Trauma Flashcards
We are the liver and spleen so susceptible to injury via blunt forces? (3)
- Heavy and relatively free to move which leads to tearing
- Soft so when starts bleeding it is propagated
- Very vascular
How much of traumatic pelvic bleeding is venous?
Around 80%
What is the mortality of an open pelvic fracture?
50%
Which patients does the FPHC consensus statement suggest may not need a binder? (5)
- Mechanism not suggestive of pelvic injury and
- Haemodynamically stable (HR<100, SBP >90)
- GCS >13
- no distracting injury
- no pain in pelvis
What does FPHC consensus statement say about type of pelvic binder used? (2)
- No good evidence for one device over another
- Best evidence currently is for SAM Splint or T-POD device
What is the FPHC consensus statement with regards to femoral fractures and suspected unstable pelvic fractures and haemodynamically unstable patients?
- if traction of legs will delay transfer +/- worsen instability of patient (via pelvic disruption), they should be pulled to length and then tied together at knees and a figure of 8 around ankle
What does JRCALC recommend with regards to transporting the distal part of of an amputation? (4)
- Remove any gross contamination
- Cover the part with a moist dressing
- Secure in plastic bag
- place bag in a container with ice
What are the protective layers of the skull from outer layer inwards
- Skull
- Dura mater
- Arachnoid mater
- Pia mater
What is the Monro-Kellie Doctrine?
The sum of the volumes of brain/CSF/blood is constant. A rise in 1 will therefore precipitate a drop in 1 or both of the others.
What 2 syndromes are associated with hyperacute head injury?
- Neuroventilatory syndrome
- Neuro-cardiac syndrome
What is neuroventilatory syndrome?
Impact brain apnoea
Concussive force to Pre-Botzinger complex of medulla oblongata
What is neurocardiac syndrome?
- Cardiogenic failure secondary to locally released noradrenaline from myocardial sympathetic nerve terminals leading to neurogenic stunned myocardium.
- creates reverse-Takusubo picture (intact apical contraction/ impaired heart base contracticility)
- pump failure may decrease further secondary to systemic cathecolamine induced afterload +/- impact brain apnoea
How is cerebral perfusion pressure calculated?
CPP = MAP - ICP
assume ICP >20cmH20 so aim MAP >80 mmHg
How much % decrease in effect does each 20mins delay in TXA cause?
10%
At what GCS does nice recommend giving TXA?
12 or less
What does JRCALC states about anti-platelet tx nd HI?
Should be conveyed unless aspirin monotherapy
What does JRCALC recommend for agitated head injuries?
Cautious use of midazolam
What are the indications for immediate CTH in children? (8)
- ? NAI
- Seizure
- GCS <14 at presentation
- GCS <15 at 2 hours
- ? skull # / tense fontanelle
- Basal skull # signs
- Focal neurological deficit
- Bruising/swelling >5cm in <1years
What are the risk factors that may require observation in paeds head injurys? (5)
- LOC >5mins
- Amnesia > 5 mins
- Abnormal drowsiness
- 3 or more vomits
- Dangerous MOI
If a child has one risk factor following head injury what should be their management?
4 hours observation
If a child has more than one risk factor following head injury what should be done?
CTH < 1hour
What are the increased risk factors needing imagine in the Canadian c-spine rules? (3)
- Over 65years
- Dangerous MOI
- Parasthesia in the extremities
What constitutes a dangerous MOI in the Canadian C-spine rules? (5)
- Fall over 3 foot or 5 stairs
- Axial load to head
- High speed MVC (>100kmph)/rollover/ejection
- Motorised recreational vehicles
- Bicycle collision
What are the low risk factors in the Canadian C-Spine rules? (5)
- Simple rear end shunt
- Sitting position in ED
- Walking at any point
- Delayed onset neck pain
- Absence of midline tenderness
How many low risk factors do you need to avoid imaging in the Canadian C-spine rules?
1
What is the final step in the Canadian C-Spine rules?
Can they rotate their neck 45 degrees left to right
What are the indications for immediate CTH in adults? (7)
- GCS <13
- GCS <15 after 2 hours
- Open/suspected skull #
- Signs basal skill #
- Seizure
- Focal neurology
- More than 1 vomit
Within what period should patients on anticoagulation have a CTH according to NICE?
8 hours
If an adult patient has no indication for CTH immediately and is not on anticoagulation, what is the next question to be asked?
Any LOC or amnesia - if no then no imaging
If yes move onto risk factors
What are the risk factors used to determine whether an adult patient needs a CTH within 8 hours who have had a LOC or amnesia? (4)
- Over 65years
- Hx bleeding/clotting disorder
- Dangerous MOI
- > 30mins retrograde amnesia (events before injury)
Describes the myotomes in the upper limb (6)
C5 - deltoid
C5/6 - biceps jerk
C6 - wrist extensors
C7 - elbow extensor/triceps jerk
C8 - finger flexors
T1 - little finger abductors
Describe the lower limb myotomes (5)
L2 - hip flexors
L4 - knee extensors
L5 - ankle dorseflexors
S1 - ankle plantar flexors
S5 - anal reflex
What dermatome is the thumb?
C6
Where is the dermatone C7?
Middle finger
What dermatone is the little finger?
C8
What dermatone is the:
1. nipple
2. xyphoid process
3. Umbilicus
- T4
- T6
- T10
Describe the dermatomes of the lower limbs (4)
- L3 = medial knee
- L4 = lateral knee
- L5 = dorsum foot + 1st-3rd toes
- S1 = lateral malleolus
What spinal levels to the sympathetic fibres extend from?
T1 - L3
What spinal levels do the parasympathetic fibres extend from?
S2-4
At what spinal level can a SCI lead to neurogenic shock?
T6 or above
What causes neurogenic shock?
Loss of sympathetic autonomic outflow
What neurology is associated with central cord syndrome?
Arms weaker than legs
What neurology is associated with anterior cord syndrome? (4)
- Complete motor loss below lesion
- Loss of pain/temp below lession
- Preserved sensation/vibration
- Autonomic dysfunction
What neurology is associated with Brown-Sequard syndrome?
- Weakness/paralysis on 1 side
- Loss on sensation on the other
What is the mechanism for acid burns?
Coagulative necrosis
What is the mechanism for alkali burns?
Liquefactive necrosis
What are alkali burns worse than acid?
Acid burns form a barrier which prevents deep penetration into the skin, alkalis cause liquefactive necrosis which means it can penetrate deeper into the skin
What is are the voltage cut off of:
- low voltage
- high voltage
- <1000V
- > 1000V
What type of current is normal low voltage and can it lead to?
- AC domestic current
- Arrhythmia
What does high voltage electricity normally cause? (3)
- Full thickness burns at both entry and exit sites (internal damage can be far worse than appears externally)
- Tissue damage secondary to heat generated by resistance of tissues - Muscle spasms/secondary trauma from being thrown causing bony/SCI
- Arrhythmia particularly if chest involved
What type of tissue leads to the most damage when conducting high voltage electricity and why?
Bone because it has the highest resistance, it is the resistance that causes heat and bone can therefore become very hot and lead to further damage once the current has stopped.
What surgical interventions might be require of high voltage burns?
- may need aggressive surgical intervention inc. fasciotomy and amputation
What can muscle damage related to high voltage burns lead to?
Myonecrosis, compartment syndrome and rhabdo with renal failure
What does a lightening strike lead to and what might be a protective factor?
Death unless it has already passed throught another object
Describe the palm method of assessing burns size and in what are the weakness of using it
- Palm INC. adducted fingers = around 1% TBSA (patients hand, not clinicians)
- Some debate as to the accuracy, particularly in small kids and obese patients
What burns assessment does the FPHC consensus statement recommend? (2)
- Lund and Browder chart
- Mersey burns app (or similar)
Describe superfical burns?
Erythema only,not included in burns calculation
What differentiates superficial burns from superficial dermal/superficial partial?
Blisters - fluid lifts dead epidermis off dermis
What is the difference between deep dermal/ partial and superficial dermal/partial? (3)
Extends into dermis
- Decreased sensation secondary to damage to nerve endings
- Hallmaark = increase CRT due to damage of dermal vascular plexus
- Can be ‘blotchy’ pink/red colour secondary to extravasation of the Hb from damaged vessels
Describe full thickness burns
Can include fat/fascia/muscle/bone
- ‘charred’ or ‘leathery’
- ‘woody’ feel
- insensitive (but surrounding non full thickness burns with be painful)
- non blanching
What questions should be asked to any burns patient? (4)
- Were they trapped and if so for how long?
- Did clothes catch fire?
- Any cooling?
- Any explosion/ were they thrown?
What level of CO is classed as severe?
> 30%
Why does CO lead to hypoxia?
CO x 240 more affinitity to Hb than oxygen which shifts 02 dissociation curve to the left
What will pulse oximetry be like with CO poisoning and why?
Normal as unable to differentiate between carboxyhaemoglobin and haemoglobin
What is a normal value of COHB in:
1. non-smokers
2. smokers
3. heavy smokers
- < 3%
- <5%
- <9%
What is the treatment (initially) for CO poisoning and why does it help?
High flow oxygen because it reduces the half life of COHb from 320mins to 80mins
What is the mechanism of cyanide poisoning?
Usually from burning plastic
Poisons mitochondria and prevents further cellular oyxgen use leading to anaerobic metabolism
What are 2 treatments available for cyanide poisoning?
- Hydroxycobalamin (Cyanokit)
- Dicobalt edetate (Kelocyanor)
To what depth should an escharotomy incision be?
Down to unburnt skin
What 3 lines should be made in a breast plate escharotomy?
- Mid clavicular to ant axillary line to costal margin bilaterally
- Transverse subcostal
- Transverse infraclavicular
What are the % burn NICE in hospital thresholds for:
1. Adults
2. Kids
3. < 18months old
- 15%
- 10%
- 8 %
What is the Parkland formula?
4 x wt (kg) x TBSA
3 x wt (kg) x TBSA (kids)
First half in initial 8 hours
Second half in following 16 hours
What does JRCALC recommend for burns fluid resusitation?
1L warmed fluids / hr (adult)
10ml/kg/hr paeds
What should the first steps be in with chemical burns?
Remove agent, removed contaminated clothes and if liquid, irrigate well
What is the recommended to use in decontaminating both acids and alkalis?
Diphoterine (normalises PH more quickly)
If Diphoterine is not available, what fluids should be use to decontaminate acids/alkalis?
Isotonic or hypertonic fluid because water can propagate chemical deeper into the skin
How long should chemical burns be irrigated for?
- until pain improved which is a useful crude sign that PH has improved
How does hydrofluric acid lead to burns?
- H+ ions dissociate on contact with skin and lead to liquefactive necrosis allowing acid to penetrate deeply
- Free flouride ions bind to calcium and magnesium ions leading to systemic hypomagnesia and hypocalcaemia
How should hydrofluric acid be treated? (4)
- Irrigate
- Calcium gluconate gel
- IV/intra-arterial calcium if extreme
- Specific agent = hexaflourine
What is the specific agent for hydrofluric acid tx?
Hexaflourine
How should tar/bitumen burns be treated?
- they are heated to around 150 degrees and cause full thickness burns
- cool with water to solidify and then remove with toluene or peanut/paraffin oil
How does the FPHC consensus statement divide airways burns? (2)
- Supraglottic (nose/oropharynx and larynx) - most common
- Infraglottic
How can infraglottic burns be caused? (5)
Steam inhalation
Aspiration of scalding liquid
Blast injury
Flammable gas under pressure
Aerosolised chemicals
What are the features of infraglottic burns? (5)
- Impaired ciliary activity
- Hypersecretion
- Oedema
- Mucosal ulceration
- Bronchial spasm
What 3 considerations should be made with intubation in patients with airway burns?
- Largest size tube that will be placed (bronchoscopy on ITU)
- Uncut (airway will swell)
- Careful with tube tie
What features have been shown to correlate with need for RSI (FPHC)? (6)
- Full thickness facial burns
- Stridor
- Resp distress
- Swelling on larygnoscopy
- Smoke inhalation
- Singed nasal hairs
When does FPHC recommend using cyanide antidote?
Suspected smoke inhalation AND:
- altered mental status
- CV instability
What 3 categories of burns severity does FPHC recommend using pre-hospital?
< 20%
20-50%
> 50 %
What does FPHC say about water cooling of thermal burns? (3)
- Water < 20 degrees (12 ideal)
- 20 mins
- Not ice water secondary to risk of tissue necrosis
What does FPHC recommend with regards to first aid for chemical burns? (3)
1.Treat any chemical burn ASAP regardless of delay to presentation
- Use amphoteric solution as first line
- Irrigate for as long as possible
When does FPHC state fluid resus should be commenced pre-hospital in:-
- adults
- paeds
> 20%
Describe the FPHC ‘threshold’ method for estimating pre-hospital fluid resusitation?
What analgesia should be avoided in burns?
NSAIDs if requiring fluid resus
When does FPHC recommend chest escharatotomy?
Circumferential or near circumferential eschar with imprending or established respiratory compromise to to thoraco-abdominal burns
What is the definition of crush injury?
Direct injury to a body part which has undergone a prolonged static compressive force sufficient to interfere with normal tissue metabolic function
What is the definition of crush syndrome?
Systemic consequences of muscle + soft tissue trauma
What 3 factors make crush syndrome more likely?
- Increased compressive force
- Increased muscle bulk
- Increased time
What is suspension syncope?
Orthostatic hypovolaemia leads to syncope if trapped in vertical position -can lead to death
Describe the two components that lead to progressive orthostatic shock in patients trapped vertically
- Orthostatic syncope
- Orthostatic hypovolaemia
- Orthostatic syncope
Cerebral perfusion compromised as autonomic/humoural + local responses fail to preserve MAP. Process made worse by: pain (vagal tone), hypovolaemia, forced erect position - Orthostatic hypovolaemia
Entrapping force/harness acts a venous tourniquet and limb congests. This leads to loss local vascular tone and leaky capillaries leading to further swelling/ tightening harness. Can progress to limb ischaemia
Describe rescue cardioplegia
Occurs on release of compressing force
- cold ‘toxic’ blood released back into systemic circulation leading to a sudden and transient increased preload. Causes atrial stretch which can lead to asystole of AF
- Simultaneous rapid drop in afterload + SVR as blood moves back into affected limb
- both lead to acute hypotension when limb released
What can make the affects of rescue cardioplegia worse?
- blood released ‘ideal cardioplegic solution’ leading to arrhythmia
- cold/hyptertonic/acidotic/ raised k+/ca2+/Mg2+/P04D
Describe the pathophysiology of crush syndrome
- Constant external mechanical force prevents cell wall integrity by forcing extracellular cations + fluid against normal electrochemical + osmotic gradient into cells
- cell wall extrusion pumps become overhwhelmed allowing water with dissociated Na+/Cl-/Ca2+ into cell
- ultimately leads to death
When is irreversible cell death caused by crush syndrome?
<1 hour but no universally accepted ‘safe time’
What is compartment syndrome?
Intramuscular compartment forces act continualy above DBP leading to comrpession and death of nerves/blood vessels/muscle
Describe the pathophysiology of compartment syndrome
Integrity of muscle cell wall breached and intracellular components move extracellular and into damaged tissue
Cell content forced into vascular compartment lead to systemic affects
How are kidneys damaged in compartment syndrome? (2)
- Direct damage of intracellular substances (proteases/purines)
- Indirect - attempt to filter acidotic plasma + myoglobin damage
How does myoglobin damage kidney?
- Myoglobin itself not nephrotoxic but when systemic acidosis lead to pH urine< 5.6 myoglobin converted to larger protein Ferrihaemate.
- This is directly nephrotoxic and causes mechanical obstruction of nephron lumen
- hypovolaemia and third space shift makes this worse
What is the protein that myoglobin becomes when urine PH < 5.6
Ferrihaemate
How should suspended patients be rescued?
ASAP and placed horizontally
What has been shown to improved outcomes in trapped earthquake patients?
Systemic resus with sodium and potassium containing fluids (20ml/kg - 10ml/kg elderly)
Describe the pain response in crush injury
Initially reduced due to endorphins and pressure neuropraxia but this will increase as limbs swell and endorphins wear off
When should alkaline diuresis be considered in crush injury?
If evacuation time >4 hours
How is alkaline diuresis performed?
- 50ml 8.4% soidum bicarbonate to each alternate 1L fluid
- If prolonged transfer alternate 5% dex to prevent sodium overload
- Aim urine PH >6.5
Really should be done in hospital
Describe the pathology of tissue damage caused by projectiles?
- Shockwave drives tissue radially leading to a temporary cavity
- Contamination drawn into this cavity, which collapse once the projectile has passed leaving a permanent cavity (smaller) and traps contamination in wound.
Why are solid organs more effected than muscle/lungs etc in terms of projectile injury?
Not very elastic, unable to stretch, therefore tolerate cavitation poorly and causes more damage
Describe the physics of a blast
- Rapid chemical transformation of solid/liquid into a gas.
- Under increased pressure this gas expands rapidly outward as a wave of pressure
What is a blast wave?
Air at leading edge of explosion is highly compressed
What is a primary blast injury?
-Only occur in high pressure explosions
- Blast wave interacts with body tissues leading to stress/shear
What areas/organs normal affected by primary blast injury? (3)
- Tympanic membrane
- Lungs
- Bowel
What can severe primary blasts causes?
Vagally mediated bradycardia/hypotension and apnoea
What is a secondary blast injury?
Fragments from device or other materials energised by the blast
With regards to secondary blast injuries what are:
1. Primary fragments
2. Secondary fragments
- From device
- From other materials energised by the blast
If fragments from other victims lead to secondary blast injuries what should be advised?
PEP
What is a tertiary blast injury?
Blast wave displaces objects in its path (blast wind) e.g. bodies thrown agains solid objects or structural collapse
What is a quaternary blast injury?
Any other explosion related injury e.g. burn, psychological trauma
What are the 6 types of lung injury caused by blast lung?
- Interstitial haematoma/oedema
- Intra-alveolar injury
- Pulmonary oedema (can be delayed)
- PTX
- Alveolar-venous fistula
- Air embolism
What are the 3 types if injury to bowel caused by blast bowel?
- Contusion
- Perforation
- Intra-luminal bleeding
Which type of bowel is most affected by ‘blast bowel’?
Large bowel
‘Blast ear’ can cause which 3 injuries?
- TM rupture
- Ossicle dislocation
- Inner ear damage
What are the 4 C’s in terms of an explosion?
Police use for their initial approach
Confirm threat
Clear people away
Cordon
Control - create Incident Control Point (ICP)
In terms of forensics post an explosion, what should we remember to do to preserve evidence? (4)
- Only touch objects to tx patients
- Only move bodies to tx patients
- When cutting off clothes try to avoid cutting through points of penetration
- Take limbs with patients even if unsalvageable
In terms of triaging post explosion, what can be a useful marker of injury and why?
TM rupture because blast injuries can deteriorate later
What denotes a high mortality in a patient injured during an explosion?
- Blast lung + amputation
Following a traumatic amputation secondary to an explosion when should we use a tourniquet?
Always - can no bleed initially due to vasospasm/cauterisation but will start to
In proximal amputations following an explosion, what other injury is likely?
Pelvic fractures - place binder emperically
What is the mortality in penetrating head if the patient is?
Alert
Voice
Pain
Unresponsive
A = 11.5%
V = 33.3%
P = 7%
U = 100%
Describe the zones of the neck?
- Clavicle to cricoid
- Cricoid to angle of mandible
- Angle of mandible to bottom of ear
Why were the neck zones divided as they are?
Zone 2 more easily explored surgical, whereas 1 and 2 more likely to need CT angiography
What does JRCALC state about giving IV fluids in paeds burns:
1. >20%
2. 10-20%
3. <10%
- Give 10ml/kg normal saline over 1 hour
- If journey time >30 mins given 10ml/kg over 1 hour
- No fluids
What is classed as a dangerous MOI in the NICE head injury guidelines (6)?
1.A fall from a height of more than 1 meter or 5 stairs
2. A high-speed RTC (pedestrian, cyclist, or vehicle occupant)
3. Roll over RTC/ ejection
4. An accident involving motorized recreational vehicles
5.Bicycle collision
6. Diving accident
What are the borders of the ‘safety triange’ for chest drains?
- Lateral aspect pec major
- Nipple line
- Lateral aspect of latissimus dorsi
What is the causes of life threatening chest trauma in order of how frequently they occur in TARN?
Flail chest ( 1 in 50 )
Tension PTX (1 in 250)
Massive HTX (1 in 1000)
Cardiac tamponade (1 in 1250)
Open PTX (1 in 10,000)
What mechanism is most commonly associated with posterior hip dislocation?
Unrestrained passengers with frontal impact
What is the effect of an:
1. engine
2. tow bar
on injuries
- Protective against frontal collisions
- Transmits energy directly to passenger cabin and bypasses crumped zonesW
What is Waddells triad?
Injury in children hit by car whilst walking:
- contralteral head injury
- intrathoracic or intrabdominal injury
- fractured femur
In a self ventilating patient with suspected PTX/tension PTX what does FPHC recommend as:
1. First line
2. Second line
3. Third line
- Needle decompressoin 2nd IC space mid clavicular
- 5th IC space mid-axillary line
- Thoracostomy followed up by CD if level 6 practitioner
What does the FPHC say about chest drains pre-hospital in their consensus statement
- Should be avoided where possible due to:
- prolongation of on-scene time
- risks of kinking
- blocking or falling out during transfers
- long-term infection risks with non-sterile insertion techniques.
It is accepted that chest
drain insertion will be necessary in some circumstances eg high-altitude aero-medical retrieval.
What is the complication rate of pre-hospital thorocostomy?
10-15%
What does FPHC recommend with respects to abx and thoracostomy?
Should be considered for pre-hospital thoracostomy, especially in cases of penetrating chest trauma, or with transport times >3 hours
What does FPHC recommend for treatment open PTX? (2)
- Commercial chest seal, vented preferably (3 sided dressing no longer recommended)
- IV abx prophx
What is the FPHC consensus statement on massive HTX? (3)
- If no respiratory compromise then drainage should be delayed until ED
- Where thoracostomy has shown significant haemorrage then a chest drain maybe beneficial to monitor blood loss, however should not significantly impact of scene time.
- Clamping chest drain for exsanguinating chest trauma, however caution needed as high chance of co-existing PTX which could tension with PPV etc.
What is the FPHC consensus statement recommendations on flail chest?
- Where possible, sit uo
- Patient may find holding their ribs helps with pain
- Pain score and suitable analgesia
- No entonox a 1/3 patients with >3 rib #s have PTX as well
What factors associated with ribs #s have been shown to lead to worse outcomes and trigger clinicians to convey to centre with CTS? (8)
- age 65 years or more
- three or more rib
fractures - bilateral flail chest
- chronic lung disease
- co-existent underlying lung injury
- anticoagulant use
- BMI >25
- oxygen saturation <90% in the Emergency Department.
What does FPHC consensus statement say about pre-hospital pericardiocentesis?
- No evidence for its use
- Can cause damage
- Unlikely to be able to aspirate clotted blood from needle
What are the 4 things needed for to indicate pre-hospital thoracotomy according to FPHC?
- Stab wounds to the chest or upper abdomen
- Cardiac arrest with loss of vital signs ≤ 15 minutes
- The suspected injury is suitable for temporary repair and control
- A chain of survival exists for definitive management following Resuscitative Thoracotomy
