Suspension, Blast & Ballistics

What is suspension trauma?

casualty who’s experiencing pre-syncopal symptoms or who’s uncons whilst suspended in a harness

Suspension trauma pathophysiology

• lower extremity venous circulation is exclusively dependent on on muscle contraction

• when suspended and immobile, a “cascading” even can occur immediately

Suspension cascade

• can’t escape vertical position with legs dangling

• 3-6 mins - venous pooling begins unless legs are moving

• 6-12 mins - obstruction of venous returns worsens as harness compresses femoral veins. harness and abdo pressure compress inferior vena cava

How to prolong tolerance of suspension?

elevation of legs by casualty or rescuer

Most common method of suicide?

hanging, accounting for 61% of all suicides in those aged >10yrs

Short drop hanging

death caused by asphyxia due to compression of airway and blood vessels in the neck

long drop hanging

death caused as a result of fracture-dislocation of upper cervical vertebrae

Management of hanging

• dynamic risk assessment

• signs of life? need for resus?

• remove/cut ligatures

• call for help early

• move pt to appropriate position for assessment and management (consider c spine)

• airway priority over c spine if req

• airway management may be difficult, potential airway inj and swelling

Management of hanging if no CPR is commenced

staff should not disturb scene to assist police with investigation

Post ROSC care of hanging

• likely to be hypoxic and agitated and may need specialist care ons

• possibility of spine/spinal cord inj

What are blast injuries caused by?

• warefare/terrorism

• gas leaks

• factories/commercial sites

• fuel refineries

• transport

Blast injuries stages

• primary - shock wave - lungs blast, bowel perforations

• secondary - fragments/debris - penetrating trauma/lacerations

• tertiary - blast wave propels pt - blunt trauma/fractures

• quaternary - burns, asphyxiation

• quinary - chemical burns, radiation, infection

Types of penetrating trauma

• stab wounds

• gunshot wounds

Stab wounds

• low velocity, low energy penetrating trauma

• multiple wounds from single weapon

Common stab wound weapons

• knife

• scissors

• ice picks

What are stab wound injuries limited to?

depth and area of penetration

What type of injury does stab wounds leave?

small external injury with significant inside damage

Gunshot wounds

• higher velocity, more energy into pt

• leaves permanent cavity in body and also creates temporary cavity when projection enters body

Cavitation

• permanent cavity formed by pathway of projectile

• temporary cavitation is relative to energy that comes with projectile

• more energy = greater temporary cavity

• same effect as explosion in body

• large exit wound but small entry wound

What happens if there’s no exit wound from a gunshot?

Ricochet inside body, increases tissue damage, pathway becomes erratic. so all kinetic energy transferred to body

Entry and exit wounds for gunshots

• entrance wound is often size of projectile

• exit wound can be considerably larger and not always in expected place

Things to consider in gunshot calls

• scene safety

• weapon type

• anatomical structures along projectile path

• crime scene

• pt care = top priority

• kinetic energy