Crisis management is an essential aspect of the practice of anesthesiology. The first principle of crisis management is to anticipate potential hazards so that they can be avoided or, at a minimum, so that robust contingency plans can be formulated. Once a crisis has occurred, the typical result is the acute deterioration of a patient’s physiologic state and an immediate 2-part response is required: (1) recognition and (2) implementation of corrective action.1 This case report discusses the accidental extubation and subsequent management of a patient with a difficult airway undergoing cervical spine surgery in the prone position. We call special attention to conducting preoperative briefings that include a discussion of prevention and management, should accidental extubation occur. The patient was reached via telephone. The intent to publish was discussed and approved by the patient and a witness signature was secured. This document is readily available.
A 30-year-old female patient presented to our institution for posterior fusion of C1-T2 vertebrae for worsening radicular symptoms of her bilateral upper extremities. Medical and surgical histories were extensive and most notable for Klippel-Feil syndrome. This is a condition where 2 or more cervical spinal vertebral bodies are congenitally fused.2,3 Her previous cervical spine surgeries included posterior C1-C2 fusion and an anterior C3-C4 fusion. Magnetic resonance imaging of the cervical spine revealed in situ hardware from those previous surgeries and current spinal stenosis at the C3-C4 level. Additional surgical history included tonsillectomy, cesarean delivery, and total hip arthroplasty. She denied previous anesthetic complications. Medical history included obstructive sleep apnea, hypertension, and rheumatoid arthritis.
On physical examination, she was 4′9″ tall and weighed 63 kg. She had a short, thick neck and a shortened mid-face with minimal mouth opening. Her neck examination revealed minimal flexion and no extension. Her thyromental distance was approximately 3 cm, and her airway examination was Mallampati class IV. Given our patient’s airway examination, the absence of previous anesthetic records, and following the Airway Approach Algorithm,4 we decided to proceed with an awake fiber optic intubation (FOI). Our concerns regarding the airway were discussed with the patient.
The patient was premedicated with IV glycopyrrolate in the preoperative area. Once in the operating room (OR), small amounts of fentanyl and midazolam were administered for sedation. The operating table and the patient’s bed were positioned with the patient’s head toward the anesthesia machine. Her airway was anesthetized with both inhaled and viscous lidocaine (total dose was kept <5 mg/kg). A 5.0-mm microlaryngeal tracheal endotracheal tube (Covidien, Dublin, Ireland) was easily passed through the right nare over a fiberoptic bronchoscope to the level of the carina. The proper endotracheal tube placement was confirmed with end-tidal CO2, auscultation of breath sounds, and visualization of the endotracheal tube within the trachea by the fiberoptic bronchoscope. Absence of neurologic damage because of the intubation was confirmed by the patient’s controlled movement of all 4 extremities. The patient was awake and breathing spontaneously up to this point. General anesthesia was then induced with an IV dose of propofol. The tube was carefully taped to the patient’s cheeks and nose, and this was further reinforced with Tegaderm (3M Health Care, St. Paul, MN) placed over the endotracheal tube tape.
After the placement of an arterial line and a second peripheral IV line, she was placed in Mayfield Pins (Integra, Plainsboro, NJ) and turned to the prone position. The head of the bed was then turned 180° from the anesthesia machine. The airway circuit and all the lines were taped on the outside of the sleds that kept the arms in place. General anesthesia was maintained via a balanced anesthetic technique.
Surgery began and proceeded without incident for approximately 45 minutes. Immediately after removal of the C-arm fluoroscope from under the operating table, a sudden loss of end-tidal CO2 was noticed by the anesthesiology resident who immediately moved to the head of the bed, assessed the patient’s airway, and discovered that the endotracheal tube was entirely out of her nare. This was an anesthetic emergency and a potential crisis. The attending anesthesiologist happened to be entering the OR just at the moment the resident announced that the patient was tracheally extubated. The attending anesthesiologist immediately positioned himself at the patient’s head and directed the anesthesiology resident to assist him by taking her position at the anesthesia machine. The anesthesia attending quickly made all OR personnel aware of the accidental extubation and then instructed the circulator nurse to call for immediate anesthesia assistance to that OR. Initial attempts to bag-mask ventilate the patient with 100% oxygen in the prone position were deemed unsuccessful (i.e., no stable, sustained capnogram pattern). The attending anesthesiologist then explained to the surgical team his next plan of action which included quickly covering the open wound with sterile towels and turning the patient from the prone to the supine position to reperform FOI. The patient’s stretcher was immediately moved back to the OR by the circulator. The OR was soon filled with additional help, including several attending anesthesiologists. While helping to turn the patient supine, the attending anesthesiologist explained to the newly arrived personnel that this was a known difficult airway patient who required awake FOI initially, was now extubated in the prone position, and would require FOI once turned supine. After the patient was repositioned from prone to supine onto the stretcher, an oral airway and nasal trumpet were placed and bag-mask ventilation was again attempted. Ventilation was now moderately difficult but possible. The patient’s vital signs were stable and her pulse oximeter never decreased below 90%, most probably because the mask ventilation was marginally effective while the patient was still prone, even though a stable capnogram pattern could not be achieved. Once supine with the ability to mask ventilate the patient definitively established, the crisis aspect of this case was largely over. Therefore, a controlled successful nasal FOI was achieved, despite the presence of significant vocal cord and supraglottic edema. A laryngeal mask airway (LMA) was prepared, and both a video laryngoscope and a code cart were brought into the room in the event that the FOI proved unsuccessful or mask ventilation failed. Given the patient’s stable vital signs and successful reintubation, the decision was made between the attending anesthesiologist and the neurosurgeon to proceed with surgery.
At the completion of the case, a joint decision was made between the anesthesiologist and the neurosurgeon to keep the patient intubated (because of the supraglottic edema noted at the time of the reintubation) but to first assess neurologic function with a wake-up test in the OR. Upon exhibiting purposeful movement of all 4 extremities to verbal prompts during the wake-up test, the patient was resedated and transported to the intensive care unit. After passing an endotracheal tube cuff leak test on postoperative day 3, she was safely extubated over an exchange catheter.
Despite an emphasis on vigilance, anesthesiologists still deal with a wide array of low-frequency, high-acuity critical events that can place a patient’s life in immediate danger. Prevention of these catastrophic events can be accomplished to a degree via extensive crisis scenario training in a simulator setting, as well as through the use of critical task checklists in the OR.1,5 Both these strategies are extensively taught and utilized at our institution. Nevertheless, no matter how much simulator training is used or how encompassing a critical task checklist may seem, the complexity of the particular situation thrust upon the anesthesiologist may well have never been covered in a formal fashion. This is essentially the situation that the authors found themselves facing—a constellation of elements (e.g., difficult airway, prone positioning, surgery underway, and accidental extubation) which, by themselves, each require careful attention but, taken as a sum, resulted in a nightmare situation. Using a critical task checklist to address the above disastrous situation most likely would have resulted in a poor outcome. There simply was no time to follow a checklist, even if there had been one addressing this exact scenario.
That is not to say that our institution’s simulator training did not play a beneficial role here. From our simulator training, we knew that rapid recognition and accurate assessment of severity (potentially catastrophic in this case) was of paramount importance. We called for additional help and communicated clearly with those already present about what our priorities were (first establishing the ability to ventilate the patient followed by resecuring the airway). We tried simple solutions first (like attempted mask ventilation while the patient was still prone) but quickly escalated our interventions (turning the patient supine) when the simple solutions proved to be unsuccessful.1
A preoperative briefing (before placing the patient prone) of what to do in case of accidental extubation would have been of great benefit in our case. These are discussions that we did not undertake explicitly but could have. Such a preoperative briefing discussion can be very succinct and should specifically assign to all OR personnel their individual roles ahead of time. It should focus on the 1 or 2 most critical contributions that should be made by each individual acting independently, yet simultaneously, with the others in the room. In addition, it must be easy to remember to ensure that critical steps are not missed and, of equal importance, not duplicated. In general, the leader in the crisis situation should not be directly involved with any of the tasks, so that he or she can keep a more global view of the situation and help with direct assistance to the patient. The leader should become directly involved if there is insufficient staffing available or if a lack of adequate skill levels suggests immediate action. Finally, there should be an effort to identify in advance the most likely causes of accidental extubation in a prone patient, so that particular attention can be focused on those causes.
A preoperative briefing (to be conducted before placing a patient prone) for what to do in case of accidental extubation should look like this:
- To minimize the risk of accidental extubation from occurring in the first place, explicit attention should be given to any potential causes, particularly mobile radiology equipment.
- In the event that an accidental extubation has occurred (or is suspected), the anesthesiology provider will first inform the surgeons and circulator and then begin efforts to mask ventilate the patient while he or she is still prone (e.g., leave the ventilator on and attempt to mask ventilate with positive pressure ventilation or assign one of another individual [e.g., a surgical resident] to squeeze the bag for ventilation). Strong consideration should be given to placing an LMA.
- The circulator nurse will call for help, page the Otolaryngology Service to the specific OR, and then immediately retrieve the regular hospital bed into the OR.
- The surgeon and the scrub technician will cover the wound with sterile towels and then unlock any head restraint devices (e.g., Mayfield Pins) in anticipation of the need to turn the patient supine.
- The attending anesthesiologist will respond quickly to any calls for help and will initially assist the anesthesiology provider to mask ventilate the patient while still prone and then assume a leadership role once more help arrives. He or she will identify tasks and ensure they are being accomplished, as well as coordinate activities, and participate directly when absolutely necessary.
- By preassigning duties to all OR personnel, the first handful of critical steps can be implemented quickly and in a simultaneous, parallel fashion.
In our case, we performed certain critical steps expeditiously (as if we had in fact carried out an action plan discussion) but other steps were more sequential in nature than they should have been. We quickly recognized both the accidental extubation and our inability to definitively mask ventilate the patient while still prone. We did not persevere with our attempts to mask ventilate while the patient was still in the prone position but rather chose to return her to supine quickly. In general, attempting to mask ventilate with the patient still prone is a rational decision in our opinion, but it should certainly not be relied upon as easy to accomplish. Insertion of an LMA while the patient is still prone has a proven potential to reestablish the ability to ventilate, thus greatly reducing the acuity of the situation.6,7 We chose to forgo attempts to place an LMA in our patient (based on our patient’s known difficult airway) and instead proceeded directly to returning her supine. In patients with difficult airways, we believe this is a reasonable decision, and one that should be addressed in advance as part of the action plan discussion.
Other aspects of our overall response would have benefited greatly from an accidental extubation preoperative briefing before the start of surgery. Calling for help, covering the wound, and bringing the regular hospital bed back into the room were all completed but were more sequential in nature than they should have been. This is interesting because the tasks on the above-proposed generic preoperative briefing that would be the responsibility of anesthesiology personnel were in fact done rapidly in our case, whereas tasks to be completed by the circulator, the surgeon, and the scrub technician were done more incrementally. This observation is in no way meant to be disparaging; rather, it highlights the fact that these tasks were not at the forefront of the minds of the circulator, the surgeon, and the scrub technician. The circulator, the surgeon, and the scrub technician are not typically involved in securing the airway to begin with and are thus less inclined to consider what critical steps to take if the airway is lost. By not including these personnel in an explicit accidental extubation preoperative briefing, we failed to rapidly benefit from those individuals’ vital contributions. By implementing the mandatory preoperative briefing for a prone case, this rare, critical event of loss of the airway will not only be brought to the attention of all OR personnel but each party will know exactly what tasks they are expected to complete and in what order.
Explicit consideration should be given ahead of time to the first item on our proposed team briefing, intraoperative events that may cause accidental extubation. One such event is the movement of mobile radiology equipment around the patient. In our case, we view the primary culprit to have been a rotating C-arm fluoroscope. Thiel et al.8 similarly attributed accidental extubation of a prone patient to the movement of an O-arm machine. Both these machines involve rotation of a massive element around the longitudinal axis of the patient and can easily snare (or perhaps dislodge and then snare) airway circuit tubing or gas sampling lines. Because elements are so massive, this dislodgment and snaring may easily go unnoticed by the radiology technician. Because a significant percentage of surgeries conducted in the prone position are neurosurgical or orthopedic, it should therefore be expected that such mobile radiology equipment will often be used in such cases. This need for mobile radiology equipment will not change. It becomes more difficult for the anesthesiology provider to monitor the movement with this equipment when the procedure involves the cervical spine, and the bed is rotated 180° away from the anesthesia provider. What can change is the amount of explicit attention paid to the movement of mobile radiology equipment toward or away from the operating field. What we should have been more vigilant about is for one of the OR personnel (e.g., circulator or anesthesiology provider) to be designated as the individual guide for the movement of the mobile radiology equipment around the patient. This person should be someone other than the radiology technician, as the equipment often blocks their field of view.
In sum, we have presented the case of an accidental extubation in a prone-positioned patient with a difficult airway. We began the case with what we considered a cautious plan—FOI. We failed however to discuss, on a formal basis with the other OR personnel, what steps we would take to minimize the risk of airway loss as others have done.9 We also failed to discuss what immediate actions would be required if we did lose the airway. We hope that this case report will call attention to the additional complexities and resultant contingencies required for prone-positioned surgery.
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