Rural Emergency Medicine

The management of Acute Traumatic Brain Injury or Head Trauma can be a significant challenge clinically, resource intensive and influenced by delayed transfer times in Rural Environments. As per Honeybul & Woods (2013), "The key initial elements remain aggressive early resuscitation followed by a comprehensive assessment of conscious level and either early consultation or transfer to a neurosurgical facility."  

This approach factors in assessing and addressing the Primary Injuries, whilst preventing further Secondary Neurological Injury (through mechanisms such as Hypoxia, Hypotension, Raised ICP, etc).

This is part of the Rural Emergency Module series (designed in particular for ACRRM Trainees).

Initial Assessment and Management


Recognise, send for help, gather resources and appropriate equipment.
Move to appropriate area dependent upon severity
Monitoring: SpO2, EtCO2, Telemetry
Early contact with Retrievals and Neurosurgeons.

Airway:
  • Early intubation in comatosed patients. Tape rather than tie ETT.
  • Intubation if agitated (increases ICP), Hypoxia (worsens ischaemia), Hyperventilating (vasoconstriction and decreased CPP)
  • Haemorrhage, vomiting and swelling from facial trauma are common causes of airway obstruction in patients with TBI, use suction as necessary.
  • Protect the C-Spine – collar/inline immobilisation/sandbags, aim to convert to sandbags to assist venous drainage.
  • Avoid NPAs + NGTs.

Breathing:
  • Assess depth of breathing and respiratory rate, SpO2 + ETCO2 monitoring
  • Correct hypoxia, maintain SpO2 >92%, titrate to blood gases. high flow oxygen 15L/min via a NRB mask
  • Aim for PaO2 > 100, PaCO2 ~35, avoid hyperventilation unless immediate risk of coning.

Circulation:
  • 2x well functioning IVCs
  • Control any external haemorrhage
  • Normovolaemia and MAP >70, Sys BP >90. 
  • Use vasopressors as available and treat anaemia with blood products
  • Venous Drainage: Head up to 30’ if C-Spine cleared, otherwise whole bed tilt to 15' 
  • If placing a central line avoid Trendelenburg position.

Disability:
  • Monitor patients level of consciousness to help determine the severity of TBI
  • Perform and document GCS (AVPU in children), limb movements and pupils regularly. Document prior to sedation/paralysis.
  • Early detection of raised ICP, avoid intracranial HTN — sustained ICP > 20mmHg
  • Suspect critically raised ICP if; Cushing’s response (Bradycardia, hypertension, apnoeas), fixed and dilated pupils and hemiparesis
  • Maintain normoglycaemia (BSL <12)
  • Consider early administration anti-epileptics to avoid seizures (Phenytoin or Keppra)

Exposure:
  • Assess for other life/limb threatening injuries.
  • Maintain normothermia (nil evidence for hypothermia  <35 )
  • Treat Coagulopathy 
  • IDC to decrease intra-abdominal pressure and monitor urine output
  • Orogastric over Nasogastric tube when and if safe to do so.
Determining the Severity of TBI



Glascow Coma Scale






Evidence of base of skull fracture:
Evidence of trans-tentorial herniation:
Peri-orbital eccymoses
Retroauricular eccymoses
CSF otorrhoea
CSF rhinorrhoea
Cranial nerve palsies (especially CN VIII)
Haemotympanum

Dilated and non-reactive pupils
Asymmetric pupils
Deterioration in neurological condition
Cushing’s reflex: BP,  HR, Irregular RR

History


Risk Groups: Elderly, Infants, Anti-coagulated patients, Chronic Alcoholics

Signs/symptoms
  • Level of consciousness and duration of loss of consciousness, return to level of alertness
  • Amnesia (retrograde, antegrade)
  • Headache, Vomiting, Seizure activity
  • Bleeding or watery drainage from nose or ears
  • Confusion/Agitation
  • Weakness or Parathesia to limbs

Allergies
Meds 
  • Anticoagulants, antiplatelets, antiepileptics

PMHx:
  • Epilepsy, Diabetes and other significant co-morbidities
  • Alcohol / Drug Abuse
  • Previous neurosurgery
  • Occupation.

Last oral intake
Events
  • Mechanism of injury, time of injury, site of injury, degree of trauma; including multi-trauma, 
  • Alcohol or other intoxicants
  • Preceding signs/symptoms (indicating a precipitating case prior to head injury – e.g. hypoglycaemia, MI)
  • Cardiovascular status and response to treatment to date.
Red Flags

  • High energy transfers
  • Low level of consciousness at presentation
  • Anticoagulation
  • Duration of Coma
  • Diffuse injury on CT
  • Hypotension
  • Age


Investigations


  • VBG – PaCO2, Glu, Na derangement
  • FBC, U&Es, INR for anticoagulated patients
  • ECG
  • Cross-match if significant blood loss.
  • Toxicology screen + Blood Alcohol level
  • Associated Trauma Radiology; e.g. FAST Scan, CXR, Pelvic Xray, etc


Neuroimaging
CT is the preferred modality if available. If not available prompt transfer to a facility that does, once Primary Assessment and Stabilisation performed. Skull x-rays are not routinely recommended.
See RANZCR Adult Head Trauma for more details on Modalities and CDRs

CT Head/Brain scans are indicated in all Moderate to Severe TBIs.  Clinical decision rules can be used to guide selection of patients appropriate for imaging who may initially present as a Mild TBI.

Canadian CT Head Injury/Trauma Rule
High Risk Criteria
 GCS <15 at 2 hours post-injury
Suspected open or depressed skull fracture
Any sign of basilar skull fracture?
Hemotympanum, raccoon eyes, Battle’s Sign, CSF oto-/rhinorrhoea
≥ 2 episodes of vomiting
Age ≥ 65

Medium Risk Criteria
Retrograde amnesia to the event ≥ 30 minutes
 “Dangerous” mechanism?
Pedestrian struck by motor vehicle, occupant ejected from motor vehicle, or fall from > 3 feet or > 5 stairs.
NEXUS II
If any of the following are present, CT is required.
If none are present, CT is not required:
 evidence of significant skull fracture
 scalp haematoma
 neurologic deficit
 altered level of alertness
 abnormal behaviour
 coagulopathy
persistent vomiting
 age 65 years or more


Click to see more details from RANZCR Guidelines - Adult Head Trauma.

Paediatric Patients
Use the PECARN rule – however other rules exist.
Inclusion criteria (ALL must be satisfied if PECARN algorithm to be applied):
  • Age < 18 years old.
  • GCS 14 or 15.
  • Presented to ED within 24 hours of head trauma (blunt)

Click to see more details from RANZCR Guidelines - Paediatric Head Trauma.

Accuracy of PECARN, CATCH, and CHALICE head injury decision rules in children  in the context of Australia was reviewed in the Lancet in 2017. 

Cranial Ultrasound could be considered in infants if limited radiology modalities available in the interim. Note ICH will only be able to be assessed in children < 1y age with open fontanelles. In older children it can be used to assess for Skull Fractures with significant limitations.

Management


Need to consider primary injury management in conjunction with ABCDE priorities, and secondary injury management. Frequent reassessment is crucial to ensure early signs of raised ICP are not missed.

Physiological and Biochemical Targets:

  • PaO2 >100 mmHg, PaCO2 ~35 mmHg 
  • Temp 36-37C,
  • MAP>70 mmHg (CPP 50-70 mmHg if ICP monitor is placed)
  • Maintaining SBP at 50 to 69 yo: >100 mmHg | 15-49 or >70 years: >110 mmHg or above for patients, may improve outcomes.
  • Glucose 6 – 10 mmol/L
  • Treating ICP >22 mm Hg is recommended because values above this level are associated with ↑ mortality
  • Monitoring should occur at least every 15 minutes until the retrieval/transfer team arrival

General Supportive Principles

As always keep FAST HUGS in BED Please in the back of your mind.
  • Nutrition: feed patients at least by day five -> decreases mortality
  • Sedation and analgesia: reduce cerebral oxygen demand, and prevent coughing and straining; both of which increase ICP
    • Propofol often a favoured sedation agent.
    • Short-acting analgesic agents are the best choice if the patient is to remain spontaneously breathing, so as not to hinder GCS assessment
  • Anti-emetics: coughing and straining increases ICP, also important to reduce risks during patient transfer
  • Antibiotics: Antibiotic prophylaxis should occur in all cases of open and penetrating injuries as well as when there is suspicion of any base of skull fractures. Tetanus prophylaxis should be administered in any penetrating brain injury patients.
  • Thromboprophylaxis: Insufficient evidence for pharmacological agents. LMWH or low-dose unfractioned heparin may be used in combination with mechanical prophylaxis. However, there is an increased risk for expansion of intracranial haemorrhage.
  • Head up position (30 degrees)
  • Ulcer prophylaxis
  • Glucose control: aim for BSL between 6-10 mmol
  • Skin/eye care and suctioning: Clean, debride, bandage and dress wounds as appropriate. Steps in the initial management should focus on control of external haemorrhage. If direct pressure fails to achieve haemostasis, than stapling and suturing should be considered.
  • Indwelling catheter: to decrease intra-abdominal pressure and monitor urine output
  • Nasogastric tube: orogastric is the preferred option in head trauma patients. Should be performed after intubation.
  • Bowel cares
  • Environment: Maintain Normothermia (Temp 36-37; give antipyretics if Temp >38C) to prevent a rise in cerebral metabolic rate.

Hyperventilation:

Used as a rescue therapy to prevent herniation.
Reduces ICP at the expense of Cerebral Blood Flow.
  • Aim for PaCO2 30mmHg
  • Monitor with EtCO2 readings or ABG.
Prolonged Hyperventilation should be avoided during the first 24 h after injury when CBF often is reduced critically.

Intubation Considerations:

The approach to intubation in head trauma patients should include optimising physiological parameters, maintenance of those parameters, preventing reflex sympathetic response and minimising complications of intubation. 

See Intubation of the Neurocritical Care Patient for further details; https://lifeinthefastlane.com/ccc/intubation-of-the-neurocritical-care-patient/.

One suggested approach:
  • Ensure adequate preoxygenation and use apnoeic oxygenation
  • Pre-treatment: IV Fentanyl + topical lignocaine (e.g. 5 ml of 4% lidocaine spray) effectively attenuates cardiovascular responses to intubation.
  • Induction Agent: Minimal or no induction dose. Propofol or thiopentone or ketamine. Be aware of Pros/Cons of each agent.
  • Paralytic: IV Rocuronium 1.2 mg/kg is agent of choice. Avoid Suxamethonium where possible.

Osmotherapy:

Used as a rescue therapy to prevent herniation.
The evidence around osmotherapy is still of insufficient quality and quantity to determine which intervention offers the best outcome for patients with Severe TBI. Treatment choice should be guided by available fluid therapy and with specialist input. 
  • Mannitol (20%):
    • Maximal effect within 20 – 40 minutes
    • Dose: 0.25-1g/kg over 5-10 minutes
    • May result in; worsening hypovolaemia, renal failure. May also require inotropic support.
  • Hypertonic Saline (3%):
    • Dose: 6-8 ml/kg of 3% solution as a bolus.
    • Useful in hypovolaemic patients as increases circulating volume, compared to Mannitol
    • Tends to last longer than Mannitol.
  • Sodium Bicarbonate: 
    • No 3% hypertonic saline/mannitol in your facility, you could consider using sodium bicarbonate.
    • 8.4% bicarbonate for osmotherapy may be conceptualized as “6% saline.
    • Suggested Dose (adults):  80-120 ml or two 50ml ampules of 8.4% sodium bicarbonate over 30 minutes. 

Seizure Management / Prophylaxis

If seizures a useful mantra is Sedate, Intubate, Ventilate.
Follow normal seizure management protocol.
Load the patient with an anticonvulsant such as Phenytoin or Keppra (levetiracetam). 

Phenytoin prophylaxis is recommended to decrease the incidence of early PTS (within 7 d of injury), when the overall benefit is thought to outweigh the complications associated with such treatment. There is insufficient evidence currently regarding the use of Keppra (levetiracetam) for prophylaxis, but it is also likely to be beneficial and is used by several Australian Health Services.

Burr Hole Evacuation

This procedure is especially important in a patient who is rapidly deteriorating and does not respond to non-surgical measures. Consult with neurosurgeon and use Telehealth as available. 
  • Indications: Patient with reduced GCS (< 8) with imaging evidence of an extra-dural haematoma causing midline shift and unequal pupils when timely neurosurgical intervention is not possible.
  • Contradictions: GCS > 8, Neurosurgical intervention available in a reasonable time frame, No Imaging (exception to this is where significant imaging delays exist and high clinical suspicion of injury)
  • Further Considerations: level of surgical experience and range of neurosurgical equipment available at the hospital.
  • Procedure: see Emergency burr holes: "How to do it" / and The Management of Acute Neurotrauma in Rural and Remote Locations section on Burr Holes for further details.

Anticoagulation reversal and Antifibrinolytics

Reversal of anticoagulation agents
  • Any patient who is taking an anticoagulant such as warfarin or other oral anticoagulants (dabigatran, rivaroxaban, apixaban) is at high risk of developing significant bleeds intracranially and elsewhere.
  • Reversal should be considered in liaison with surgeons and/or haematologist

Tranexamic Acid
  • Insufficient evidence to recommend routine administration of Tranexamic Acid solely for TBI.

References/Further Resources






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