Penetrating neck injuries

General principles
Assume the knife/etc. is of any length, penetrated to any depth, and hit any structure. 
Apply pinpoint (focal) pressure if needed, not general pressure.
If airway slashed open, intubate it if able!
Gunshot wounds are very different to stab wounds due to cavitation injury.


Examination

Neck Zones

• Zone 1: clavicles to crycoid
• Zone 2: crycoid to angle of jaw
• Zone 3: above angle of jaw

Don't forget to check the hairline, ears etc.

Management
Traditional workup was to explore all Zone 2 injuries and angiography/panendoscopy to Zone 1 and 3.  Forget this. 
Remember the hole doesn't necessary correlate with the injury.  Does the patient have hard signs of vascular or aerodigestive tract injury?  If so, there's no role for radiologic investigation, these patients need to go to the OT.
However, the vast majority of patients have soft signs - these patients need CT angiography.  CT angiography has a Sensitivity of 100% and Specificity in the 90% (in the absence of fragments causing artifact, such as bullets).
Should you probe the wound?  Probably not.