What is the recommended approach for trauma anesthesia?

Trauma Anesthesia Management

The recommended approach for trauma anesthesia involves a rapid sequence induction with ketamine (1-2 mg/kg) for hemodynamically unstable patients, combined with neuromuscular blockade using rocuronium (1 mg/kg), while maintaining systolic blood pressure >110 mmHg and ensuring normocapnia (PaCO2 4.5-5.0 kPa) during mechanical ventilation. 1

Pre-Anesthetic Preparation

• Warm the operating room and prepare essential medications before patient arrival
• Ensure availability of:
  • Hypnotics (propofol, midazolam, ketamine)
  • Neuromuscular blocking agents (rocuronium, suxamethonium)
  • Opioid analgesics (fentanyl, alfentanil, remifentanil)
  • Vasopressors (ephedrine, metaraminol, noradrenaline)
  • Resuscitation drugs
  • Intravenous fluids (0.9% saline)
  • Cross-matched blood 1

Airway Management

Indications for Intubation in Trauma

• GCS ≤ 8
• Deteriorating consciousness (fall in GCS ≥2 points or motor score ≥1 point)
• Loss of protective laryngeal reflexes
• Failure to achieve adequate oxygenation (PaO2 ≥ 13 kPa)
• Hypercarbia (PaCO2 > 6 kPa) or spontaneous hyperventilation (PaCO2 < 4.0 kPa)
• Bilateral mandibular fractures
• Copious bleeding into mouth
• Seizures 1

Intubation Technique

• Use rapid sequence induction with manual in-line stabilization of cervical spine
• Maintain head-up tilt when possible
• Apply cricoid pressure if risk of aspiration
• Confirm tube placement with waveform capnography
• Secure tube with adhesive tape rather than circumferential ties (to prevent impaired venous drainage) 1

Induction Agents

For Hemodynamically Unstable Trauma Patients:

• Ketamine: 1-2 mg/kg IV - preferred for hemodynamic stability 1, 2
  • Previously avoided in head injury but now recognized as safe and effective 1
  • Induction dose: 1-4.5 mg/kg IV (administered over 60 seconds) 2

For Hemodynamically Stable Patients:

• Propofol: Titrated dose to maintain adequate MAP
  • Neuroanesthesia dose: 0.9-6.9 mg/kg induction, 68-425 mcg/kg/min maintenance 3
  • Advantage: Decreases cerebrospinal fluid pressure by 46% ± 14% 3
  • Caution: May cause significant hypotension in hypovolemic patients

Analgesics:

• High-dose fentanyl (3-5 μg/kg)
• Alfentanil (10-20 μg/kg)
• Remifentanil TCI (≥3 ng/ml) 1

Neuromuscular Blockade:

• Suxamethonium 1.5 mg/kg or
• Rocuronium 1 mg/kg 1

Hemodynamic Management

Blood Pressure Targets:

• Traumatic brain injury: SBP >110 mmHg (MAP >90 mmHg)
  • SBP <150 mmHg if within 6 hours of symptom onset without immediate surgery
• Have vasopressors immediately available (ephedrine, metaraminol) 1

Fluid Management:

• Correct hypovolemia before transport
• Use 0.9% saline as primary fluid
• Ensure blood products are available for significant hemorrhage
• Tranexamic acid administration for hemorrhagic trauma 1

Ventilation Strategy

• Target PaCO2: 4.5-5.0 kPa (normocapnia)
• Brief period of PaCO2 4.0-4.5 kPa only if impending uncal herniation
• Target PaO2 ≥13 kPa
• Use minimum 5 cmH2O PEEP to prevent atelectasis
• PEEP up to 10 cmH2O does not adversely affect cerebral perfusion 1
• Transport ventilators preferred over hand ventilation to avoid hyperventilation 1

Maintenance of Anesthesia

• Continuous infusion of sedative (propofol or midazolam)
• Small, frequent doses titrated to physiological variables
• Consider TCI regimens for longer transfers
• Maintain neuromuscular blockade during transport
• Position patient with 20-30° head-up tilt when possible 1

Special Considerations

Head Injury:

• Avoid hypotension and hypoxia at all costs
• Maintain normocapnia
• Consider mannitol (0.5 g/kg) or hypertonic saline (2 ml/kg of 3% saline) for signs of increased ICP 1

Massive Hemorrhage:

• Damage control surgery takes precedence over transfer
• Ensure adequate blood product resuscitation before transport
• Consider balanced transfusion with FFP and platelets 1

Pre-Transfer Checklist:

• Arterial blood gases (validate end-tidal CO2, check electrolytes, glucose)
• Complete imaging (CT head, chest, abdomen, pelvis, c-spine)
• Secure all drains (convert underwater seals to Heimlich valves)
• Core temperature monitoring (aim for normothermia 36-37°C)
• Administer anticonvulsants if seizures occurred 1

Common Pitfalls

1. Failure to recognize hypovolemia before induction leading to profound hypotension
2. Hyperventilation causing cerebral vasoconstriction and worsened outcomes
3. Inadequate sedation during transport leading to awareness or ICP spikes
4. Delayed recognition of pneumothorax during positive pressure ventilation
5. Circumferential neck ties impeding venous drainage and raising ICP

Trauma anesthesia requires careful balance between maintaining cerebral perfusion and managing other injuries. The approach must be tailored to the specific injuries while adhering to principles of damage control resuscitation and anesthesia.