The Trauma Patient

Verena Schandera

Dhimitri A. Nikolla

Jestin N. Carlson

CASE

A 47-year-old morbidly obese male with a history of obstructive sleep apnea is admitted to the trauma intensive care unit (ICU) after falling from a chair while changing a light bulb. He was diagnosed with a vertebral plana fracture of the first thoracic vertebra with retropulsion and multiple left-sided rib fractures with associated pulmonary contusion. On presentation to the trauma ICU, his airway is intact, and his vital signs are stable, including his oxygen saturation of 92% on 5 L/min of supplemental oxygen via nasal cannula. However, during afternoon rounds, he is noted to be drowsy, tachypneic, and hypotensive. He does not improve despite supportive measures.

How would you proceed with his airway management?

GENERAL APPROACH TO THE TRAUMA AIRWAY

Airway management of critically ill trauma patients encompasses a spectrum of care from monitoring respiratory status to providing noninvasive respiratory support to performing rapid sequence intubation (RSI). Proper airway management is a complex and continuous process throughout the acute care of every trauma patient. However, escalation of airway management must be balanced with the overall trauma resuscitation to prioritize hemodynamic stability since more invasive airway maneuvers may impact hemodynamics.

The decision to place an advanced airway in a trauma patient is complex and driven by multiple factors. Common indications for advanced airway placement in trauma include an altered level of consciousness due to traumatic injury (e.g., traumatic brain injury [TBI]), airway edema (e.g., inhalation injury), direct airway trauma (e.g., expanding neck hematoma), and the immediate need for painful surgical interventions. In addition, more relative indications include combative behavior precluding adequate evaluation in the setting of a major mechanism of injury as well as any predicted clinical deterioration where delaying placement of the advanced airway might magnify the risk of complications.

ASSESSMENT AND PREPARATION

Both anatomical and physiologic factors may impact the probability of successful intubation.¹ Therefore, since multiple intubation attempts are associated with major peri-intubation adverse events and cardiac arrest,²^,³^,⁴ assessment and preparation for intubation must be directed to both anatomical and physiologic factors to enable first-attempt success and good patient outcomes.

ANATOMIC CONSIDERATIONS

Difficult airway anatomy can directly impair laryngoscopy and endotracheal tube placement, reducing first-attempt success.⁵^,⁶ Therefore, the clinician should be prepared for anatomical
difficulties when intubating all trauma patients. This includes proper assessment and preparation for an unsuccessful first attempt that informs rescue attempt decisions, especially escalating to an emergent front-of-neck airway (eFONA), that is, cricothyrotomy.

Many anatomical predictors of difficult intubation exist; however, none reliably excludes difficult intubation.⁷ For example, an abnormal upper lip bite test in the operating room increases the probability of difficult intubation more than other common clinical findings such as short hyomental distance, retrognathia, the modified Mallampati score, and the Wilson score.⁷ However, among trauma patients intubated in the emergency department, a quick surgical airway assessment for trauma (qSAT) score of ≥1 may aid clinicians in preparing for a surgical airway.⁸ The score consists of male sex, facial injury, and cervical area injury; the presence of at least one component has a sensitivity of 87% and specificity of 29% for predicting a surgical airway.⁸ Nevertheless, several findings may guide decisions to escalate to more invasive airway procedures, including head, oral, or neck trauma, limited neck mobility or cervical immobilization, reduced mouth opening, airway obstruction, and airway soiling.

PHYSIOLOGIC CONSIDERATIONS

Physiologically difficult airways (e.g., patients with hypoxemia, hypotension, metabolic acidosis, etc.) place patients at risk of peri-intubation complications and poor outcomes, particularly hypoxic arrest and circulatory collapse.¹ Therefore, unstable trauma patients require careful consideration for balancing continued resuscitation versus immediate placement of an advanced airway.⁹

Similarly, postintubation hypotension should be avoided. Trauma patients experiencing postintubation hypotension have higher mortality than those who do not.¹⁰ Strong predictors of postintubation hypotension among trauma patients include age >65 years old, preintubation systolic blood pressure of <130 mm Hg, and preintubation oxygen saturation of <90%.¹¹ Therefore, clinicians should prioritize preoxygenation to prevent desaturation¹² and consider vasopressors to prevent critical postintubation hypotension in addition to typical resuscitative interventions such as blood administration.¹³

AIRWAY MANAGEMENT STRATEGIES

Oxygenation/Preoxygenation

Noninvasive interventions should be considered first in trauma patients requiring respiratory support with a patent airway. Supplemental oxygen via nasal cannula or facemask facilitates oxygenation without ventilatory support. However, high-flow nasal oxygen (HFNO) and noninvasive positive airway pressure ventilation (NIPPV) provide oxygenation and ventilation without requiring an invasive airway.¹⁴^,¹⁵ In addition, if endotracheal intubation is planned, noninvasive respiratory support interventions may improve preoxygenation.¹⁶ As with nontrauma intubations, the goal is nitrogen washout which requires tidal volume breathing of the highest concentration oxygen possible for a minimum of 3 minutes. Please refer to Chapter 17 for the principles of preoxygenation in the context of airway management.

Endotracheal Intubation

When deciding to proceed with intubation, several trauma-specific factors should be considered, including distorted anatomy (e.g., blood in the airway or expanding neck hematoma) and limited neck mobility due to concern for cervical spine injury. The rate of rescue surgical airways is more common among patients intubated for trauma indications than for medical indications.¹⁷

During intubation, patients should be placed in the head up and foot downward position while maintaining spinal precautions. This positions the stomach below the glottic opening, potentially decreasing the risk of aspiration. However, ramping the patient to 25 degrees has not improved first-attempt success or peri-intubation hypoxemia in critically ill patients compared to the sniffing position.¹⁸ Preintubation gastric drainage is not routinely recommended, as passing the gastric tube through the esophageal sphincter can promote regurgitation and vomiting.

Both direct laryngoscopy (DL) and video laryngoscopy (VL) have been used in trauma patients, and the use of VL has grown throughout U.S. hospitals. However, VL is associated with an increased odds of first-attempt success among trauma patients.¹⁹ Despite concerns that VL cannot be used in a soiled airway, studies have found similar performance between DL and VL in
patients with airway soiling.²⁰^,²¹ In addition, VL offers other advantages, including the ability for the airway images to be visible to the entire critical care team and aid in troubleshooting and managing potential difficulties. Particularly when neutral C-spine position must be maintained during intubation hyperangulated VL is likely the optimal device for intubation.

Protecting the Cervical Spine

Trauma patients should be assumed to have a C-spine injury until ruled out. C-spine injuries are present in 2% to 3% of trauma patients with an increased risk (6% to 8%) among patients with facial injuries.²² However, airway management should not be delayed for imaging the C-spine. Therefore, clinicians must manage the trauma airway in a way that minimizes further injury to the C-spine. Unfortunately, airway management with a C-collar in place limits alignment of the nasopharyngeal, oropharyngeal, and laryngeal axes, compromising visualization of the glottic opening. A solution to this issue is holding manual inline stabilization (MILS). This procedure involves removing the C-collar and having an assistant manually hold the trauma patient’s head and neck to minimize lateral C-spine movement. MILS should only immobilize the head and neck without restricting the mandible (Fig. 33.1). However, even when done correctly, MILS increases the difficulty compared to patients without spinal precautions.²³ All airway maneuvers will cause some small degree of cervical spine movement but are unlikely to cause further cervical spine injury.²⁴ In theory, a hyperangulated blade should be able to “look around” the curve of the base of the tongue and allow visualization of the glottic opening without manipulation of the cervical spine. Still, endotracheal tube delivery is often a challenge with these devices. Flexible endoscopic intubation may result in the least amount of cervical displacement, especially at C1/C2, but randomized controlled trials are lacking.²⁵ If within the skillset of the intubating provider, flexible endoscopic intubation, either alone or in combination with a laryngoscope (Chapter 28, Combination techniques) can be considered in patients with known or strongly suspected unstable C-spine fractures or in those with coexisting anterior neck injuries with distorted anatomy, provided sufficient time, appropriate equipment, and expertise are available.

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