S21C263 - Penetrating trauma to the extremities

Question 1

ABI - ankle brachial index

Answer 1

-does not reliable detect nonocclusive arterial disease eg. intimal flaps and pseudoaneurysms -diagnostic accuracy can be as high as 95% -how to perform: place pt supine, measure SBP in all 4 limbs, for ankle place standard cuff around ankle above malleoli, use a doppler flowmeter to detect the SBP -calculate ABI by dividing the ankle SBP by the greater of the 2 systolic upper extremity SBP -ABI >1 is normal -ABI of 0.5-0.9 is indicative of injury -a difference of >20mmHg b/w upper extremities is indicative of injury to an UE -underlying PVD or hypothermia can affect ABI

Question 2

Signs of Extremity vascular trauma

Answer 2

HARD SIGNS

• absent/diminished pulses
• obvious arterial bleeding
• large expanding/pulsatile hematoma
• audible bruit
• palpable thrill
• distal ischemia (5 Ps: pain, pallor, paralysis, paresthesias, poikilothermia)
• soft signs: small hematoma, unexplained HoTN, hx of hemorrhage, proximity of injury to major vasc structures, complex #, injury to anatomically related nerve

Question 3

pattern from bullets:

Answer 3

• drill hole pattern: seen in proximal humerus, pelvis, distal femur
• unicortical #: from tangential bullet impact
• spiral #: distant fro site of impact, occurs if bone under torsional stress
• simple #: caused by indirect damage from a temporary cavity caused by a GSW
• comminuted
• air in joint = joint penetration - ortho consult

Question 4

Imaging of penetrating trauma to limbs:

Answer 4

-angiography is negative in 80-90% of cases w/o hard signs of vascular injury and

Question 5

Nerves of the Extremities:

Answer 5

-

Question 6

Pts with soft signs

Answer 6

-often managed with observation for 24h with serial examinations

Question 7

Bone # with penetrating injury: mgmt

Answer 7

• treat as for open #
• Abx: cephalosporin and gentamicin
• will need surgical debridement

Question 8

Irrigation for penetrating injuries:

Answer 8

• 500cc-1000cc at high pressures (15-20 lbs per square inch)
• 60cc syringe with 18g catheter or wound irrigator
• saline or tap water
• antiseptic solutions may be harmful
• if wound >3h old, gentle scrubbing is recommended

Question 9

Soft tissue foreign body

Answer 9

• glass, metal, gravel, bone are visible on plain film
• wood not seen on plain film but is seen on u/s
• CT scan can be useful for readioluecent and opaque FB

Question 10

Wound closure after penetrating trauma

Answer 10

• pts with delayed presentation, contaminated wounds, soft tissue foreign bodies, extensive tissue destruction… benefit from delayed primary closure after 72h if no signs of infx at that time
• rate of infxn in GSW or stab wound is 1.8%