Anaesthesia and analgesia for the trauma patient

• Triaging the trauma patient

  Focus on major body systems assessment: heart rate, respiratory, thoracic auscultation, peripheral pulse quality, mentation, pupil size, PLR, temperature.

  Pulse oximetry: value less than 95% may indicate hypoxaemia.

  ECG: Haemodynaically unstable ani,als may develop arrythmias.

  Blood pressure monitoring - Doppler or oscillometric monitoring to determine the presence of hypovolaemic shock and need for fluid resuscitation.

  POCUS/EPOC,PCV/TS
• What are the best analgesics for a trauma patient?

  Methadone or fentanyl: full mu agonists.

  Ketamine: NMDA receptor antagonist.

  Paracetamol: can be used as an adjunct.

  Consider giving IM opioid if vascular access not easily and rapidly obtained.

  AVOID NSAIDs AND ALPH—2 AGONISTS IN PATIENTS WITH CARDIOVASCULAR INSTABILITY!!!!!
• What are the aims of stabilisation?

  To provide analgesia

  Improve Haemodynamics

  Improve ventilation

  Improve oxygen carrying capacity

  Mitigate the effect of anaesthetic drugs on body systems.

  Reduce the risk to the patient
• How do you stabilise a haemorrhage?

  Fluid resuscitation, consider need for transfusion, consider body bandage for haemoabdomen if cost concerns, given tranexamic acid (TXA).
• How do you stabilise a head trauma?

  Monitor and maintain blood pressure, provide supplemental oxygen, take steps to improve ventilation, consider hypertonic saline or mannitol.
• How do you stabilise a haemothorax/pneumothorax?

  Thoracocentesis to allow lung expansion and improve saturation, supplement oxygen.
• How do you stabilise fractures?

  Splint or bandage as appropriate (need lots of analgesia and don’t try to reduce in conscious patient though).
• What premedication can you use for trauma patients?

  Opiod IV

  Opioid + benzodiazepine IV

  +/- Ketamine IV.

  +/- Alfaxalone (fractious cat) IM

  AVOID ACEPROMAZINE AND ALPHA-2 AGONISTS IN PATIENTS WITH CARDIOVASCULAR INSTABILITY.
• Pre-oxygenation for trauma patients

  3-5 minutes via a tight-fitting face mask ideal.

  Increased FiO2.

  Replaces the nitrogen portion of the FRC with oxygen.

  Acts as a reservoir of oxygen in the lungs which increases the time to desaturation at induction.
• Induction of trauma patients

  Inductions agents:

  • Propofol, Alfaxalone, ketamine (consider co-induction with midazolam, ketamine, fentanyl).

  Administer slowly to effect:

  • Animals with poor cardiac output will have a slower induction time with injectable agents.

  May need very low dose:

  • May be possible to intubate with just premed in a very compromised patients.
• Intubation for trauma patients

  Selection of different sized ET tubes, tube tie, laryngoscope, cuff inflator.

  In head trauma patients ensure adequate depth of anaesthesia before attempting intubation and ensure lidocaine spray has contacted the larynx in cats (coughing causes a sudden increase in ICP).

  Consider the potential need for tracheotomy in patients with facial trauma (be prepared to do this if necessary.

  Trans-mylohyoid intubation is an option in facial trauma Pateints to allow surgical access to the mandible and maxilla.
• Maintenance of anaesthesia with trauma patients

  Inhalational agents - sevoflurane or isoflurane - aim to reduce percentage of volatile percentage of volatile agent required.

  Consider PIVA or TIVA

  Ketamine is commonly used in trauma patients because of its utility in cardio-vascularly unstable patients.
• Local anaesthesia for trauma patients

  Provide local anaesthesia wherever possible to provide analgesia, reduce sympathetic stimulation intraoperatively, reduced MAC and dose requirements, provides post-operative analgesia.

  • Nerve/fascial plane blocks.
  • Splash blocks
  • Line/ ring blocks
  • Chest drains
  • Intra-abdominal.
• Ventilation support for trauma patients

  Patients with a history of trauma may require ventilatory support (may need to tolerate mild hypercapnia).

  Diaphragmatic hernia - keep in sternal for as much of the anaesthetic as possible, desaturation can occur rapidly when positioned in dorsal recumbency, elevate the thorax, initiate IPPV.

  Pulmonary contusions

  Pneumothorax

  Haemorrhage/hypotension.
• Monitoring the trauma patient - EtCO2

  Appreciation of the Capnography waveform can help identify problems with ventilation, tissue perfusion and circulation, airway obstruction and issues with equipment.

  In a normal patient the difference between PaCO2 and EtCO2 is minimal (2-5mmHg), but this can increase with e.g. V/Q mismatch, increased dead space or massive reduction in pulmonary perfusion e.g. cardiac arrest or severe haemorrhage.

  
• Monitoring the trauma patient - Pulse oximetry (SPO2) and arterial blood gas analysis

  Pulse oximetry (SPO2) indicated haemoglobin saturation with oxygen.

  Arterial blood gas analysis measures PaO2, the partial pressure of oxygen in the blood.

  Low SPO2 (<90%) or low PaO2 (<60mmHg) indicate hypoxaemia.

  The A-gradient can indicate the origin of hypoxaemia
• Monitoring the trauma patient - temperature

  Temperature can be monitored with oesophageal or rectal temperature probe.

  Hypothermia is often a negative prognostic indicator, along with coagulopathy and acidosis.

  Active cooling in TBIs reduced cerebral metabolism and blood flow but is controversial in people. However, take care with active rewarming.

  Avoid hypo and hyperthermia.
• Monitoring the trauma patient - blood pressure and hypotension

  Blood pressure measurement:

  • Oscillometeric
  • Doppler
  • Invasive

  Hypotension:

  • Reduce inhalation agent
  • Try PIVA if needed.
  • IVFT boluses.
  • Consider anticholinergics if bradycardic
  • Consider vassopressors (e.g. ephedrine, noradrenaline)

  Permissive hypotension in bleeding patients - MAP not TBI.
• Recovering the trauma patients

  Monitor until extubated and lifting head.

  Many patients with a history of trauma will require significant ongoing support.

  Post-op care plan should include analgesia, wound care, monitoring requirements (e.g. blood pressure, PCV/TS, urinary output, respiratory rate and effort), catheter care, oxygen supplementation, feeding.