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Tags: Airway, Trauma

Airway in trauma

primary goals are to intubate the trachea successfully in the shortest possible time, maintain oxygenation and ventilation, and protect the lungs from aspiration of gastric contents or blood

Secondary goals include facilitating inter- or intrahospital transfer, urgent surgery or controlled artificial ventilation for suspected brain injury.

Key considerations & challenges

• limited time for assessment
• ↑ aspiration risk
  • unfasted
  • ↓ consciousness
• unstable C spine
• difficult laryngoscopy
  • airway swelling
  • distorted anatomy
  • ↓ MO
  • soiled airway
    • blood
    • teeth
    • gastric contents
• uncooperative patient
  • hypoxia
  • HI
  • intoxication

C spine protection

NEXUS

• the absence of tenderness at the posterior midline of the cervical spine;
• the absence of a focal neurologic deficit;
• a normal level of alertness;
• no evidence of intoxication;
• absence of clinically apparent pain that might distract the patient from the pain of CSI.

Cadaveric studies have found that rigid collars are ineffective in reducing spinal movement and in some circumstances may even increase it. Moreover, they can cause pressure injuries and make some aspects of airway management more difficult (e.g. direct laryngoscopy). In hospital, the use of head blocks or rolls, tape and a hard trauma mattress are recommended for routine immobilisation of the cervical spine.

MILS

Manual in-line stabilisation is a technique that is used widely to stabilise the cervical spine during airway management. It requires a dedicated assistant, normally positioned at the side of the patient, whose job it is to maintain neutral alignment of the head and neck, by cradling the mastoid processes and occiput of the patient. Compared with a collar, it allows greater mouth opening but there is a paucity of high-quality evidence for MILS in terms of patient outcomes, and poor technique has the potential to cause iatrogenic harm and increase the risk of CSI

Stabilisation of the cervical spine is known to increase the difficulty of laryngoscopy and intubation

Patients who are shocked or hypovolaemic may benefit from rapid restoration of circulating volume before induction of anaesthesia

Overzealous positive pressure ventilation can also contribute to haemodynamic compromise in the presence of hypovolaemia

RSI

Ketamine, normally given in a dose of 2 mg kg−1 is a popular choice in trauma. Suxamethonium 1–2 mg kg−1 or rocuronium 1.0–1.2 mg kg−1 are both acceptable choices for achieving rapid onset neuromuscular block, although rocuronium has become increasingly popular because of its potential for immediate reversal. Suxamethonium may cause an increase in basal metabolic rate, extracellular potassium, gastric, intracranial and intraocular pressures, perhaps tilting the balance in favour of rocuronium in trauma.

DSI

In DSI, sedation (normally with ketamine) is used to facilitate optimal preoxygenation of the lungs, followed by an induction dose of a hypnotic agent and the NMBD. The risk of aspiration should be weighed alongside other risks including failed intubation, cardiovascular instability and hypoxia. If agitation from altered consciousness or severe pain prevents effective preoxygenation, then it may be appropriate to give analgesics or judicious doses of sedative drugs to allow this before the intubation attempt.

TBI
Patients with suspected traumatic brain injury (TBI) often require tracheal intubation not only for airway protection, but also for controlled ventilation to minimise secondary brain injury. Core to preventing secondary brain injury is adequate cerebral perfusion and oxygenation, and low cerebral metabolic demand. Brain-injured patients may have impaired cerebral autoregulation and raised intracranial pressure (ICP) making them vulnerable to cerebral hypoperfusion after induction of anaesthesia. Surges in ICP, such as those caused by laryngoscopy, may also precipitate cerebral herniation. Haemorrhagic transformation of cerebral contusions and worsening of haemorrhagic lesions may progress to devastating brain injuries.

References

In-Hospital Management of the Airway in Trauma

Airway Consideration in Maxillofacial Trauma

Airway Management in Penetrating Thoracic Trauma