Your worst nightmare was just wheeled into the OR: a patient you can neither intubate nor ventilate. Secretions in the airway. Big tongue. You can't see much of anything. This has difficult airway written all over it. When seconds matter most, will you be prepared? Here's advice from anesthesia providers on how to quickly and safely secure a difficult airway.

1. Anticipate problems. During your airway exam and evaluation, screen for red flags, says Marty Resnik, CRNA, president of CRNA Anesthesia Associates in Cleveland Heights, Ohio. "Know what trouble you can get into before you start the case," he says. "Proper evaluation is no guarantee, but it will help identify potential difficult airways." The more of these red flags you see, the greater the potential for a difficult airway, he says.

• Mallampati classification of 3 or 4. This is a rating for how far you can see into a patient's mouth while the patient is seated upright with his head in neutral position, his mouth open as wide as possible and his tongue extended to maximum. The higher the score, the less you can see and the more difficult the intubation will be. It's widely held that the intubation failure rate for a Mallampati class 4 is higher than 10%. Note that Mallampati classification may fail to predict difficult intubations more than half the time.
• Evaluate the 3-3-2 rule. Another simple way to predict the ease of intubation is to take some measurements. The distance between the patient's incisor teeth should be at least 3 finger breadths (3), the distance between the hyoid bone and the chin should be at least 3 finger breadths (3), and the distance between the thyroid notch and the floor of the mouth should be at least 2 finger breadths (2).
• Observe other physical signs. Certain anatomical features make direct laryngoscopy difficult, including an inability to prognath the jaw bone, a limited range of motion of the neck, a short, wide neck, morbid obesity and a history of sleep apnea.

2. Give premedicants. Always give the anticholinergic glycopyrrolate to any patient with a questionable airway, says J.P. Abenstein, MD, MSEE, associate professor of anesthesiology at the Mayo Clinic in Rochester, Minn. He says the injectable improves uptake of local anesthesia for awake intubation and decreases excessive pharyngeal, tracheal and bronchial secretions to facilitate visualization.

3. Use pre-op pain meds only as needed. Avoid the routine administration of pre-operative opioids before propofol induction to patients who aren't in pain or unusually anxious. This will better preserve patients' drives to breathe spontaneously, says Barry L. Friedberg, MD, of Cosmetic Surgery Anesthesia in Newport Beach, Calif. He says a reasonable midazolam substitute is oral clonidine, provided that you can achieve a 2.5- to 5.0-mg/kg concentration. For patients weighing between 95 and 175 pounds, 0.2mg of oral clonidine 30 to 60 minutes prior to surgery has been shown to be effective in reducing propofol requirements for both induction and maintenance with bispectral index (BIS)?monitoring.

BIS monitoring is most useful if you trend electromyographic (EMG) readings as a secondary trace to the BIS, says Dr. Friedberg. He explains: Incrementally (50mg/kg, for example) titrate patients' propofol and stop mini-bolusing once EMG begins to descend. EMG will drop before BIS. Inducing in this manner prevents overshooting the hypnotic dose of propofol, preserves pharyngeal muscle tone and avoids creating the difficult airway in the first place.

4. Go easy on the propofol. This is about the 19-fold interindividual difference in how the drug is metabolized and how induction doses based on body weight may overshoot many patients' individual hypnotic requirements to produce a loss of airway muscle tone with transient apnea. "Bolus propofol inductions may take a patient who was formerly able to maintain his own airway and breathe satisfactorily on room air and create a patient dependent on the anesthesia provider for ventilation and oxygenation," says Dr. Friedberg.

Many anesthesia providers routinely induce their elective patients' anesthesia, for example, with a bolus of propofol (1.5 to 2.5 mg/kg), says Dr. Friedberg. "Even in experienced hands, the best guess for a propofol bolus can often be in error," he adds.

5. Get reacquainted with mask ventilation. As propofol and pentothal become increasingly difficult to obtain, the frequency of anecdotal reports of anesthesia providers once again using mask induction techniques is on the rise, says Jay Horowitz, CRNA, the president of Quality Anesthesia Care Corp. in Sarasota, Fla. As a student anesthetist in the late 1980s, Mr. Horowitz remembers his mentors insisting that he master the mask technique before moving on to more complex airway management skills.

"Occasionally, that meant hours of masking at a time, and hours of post-op wrist and finger cramping," he says. "Strong hands, an oral airway and a set of mask straps in various and flexible combinations produced satisfactory airway control and promoted excellent surgical anesthesia. Anesthetic depth and respiratory effort was manageable from spontaneous to controlled ventilation, and with the 3 fingers of your left hand under the patient's mandible, you could feel the rate, rhythm and strength of the patient's pulse."

The overwhelming popularity of the laryngeal mask airway has bumped face-mask ventilation down several notches, says Mr. Horowitz. "Yet it remains an integral part of the difficult airway algo-rithm, can be cost-effective and can truly save lives," he says.

While especially convenient, easy to use and able to free up the anesthetist's hands, placing LMAs requires either an IV induction or very deep sedation, says Mr. Horowitz. Then there's the cost to consider. Though not extraordinarily expensive — and perhaps worth the added expense, says Mr. Horowitz — LMAs represent an increased cost in patients "who can easily be managed with a mask by a skilled anesthetist, since we generally mask patients after IV induction and before LMA insertion anyway."

6. Learn to use LMAs. When you can't ventilate or intubate, LMAs can be a bridge. Compared with endotracheal intubation, the LMA technique is considered easy to teach and learn. "I'm impressed with the short LMA learning curve and the minimal narcotic needed when titrating to respiratory rate," says Mr. Horowitz. "With the inclusion of 30mg ketorolac in my care plan, I have comfortable, awake and alert patients ready for timely post-op discharge."

7. Invest in the latest equipment. Mr. Resnik doesn't own a video laryngoscope. At least not yet. "But it might save one life," he says. "One irresolvable airway crisis could result in financial and mental anguish that far outweighs the cost of a videoscope. One day it might be standard of care to have a video laryngoscope."

He's trialed 2 so far, using each a handful of times. "The intubation success rate is extremely high for the difficult airway when compared to traditional laryngoscopes," he says. "In the sedation cases that we do, you can lose an airway. There's the potential for aspiration. If anything from the stomach ends up in the lungs, the patient will have serious trouble breathing and you need to get a tube in there to secure the airway as soon as possible. It'd be nice to have an additional tool around other than a traditional laryngosope to do that with."

Of course, an emergency airway cart should also be available, stocked with a variety of laryngoscope blades, video laryngoscope, fiberoptic scope, retrograde intubation kit, light wand and cricothyroidotomy kit.

8. Swallow your foolish pride. When confronted with a difficult intubation, consider waking the patient before attempting too many airway maneuvers that may lead to the loss of the airway, says Mr. Resnik. Don't be afraid to call for assistance. It's like missing an IV, he says. If you can't do it after a couple of tries, maybe someone else can pop it in on the first try. "Always do what's safest for the patient," says Mr. Resnik. "Don't be pressured by a surgeon waiting to start the case or a center that'll lose money if the case is canceled."