A 52-year-old worker of normal body habitus was injured in a fall from approximately 15 feet (5 m) of height. He sustained fractures to the vertebral bodies of C3 and C4, as well as a C5 transverse process fracture. He was retrieved by an ambulance team and admitted to the hospital in a hemodynamically stable condition. His breathing on admission was noted to be “normal,” albeit with decreased air entry to the right side. An infiltrate on chest x-ray was consistent with aspiration. Neurologically, the patient was awake and alert. He had evidence of a Brown-Sequard syndrome with an almost complete paralysis of his left limbs and a sensory deficit on his right.

The patient’s neck had been placed in a rigid cervical collar at the scene and he was given oxygen via a face mask. Tracheal intubation was performed uneventfully by awake flexible bronchoscopic intubation in the operating room (OR) for dorsal fixation of his C-spine. Completion of internal fixation by ventral stabilization was planned at a later date and in the interim the patient was placed in a halo frame for external fixation (Figure 31–1). He was then transferred to the intensive care unit (ICU) intubated and ventilated, as his oxygen requirements had increased to 60%. An aspiration pneumonia was suspected and he was sedated and ventilated according to a lung protective ventilation strategy.

Past medical history included hypertension, gastroesophageal reflux disease (GERD), and a question of significant alcohol consumption.

By day 3 of his ICU admission, the pulmonary situation had improved marginally. He still required an FiO₂ of 0.45 and was breathing spontaneously with pressure support of 12 cm H₂O and positive end-expiratory pressure (PEEP) of 10 cm H₂O. Attempts to wean the pressure support had failed at that point, resulting in tachypnea and oxygen desaturation. Thick purulent sputum was being suctioned from his endotracheal tube (ETT) twice per shift, and he was receiving empiric antibiotics to treat his presumed pneumonia.

Agitation had become a major issue, thought to be delirium tremens secondary to alcohol withdrawal. A cranial CT had ruled out posttraumatic intracerebral hemorrhage as the underlying cause. The patient was difficult to manage, often requiring more than one nurse at the bedside, and he had tried to remove lines and ETT with his functioning hand. For this reason he required passive restraints and sedation.

On day 4, the bedside nurse called urgently to report that the patient had bitten on the tube in severe agitation. To prevent kinking of the tube during surgery, the patient had been intubated with a wire-reinforced (armored) ETT, and had unfortunately not undergone an exchange to a regular ETT prior to transfer to the ICU. The reinforced ETT was now flattened at the level of the patient’s teeth (Figure 31–2), causing acute obstruction by its significantly reduced inner diameter. The patient was being inadequately ventilated, with a decrease in minute ventilation and a drop of SpO₂ to 87%, together with hemodynamic decompensation.

Medical Considerations

Is the Patient at Acute Risk of Suffering Harm?

Hemodynamics and gas exchange must be included in assessing the need for emergency treatment. While an SpO₂ of 87% is certainly abnormally low, it might not impose an acute danger to the patient in the short term. Two factors are important: whether the patient’s organs are at risk of hypoperfusion (and thus cellular hypoxia) and if sufficient oxygen-carrying capacity exists to compensate for a lower oxygen saturation.

Oxygen-carrying capacity (or oxygen delivery) depends on cardiac output, hemoglobin concentration, and hemoglobin oxygen saturation. The patient was slightly anemic (Hgb 110 g dL⁻¹), although with an increase in heart rate from 81 to 105 beats·per minute following development of the tube obstruction, some compensation had occurred by increasing cardiac output to maintain oxygen delivery.

The patient was not known to have coronary artery or cerebrovascular disease; he had no specific risk factors and was thus unlikely to have hypoperfusion of vital organs. As such, a borderline SpO₂ could be tolerated for a short period of time.

On the other hand, acute obstruction of the artificial airway will lead to severe dyspnea and increased respiratory effort. The patient is forced to increase respiratory drive, thus generating more negative inspiratory pressure to maintain tidal volume. This can be quite dangerous for the risk of developing negative pressure pulmonary edema or post-obstructive pulmonary edema (POPE, see Chapter 61). We can conclude that this patient needs urgent troubleshooting including an emergency ETT exchange to prevent further harm.

What Are the Management Options for This Situation?

In a prospective multicenter study involving 426 ICU patients, Boulain¹ reported that 57 episodes of self-extubation occurred in 46 patients (11%) and of these, 18 patients did not require reintubation after their first (or only) episode of self-extubation. Therefore, it is necessary to assess the patient’s ability to breathe unassisted and determine the need for further ventilatory assistance. While it is possible that a subgroup of self-extubated patients not yet capable of completely breathing on their own may be amenable to noninvasive ventilation (NIV), this patient’s halo frame precluded NIV due to technical constraints.

Indicators for the ability to ventilate include respiratory rate, the patient’s work of breathing, and gas exchange. In this patient, an increase in heart and respiratory rate and the decrease in SpO₂, combined with clearly visible usage of accessory muscles of respiration indicated the need for further ventilatory support. His respiratory failure was likely multifactorial, including the aspiration pneumonia as well as compromised intercostal and diaphragmatic muscular function due to his high spinal cord injury. As the patient needed further ventilatory assistance, an ETT exchange was indicated.

Airway Considerations

What Should be the Initial Management?

First, the patient should be placed on FiO₂ of 1.0 to improve oxygenation. This increased the SpO₂ to 91%, which helped to buy some time to adequately prepare for the tube exchange procedure. Second, the respiratory drive has to be reduced to decrease the risk of POPE. Therefore, sedation was increased and the patient received 10 mg of morphine IV. The inspiratory pressure from the ventilator was increased to overcome airway resistance. To help with expiration and prevent dynamic hyperinflation, an artificial cuff leak was created by deflating the ETT cuff to the point of an audible leak during expiration. In this manner, some degree of minute ventilation was maintained, as not all of the delivered tidal volume escaped and the patient continued spontaneous breathing efforts.

Alternative approaches in the case of life-threatening hypoxemia should aim to temporarily restore oxygenation until a definitive airway can be placed. The existing ETT, if ineffective, can be removed and the patient’s respiratory efforts assisted with bag-mask-ventilation. Ventilation can be improved by use of an oropharyngeal or nasopharyngeal airway, if tolerated. However, in most cases, even with a leaky cuff, some ventilation can be maintained through an ETT by hyperventilating with high flows and respiratory rate (>30 breaths per minute), mimicking high-frequency ventilation.

The high-frequency oscillation (HFO) mode of ventilation can provide sufficient oxygenation even with a cuff leak. Indeed, during routine use of HFO, a cuff leak is sometimes purposefully used to improve ventilation. It is an ideal rescue maneuver in a situation where a patient’s oxygen desaturates and cannot be ventilated by other means. This option could be considered before a leaky tube was removed. HFO would be the preferred technique in this situation if the patient had profound gas exchange impairment, such as ARDS, to be used until arrangements for safe ETT exchange were made.

There should always be alternatives at hand in case the first attempt to reintubate the patient fails following removal of the faulty ETT. These can follow the ASA algorithm for the difficult airway and might include, but are not confined to: smaller ETTs; alternatives to direct laryngoscopy (DL); an appropriately sized EGD (ideally second generation, intubating type); flexible bronchoscope and cricothyrotomy equipment. More help should be obtained: a difficult situation such as this can always be better managed with additional experienced medical and nursing staff. Calling for additional expertise is not a sign of incompetence, but of professionalism!

How Might the Presence of a Halo Jacket Impact Airway Management?

The presence of a halo jacket can adversely impact all facets of airway management. In this case, tracheal intubation had initially been performed by a flexible bronchoscope awake in this patient, and the glottis view under DL had not been assessed thereafter. The halo jacket usually fixes the head in a neutral position, and prevents any flexion or extension of the neck (Figure 31–1). With attempted DL, it is likely that at best a Cormack–Lehane grade 3 view will be achieved. Tracheal intubation is more likely to succeed with alternatives to DL, such as flexible or rigid fiber- or video-optic devices,² although these too can fail in this scenario (see Chapters 10 and 11). Should intubation fail and the patient require oxygenation by positive pressure ventilation between attempts, BMV could also prove challenging due to limited head extension, and for the same reason, EGD insertion may be difficult. Finally, cricothyrotomy is usually performed with the head extended, so this can also be expected to be somewhat more difficult in the patient with a halo jacket.

In this agitated and uncooperative patient, it is unlikely that application of topical airway anesthesia, light sedation, and “awake look” assessment, for example, by video-laryngoscope (VL) will be an option; deeper sedation carries the risk of apnea. Alternative approaches must be considered.

What Other Risks Are Inherent in This Situation?

Enteral nutrition imposes an additional risk for aspiration while the airway is unprotected. Enteral feeds should be stopped immediately and the feeding tube suctioned to clear as much content as possible from the stomach.