A morbidly obese patient recently died in a Boston-area hospital after becoming hypoxic between the OR and PACU. The incident provided a startling reminder for those of us charged with establishing and maintaining the airway that losing the airway and risking irreversible hypoxia are real and constant threats to every anesthesia provider. During anesthesia care, all protocols are secondary to airway concerns. An airway becomes difficult when a conventionally trained anesthesia provider experiences difficulty with facemask ventilation, tracheal intubation or both. Here are tips to help avoid potential problems.

1. Conduct an airway history. Do so on all patients before you initiate anesthetic care. The history is intended to detect medical, surgical and anesthetic factors that may predict the presence of a difficult airway. Examination of previous anesthesia records may also yield useful information, including intubation difficulties during past surgeries and descriptions of challenging airway anatomy.

2. Conduct an airway exam. Although published evidence doesn't make a direct connection between performing physical exams and accurately predicting a difficult airway, suggestive data show that findings obtained from airway exams may be related to challenging airways. This support is based on recognized associations between the difficult airway and a variety of anatomical characteristics that make viewing the glottal opening difficult. Keep in mind, however, that no single feature of the airway exam can predict a difficult airway and no rating system is fail-safe.

3. Consider physical warning signs. Certainly you must consider morbidly obese patients prime difficult airway candidates. Many of these patients present with histories of obstructive sleep apnea due to excess fatty tissue in their oropharynx. Other patients who have short, thick necks or who can't touch the tip of their chin to their chest may be difficult to intubate. Still others who have recessed chins or a prominent overbite, or who have received radiation treatments to the neck, may pose intubation challenges.

That being said, I've worked on thin patients in excellent health who presented with no warning signs of a difficult airway. In the OR, however, they were extremely difficult to intubate. Anesthesia providers must always be on the lookout for the difficult airway and set a plan for managing it during and after surgery.

4. Do what you're good at. According to the American Society of Anesthesiologists' difficult airway task force, you must assess the likelihood and clinical impact of difficult ventilation, difficult intubation, difficulty with patient cooperation or consent and difficult tracheostomy. That strategy should begin with you measuring your confidence in establishing successful ventilation. If you're confident that the patient can be ventilated or that you can establish surgical access to the airway, the treatment decision tree will have many more branches. Trying unfamiliar techniques is a recipe for failure. Establish strategies based on your skill set.

5. Choose your strategy. Consider three basic choices for intubating the difficult airway:

• Awake intubation vs. intubation after induction of general anesthesia. Use awake fiberoptic intubation on cooperative patients who are considered difficult to ventilate. This is not viable in pediatric populations or on patients unlikely to cooperate (the mentally retarded, for example).
• Noninvasive vs. invasive techniques. If surgical or invasive techniques are considered, prep the area of the neck and infiltrate it with a local anesthetic. A surgeon skilled in tracheotomy must be available and present.
• Preservation of spontaneous ventilation vs. ablation of spontaneous ventilation. Avoid using induction agents on patients who are difficult to intubate and ventilate.

Your extubation plan
Plans to extubate the difficult airway depend on the surgery, the condition of the patient and a provider's skills and preferences. When patients can't maintain ventilation on their own after extubation, it's not uncommon for the difficulties to occur in transit from the OR to recovery. It's then that we need to closely monitor the extubated patient. Place medications, a laryngoscope, supplemental oxygen and extra ventilation tubes in a basin on the patient's stretcher. The needed supplies travel along with the patient, within easy reach if they're needed quickly.

One invaluable tool for managing the extubated difficult airway is a rigid, hollow device used for expediting reintubation should it become necessary. This type of device — a ventilating tube changer is one example — is inserted through the lumen of the tracheal tube before the tube is removed. The ventilating tube changer acts as a catheter of sorts, letting you access the airway quickly and easily in the event of a post-op airway emergency.

For the record
After working a difficult airway case, you must document the episode in the patient's record for future reference. When you record a difficult case, describe:

• the airway difficulties that you encountered; distinguish between difficulties in face mask or LMA ventilation and difficulties in tracheal intubation; and
• the various airway management techniques that were employed, including the extent to which each of the techniques served a beneficial or detrimental role in management of the difficult airway.