Trauma CPGs Flashcards
Define shock
A condition where organs and tissues are not receiving adequate flow of blood, depriving the cells of oxygen and nutrients and allows the build up of waste products
Types of shock/fluid loss
- hypovolaemia: intravascular volume has decreased
- cardiogenic: failure of heart to pump effectively
- neurogenic: sympathetic nervous system fails - vasodilation
- septic: infection causes blood vessels to dilate - hypotension
- anaphylactic: systemic allergic reaction - vasodilation - increased capillary permeability - hypotension
- obstructive: blood flow is stopped (tamponade, PE)
Neurogenic shock patho
- injury to spinal cord
- loss of sympathetic vascular tone
- vasodilation
- decreased venous return
- decreased stroke volume
- decreased cardiac output
- hpotension, bradycardia
Shock Process
Stage 1: injury
2: slow continuing haemorrhage - reduced VR and CO, detection by baroreceptors, via SNS to cardiovascular centre
3. Vasoconstriction - SNS/catecholamine mediated, reduced IHP, renin angiotensin
4. tachycardia - SNS/catecholamine mediated, optimal CO, renin angiotensin
5. decompensation - limit of compensation reached, collapse, brief increase in BP, poor perfusion - hypoxia/hypercarbia/wastes - vasodilation/inflammatory response and BP falls
6. Irreversible shock - leaky capillaries, clotting, profound organ damage, low BP
Modifying factors of fluid admin
Head injury - BP over 120 to maintain MAP and CPP
GI bleed - accept BP 80-100 as fluid may blow off clots
Uncontrolled haemorrhage - accept carotid, haemodilution, fluid may blow off clots
Spinal injury - up to 500ml bolus, hT caused by vasodilation
Chest injury - decompress, hT caused by increase ITP hence reduced VR
Diving - 1lt over 15-20 mins, then 1lt every 4 hours unless refuced perfusion: 20ml/kg
Life threatening chest injuries identified in primary survey
Airway obstruction - inadequate oxygenation in blood
Tension - one way valve, increase ITP and reduced VR
Open pneumothorax - if opening of wound greater than trachea, sucking chest wound: resp failure
Massive haemothorax - accumulation of blood in intrapleural space
I
Cardiac tamponade - accumulation of blood or fluid within the pericardial sac, impeding VR and CO
Chest injuries found on secondary survey
Flail chest - #2 or more adjacent ribs or sternum at 2 or more points causing moving segment
Aortic transection - mechanism involving high deceleration forces can cause transection usually to proximal descending section
Tracheal injury - reduced airway function
Pulmonary contusion - leakage of blood into alveoli and interstitium, culminating in consolidation and atelectasis (collapsed alveoli) causing hypoxia
Oesophageal rupture - ruptured oesophagus after blunt trauma is rare, but can be caused by valsalva
Diaphragm rupture - significant blunt force to abdo can force contents to rupture diaphragm causing resp compromise due to abdo content impeding lung expansion
Definition of a simple pneumothorax
presence of air in the pleural space caused by rupture of visceral or parietal pleura or chest wall
Patho of Simple Pneumothorax
-as air separates the 2 pleura, it destroys the negative pressure of pleural space and disrupts the equilibrium between elastic recoil forces of the lung and chest wall
Signs and symptoms of pneumothorax
Chest trauma Resp distress Absent breath sounds to one side Poor perfusion (hT) Increased jugular vein distension Subcutaneous emphysema Tracheal shift away from injured side
Tension pneumothorax definition
creation of a one way valve causes lung to collapse as pleural pressure exceeds atmospheric pressure therefore high pressures push against the lung causing compression and displacement of mediastinum, increased ITP compresses major vessels reducing VR and CO
Patho of tension pneumothorax
- penetration of chest wall/lung tissue forms a one way valve
- air enters pleural space during inspiration (period of low ITP)
- air is trapped during expiration - hyperinflation
- ITP increases, exceeding atmospheric pressure and lung collapses
- slowly pressure increases to greater than SVC and IVC
- rapid decrease in VR, CO and conscious state
Signs and symptoms of tension pneumothorax
Simple: unequal breath sounds, low spo2 RA, subcutaneous emphysema Tension: increase peak inspiratory pressure/stiff bag -increased JVP -reduced etco2 -reduced conscious state -poor perfusion -tracheal shift -low spo2 on supp o2
Primary head injury
initial injury sustained at time of traumatic event: lacerations, avulsions, compression, concussion, contusions, haemorrhage
Secondary head injury
after initial insult - swelling - reduced blood flow to brain - hypoxia - vasodilation - increased blood flow to brain - increased ICP - continuing process
- hypoxia: vasodilation - increased ICP
- hypercapnia: increase co2- cerebral vasodilation - increased blood flow - increase ICP
- hT/hypovolaemia: reduced o2 - hypoxia - vasodilation - increased ICP
- haemorrhage: increase ICP
- Hypertension: increased ICP - ischaemia -necrosis
5HEDS
5mins LOC Head injury (# skull, boggy mass, haematoma) Emesis greater than 1 Neuro deficit Seizure
Cushing’s Triad
reduced HR
increased BP
irregular breathing
Types of primary head injury
Concussion
Contusion
Compression
Concussion explained
mild-mod impact - the function of the brain stem (RAS) which is reponsible for regulating arousal and sleep wake transitions, or both cerebral cortices is temporarily disturbed - brief ACS - periods of drowsiness, restlessness, confusion
Contusion explained
Bruising to brain - structural change to brain tissue - neuro deficits - may cause LOC
May be injury to site of impact (coup) or opposite side (contrecoup)
Compression explained
Haemorrhage into brain or surrounding cavity with increased pressure in cranial vault
Reduced VR out of head and arterial blood squeezed out causing hypoxia and swelling
Intracellular ischaemia and loss of auto regulation causing altered permeability of cell membrane causing interstitial oedema which increases pressure on brain tissue
Types of Cerebral Haemorrhages
Extradural - hx between cranium and dura
Subdural - hx between dura and surface of brain
Subarachnoid - intracranial bleeding into CSF
Intracerebral - collection of blood within substance of the brain
Diffuse Axonal Injury
trauma from shearing or stretching of axonal fibers cause by acceleration or decceleration forces
Cushing’s triad explained
Bradycardia- effected CNX, vagal nerve. Trauma should have increased HR therefore low HR is suspicious
Hypertension - sympathetic response to bradycardia which increases pulse pressure or compensatory response to bleeding/swelling of brain
Altered resps - neural control for breathing compromised therefore respiration only in response to lower brain stem stimulus causing altered co2 levels with subsequent cheyne stokes resps
RAS = ACS, vasomotor centre = vasoconstriction = HT, cardioinhibitory centre = pressure on vagus nerve = bradycardia, resp centre = cheyne stokes/CNH resps
Early signs of increased ITP
- headache
- agitation
- slow, deep resps
- unequal pupils
- nausea and vomiting
- ACS
Late signs of increased ITP
- decorticate, decerebrate posturing
- paralysis
- cushing’s triad
- febrile - temp regulation failure