Trauma VIVA 2

pathophysiology of a tension pneumothorax

• air becomes trapped in the pleural space

• as a result of positive pressure or decreased ventilatory effort (fatigue) the air in the pleural space expands

• this increased pressure collapses the lung

• a injury to lung acts as a one-way valve that allows air into the pleural space, but not out - on exhalation injury seals

how is a pneumothorax treated in hospital?

• open thoracostomy

• tube thoracostomy

• a chest tube is inserted into the pleural space to remove air or fluid between the 4th or 5th intercostal

• the tube is a closed one-way drainage system preventing air from re-entering

• can also be done by HEMS

sucking chest wound pathophysiology

• a pneumothorax associated with chest wall defect (eg penetrating injury)

• air enters pleural space directly from external environment, and causes lung to collapse

• open pneumothorax

• air moves in and out of sucking chest wound

what is the treatment for open pneumothorax?

• chest seal

• chest tube

• surgical repair of injury site

how does a chest seal work in open pneumothorax?

• prevents outside air from entering chest cavity during inhalation

what is a haemothorax?

• accumilation of blood in the pleural space often caused by thorax injury

what is the treatment for haemothorax?

• thoracotstamy drains blood from the pleural space allowing the lung to expand

• HEMS can perform thoracostamy (tube or open)

• TXA

• high flow oxygen

• immediate transport

• permissive hypertension/bloods

flail chest pathophysiology

• two or more rib fractures per rib in three or more ribs

• causes free floating segment

• results in paradoxical movement of the chest wall

• instability of chest wall prevents lungs from fully expanding leading to breathing difficulties

• additionally pain results in shallow breathing

• this is an injury that may cause pulmonary contusion which then impairs gas exchange

flail chest treatment

• oxygen

• pain management

• positioning

• low threshold for advanced car team as these pts can deteriorate quickly

what is obstructive shock?

• physical/mechanical obstruction that prevents the heart from filling or pumping effectively

• this leads to impaired cardiac output

causes of obstructive shock

• cardiac tamponade

• tension pneumothorax (mediastinal shift?)

• PE

what is a primary brain injury?

• occurs at the time of impact

• direct injury to the brain

• damage done - aim to reduce/control secondary brain injury

what is a secondary brain injury?

• later + indirect injury to the brain that occurs after primary brain injury

• occurs as a result of physiological factors (eg inflammation, reduced o2 etc)

• systemic causes

what is a coup/contra-coup injury?

• severe TBI/focal brain injury

• impact to skull causes brain to move within skull (coup)

• brain hits opposite point of skull (contra-coup)

what is a focal brain injury?

• localised injury to a specific area of the brain

• commonly caused by contusions, lacerations for vessel damage

what is a brain contusion?

• TBI

• localised bruising/bleeding on the brain surface often caused by direct impact

• size of contusion determines extent of injury

what is a diffuse axonal injury?

• A TBI

• caused by shearing of nerve fibres and white matter which causes damage and disrupts the transmission of electrical impulses

• happens when brain rapidly accelerates/decelerates inside of the skull

• causes widespread damage

• happens after high speed accidents

what are the types of skull fracture?

• linear (80%) - straight line fracture

• depressed - broken skull pressed inwards towards brain

• open/closed

• basilar - fracture to base of skull

systemic causes of secondary brain injury

• hypoxia

• increased/decreased CO2

• hypotension

• anaemia

• BM changes

intracranial causes of secondary brain injury

• seizures

• cerebral oedema

• haematoma

• increased ICP

warning signs of increased ICP

• decreased GCS

• sluggish non-reactive pupils

• hemiplegia

• hemiparalysis

• cushings triad

cushings triad

• increased ICP

• bradycardia

• widened pulse pressure/hypertension

• irregular resps

what is the Monroe Kelly hypothesis?

• the skull is a rigid box and its volume is fixed

• CFS, blood and brain tissue fill the skull

• an increase in one of these components decreases the room left in the skull and thus increases intracranial pressure

what order is the spinal column anatomy

• cervical - 7

• thoracic - 12

• lumbar - 5

• sacrum - 5

• coccyx - 4

what is the pathophysiology of spinal trauma

• within the spinal cord are the motor and sensory nerve tracts

• damage to these areas may result in weakness or paralysis, pain

impact of high cervical injury

• loss of total ability to breathe

• c3, 4 and 5 keep the diaphragm alive

• can cause complete paralysis neck down

• loss of autonomic control

impact of lower thoracicl injury

• T2-11 keep intercostals from heaven

• diaphragm functions, loss of intercostal muscles

hypotension associated with spinal trauma

• hypotension occurs as a result of loss of sympathetic nervous control

• loss of SNS control results in vasodilation, bradycardia and warm dry skin (results in blood pooling)

• common in injuries above T6

• neurogenic shock

• hypovolemia needs to be treated as primary cause

how should increased ICP be prevented?

• head packaging up

• no ligatures

• reduce gagging/vomitting (mindful of adjuncts + ondans)

• analgesia

• minimise restraint

pathophysiology of pelvic injury

• usually occur as a result of high force blunt injury and are associated with polyinjury

• high energy damages pelvis (eg pelvic ring)

• shearing and tearing forces damage major vessels causing massive internal bleeding (entire blood volume can be lost into pelvis)

• this can result in haemorragic shock

what is an anterior/posterior pelvic fracture?

• open book fracture

• fractures that widen the pelvis

• severe risk of bleeding and neuromuscular injury

• pt needs massive blood therapy and haemorrhage control

what is the in hospital treatment for open book pelvic fracture?

• patient stabilisation - aggressive fluid resuscitation with major blood transfusions

• pelvic binding to stabilise pelvis and stop bleed

• peritoneal packing

• surgical intervention to fix pelvis

• antibiotics, pain meds, wound cleaning, rehab

what are the two types of pelvic fractures?

• stable - fracture to pelvic ring however it remains intact

• unstable - fractures to pelvic ring in two or more places making it unstable. often associated is bleeding

cardiac tamponade pathophysiology

• blood fills the pericardium which increases pressure within the sac

• this results in the heart being unable to refill or pump blood into circulation

• the chambers become depressed limiting filling of heart and reducing stroke volume

• results in reduced cardiac output

• type of obstructive shock

• caused often my penetrating injuries

cardiac tamponade treatment

• HEMs can perform clamshell thoracotamy

• surgical procedure to expose and access the thoracic cavity

• cardiac tamponade can be identified

• blood can be removed from the pericardial sac

• open cardiac massage can be performed to restart the heart

what is a mid shaft femur fracture?

• a fracture to the mid point of the thighbone

• requires severe force

• these fractures carry the risk of internal haemorrhage as the femoral shaft is highly vascular (1.5L)

• risk of hemorrhagic shock

how is a mid shaft femur fracture treated?

• Kendrick spint

• applies traction to limb and aligns fracture ends

• surrounding muscle and tissue tighten to compress vessels

contraindication of kendrick splint

• tib/fib fracture

• ankle, foot, lower leg injury

what is an open thoracotstamy

• CCP skill

• surgical procedure

• large incision to chest wall with the intention to decompress a tension pneumothorax by attending to air leaks and the injured lung

• used in cardiac arrest in suspected TP cause

what is a pneumonix?

• large-bore needle used to decompress TP in self ventilating pt

• CCP skill

what is a surgical cricothyroidectomy?

• scalpel, bougie and tube

• gaining front of neck access in cardiac arrest

• airway obstruction/occlusion

• CCP skill

what is a rapid sequence induction?

• anaesthesia to place ET tube

• used in pts with traumatic injury who have lost their airway

• common in TBIs

what is a resuscitative hysterectomy?

• surgical procedure to remove foetus from uterus of pregnant pt in cardiac arrest with traumatic pathology

• aims to improve the mothers survival by improving cardiac output by relieving pressure on vessels

neurogenic shock triad

• neurogenic shock is a type of obstructive shock

• Bradycardia

• hypotension

• peripheral vasodilation (warm, flushed, dry skin)

why does flail chest cause paradoxical movement

• the flail segment moves as a result of pressure changes

• the rest of the chest wall moves as a result of muscle action

• the segment no longer has this muscle support

traumatic causes of cardiac tamponade

• penetrating wounds eg stabbing, impalements

• blunt trauma eg impact into steering wheel in RTC

• gunshot wounds

medical causes of cardiac tamponade

• infectious pericarditis

• aortic dissection

what is the trauma triad of death?

• each condition exacerbates the other, leading to rapid deterioration so needs to be rapidly acknowledged and addressed

• acidosis - impaires enzyme reactions, speeds up fibrinogen breakdown and reduces platelet function

• hypothermia - impaired enzyme reactions necessary for blood clotting

• impaired clotting

• all results in severe blood loss in trauma patients

underlying process of trauma triad of death

• hypovolemic shock results in inadequate tissue perfusion which kickstarts triad

• hypoxia causes cells to use anaerobic respiration which releases lactic acid into bloodstream causing acidosis, affecting coagulation

• bloodloss and reduction in metabolic processes cause hypothermia, which impacts platelet production and enzyme reactions necessary for clotting

• acidosis and hypothermia result in coagulopathy

what specialties are available at MTC?

• orthopaedic surgery

• neurosurgery

• vascular services

• cardiothoracic surgery

• maxillo facial + plastics

• specialised trauma teams

• 27/4 access to these teams

what specialties are available at trauma centres

• trauma centres offer immediate resuscitation, stabilization, and care for less severe injuries

• patients for severe life threatening injuries may need to later be transferred to MTC after stabilisation

what are the negative impacts of secondary transfer from TC to MTC?

• treatment delay

• risk of deterioration during transfer

what type of injuries may lead to neurogenic shock

• injury to the spinal cord - often above T6

• penetrating injuries that damage the spinal cord

• side effects from spinal cord Anastasia

• inflammation of spinal cord - transverse myelitis

how do seizures cause secondary brain injury?

• contribute to hypoxia

• exitotoxicity causes cell death

why does hypoxia cause secondary brain injury

• depleted ATP

• this causes excess glutamate production which causes exitotoxicity

• this causes neurones to become damaged or die

why does hypercapnia cause secondary brain injury?

• causes cerebral vasodilation which increases blood flow in the brain which thus increases ICP further

why does hypocapnea cause secondary brain injury?

• causes cerebral vasoconstriction

• reduces blood flow to the brain which causes hypoxia and tissue death

differentiating between tension pneumothorax and haemothorax?

• percussion - TP hyperesonant (air), haemothorax (hyporesonant (blood)

• TP - distended neck veins, haemothorax flat neck veins due to hypovolemia

• TP = obstructive shock, mediastinal shift. haemothorax = hypovolemic shock

txa indication

• head injury pt GCS 12 or less

• suspected significant internal/external bleed

• confirmed miscarriage with excessive bleeding

• PPH

• within 3 hrs of injury

txa contraindications

• known allergy

• injury started more than 3hrs ago

• suspected GI bleed

txa dose

• adults 1G

• IV, IO, IM in trauma

paracetamol indication

• pain relief (mild/moderate)

• high temp with discomfort

what is the dosage for IV paracetamol?

• 1G every 4-6 hrs

indication for morphine

• severe pain

contraindications for morphine

• respiratory depression (-10 breaths per min)

• hypotension (-90 systolic)

• head injury with only pain response/ - GCS 9)

• known hypersensitivity

what is the dosage of morphine?

• up to 10mg initial dose

• max dose of 20mg

indication for ondansetron

• nausea/vommiting

• this can increase ICP

contraindication for ondansetron

• known sensitivity

• congenital long QT

• infants under a month

dosage of ondansetron

• initial dose of 4MG

• max dose of 8MG

• dose interval of 30 mins

• to be given over 2 mins

co-amoxiclav dosage

• over 40kg - 1.2G

• slow injection over 3-4 mins

when is an IO indicated

• trauma (eg burns, hypothermia, TCA, PPH, shock)

• cardiac (eg cardiac arrest, MI)

• neuro (status epilepticus, stroke, head injury, RSI)

• respiratory (all respiratory emergencies)

• systemic (sepsis, sickle cell crisis, DKA, dehydration)

• when medication/fluids are needed immediately

what are contraindications of IO access?

• prosthesis (eg knee replacement)

• trauma to bone

• no anatomical landmarks

• local infection

• recent IO (in same bone within 48 hours)

what are the sites for IO access

• humeral head

• distal femur (paeds)

• tibial tuberosity

• medial malleolus

bilaterally!!!

what are the IO needle sizes?

• pink 15mm - 3-39 KG

• blue 25mm - more 3 KG

• yellow 45mm - 40KG

how should the correct needle be selected?

• depress skin tissue with thumb to gauge depth

• confirm with 5mm mark

how should drugs be administered into an IO site?

• drugs can’t be dripped, they need to be pushed

• eg used three way tap for fluids

under what circumstances can IO be administered in a conscious patient?

• altered mental status/GCS less than 8

• respiratory compromise SPO2 less than 80 after O2, RR less than 10 or more than 40

• systolic BP less than 90

• pts in immediate need of medications

• profound hypovolemia with altered mental status

what are the indications of needle thoracocentisis

• presenting with clinical signs and symptoms of tension pneumothorax

what are the contraindications for needle thoracocentesis?

• no tension pneumothorax suggested

how successeful is needle decompression?

• canullas will fail in over 1/3 of pts

what is the landmark for needle decompression?

• second intercostal space

• midclavicular line

• above third rib

what are some possible complications of needle decompression?

• failure

• haematoma

• pneumothorax

• lung laceration

• haemothorax

• blocked cannula

• displaced cannula

• subcutaneous emphysema

• air embolism

what is the landmark for needle cric?

• ID cricothyroid membrane in midline between Adams apple (thyroid cartilage)

• and the cricoid cartilage (next prominent cartilage down from Adams apple)

how is needle cric done?

• remove cap and filter of 14g cannula

• draw up 2mls air in 10ml syringe

• attach o2 tubing to 3 way tap

• ID landmark

• insert cannula at 45 degrees at a downwards angle + push until give is felt, white aspirating syringe

• if air does not enter syringe at this point consider fat plug

• remove needle (sharps bin!) and respirate to confirm placement

• secure with tape

• remove syringe + attach three way tap with o2 tubing on 15L

• occlude open port for 1 second for inhalation, then release for 4 seconds exhalation

• safe duration of technique is 30-45 mins

what are the indications of needle cricothyroidotomy?

• pts in need of oxygen due to life threatening upper airway obstruction

• can’t intubate, can’t ventilate

what are contraindications for needle cric?

• ability to secure airway by other means

• unable to locate/identify landmark

• airway trauma rendering access via cricothyroid membrane futile

what are some possible complications of needle cric?

• failure

• blocked cannula

• displaced cannula

• posterior trachea puncture

• subcutaneous emphysema

• hypercapnia

• inability to ventilate

when is external jugular vein cannulation indicated?

• if IO and peripheral access have both failed/been ruled out

what are contraindications of EJV cannulation?

• patients under 18

• landmarks cant be identified

• one attempt only

• should not be first point of attempted access

what are some potential complications of EJV cannulation?

• damage to surrounding nerves

• damage to surrounding blood vessels including carotid artery

• air embolus

potential complications of IO

• extravasation - fluids/medications leak into surrounding soft tissue, potentially causing compartment syndrome, tissue necrosis, or skin necrosis

how is EJV cannulation done?

• Lay patient supine or even head down slightly.

• Turn patient’s head to the opposite side.

• Finger on EJV near clavicle to help with tourniquet effect.

• Aseptic.

• Insert midway down the EJV.

• Cannulate in a caudal direction, superficially (10-25 degrees).

• Dispose of sharp in sharps bin and secure cannula.

how is IO done?

• Aim the needle tip downward at a 45 degree angle to the horizontal plane/90 degrees

• Adults: Gently drill into the bone 2cm or until the hub reaches the skin, or you
  feel the ‘pop’.

• Infants: Stop when you feel the ‘pop’ or ‘give’.

what is a burn?

• injury caused by exposure to heat/electricity/chemicals/radiation

• most commonly affects skin, may also affect airways, lungs, muscle, bone and internal organs

what burns are complex?

• all electrical and chemical burns

• thermal burns covering critical area

• more than 15% TBSA of adult

• more than 10% TBSA of child

• more than 5% TBSA of child under 1

what are the critical areas?

• face

• hands

• feet

• perineum

• genitals

• major joints

what are the three layers of skin?

• epidermis (outermost layer)

• demis (nerve endings, blood vessels)

• subcutaneous (fat and muscle)

what are the types of burns?

• superficial epidermal burns

• superficial dermal burns

• deep dermal thickness burns

• full thickness burns

what are superficial epidermal burns?

• involves epidermis only

• red + painful

• no blistering, no scarring

• heals within 7 days

what are superficial dermal burns?

• involves epidermis and upper dermis

• pale pink, fine blisters, blanches to pressure

• extremely painful

• heals within 14 days