 IJV interrupted – attempt to repair one)
• Branches of external carotid artery may ligated because collateral circulation is good