++
The following two illustrative examples involving femoral VV-ECMO support for difficult airway management highlight its utility in the setting of (1) anticipated/elective and (2) unanticipated/emergency extremely difficult airway situations.
+++
Case 1: Anticipated/Elective “Impossible” Airway
++
An otherwise healthy 28-year-old female with a friable inflammatory myofibroblastic tracheal malignancy complains of dyspnea and hemoptysis. The tumor mass is located mid-trachea on the left anterolateral wall causing significant tracheal obstruction (90%). Traditional difficult airway management strategies are anticipated to be successful in placing an endotracheal tube (ETT) in the trachea, but may fail to achieve ventilation and oxygenation because of the obstructing friable tracheal mass located distally. Additionally, the potential for major airway bleeding makes such a strategy likely to be unsafe, potentially compromising ventilation and any subsequent salvage efforts to re-secure the airway. A front-of-neck airway (FONA) in such circumstances (planned tracheotomy and emergency cricothyrotomy) would incur similar risks.
+++
Case 2: Unanticipated/Urgent/Emergency “Impossible” Airway (i.e., Airway Crisis)
++
A 68-year-old male presents for urgent cardiac surgery (to address high-grade left main coronary artery disease and severe aortic stenosis). Beyond these cardiovascular conditions, pertinent history includes severe gastroesophageal reflux disease and limited head and neck mobility (due to radiation following excision of a squamous cell carcinoma from the base of the tongue). Preoperative airway exam reveals limited mouth opening and a Mallampati III score. Predicting a difficult airway, after thoughtful consideration and preparation, the anesthesiologist plans for flexible bronchoscopy-guided asleep tracheal intubation. Following denitrogenation, gentle initiation of anesthesia is achieved with intravenous propofol (without muscle relaxation), and face-mask ventilation (FMV) is possible. The anesthesiologist’s attempts to pass a flexible bronchoscope, with video-laryngoscope assistance, into the airway through the mouth are unsuccessful. At this point, the patient develops trismus, which is additive to challenges presented by his preexisting limited mouth opening and prevents successful placement of an oral airway or laryngeal mask airway. The practitioner administers intravenous succinylcholine to achieve full muscle relaxation, but still cannot achieve transoral endotracheal intubation with either direct or video-assisted laryngoscopy. FMV becomes barely adequate and worsens and, presumably due to the effects of radiation and prior neck surgery, several attempts at needle cricothyrotomy also fail to access the airway.
++
This text describes established difficult airway management strategies for the practitioner with a common theme involving simultaneously addressing the critical dual needs of the patient: (1) to preserve oxygenation and ventilation through the lung interface, while (2) safely securing the difficult airway. Yet what is the practitioner going to do in the rare, but terrifying, circumstance when such traditional techniques are considered unsafe, or worse fail? In this context, recent innovations now make available novel strategies that leverage support provided by extracorporeal membrane oxygenation (ECMO) to permit separation of these two tasks. By assuming control of respiratory functions without involving the lung interface, ECMO allows the ...