Trauma

Question 1

What are the tenets of trauma laparotomy?

Answer 1

1. Rapid entry via adequate incision
2. Control of massive haemorrhage by
   
   • Identification of source
   • Packing
   • Direct control
   • Proximal (source) control
3. Identification of injuries
4. Control of contamination
5. Recontruction as physiological state allows

Question 2

Discuss the evidence for primary repair versus diversion in traumatic colonic injuries

Answer 2

Dogmatic practice post WWII was diversion for all colonic injuries. That practice has since been challengd with increasing use of primary repair for penetrating colon injuries.

The Cochrane metanalysis of 2003 included ~700 patients with penetrating colonic injury; it demonstrated that total complications, total infectious complications, abdominal infections and wound complications all favored primary repair.

Question 3

What is Damage Control Surgery?

Answer 3

Damage Control Resuscitation and Damage Control Surgery are a deliberate and pre-emptive set of non-traditional resuscitative and surgical manoeuvers used to reverse the pre-terminal effect of exsanguination, massive injury, and shock.

The primary goal is to temporize injuries with abbreviated surgery to allow for correction of physiological abnormalities.

Question 4

Describe techniques of reducing intra-cranial pressure

Answer 4

1. Hyperventilation; lowering PaCO₂ by 1mmHg reduces cerebral blood flow by 3 percent. Aim for levels of 26-30mmHg
2. Mannitol according to local protocol
3. Hypertonic saline according to local protocol
4. High-dose Barbiturate or Propofol for refractory cases
5. Surgery - Burr Holes or Craniotomy

*High dose steroids do not improve outcome and are associated with increased mortality!

Question 5

Discuss the classification of burns by depth

Answer 5

• superficial burn
  
  • painful, dry, not blistered
  • will fade on own within 7days, no debridement
  • not calculated in TBSA
• superficial partial thickness
  
  • entire epidermis down to BM & no more than upper 1/3 dermis
  • bc large no of remaining epithelial cells & good blood supply, v small zone of injury or stasis below burn eschar
  • rapid re-epithelialisation in 1-2wks
  • wet, often blistered, painful ++, red or white, blanches on pressure
  • skin still feels elastic & supple, hair remains attached when pulled
  • generally heal w/o SSG, usu within 10-14 days, don’t scar
• deep partial thickness
  
  • entire epidermis down to BM & middle third dermis
  • depth of wound has signif risk of conversion; zone of stasis much larger than in SPT injury bc of lower blood flow & greater initial injury to remaining epidermal cells
  • re-epithelialisation much slower (2-3wks) due to fewer remaining epidermal cells & a lesser blood supply
    
    • more collagen deposition will occur espec if wound not excised & grafted within 3wks
  • often a mixture of wet & dry; the drier it is, the deeper
    
    • sensation variable but still present to touch, though often less painful
    • skin texture thicker & more rubbery
    • red patches don’t blanche - ‘fixed skin staining’ due to capillary stasis
    • hairs will come out readily when pulled
  • if not excisedtake 4-6wks to heal & scar badly
    
    • function of a re-epithelialised DPT burn is poor due to fragility of epidermis & rigidity of scar-laden dermis
• full thickness
  
  • entire epidermis & at least 2/3 dermis, leaving v few dermis & epidermal cells to regenerate
  • spontaneous healing v slow, over 4wks w usually severe scarring/contracture if not grafted & high risk of infection
  • thick, dry, insensate, leathery, usu black or yellow
    
    • thormbosis often visible in surface vessels
    • hairs burned off
  • may need escharotomies/fasciotomies if full-thickness circumferential
  • need early excision and grafting

Question 6

What are the indications for rib-plating?

Answer 6

• Flail chest with resultant respiratory failure requiring mechanical ventilation is the only indication for rib fracture fixation for which a strong evidence base exists.
• In this population, there are
  • reduced intubation times and
  • reduced tracheostomy requirements.

Question 7

Describe the theatre set-up for a trauma

Answer 7

• Experienced assisstant and scrub nurse
• Headlight
• Warm theatre
• Bair Huggers
• Two Yankauer suckers
• 20 large packs
• Cell-saver
• Omnitract
• Vascular set and thoracotomy set
• Fogarty, Haemostatic agents, Shunts

Question 8

Describe the principles of vascular surgery in trauma

Answer 8

1. Prepare the patient for wide access
2. Proximal control
   
   • Consider adjuncts such as IR for junctional areas
3. Distal control
4. Temporise injuries in DCS; shunt
5. Repair injury with vascular surgeon
6. Adjuncts in vascular surgery
   
   • Fasciotomies
   • _Tissue coverag_e of vascular repairs

Question 9

How is neurological disability grossly calculated?

What is a simplicfication of this score?

Answer 9

With good interobserver reliability and ease of use, the admission Glasgow Coma Scale has been linked to prognosis prediction for a number of conditions, including traumatic brain injury, subarachnoid hemorrhage, and bacterial meningitis.

AVPU is a simplification where:

A = 15

V = 12

P = 8

U = 3

Question 10

What is the Injury Severity Score?

Answer 10

The Injury Severity Score (ISS) is an anatomical scoring system that provides an overall score for patients with multiple injuries. Each injury is assigned an Abbreviated Injury Scale(AIS) score and is allocated to one of six body regions (Head, Face, Chest, Abdomen, Extremities (including Pelvis), External).

Only the highest AIS score in each body region is used. The 3 most severely injured body regions have their score squared and added together to produce the ISS score.

The ISS score is virtually the only anatomical scoring system in use and correlates linearly with mortality, morbidity, hospital stay and other measures of severity.

Question 11

Describe the classification of splenic trauma

Answer 11

American Association of Surgical Trauma classifies splenic injury according to degree of subcapsular haematoma, depth of laceration, or size of intraparenchymal haematoma:

Question 12

Describe the classification of liver trauma

Answer 12

AAST classification is based on degree of subcapsular haematoma, depth of laceration, or size of parenchymal haematoma:

Question 13

Describe the classification of retroperitoneal trauma

Answer 13

The retroperitoneum is traditionally classified into three zones; a central zone, a (bi)lateral zone, and a pelvic zone

The management algorithm is based on which zone is injured, the mechanism of injury, and whether the haematoma is rapidly expanding.

Zone 1

• Always explored
• Supramesocolic and inframesocolic compartments

Zone 2

• Blunt injury; explore only if haematoma expanding
• Penetrating injury; explore

Zone 3

• Avoid exploration wherever possible; aim for packing and angioembolization
• May require exploration with major vascular injury to lower limb (^e.g. no palpable femoral pulse)

Question 14

Describe the classification of pancreatic trauma

Answer 14

The AAST uses the degree of parenchymal injury as well as the status of the duct to stratify pancreatic trauma:

Question 15

Describe the classification of duodenal trauma

Answer 15

The AAST classification uses number of haematomas, or the circumferential extent of laceration to stratify duodenal injuries:

Question 16

Describe the classification of small bowel and colonic trauma

Answer 16

The AAST stratifies both colonic and small bowel injuries according to the degree of circumferential injury

Question 17

Describe the classification of renal trauma

Answer 17

The AAST classification is based on the depth of parenchymal injury or the degree to which the collecting system or major vasculature is injured:

• Grade I
  
  • haematoma
    
    • subcapsular haematoma and/or parenchymal contusion w/o laceration (operatively non-expanding subcapsular haematoma)
  • laceration
    
    • none
• Grade II
  
  • haematoma
    
    • perirenal haematoma confined to Gerota’s fascia (operatively subcapsular haematoma 10-50% surface area or intraparenchymal haematoma <5cm diameter)
  • laceration
    
    • renal parenchymal lac ≤1cm depth w/o urinary extravasation
• Grade III
  
  • laceration
    
    • renal parenchymal lac >1cm depth w/o collecting system rupture or urinary extravasation
  • vascular
    
    • any injury in presence of a kidney vascular injury or active bleeding contained within Gerota’s fascia
• Grade IV
  
  • laceration
    
    • parenchymal lac extending into urinary collecting system w urinary extravasation
  • disruption/vascular
    
    • renal pelvis lac and/or complete ureteropelvic disruption
    • segmental renal vein or artery injury
    • active bleeding beyond Gerota’s fascia into retroperitoneum or peritoneum
    • segmental or complete kidney infarction(s) due to vessel thrombosis w/o active bleeding
• Grade V
  
  • vascular injury
    
    • main renal artery or vein lac or avulsion of hilum
    • devascularised kidney w active bleeding
  • disruption
    
    • shattered kidney w loss of identifiable parenchymal anatomy

Question 18

Describe the classification of bladder trauma

Answer 18

The AAST system stratifies severity based on size of laceration and whether the injury is extra-peritoneal or intra-peritoneal:

Question 19

Describe the classification of Pelvic Fractures

Answer 19

The Tile Classification is based on which part/s of the pelvic ring are fractured, and to what degree the pelvis is therefore unstable. Type A fractures are stable, Type B are rotationally unstable, and Type C are both vertically and horizontally unstable.

Question 20

Describe the classification of blast injury

Answer 20

• Primary blast injury
  
  • Barotrauma from the blast wave
  • Gas-containing organs affected (TM, caecum, lungs)
• Secondary blast injury
  
  • Objects strike individual
• Teritiary blast injury
  
  • Individual strikes object
  • Traumatic sequelae of persons being thrown causing impact or deceleration injuries
• Quarternary blast injury
  
  • Miscellaneous injury
  • Infection, burns etc.

Question 21

Describe the assessment of a mangled extremity in terms of predicting need for amputation versus preservation.

Answer 21

The Mangled Extremity Severity Score (M.E.S.S.) stratifies risk according to the degree of Ischaemia, Soft tissue/skeletal injury type, Shock, and Age (I.S.S.A.): A score of greater than 7 predicts amputation (in retrospective series).

The N.I.S.S.S.A. scoring system includes nerve injury and the degree of soft tissue contamination is therefore more sensitive and specific; a score greater than 11 predicts amputation.

Question 22

How is Traumatic Brain Injury Classified?

Answer 22

• Mild TBI
  
  • Brief LOC for a few seconds/minutes, post-traumatic amnesia for less than an hour, normal CT, and GCS 13-15
• Moderate TBI
  
  • LOC for less than 24 hours, PTA for 1-24 hours, abnormal CT, GCS of 9-12
• Severe TBI
  
  • LOC or coma for >24 hours, PTA for more than 24 hours, abnormal CT, GCS 3-8

Question 23

Describe the pathophysiology of trauma coagulopathy

Answer 23

Trauma-induced coagulopathy is generated by the following pathophysiological mechanisms:

1. Coagulation activation
   
   • Procoagulants in the systemic circulation
   • Impairment of endogenous anticoagulant activity
   • Thrombin generation in the systemic circulation
2. Hyper-fibrino(geno)lysis
   
   • Acute release of t-PA-induced hyperfibrino(geno)lysis
   • Coagulation activation-induced fibrino(geno)lysis
3. Consumption coagulopathy

Question 24

What is a blast injury?

Answer 24

The physiological and anatomical insult to the human body caused by the physical properties of an explosion. Blast wave = shockwave that results from the explosion. Blast front = its leading edge. Blast wind = the rush of air caused by the blast wave.

In open air: force of blast rapidly dissipates

Within confined spaces: blast wave is magnified by its reflection off walls, floor and ceilings, increasing its destructive potential

Underwater: bc water is less compressible than air, an underwater blast wave propagates at high speeds & loses energy less quickly over long distances, being ~3x greater in strength than that which is detonated in air

Question 25

How are blunt cerebrovascular injuries graded?

Answer 25

Denver system - 5 grades grade 1 = intimal irregularity or dissection w \<25% luminal narrowing grade 2 = dissection or intramural haematoma w ≥25% luminal narrowing, intraluminal clot or visible flap grade 3 = pseudoaneurysm or non-haemodynamically significant AV fistula grade 4 = complete occlusion grade 5 = transection with active bleeding or haemodynamically significant AV fistula - often lethal

Question 26

Who should get a CTA to look for blunt cerebrovascular injury?

Answer 26

BCVI = non-penetrating injury to carotid or vertebral arteries Signs/symptoms of BCVI (emergency CTA): * potential arterial haemorrhage from neck/nose mouth * expanding cervical haematoma * cervical bruit in pt \<50 * focal neurological defect: TIA, hemiparesis, vertebrobasilar symptoms, Horner's syndrome * stroke on CT or MRI * neurologic deficit inconsistent w head CT Risk factors for BCVI (urgent CTA): * high energy transfer mechanism * displaced midface fracture (Le Fort II or III) * mandible fracture * complex skull fracture/basilar skull fracture/occipital condyle fracture * severe TBI w GCS \<6 * cervical spine fracture, subluxation or ligamentous injury at any level * near-hanging w anoxic brain injury * clothesline-type injury or seat-belt abrasion w significant swelling, pain or altered MS * TBI w thoracic injuries * scalp degloving * thoracic vascular injuries * blunt cardiac rupture * upper rib fractures

Question 27

What is the significance of blunt cerebrovascular injury following blunt neck trauma? What is the pathophysiology?

Answer 27

* stroke rates for internal carotid injuries up to 40%, vertebral injuries up to 25% * mortality rate for stroke after blunt carotid injury 25%, and ~50% survivors have permanent severe neuro deficits * Pathophys: stretching or impingement of vessel wall as head & neck are forcefully moved in flex/ex or rotation causes * intimal tears & exposure of subintimal layers to blood flow & consequently thrombus formation which can partially or completely occlude vessel lumen, * dissection in wall * pseudoaneurysm * complete occlusion of vessel * transection of vessel * sequelae: strokes due to embolism form injury or complete occlusion of vessel

Question 28

What is the management of blunt cerebrovascular injury?

Answer 28

* grade 1: antithrombotic therapy (heparin infusion in hosp, antiplatelets on discharge) * reimage in 7-10 days; if healed, stop ATA; if not, continue for 3-6mo & reimage * grades II-V: if surgically accessible, and patient has not suffered a complete stroke ,operate * grades II-IV: if not surgically accessible, ATA same as above * on reimage in 7-10 days, only consider stenting for severe luminal narrowing, symptomatology or markedly expanding haematoma * grade V: if not surgically accessible, endovascular treatment

Question 29

Hard signs for neck injury

Answer 29

* Vascular * severe haemorrhage * pulsatile or expanding haematoma * shock refractory to IV fluid resus * absent or decreased radial pulse * bruit or thrill * neurological deficit consistent w stroke * oesophageal * massive haemoptysis * tracheal * massive haemoptysis * respiratory distress * air bubbling through wound * ?severe subcut emphysema (or soft sign)

Question 30

Soft signs for neck injury

Answer 30

* stable haematoma * hoarse voice/dysphonia * dysphagia * mild subcut emphysema/mediastinal air * minor haematemesis or haemoptysis * proximity wounds * minor haemorrhage * mild hypotension responding to IV fluid

Question 31

Zones of the neck

Answer 31

* zone I = sternal notch to lower border cricoid * great vessels, trachea, oesophagus, thoracic duct, upper mediastinum, lung apices * zone II = cricoid to angle of mandible * carotid and vertebral arteries, internal jugular, pharynx, larynx, oesophagus * zone III = angle of mandible to base of skull * pharynx, distal extracranial carotid and vertebral arteries, segments of jugular veins

Question 32

What are the 5 options when vascular damage is encountered in trauma?

Answer 32

Vessels may be * repaired * replaced (grafted) * ligated (and bypassed) * stented * shunted

Question 33

How is the severity of injury of open fractures classified?

Answer 33

Gustilo classification Grade I, grade II, grade III, grade IIIA, grade IIIB, grade IIIC based on size of wound, degree of soft tissue injury, degree of contamination of wound bed, degree of comminution of fracture, and whether there is major vascular injury requiring repair for limb salvage

Question 34

Discuss compartment syndrome

Answer 34

* increasing pressure within the closed fascial space of a limb compromises blood supply of muscle * may occur after extremity injury * reperfusion following vascular repair plays major role * classic signs = 5Ps but unreliable & late signs * pain, pain on active movement & pain on passive stretch should raise suspicion * others = paraesthesia, paralysis, pallor, pulselessness * if in doubt can measure intra-compartment pressure * espec useful if unconscious/sedated * can have compartment syndrome w palpable pulse/recordable on Doppler * take measurements on both lower legs, at same place (eg in tib ant muscle 2cm below &lateral to tibial tubercle) for comparison * treated by urgent fasciotomy * must be done before arterial exploration when obivous arterial injury exists, or where there is suspicion of high intra-compartmental pressures

Question 35

Describe your technique for lower leg fasciotomy

Answer 35

2 incision, 4 compartment fasciotomy * skin must be opened widely to allow good view of underlying fascia; is critical fascia is split over its entire length which can only be done under direct vision * care not to damage saphenous veins, and on lateral side common peroneal nerve branches * 2 long incisions * lateral incision * starts anterolaterally over fibula, 2-3cm below the head * retract skin * make transverse incision at mid-point across the septum * cut fascia on either side of septum using curved scissors - 'H' incision across lateral and anterior compartments * common peroneal nerve, running down entire lateral side as far as 2cm above lateral malleolus should be identified & preserved * medial incision * long posteromedial incision made 2cm medial to and below tibial tuberosity, running down entire lower leg, 2-3cm behind posteiror border of tibia, as far as 2cm above medial malleolus posterior to medial border of tibia * subcut tissue pushed away by blunt dissection & superficial adn deep posterior compartments opened separately * care not to damage saphenous veins

Question 36

What compartments need to be released for fasciotomies of the upper leg, upper and lower arm?

Answer 36

* upper leg * quads (ventral) * hamstrings (dorsal) * adductors (medial * upper arm * biceps (ventral) * triceps (dorsal) * lower arm * extensors (dorsal) * flexors (ventral) - with release of carpal tunnel distally & division of lacertus fibrosis in elbow region proximally

Question 37

Indications and contraindications for ED thoracotomy

Answer 37

Indications * penetrating chest trauma w signs of life in past 10-15 mins * best evidence for survival is in pts w a single penetrating stab wound to chest * while primarily performed on pts in cardiac arrest, pts that are peri-arrest w hypotension (SBP \<70mmHg) unresponsive to chest decompression and blood products w penetrating chest trauma could be considered for resuscitative thoracotomy in ED if operating room not immediately available * controversial indications * penetrating extra-thoracic trauma w cardiac arrest * blunt (thoracic) trauma w signs of life on arrival to ED who then have cardiac arrest * NB injuries often more complex & not easily treatable by non-surgeons * USS evidence of cardiac tamponade may indicate pts w potentially favourable outcome Contraindictations * penetrating trauma w CPR in progress \>15mins and no signs of life * blunt trauma w no signs of life on arrival to ED * other injuries incompatible w survival (eg severe TBI)

Question 38

What are the 'signs of life' when considering an ED thoracotomy

Answer 38

* pupillary response * spontaneous ventilation * presence of a carotid pulse * any measurable blood pressure * spontaneous limb movement * cardiac activity seen on USS or ECG