Avoiding Difficult Intubation Of The Easy Airway

We’ve all done it. It’s extremely easy to make any otherwise routine intubation difficult just by failing to properly position the patient or to use optimal technique. Let’s see how to avoid this pitfall. (All illustrations by Christine Whitten MD, Anyone Can Intubate).

Optimize Head Position

Optimize the patient’s head/neck position as best you can for the situation. This is especially important if the patient is obese. Placing the patient’s head in the optimal sniffing position will make visualizing the larynx easier. A poorly positioned head can make any intubation difficult.

Place ear canals level with sternal notch. You can use folded towels, sheets or even a pillow under the head. Make sure that the head support is not so high that it keeps you from tilting the head backwards.

The board chest and breast tissue of the obese patient can hamper placement of the laryngoscope and make visualization difficult. Ramping the patient to ensure a good sniffing position makes laryngoscopy easier. Don't make the head support too high. Make sure that you can still tilt the head back.

The board chest and breast tissue of the obese patient can hamper placement of the laryngoscope and make visualization difficult. Ramping the patient to ensure a good sniffing position makes laryngoscopy easier. Don’t make the head support too high. Make sure that you can still tilt the head back.

In infants and toddlers the support should go under the shoulders. Children younger than 2 years often have enough effective sniffing position due to their rounded occiput. You don’t need any additional head lift. In older children, place the support under the head, similar to the adult although the support needs to be smaller.

for children older than 2 years, placing a small folded towel under the head gives a good sniffing position. For children less than 2 years the towel should go under the shoulders to compensate for the large round occiput.

for children older than 2 years, placing a small folded towel under the head gives a good sniffing position. For children less than 2 years the towel should go under the shoulders to compensate for the large round occiput and to bring the axes of the airway into alignment.

Optimize Position On The Bed

Don’t be afraid to move the patient if you can’t reach the airway easily. Not only must you be able to be able to manipulate the head and neck for intubation, In addition, if you can’t intubate you also have to be able to ventilate the patient from that position. If the patient is out of reach you make your job at best difficult and at worst impossible.

If you can't reach the patient easily you can intubate and ventilate well. Don't be afraid to ask for help moving the patient or for supports for the head.

If you can’t reach the patient easily you can intubate and ventilate well, as in the figure on the left. Don’t be afraid to ask for help moving the patient or for supports for the head.

Avoid Overextension of Head

Overextension of the head makes the larynx appear more anterior and makes it difficult to place the tip of the endotracheal tube in the correct plane to enter the larynx.

Overextension of the head and neck can make even the normal the larynx appear very anterior during laryngoscopy.

Overextension of the head and neck can make even the normal the larynx appear very anterior during laryngoscopy and make intubation difficult.

Open Mouth As Wide As Possible

If you don’t open the mouth wide you make blade insertion difficult and impair your ability to see what you are doing inside the mouth. You are most likely to do this is the patient is missing their front teeth because you can see often the larynx, you simply haven’t given yourself enough room to maneuver your laryngoscope or your tube.

If you fail to open the mouth as wide as you can you will not have room to maneuver your blade, insert your endotracheal tube, or see the larynx.

If you fail to open the mouth as wide as you can you will not have room to maneuver your blade, insert your endotracheal tube, or see the larynx.

As you’re opening the mouth as wide as you can, place your fingers as far to the right side of the mouth as you can. This gives you more room to insert your laryngoscope blade initially to the right of the tongue. You will then sweep the tongue to the left and hold it there.

You must place your fingers as far to the right as you can or you will block insertion of the laryngoscope blade.

You must place your fingers as far to the right as you can or you will block insertion of the laryngoscope blade.

Don’t Insert Your Blade In The Middle Of The Tongue

A blade placed in the middle of the tongue will cause the tongue to mound up on either side, blocking your view and preventing tube insertion. Place your blade to the right of the tongue and then sweep the tongue to the left and out of the way. This movement typically places the blade very close to the midline: a very stable position for lifting, balancing, and controlling the head.

A blade placed in the middle of the tongue will cause the tongue tissue to mound on either side, block both insertion of the blade as well as your tube.

A blade placed in the middle of the tongue will cause the tongue tissue to mound on either side, block both insertion of the blade as well as your tube.

Don’t Insert The Blade Too Deep

Don’t insert the blade too deep. If you can’t see landmarks you may be hiding the entire larynx underneath your blade. Slowing slide the blade back while watching. The larynx will often pop into view .

If you insert your blade too deep you will hide the larynx underneath. This action also tents the esophagus and can made it mimic the glottic opening if you are not careful.

If you insert your blade too deep you will hide the larynx underneath. This action also tents the esophagus and can made it mimic the glottic opening if you are not careful.

When inserting your blade watch for the tip of the epiglottis. Once you see it, fine-tune your blade position before you start the final lift.

Don’t Mistake The Esophagus for The Larynx

As you can see in the photo above, when the blade is too deep, you will be looking at the esophagus under tension. Sometimes the triangular tenting of the tissue can mimic the vocal cord opening if you don’t have a clear view. Again, if you’re not sure about landmarks back the blade up slightly while watching.

Don’t Be Afraid To Lift The Head

Don’t be afraid to lift the head. While you may not need to lift the head much if the head is well positioned in the sniffing position, you will often find you need to suspend the head on your blade to straight the intubation path. If you are gentle you will not hurt the patient.

If you need help holding the head up ask your assistant to help you. Make sure your assistant supports the head without moving it, as unexpected shifting of the head during laryngoscopy can break teeth.

When you ask your assistant to help lift the head, their support must be steady. Any movement can cause you to break teeth. Having them rest the head on a balled fist which rests on the bed is very stable.

When you ask your assistant to help lift the head, their support must be steady. Any movement can cause you to break teeth. Having them rest the head on a balled fist which rests on the bed is very stable.

And while you are lifting, make sure you’re not pinching the lower lip against the teeth with your blade. You can cut the lip. This same advice also goes for the upper teeth but remember, you are lifting up and away and should not even be pressing against those upper teeth.

Never Rotate Your Blade Against The Teeth

It bears repeating: don’t rotate your blade against the teeth. Always lift upward and away, keeping your wrist stiff and your elbow fairly rigid. Again, don’t be afraid to lift.

Never rotate your wrist against the teeth or you will break them. Lift the head up and away from you.

Never rotate your wrist against the teeth or you will break them. Lift the head up and away from you.

Stylets Can Sometimes Prevent ETT Insertion

Stylets are invaluable during intubation, but if too sharply bent they can prevent you from sliding the tube into the trachea. If you can’t advance the tube, fix your tube firmly in position and either back the stylet out several cm with your thumb, or have your assistant pull it back slightly. This makes the tip more flexible, allowing you to advance it.

A stylet can sometimes prevent endotracheal tube insertion if it is too bent. Withdrawing it slightly to make the tip of the tube more flexible can help.

A stylet can sometimes prevent endotracheal tube insertion if it is too bent. Withdrawing it slightly to make the tip of the tube more flexible can help.

Slowly rotating the tube often allows the bevel to slip off the anterior commissure and slide down the trachea when it’s caught.

If the tip of the endotracheal tube is caught on the anterior commissure, rotating it until the tip slips off can be a helpful trick.

If the tip of the endotracheal tube is caught on the anterior commissure, rotating it until the tip slips off can be a helpful trick.

You can always change the shape of your stylet. Sometimes a curved stylet will let you maneuver inside the mouth better. Don’t be afraid to change the shape of your stylet. Stylets make the ETT more rigid. Be gentle when using one.

Putting a smooth curve on the entire stylet can sometimes make tube passage easier in selected patients.

Putting a smooth curve on the entire stylet can sometimes make tube passage easier in selected patients.

Don’t bend the stylet so sharply that you will have trouble removing it. Check before you start to see if you can slide the stylet in and out.

Use Helpers

I tell my students that intubation is a team sport. Ask your assistants to help you optimize position, stabilize or lift the head, pull the cheek out of the way, provide cricoid pressure. Tell your team what you need them to do.

Intubation is a team effort. Don't be afraid to ask for help improving your view.

Intubation is a team effort. Don’t be afraid to ask for help improving your view.

While it may be difficult to intubate selected patients, careful attention to detail can make most intubations easy.

May The Force Be With You

Christine Whitten MD, author, Anyone Can Intubate 5th Edition

 

7 thoughts on “Avoiding Difficult Intubation Of The Easy Airway

  1. I find your blog posts very helpful in kind of understanding what happened to me when I was delivering via emergency cs my baby 2 years ago. I had difficultry in intubation and the anesthesiologist said it was because of my asthma [during my pregnancy i did not have any asthma attacks at all].. I am wondering of anesthesia can trigger asthmatic attacks while under it? Or is it just my fault? They also said they didn’t intubated me after what happened they just used a mask all throughout the operation. They have injured my right vocal cords leaving it scarred and now I am hoarse and breathy souding for life [contradictong what my doctors said that it will only be temporary] ; and my left vocal cord paralyzed for 9 months and I don’t have the strength to ask any doctor here in my area because I feel sad and traumatized. Hoping for enlightenment with your response kind doctor..

    • Caitlin
      I’m so sorry to hear about the difficulty you had with anesthesia. It’s always hard to comment on a case when one wasn’t there and does not have access to the clinical description of what happened. My answers will of necessity have to be general in nature.

      Laboring patients undergoing emergency general anesthesia are at very high risk of potential complications because their airways are often already swollen from the hormonal changes of pregnancy, the stresses of labor, and the administration of IV fluid. Pregnant patients are also at high risk of vomiting and aspiration, which can be dangerous under general anesthesia.

      It’s for these reasons that we usually prefer to give a type of regional anesthetic, like a spinal or epidural, when we can because it leaves the mom awake and in control of her own breathing. However, if the baby is not tolerating labor, there may not be time to do safely do spinal anesthetic without putting the baby’s life at risk. In this case general anesthesia is quickly begun.

      The fact that you had an asthma attack during anesthesia is not your fault in any way. Nor it is likely to be the fault of the anesthesiologist. It can just happen. Anesthesia itself can trigger an asthma attack. Patients with a history of asthma have lungs that are more reactive to stimuli than average lungs. This means that irritating things, such as the strong chemical smells from our anesthetic gases or the actual touching of the larynx, as done during an attempted intubation, can trigger spasm of the air passages.

      The fact that your anesthesiologist stopped the intubation attempt and then used a mask to ventilate you was acceptable practice. Because two patients, the mom and the baby, are living off the same oxygen supply it’s critical that ventilation be begun immediately after the start of anesthetic to avoid a drop in oxygen level. Low oxygen can injure the baby, who is already known to be stressed and in need of urgent delivery. Ventilation with oxygen is more important than intubation itself. Prolonging an intubation attempt would have delayed both of the baby and perhaps caused more injury.

      Paralysis of the vocal cords typically occurs when either the tube or the tube cuff compresses the nerves that move the vocal cords during prolonged intubation. You were not successfully intubated so this is unlikely to be the cause. It’s possible that the two cartilages that anchor the vocal cords, called the arytenoids, were injured during the attempt. Your doctors were correct in saying that usually such paralysis resolves over time, but not always.

      My recommendation to you is to follow up with a local head and neck physician, if you have not already done so. Treatment options, and there may be treatment options, depend on the actual diagnosis. Voice therapy is normally the first treatment tried. After voice therapy, the decision for surgery depends on the severity of the symptoms, vocal needs of the patient, position of paralyzed vocal folds, prognosis for recovery, and the cause of the paralysis. Sometimes the vocal cord can be injected with a stiffening agent to make the voice stronger. I encourage you to visit your doctor and find out what options are open to you. I hope this information is helpful to you and I wish you luck.

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