PODCAST: Trauma Airway and Airway Trauma

Management of the soiled airway in the trauma patient

• Prepare your team and equipment ahead of time.
• Double all your equipment (ie. O2, 2 DeCanto or meconium aspirator suction catheters).
• The SALAD technique can be used for soiled airway intubations.
• Use just enough suction to clear the airway, and no more, because O2 delivered to the airway is also being suctioned out.
• Give the paralytic enough time to work manipulating the airway to decrease the risk of vomiting.

Pearl: in the soiled airway, suction just enough to clear the airway and no more, as further suctioning will remove critical supplemental oxygen from the airway

Airway medications: Optimal dosing in the hemodynamically unstable trauma patient

The classic teaching to give half of the usual induction dose and double the paralytic dose in hemodynamically unstable patients may not lead to better outcomes. There is mixed evidence about dosing induction and paralytic agents for these patients, but there are a few general principles that can help guide our decisions:

• Our patients should be adequately resuscitated before receiving induction medications. If you give a lower-than-normal dose of ketamine to an under-resuscitated patient even if they have pressors running, they may still crash. Pay attention to the shock index and aim for it to be <1 before intubation.
• Remember also that the transition to positive pressure ventilation decreases preload further and can worsen hemodynamics
• Be judicious in dosing the induction agent (our experts recommend this despite limit evidence)
• Consider titrating your induction agent to effect as in a rapid Delayed Sequence Intubation (DSI)
• Our experts also recommend using a high paralytic dose to ensure adequate and timely paralysis

Airway management in head injured patients

The initial management of head injured patients has significant long-term effects that may be overlooked in the ED. Even transient hypotension, hypoxia, and hyperventilation have shown in observational studies to have significant morbidity/ mortality consequences. We may not see the effects of these episodes in the trauma bay, but we have a duty to prevent them whenever possible.

BP targets in head injured trauma patients

In head injured polytrauma patients with other sources of bleeding, you may have competing priorities with respect to BP targets. For the rest of the body, be inclined to tolerate a lower MAP, but for the head injury a higher sBP target is preferred. If the patient is posturing with signs of raised ICP, target a higher sBP. If they have a mid-range GCS, no signs of raised ICP and hemorrhage is the most important clinical priority, be less aggressive with the BP target. Based on current evidence:

• For patients with an isolated head injury, sBP target = 100-140 mmHg.
• For patients with a spinal cord injury, MAP target = 80-85 mmHg.

Key considerations prior to intubating a head injured patient

• Prior to intubation, perform a brief but specific neurologic examination before intubation. This should include pupils, posturing, GCS (include information about the individual components), and lateralizing findings; the brief neuro exam is often overlooked, and once the patient is paralyzed, it’s difficult to assess what their true baseline was – this can profoundly impact both the immediate and long-term decision-making process, especially when neurosurgeons get involved.
• Using waveform capnography while preoxygenating to help assess adequacy of airway seal. It also helps to avoid hypo/hyperventilating.
• Have hypertonic saline available to give if signs of raised ICP
• Consider pre-intubation arterial line for more accurate monitoring. This can allow for responsive titration of induction medications.
• In general, use ketamine (or etomidate if you have access) and rocuronium to intubate these patients; propofol is a reasonable alternative if there is no concomitant hemorrhage and they are hypertensive.
• Consider pre-intubation fentanyl (adult dose 200-300 mcg) to blunt the sympathetic response to intubation, but be ready to act because this may, rarely, cause apnea
• Consider pre-emptive vasopressors; if you anticipate a drop in blood pressure during intubation, having norepinephrine ready and potentially even running before induction.

Post-intubation care is just as important as preparation, if not more. Employ reverse Trendelenburg, head of bed 30 to 40 degrees, hypertonic saline if appropriate, monitor end-tidal CO2 (if blown pupil, target pCO2 between 30-35), and appropriate post-intubation sedation and analgesia (usually propofol and fentanyl) to target BP. Monitor pupils post-intubation for signs of deterioration.

For more on Neuroprotective Intubation check EM Quick Hits 55 

Airway in the agitated trauma patient

Management of the agitated trauma patient is closely related to the management of the head injured patient. The main priority is to gain rapid control of the situation as this is a potential safety issue for both the patient and staff. if IV access not available, our experts recommend using IM ketamine (usual adult dose 200-400 mg IM). The next priority is to get IV access, vital signs, and complete a brief examination to assess injuries/ neurologic status. If the patient requires more sedation, consider titrating in more ketamine or midazolam once IV access is established. This upfront sedation allows for a Delayed Sequence Intubation (DSI)-like approach to intubation if required.

Clinical Pearl: Critical hypoxia can present as agitation. To fix the agitation, first fix the critical hypoxia.

For more on Emergency Management of the Agitated Patient check EM Cases Ep 115

Take-home points for airway assessment and management in trauma

• Trauma resuscitation should focus on the most immediate threats to life, sometimes requiring prioritization of circulation, airway, and breathing in a flexible CAB or CBA order. Massive hemorrhage, severe airway compromise and obstructive shock may all demand emergent intervention.
• Decisions around whether to intubation and when to intubate in trauma are complex. Key factors to consider include: hemodynamic stability, dynamic airway, critical hypoxia, intractable pain and agitation. Remember: context trumps procedure.
• In penetrating neck trauma, focus on hard signs versus soft signs rather than just the neck zone to dictate management. If hard signs, this patient needs immediate OR. If soft signs, consider imaging first. Avoid unnecessary positive pressure ventilation to prevent worsening shock and worsening subcutaneous emphysema.
• For the soiled airway in trauma, have large bore suction equipment available. The SALAD technique can help manage soiled airways, but use suction with caution to minimize interruption of O2 delivery to the patient.
• For head injured patients, prevent any hypoxia, hypotension, and hypo/hyperventilation to reduce long-term morbidity and mortality. Remember to select BP target tailored to the most life-threatening clinical problem when head injury occurs in the context of polytrauma. Consider pre-intubation arterial line.
• In agitated trauma patients, prioritize safety with rapid IM sedation (ie. ketamine) if IV access is unavailable, then reassess to determine if intubation is indicated.
• Lower doses of induction agents and higher doses of paralytics may be beneficial in hemodynamically unstable patients. Aim to resuscitate to a shock index of <1 before intubation and titrate induction medications carefully.
• Use end-tidal CO2 throughout the pre-oxegentation, intubation and post-intubation phases to help guide management