Trauma Flashcards
(143 cards)
1
Q
List the items in primary survey
A
Airway, with cervical spine control
Breathing - look, listen and feel
Circulation and haemorrhage control
Disability - rapid assessment of neurological function
Exposure, includes considering the environment and preventing hypothermia
2
Q
How should high-concentration oxygen be delivered in a unintubated, spontaneously breathing patient
A
Mask and non-rebreathing reservoir bag (FiO2 = 0.85)
3
Q
Describe the technique for emergency intubation of a severely-injured patient with a potential cervical spine injury
A
- Manual in-line stabilization of the cervical spine. An assistant grasps the mastoid processes and holds the head down firmly on to the trolley to reduce neck movement during intubation. Do not apply traction to the neck
- Preoxygenation
- IV induction of anaesthesia. Be very careful with patients who may be hypovolaemic and, whenever possible, give fluid before inducing anaesthesia
- Paralysis with suxamethonium 1.5mg/kg or rocuronium 1mg/kg
- Application of cricoid pressure using one or two hands
- Direct laryngoscopy and oral intubation
4
Q
What provides a temporary airway if intubation is impossible
A
laryngeal mask airway
5
Q
Airway - List the generally recognized indications for immediate intubation of the severely-injured patient
A
Airway obstruction unrelieved by basic airway manoeuvres
Impending airway obstruction (facial burns, inhalation injury)
GCS <9
* head-injury with a higher GCS is likely intubated to enable CT scan
Haemorrhage from maxillofacial injuries compromising the airway
Respiratory failure secondary to chest or neurological injury
Resuscitative surgery
Uncooperative patients requiring further investigations
6
Q
Breathing - List the indications for intubation of a patient with immediately life-threatening injuries include
A
Tension pneumothorax
Open pneurmothorax
Massive haemothorax
Flail chest
Cardiac tamponade
7
Q
List the signs in tension pneumothorax
A
reduced chest movement
reduced breath sounds
resonant percussion note on the affected side
respiratory distress, hypotension, tachycardia
Late sign: tracheal deviation to the opposite site
8
Q
What is the treatment for tension pneumothorax
A
Immediate decompression with a large cannula placed in the 2nd intercostal space (mid-clavicular line) on the affected side
When IV access has been obtained, insert a large surgical chest drain (32 FG in the 5th intercostal space (anterior axillary) line and connect to an underwater seal drain
9
Q
Define Massive haemothorax
A
> 1500 ml blood in a hemithorax, causes reduced chest movement, dull percussion note and hypoxemia
10
Q
Give the signs suggestive of cardiac tamponade
A
Distended neck veins + hypotension
11
Q
How is cardiac tamponade diagnosed in a trauma facility
A
Ultrasound
12
Q
Classification of Haemorrhage - What does a fall in systolic pressure suggest
A
> 30% (1500ml) loss of total blood volume
Class II haemorrhage
13
Q
Classification of Haemorrhage - What does a deteriorating conscious level due to hypovolaemia suggest
A
> 40-50% (2500ml) loss of total blood volume
Class IV haemorrhage
14
Q
How is vascular access established during the primary survey
A
Insert two short, large-bore IV cannulae (14 G)
- Take blood samples for FBC, electrolytes and crossmatch from the first cannula.
Insert an arterial cannula for blood gas sampling and invasive pressure monitoring
15
Q
What options are there for vascular access if peripheral access is difficult
A
External jugular vein or femoral vein, avoiding abdominal, pelvic or leg injury
Cut-down on a peripheral vein, e.g. the long saphenous vein at the ankle
Cannulate a central vein
Intra-osseus access (proximal tibia or humerus)
16
Q
What may Hartmann’s solution cause in patients with severe brain injury
A
Cerebral oedema (hypotonic)
17
Q
How is Disability and Exposure performed in primary survery
A
Disability - rapid neurological assessment
Exposure and environmental control - undressing completely and protect from hypothermia with warm blankets.
Urinary catheter - urine output is a good indicator of the adequacy of resuscitation.
Gastric tube - drain the stomach contents and reduce the risk of aspiration. Orogastric route if sus basal skull fracture
All patients require a CXR and once stable, a CT of the head, chest, abdomen and pelvis is required
18
Q
Classification of Haemorrhage - What does tachypnoea suggest
A
Acute blood loss of 1000ml
Class II haemorrhage
19
Q
Classification of Haemorrhage - What does increase in diastolic blood pressure suggest
A
Acute blood loss of 1000ml
Class II haemorrhage (vasoconstriction)
20
Q
What are the five key principles for examining trauma patients?
A
Look
Listen
Feel
Move
Immobilize
21
Q
The Secondary Survey - what should examining the head involve
A
LOOK
Scalp
* lacerations/bruising
* Examine the forehead, through the hair and behind both ears
Eyes
* Equal size, pupillary response to light
* Check visual acuity and fields of view
* Objects in the eyes
* Fundi (haemorrhage, emboli, lens dislocation, ocular entrapment)
* Remove contact lenses
Ears
Mouth - foreign objects, loose teeth, missing teeth, dentures
Orifices - CSF, blood
LISTEN - upper airway noises / gurgling suggesting a compromised airway
FEEL, MOVE, IMMOBILISE - Test the head bones and neck joints for tenderness
22
Q
The Secondary Survey - what should examining the chest involve
A
LOOK
* normal architecture (no flail segments) at the front, back, and sides
* Equal chest expansion, smooth excursion of the thorax bilaterally
* Accessory muscle use
* Bruising
* Obvious penetrating injury
* Scars suggestive of previous operations or trauma
LISTEN - equal air entry
FEEL - start at the back and work to the front
* Tenderness of the thoracic spine
* Tenderness of the chest wall
* Fractures of the sternumThe Secondary Survey - what should examining the chest involve
23
Q
The Secondary Survey - what should examining the abdomen involve
A
LOOK
Paradoxical movement of the abdomen in respiration
Bruising, obvious penetrating injury, abdominal distension at the front, back and sides
In females - gravid uterus
In males - priapism (SCI)
FEEL
Organomegaly and a palpable bladder
Tenderness in the lumbar spine and steps in the spinal column
Anal sphincter tone and intact rectal walls during a digital rectal examination
A high riding prostate
Any loss of the normal contours of the bony pelvis
24
Q
The Secondary Survey - what should examining the Upper and Lower Limbs involve
A
LOOK - abrasions and cuts
LISTEN - abnormal noises on movement
FEEL - joints, long bones and muscle bulk compartments for abnormal fluctuance or tightening
MOVE
25
List the indications for immediate and urgent intuition
Immediate
* Life-threatening hypoxaemia
* Inadequate facemask seal
Urgent
* To protect the lower respiratory tract from aspiration of blood/stomach contents.
* To preserve the airway from anticipated obstruction by:
oedema (e.g. from burns), haematoma
* Control ICP (ventilating the lungs to maintain the PaCO2 at 4.5–5.0 kPa)
* Therapeutic and diagnostic procedures in uncooperative patients
26
During intubation, what is cricoid pressure applied to do?
Reduce the risk of pulmonary contamination with gastric contents.
27
List the steps in rapid sequence induction
1. Preparation - routine monitors
2. Apply MILS - An assistant kneeling beside the intubator holds the patient’s mastoid processes firmly down on the trolley:
* MILS must oppose the force generated by direct laryngoscopy which rotates the occipito-atlanto-axial complex
* Pre-oxygenation - 100% oxygen for 3 mins through tight-fitting mask
* Do not apply traction
3. RSI
* Apply gentle cricoid pressure
* Give the induction drug followed immediately by suxamethonium chloride
* Monitor for haemodynamic instability
* Increase cricoid pressure as anaesthesia is induced
3. RSI intubation - Attempt laryngoscopy and intubation after paralysis
28
What percentage of intubations are difficult after RSI in the ED
10%
29
List the steps in failed intubation
1. Reoxygenate
If SpO2>92%, up to three intubation attempts
If SpO2<92%, reoxygenate with bag-mask, oro/nasopharyngeal airway, reduce cricoid pressure
2. Airway Adjuncts - LMA (max 2 attempts)
3. Surgical / needle cricothyroidotomy
30
Where is the incision for a surgical cricothyroidotomy made
horizontal incision is made over the cricothyroid membrane (above the cricoid cartilage)
31
List the GCS classification of head injuries
Mild: GCS 13-15
Moderate: GCS 9-12
Severe: GCS 3-8
32
What is the normal ICP
7 to 15 mm Hg
33
What fluid should be used for resuscitation in head injury? Why?
0.9% saline
Slightly hypertonic with a sodium content of 154 mmol/L thus least likely to exacerbate cerebral oedema.
34
What is ICP usually assumed to be after severe head injury
20 mmHg
35
What is the indication for intubation and ventilation for transfer after brain injury?
GCS≤8
Significantly deteriorating conscious level - fall in motor score ≥2
Hypoxaemia (PaO2 <13 kPa on O2)
Hypercarbia (PaCO2 >6 kPa)
Spontaneous hyperventilation causing PaCO2 <4.0 kPa
Bilateral fractured mandible
Copious bleeding into the mouth, e.g. from skull base fracture
Seizures
36
List the referral criteria for neurosurgery
Those with new intracranial pathology, i.e. extradural, subdural, intracerebral/contusion, subarachnoid blood
GCS of 8 or less after resuscitation
Unexplained confusion for more than 4 hours
Deterioration in GCS after admission (fall in motor score particularly significant)
Progressive focal neurological signs
Seizure without full recovery
Definite or suspected penetrating injury
A CSF leak
37
List the information to be included for neurosurgery referral
History
* Mechanism of injury and subsequent events
* Past medical history
* Drugs (especially anticoagulants)
Examination
* GCS (motor score and trends especially important)
* Pupillary responses
* Focal neurological deficits
* Seizures
* MAP and SpO2
* Other injuries
Investigation
* CT head
* Cervical spine (C-spine)
* Coagulation
Treatment
* Intubation
* Phenytoin
* Mannitol
* Sedation
38
What are the signs of coning?
Reduction in GCS
Bradycardia, tachycardia and hypertension
Irregular breathing
Fixed dilated pupil(s)
39
List the immediate measures to take when signs of coning are showing
1. Check ABC - is the airway clear, SpO2 and end-tidal CO2 within range, MAP>80 mmHg?
2. Simple measures to reduce ICP - 30º head-up tilt and ensuring the head is in the neutral position.
3. Begin hyperventilation to PaCO2 of 4.0-4.5 kPa
4. Give mannitol 0.5-1 g/kg stat
5. Refer to (or update) neurosurgeons
40
What features are associated with a poor prognosis after TBI
Hypotension
Mechanism - penetrating, non-accidental injury in age <5, pedestrians and cyclists in RTA, ejection from vehicle
Age >65 years
Female gender
Fixed pupil (bilateral worse than unilateral)
GCS 8 or less - the probability of poor outcome increases as GCS decreases
CT findings - midline shift, compressed basal cisterns, traumatic subarachnoid haemorrhage, subdural worse than extradural for given severity
Genetics - apolipoprotein E
41
When is DVT prophylaxis following head injury started
delayed by 48-72 hours
42
List the management goals in TBI
AIRWAY - Early tracheal intubation if GCS≤8 or unable to maintain respiratory goals
BREATHING
* Avoid hypoxia, maintain SaO2>97%, PaO2>11kPa
* Hyperventilation, maintain PaCO2 4.5-5kPa for impending herniation
CIRCULATION
* Avoid hypotension, maintain MAP>80mmHg
* Replace IV volume, avoid hypotonic and glucose-containing solutions
* Use blood as necessary, reverse existing coagulopathy
* Vasopressor as necessary to maintain CPP
DISABILITY - BRAIN
* Monitor ICP, avoid ICP>20mmHg
* Maintain CPP>60mmHg
* Adequate sedation and analgesia
* Hyperosmolar therapy, keep Na+ < 155mmol/L, Posm < 320 mosm/L
* CSF drainage
* Treat seizures
* Barbiturate coma, DC, hypothermia if elevated ICP refractory to standard medical care
METABOLIC
* Monitor blood glucose, aim for glucose 6-10 mmol/L
* Avoid hyperthermia
* DVT thromboprophylaxis
43
How is MAP calculated
MAP = DP + 1/3(SP – DP)
44
What is the target CPP
>60 mmHg
45
What is the target glucose level in TBI
6-10 mmol/L
46
Define infarct core and ischaemic penumbra
Core = tissue damage is irreversible
Penumbra = tissue is at risk but may be restored to health with appropriate management
47
List two types of cerebral oedema
Vasogenic - ECF accumulation from Starling's forces across a disrupted blood-brain barrier
Cytotoxic - intracellular fluid accumulation due to cell membrane failure
48
Which kind of cerebral oedema predominate in TBI
Cytotoxic cerebral oedema
49
List the signs for subfalcine herniation
Asymptomatic
Contralateral limb weakness + frontal infarcts (ACA)
50
List the signs for tentorial herniation
Ipsilateral fixed pupil + contralateral hemiparesis
PCA may be compressed and perforating pontine arteries torn
False localising signs - movement of the midbrain is of sufficient magnitude to compress the contralateral third nerve and cerebral peduncle
51
List the Cushing's triad
Bradycardia
Hypertension
Altered respiratory pattern (brainstem ischaemia/compression)
52
When is ICP monitoring recommended?
Severe TBI with abnormal CT (contusions, haematomas, herniation, swelling, compressed basal cisterns)
Severe TBI with normal CT + any two of poor prognostic features:
* Age >40years
* Systolic BP<90mmHg
* Motor posturing
53
What is the gold standard ICP Monitoring Device
Intraventricular catheter
54
List the three components of the ICP waveform
P1 Percussion wave - ejection of blood from the heart, transmitted via the choroid plexus in the lateral ventricles
P2 Tidal wave - increase in the venous compartment, cerebral oedema, mass, or vasomotor paralysis. P2 is usually 80% of P1.
P3 Dicrotic wave - aortic valve closure
55
What change on the ICP waveform is an indicator of raised ICP and reduced intracranial compliance
Raised P2 wave
56
What are Lundberg A waves and Lundberg B waves
A - steep increases (50-100 mmHg) in ICP lasting for 5 to 10 minutes
B - rhythmic oscillations, sharply peaked, occurring every 1-2 min. ICP increases in a crescendo manner to 20-30 mm Hg from a variable baseline, and are not sustained.
57
What do Lundberg A waves represent
Very low CPP and ischaemia. Sign for the development of brain herniation if ICP is left untreated
58
What do Lundberg B waves represent
Vasomotor changes and are associated with an unstable ICP
59
List the advantages and disadvantages of mannitol
Advantages
* Familiar dose schedule (0.25-1 g/kg bolus IV)
* Easily available
Disadvantages
* Intravascular volume depletion
* Electrolyte imbalance
* Rebound increases in ICP
60
List the advantages and disadvantages of hypertonic saline
Advantages
* Intravascular volume expansion
* No rebound phenomenon
* Effective in mannitol-refractory patients
* Possible anti-inflammatory effects
Disadvantages
* Hyperchloraemia and hyperchloraemic acidosis (unknown significance)
* Aggravation of pulmonary oedema
* Risk of osmotic myelinolysis in previously hyponatremic patients
61
What should mannitol use be combined with
Small (10-20 mg) dose of furosemide
62
List the complications of therapeutic hypothermia
Coagulopathy
Hypokalaemia (urinary K+, Mg2+, PO4-, Ca2+ loss)
Pancreatitis
Hyperglycaemia (insulin resistance)
Pneumonia (hypothermia is immunosuppressive)
Elevated liver enzyme
63
What is a final step in the medical therapy of refractory raised ICP, especially if surgery in not indicated
Barbiturate coma with thiopentone at 3-5 mg/kg/h
* achieve burst suppression on the EEG
64
List the drawbacks of thiopentone induced barbiturate coma
Hypotension
Pneumonia
Difficult neurological assessment (fixed pupils)
Accumulates so waking is significantly delayed
65
What kind of cerebral perfusion does Lund therapy specifically control
penumbra microcirculatory
66
List the two principles in Lund Concept for Traumatic Brain injury
Reduce fluid shift from capillaries into brain parenchyma (brain oedema), by preserving capillary colloid osmotic pressure and reducing capillary hydrostatic pressure
Improve cerebral microcirculation, by avoiding arterial vasoconstrictors
67
List the approaches in Lund therapy for TBI
Preserve osmotic pressure
* albumin
* blood products
* diuretics
Reduce hydrostatic pressure
* metoprolol
* clonidine
* thiopentone
* dihydroergotamine (precapillary vasoconstriction)
CPP target
* if ICP normal aim for 60-70mmHg
* if ICP elevated aim for CPP of 50mmHg
Vasoactive use
* avoid dobutamine (cerebral vasodilatation)
* avoid noradrenaline (cerebral vasoconstriction)
68
What are the contents of the skull?
Brain tissue (80-85% volume)
Blood (10% volume)
CSF (5-10% volume)
69
How should you assess for C-spine instability?
Physical exam: midline neck pain, tenderness over the cervical spinous processes, neurological deficit
CT: from the occiput to T1 at 3 mm intervals
70
How are patients who require radiological interrogation to rule out a bony C-spine injury identified
The National Emergency X-Ray Utilization Study (NEXUS) criteria
* Focal neurological deficit
* Midline spinal tenderness
* Altered level of consciousness
* Distracting injury
* Intoxication
Canadian C-spine rule
High-risk factors
* Age ≥65 years
* Dangerous mechanism
* Paresthesias in extremities
Unable to actively rotate neck
No low-risk factor which allows safe assessment of range of motion
* Simple rear end MVC
* Sitting position in ED
* Ambulatory at any time
* Delayed onset of neck pain
* Absence of midline C-spine tenderness
71
What views are required of x-rays of the cervical spine
Lateral (skull base to at least the inferior portion of T1)
Anteroposterior
Open-mouth odontoid view (including articulations between C1 and C2)
72
What can significant injury to the cervical spinal cord cause
Tetraplegia/four limb weakness
Respiratory compromise
Bradycardia + hypotension (neurogenic shock)
73
What should assessment of the patient for C-spine neurological injury in the secondary survey
Motor and sensory levels
Reflexes
Log roll: spinal tenderness, deformity, obvious injury; perianal sensation and tone
Bowel sounds (peristalsis is absent in cervical spinal cord injury)
Evidence of bladder distension
74
List The American Spinal Injury Association (ASIA) International Standards for Neurological Classification of Spinal Cord Injury
A (Complete) - No sensory or motor function is preserved in the sacral segments S4-S5
B (Sensory Incomplete) - Sensory is preserved (but not motor function) below the neurological level and includes the sacral segments S4-S5 (light touch or pin prick at S4-S5 or deep anal pressure)
C (Motor Incomplete) - Motor function is preserved below the neurological level and more than half of key muscle functions below the level of injury have a muscle grade < 3
D (Motor Incomplete) - Motor function is preserved below the neurological level and at least half of key muscle functions below the level of injury have a muscle grade of ≥ 3
E (Normal)
75
What should be used to pharmacologically optimize intubating conditions in C-spine injury
Modified rapid sequence induction
* Alfentanil
* Ketamine
* Rocuronium
76
What should be the target MAP to ensure continuous perfusion to the spinal cord
>85 mmHg
77
What are common stimulants to autonomic hyperreflexia
Bladder and rectal distension
78
Why is the lower cervical spinal cord is more prone to injury
The cervical spinal canal is narrower in its caudally than cephalic
79
What is the first cervical vertebra that articulates the foramen magnum of the skull to the rest of the cervical column
Atlas
(Sits on the axis/C2)
80
What should be avoided in all cases 72 hours after SCI and why?
Suxamethonium
Extrajunctional acetylcholine receptors develop at the neuromuscular junction in acute spinal cord injury - stimulation of these receptors by suxamethonium can lead to a dangerous rise in serum potassium.
81
What kind of injury can be caused by cervical spine vertical compression
Fractures of the atlas ring (Jefferson fracture)
Burst fractures of lower vertebrae
82
What kind of injury can be caused by cervical spine hyperflexion
Crush fractures of vertebral bodies
Rupture of supraspinous ligaments
Vertebral dislocations
In combination with rotational forces
* Disruption of the posterior ligaments
* Facet joint dislocation
83
What kind of injury can be caused by cervical spine hyperextension
Pedicle fracture of C2
Fractures of the odontoid process and cervical vertebral bodies
84
What is the most common cause of thoracolumbar fractures
road traffic collisions
85
How many facets does each thoracic vertebra have
6 facets
Two are located on the transverse process and 4 demi-facets are located on the superior and inferior posterolateral surfaces of the vertebrae
86
List the anatomical composition of the vertical columns
Anterior column
* Anterior longitudinal ligament.
* Anterior 2/3 of the vertebral body.
* Anterior 2/3 of the intervertebral disc.
Middle column
* Posterior 1/3 of the vertebral body.
* Posterior 1/3 of the intervertebral disc.
* Posterior longitudinal ligament.
Posterior column (anything posterior to PLL)
* Pedicles
* Facet joints and articular processes
* Ligamentum flavum
* Neural arch
* Interspinal and capsular ligaments
87
When does spinal instability occur
When 2 contiguous columns are affected
88
List the major branches of the lumbar plexus
iliohypogastric nerve (L1, T12)
ilioinguinal nerve (L1)
genitofemoral nerve (L1, 2)
lateral cutaneous nerve (L2, 3)
femoral nerve (L2, 3, 4)
obturator nerve (L2, 3, 4)
89
What is the lumbar sympathetic chain formed by
Preganglionic neurons from L1 to L3
90
What is the thoracic sympathetic chain formed by
T1 to T12
91
List the 4 feature types described in thoracolumbar injury
Compression fractures - anterior column affected by axial loading and flexional forces. Bony fragments are not displaced
Burst fractures - anterior and middle ± posterior columns, are affected by axial loading forces. Bony fragments become dispersed
Wedge fracture - anterior column in flexion affected by axial loading forces
Fracture dislocation - intervertebral disc, facet joints and ligamentous complex all disrupted by translational forces with consequential displacement of the neighbouring vertebra. Always results in total spinal cord disruption
92
List the NICE guideline features for spinal immobilisation
Significant distracting injuries
Under the influence of drugs/alcohol
Confused/uncooperative
Reduced conscious level
Any spinal pain
Any hand/foot weakness
Altered/absent sensation in the hands/feet
Priapism
History of past spinal problems (previous spinal surgery, conditions predisposing to spinal instability, osteoporosis)
93
List the signs for anterior cord syndrome
Motor function, pain and temperature sensation are all lost below the level of the injury
Touch and proprioception are preserved.
94
List the signs for Brown-Sequard syndrome
ipsilateral loss of motor function, proprioception, touch and vibration sensation
contralateral loss of pain and temperature sensation.
95
List the signs for posterior cord syndrome
Loss of proprioception and vibration sensation
Preservation of motor function, pain, temperature and touch sensation.
96
What can be used to treat bradycardia in spinal cord injury
Glycopyrrolate or atropine
97
Give the mechanism of neurogenic shock in spinal cord injury
Injuries above T6 and disruption of the descending sympathetic tracts
Leads to unopposed parasympathetic activity from the vagus nerve
Causes hypotension without compensatory tachycardia and possibly bradycardia
Caudal to the level of injury, the skin may appear warm and flushed due to vasodilatation
98
Spinal shock often accompanies neurogenic shock. How does spinal shock present
flaccid paralysis, anaesthesia, absent bladder and bowel function and loss of reflex activity.
99
In what level of SCI is autonomic dysreflexia seen
Injuries above T6
100
Give the mechanism of autonomic dysreflexia
Unopposed sympathetic activity below the level of the injury in response to a stimuli which produces vasoconstriction and hypertension.
Compensatory parasympathetic activation above the level of the lesion results in bradycardia and vasodilatation.
Usually develops within the first year after injury and is unlikely within the first few weeks.
101
Describe the cellular level pathophysiology for circulatory shock in trauma
Hemorrhagic shock occurs when O2 demand exceeds delivery, disrupting aerobic metabolism.
When mitochondrial O2 <2 mmHg: Oxidative phosphorylation is inhibited. Pyruvate cannot enter the Krebs cycle.
Pyruvate undergoes anaerobic metabolism, converting to lactate to regenerate NAD+ (inefficient in producing ATP but allows some cellular respiration under low oxygen)
Consequences of anaerobic metabolism: Oxygen debt develops + Inorganic phosphates and free radicals accumulate, leading to metabolic acidosis.
Reduced heat production exacerbates hypothermia.
As ATP depletes, cell membrane pumps fail, disrupting cell homeostasis.
Cell death occurs via Necrosis, apoptosis, or necroptosis.
Damage-Associated Molecular Patterns (DAMPs), including mtDNA, are released, triggering a systemic inflammatory response.
102
What proportion of trauma patients have an established coagulopathy on arrival in the emergency department
25%
103
Describe the pathophysiology of acute traumatic coagulopathy
Catecholamine surge and mounting oxygen debt cause Endotheliopathy, where the protective endothelial glycocalyx is shed at both local and remote injury sites.
Shedding of the glycocalyx results in Increased vascular permeability, Increased plasmin activity and auto-heparinization.
These changes lead to Pathologic hyperfibrinolysis and Diffuse coagulopathy (acute traumatic coagulopathy)
104
What is the lethal triad in trauma patients
Coagulopathy
Hypothermia
Acidosis
105
List the maladaptive mechanisms underlying circulatory decompensation
Metabolic acidosis
Cardiogenic shock
Sympathetic escape
Cerebral hypoxia
Systemic inflammatory response
106
At which point is a patient deemed to be in decompensated shock
Severe hypoxia and acidosis lead to failure of the myocardium with a sudden decrease in blood pressure.
107
List the principles of damage control resuscitation
Balanced resuscitation (delayed resuscitation/permissive hypotension/minimal normotension)
Haemostatic resuscitation
* Early transfusion to maintain circulating volume and appropriate activation of massive transfusion protocol
* Minimise crystalloid infusion (<3 litres in first 6 hours)
* Goal-directed correction of coagulopathy
* Avoid/correct hypothermia
* Prevent acidaemia
Damage Control Surgery (DCS)
108
Give the aim and rationale for Balanced Resuscitation
AIM = maintain the minimum blood pressure necessary to perfuse vital organs
RATIONALE = elevations in blood pressure before surgical haemostasis may compromise a tenuous clot resulting in further bleeding.
109
Give the technique in Balanced Resuscitation
Fluid/blood product administration with target systolic blood pressure 90mmHg (MAP 65mmHg) along with concurrent signs of major organ hypoperfusion such as altered mentation in the absence of head trauma.
110
Give the contraindication for Balanced Resuscitation
Head injury
111
Describe the Haemostatic resuscitation approach
Early use of blood products - fresh frozen plasma (FFP), platelets (PLT), and packed red blood cells (PRBC), as primary resuscitation fluids to treat intrinsic acute traumatic coagulopathy and prevent dilutional coagulopathy.
PRBC:FFP:PLT = 1:1:1
In practice: a pool of platelets is administered after the 4 units of PRBCs and FFP
112
List the definitions of massive transfusion
Transfusion of ≥10 units of packed red blood cells (PRBC) within a 24-hour period
Transfusion of ≥4 units of PRBCs in a 1-hour period with anticipation of continued need for blood product support
Replacement of one entire blood volume within a 24-hour period
Replacement of 50% of total blood volume (TBV) within a 3-hour period
113
Define critical administration threshold. What's its prognostic significance?
The transfusion of ≥3 PRBC units within any 1-hour time window within the first 24 hours.
Trauma patients who reach CAT soon after presentation or trigger CAT multiple times have been shown to have a significantly increased mortality
114
Describe the role of Ca2+ in massive transfusion protocols
Ca2+ is an important cofactor in the coagulation cascade
Citrate is used as an anticoagulant in blood products.
In patients with haemorrhagic shock receiving large volumes of blood products, citrate will chelate Ca2+ causing progressive coagulopathy and severe/life-threatening hypoCa2+. (less common if normal liver function)
Empirical administration of Ca2+is recommended after transfusion of the first four units of any blood product.
Further Ca2+therapy should be guided by frequent measurement and be maintained at a concentration of at least 1 mmol/L.
115
Describe the role of Tranexamic acid in massive transfusion protocols
Hyperfinbrinolysis contributes to the acute coagulopathy of trauma.
TXA inhibits plasmin formation, significantly reduce morbidity and mortality in trauma patients with haemorrhagic shock if administered within 3 hours of injury
The benefit of tranexamic acid administration decreases by 10% for every 15 min of treatment delay until 3 hours after the onset of haemorrhage, when there is no benefit to its administration
116
List the four-phase technique in damage control surgery
Damage Control Part Zero (DC 0) - Pre-hospital + ED
Damage Control Part One (DC I) - Operating theatre. Clinical priorities = haemorrhage control and limitation of contamination
Damage Control Part Two (DC II) - PostOp admission to ICU. Reverse hypotension related metabolic failure and correction of physiological and biochemical abnormalities
Damage Control Part Three (DC III) - planned return to theatre for re-exploration and definitive repair of all injuries
117
What nerves innervate the baroreceptors in carotid sinus and aortic arch
Carotid sinus - CNIX
Aortic arch - CNX
118
List the therapeutic targets for massive transfusion protocols
Temperature >35°C
Acid-base balance
* pH >7.2
* BE >-6 mEq/L
* Lactate <4 mmol/L
Haemoglobin 80-100g/L
Platelet ≥75x10^9/L (>100x10^9 if head injury/intracranial haemorrhage)
PT/APTT ≤1.5x normal
Fibrinogen ≥1.5g/L
Ionized calcium >1mmol/L
119
List five chest injuries that are immediately life-threatening
Tension pneumothorax
Open pneumothorax
Massive haemothorax
Flail chest
Cardiac tamponade
120
List 6 potentially life-threatening injuries that may be identified by careful examination of the chest during the secondary survey
Pulmonary contusion
Cardiac contusion
Aortic rupture (blunt thoracic aortic injury)
Ruptured diaphragm
Oesophageal perforation
Rupture of the tracheobronchial tree
121
What is the earliest indication of pulmonary contusion
hypoxaemia (reduced PaO2 / FiO2 ratio)
122
Give the X ray sign of pulmonary contusion
infiltrates over the affected area
123
Give the investigation to confirm the diagnosis of cardiac contusion
echocardiography
124
What is the most frequently injured site for cardiac contusion
Right ventricle
Predominantly an anterior structure
125
What is the commonest site for Blunt Thoracic Aortic Injury. Describe the mechanism.
Aortic isthmus - just distal to the origin of the left subclavian artery at the level of the ligamentum arteriosum
Deceleration produces huge shear forces at this site because the relatively mobile aortic arch travels forward relative to the fixed descending aorta.
126
Give the chest x ray signs for Blunt Thoracic Aortic Injury
Widened mediastinum
Loss of aorto-pulmonary window
Deviation of trachea / NG tube to the right
Downward displacement of left mediastinum bronchi
Left pleural cap
Left haemothorax
Abnormal aortic countour
Loss of aortic knob
127
Which side does rupture of diaphragm most frequently occur
75% of ruptures occur on the left side
128
Give the x ray signs for rupture of the diaphragm
Elevated hemidiaphragm
Gas bubbles above the diaphragm
Shift of the mediastinum to the opposite side
NG tube in the chest
129
How is definitive diagnosis for rupture of the diaphragm made
X ray with contrast media through the NG tube
130
List the symptoms and signs of oesophageal perforation
Severe chest and abdominal pain
CXR: mediastinal air
Gastric contents may appear in the chest drain
131
Which viscera are the three most commonly injured in blunt abdominal trauma
40-45% Spleen
35-45% Liver
5-10% Small bowel, colon, kidneys
132
Assessing Abdominal Trauma - what is the correct examination order
1. Inspection
2. Palpation
3. Percussion
4. Auscultation
133
Give the likely pattern of injury with Lap-belt bruising
Tears/avulsion of the mesentery
Rupture of small bowel/colon
Thrombosis of iliac arteries/abdominal aorta
Spinal hyperflexion (Chance's fracture of the lumbar vertebrae)
134
What is Chance's fracture
Horizontal fracture through the spinous process and posterior structures of the vertebrae.
Any vertebra from T12 to L4 can be affected, with L2 having the highest incidence of fracture.
In up to 78% of patients in one study who had this type of injury, there were associated intestinal injuries.
135
Give the likely pattern of injury with Grey Turner's sign
(Ecchymosis in the flanks)
Retroperitoneal haemorrhage
136
Give the likely pattern of injury with Shoulder harness bruising
Fractures to the lower ribs
Compression injuries to the abdominal viscera in the thoracoabdominal cavity.
137
Give the likely pattern of injury with Cullen's sign
(Peri-umbilical bruising)
Retroperitoneal haemorrhage
Usually takes 24-48 h to appear
If accompanied by bruising of the flank, may be indicative of pancreatic necrosis with retroperitoneal/intraabdominal bleeding.
138
What may involuntary guarding suggest
Peritoneal irritation - Leakage of intestinal content
139
What is Rebound tenderness and what does it suggest
when the palpating hand compressing the abdomen is rapidly removed resulting in sharp, severe localized pain at the previous site of compression.
peritonism due to leakage of gastric contents rather than haemoperitoneum.
140
List the advantages and disadvantages of FAST scan
Advantages
* Non-invasive
* Rapid to perform
* Repeatable
* Can be used at the bedside in the haemodynamically unstable patient
Disadvantages
* Cannot reliably detect contained solid visceral injury without free-fluid
* Cannot detect retroperitoneal haemorrhage
* Rarely identifies hollow viscus injury
141
Why do all trauma patients undergoing endotracheal intubation require an NGT
Decompression of stomach to relieve acute gastric dilatation, empty gastric contents and reduce the risk of aspiration.
142
Give the likely pattern of injury with Perineal/scrotal bruising
Pelvic fracture
143
