Trauma - head and thorax Flashcards
What is the first consideration when assessing a head trauma?
Can the animal breathe
- Bony structures – crushed nasal bones
- Soft tissue – oral bleeding (tongue) and aspiration risk, or crushed/damaged airway/larynx
What is the second consideration when assessing a head trauma?
The brain - evidence of TBI (traumatic brain injury)
Bony structures – depressed skull fracture
Soft tissue – direct concussive trauma to the brain
What are the tertiary considerations when assessing a head trauma?
Other non-life threatening injuries e.g., A broken jaw, Proptosis of the eye
How can you assess a patients breathing in a head trauma case?
Assess respiratory rate, effort, signs of cyanosis, pulse oximetry.
What should you do if you are concerned a head trauma patient cannot breath?
instigate emergency therapy:
- oxygen therapy if the airway is patent (open)
- If the airway is not patent, then rapid induction and intubation
- Have suction available to help clear the airway (machine or with a urinary catheter and a big syringe)
- If intubation fails, then emergency tracheostomy
Give examples of Primary TBIs
- Concussion (no histopathological changes, self limiting)
- Contusion – bruising and oedema of the brain increasing intracranial pressure (ICP)
- Haematoma – cerebral, subdural or epidural, all leading to increased ICP
- Laceration – a ‘rip’ in the parenchyma of the brain
Give example of secondary injury in TBIs
- Huge excitation of the neurological tissues depletes ATP and energy stores leading to neuronal damage.
- Pro-inflammatory state also causes neuronal damage and generation of free-radicals
- Disruption of the blood-brain barrier and a loss of the brains capability to regulate cerebral perfusion
Results in the brain being very sensitive to changes in peripheral blood pressure, ischaemic injury and further neuronal death.
Secondary damage is more severe than primary in most cases
How can you assess a TBI?
Neuro assessment:
- mentation
- eyes
- Cushing’s reflex
- Blood glucose elevates after TBI (due to catecholamine release => gluconeogenesis)
Describe the observations you may see in an eye assessment of a TBI
Bilateral miosis with reduced PLR – variable prognosis
Unilateral mydriasis with reduced PLR – guarded prognosis
Bilateral mydriasis or normal size pupils with no PLR – poor prognosis (“the eyes have blown”)
What is the Cushing’s reflex in a TBI and how can you assess it?
Cushing’s reflex = cerebral response to ischaemia
- Marked increase in MAP (hypertension) with a marked counteractive reduction in heart rate (Bradycardia)
- can suggest brain herniation
- SEVERE - poor prognosis
How is a TBI treated?
Reduce ICP (intra-cranial pressure):
- hypertonic fluids
- hypertonic saline or mannitol (sugar based so does not affect Na levels)
- pulls fluid out of the brain
- hypertonic saline probably better choice
Normalise perfusion:
maintain normal MAP
- Hypotension - fluid therapy +/- vasopressor
- Hypertension - pain relief, anti-hypertensive meds
maintain CO2
- hypercapnia causes cerebral vasodilation and may worsen ICP, hypocapnia causes cerebral vasoconstriction reduced perfusion
- intubate and ventilate if does not improve once MAP is normal
What are the 2 main types of thoracic trauma?
Blunt and penetrating
Give examples of blunt thoracic traumas
Bruising/contusions, swelling/oedema
Possible lung rupture from the acute increase in pressure
Rupture of the diaphragm and subsequent herniation of abdominal contents
Orthopaedic e.g. rib fractures - Secondary penetrating injury from rib fractures
Give examples of penetrating thoracic traumas
Direct injury of lungs/airways
Direct injury of major vessels or the heart
External contamination of the thorax
Oesophageal injury
How is thoracic trauma assessed?
Normal triage:
- baseline parameters
- TPMR
- BP
- pain assessment
- neuro exam
- POCUS
Label these aspects of the normal lung ultrasound
What is this lung pathology?
Pneumothorax with ‘lung point’
Glide sign is present on the left absent on the right
Pleura no longer touching => no glide sign
What is this lung pathology?
Pulmonary contusions (B-lines)
What is this POCUS pathology in a thoracic trauma?
Pleural effusion
What further diagnostics should be done when POCUS indicates pleural effusion
Thoracocentesis for pneumothorax and pleural effusions to categorise fluid
Peripheral blood samples can then confirm if the pleural effusion is truly blood – the PCV should be similar.
Blood gas analysis (arterial sample) may be useful to help direct oxygen therapy.
Blood lactate will elevate with anaerobic respiration, so is also a useful surrogate marker for needing oxygen therapy if blood pressure is normal.
What is tension pneumothorax and what does it lead to?
The pressure from the pneumothorax is exceeding right sided filling pressure of the heart:
- Venous return drops
- Cardiac output drops
- Death
How can tension pneumothorax be identified?
Pneumothorax on pocus with signs of obstructive shock - enlarged caudal vena cava
Radiography is dramatic but you won’t always have time to confirm.
What is the treatment for persistent pneumothorax?
chest drain placement
How is tension pneumothorax treated?
Thoracocentesis immediately – butterfly catheter or a needle with an extension line, three way tap and a syringe.
Outcome should be immediate restoration of cardiac output
Place chest drain to avoid repeat
What is the treatment for traumatic haemothorax
Drain until ventilation improves (not further)
Consider transfusion
Surgery if no improvement
What is the treatment for chylothorax?
Chest drain
Will probably need surgery e.g., thoracic duct ligation
How are diaphragmatic hernias treated?
Further imaging - radiography confirms diagnosis
If stable - wait 24hrs before surgery
If unstable - intubate, ventilate, surgery
How are penetrating injuries treated?
Anaesthesia to ventilate patient until wound closure
Wound management:
- clip, clean, sterilise
- do not use hibiscrub (damaging to cell membranes if enters thoracic cavity), use saline
- radiograph for foreign material
- close wound
- place chest drain
- lavage and drain chest
Antibiotics:
- broad spectrum with good penetration (amoxicillin/clavulanate)
Submit fluid samples for culture and sensitivity
