Laryngospasm is a Life-Threatening Emergency

Laryngospasm is one of the more frightening events in anesthesia: the protective, reflex, spasmodic closure of the vocal cords that occurs when the vocal cords are stimulated.  When laryngospasm occurs, vocal cord closure can be so forceful that it can prevent all ventilation or even the passage of the endotracheal tube. Life-threatening hypoxia can quickly follow. Other potential complications include post obstructive pulmonary edema, and possibly even cardiac arrest.

Photo of laryngospasm demonstrating closure of the vocal cords and false cords

Although it can occur in the awake patient — the choking, high-pitched stridor and struggle to breath you experience when you aspirate water is a good example— laryngospasm is most dangerous when it occurs in a semi-conscious patient. Semi-consciousness produces a state when airway protective reflexes are hyperactive and the reflexes to turn them off are poorly operative. Semi-consciousness is present in Stage II of an anesthetic during both induction and emergence, which is why laryngospasm is so common in anesthesia. Patients suffering from head trauma or heavy sedation are also at risk.

A quick review of movement of laryngeal muscles will help us understand why laryngospasm can prevent ventilation. There are 3 major types of laryngeal movement.

  • Movements affecting tension of the vocal cords
  • Movements swinging the vocal cords open and closed
  • Movements that close off and protect the larynx

CHANGING TENSION OF THE VOCAL CORDS

Illustration showing how the thyroid cartilage can pivot on the cricoid cartilage, changing tension and slant angle of the vocal cords.

Movement affecting the tension of the vocal cords, like the pitch of the voice, occurs by rocking the thyroid cartilage backward and forward on the cricoid cartilage at the cricothyroid joint.

One only has to listen to a singer to realize the dynamic control of pitch that changes in vocal cord tension produce.

OPENING AND CLOSING THE VOCAL CORDS

Movements that swing the vocal cords open (abduction) or closed (adduction) occur by swiveling the arytenoid cartilages on the back of the cricoid ring. Our vocal cords pivot constantly during the breathing cycle: opening during inhalation, closing into a slightly separated rest position after exhalation. During forceful inspiration or during hyperventilation, the cords open widely, producing an oval shaped opening. This minimizes resistance to breathing.

Illustration of the laryngeal muscles and how they open and close the vocal cords.

Recurrent laryngeal nerve injury causes vocal cord paralysis on the affected side. The now flaccid vocal cord assumes the mostly closed rest position, producing partial airway obstruction and hoarseness.

CLOSING OFF THE LARYNX

Illustration of the extrinsic muscles of the larynx. From Anyone Can Intubate, 5th Edition

Extrinsic muscles of the larynx. From Anyone Can Intubate, 5th Edition

Movements that close off the top of the larynx protect it during swallowing or from aspiration.

Muscles, called extrinsic muscles, which move and support the larynx within the neck, surround the outside of the larynx. This up and down movement of the larynx helps function. For example, during inspiration, the entire larynx falls downward in the neck, a movement that pulls the epiglottis up and away from the glottis, further opening the airway.

During coughing and swallowing, the larynx rises in the neck. This higher position causes the epiglottis and the back of the tongue to drop downward over the glottis, closing it off. In this video you can see the upward laryngeal and epiglottis movement during swallowing.

Place your hand on your larynx as you breathe and swallow to feel these up and down movements.

Illustration showing 3 stages during swallowing to demonstrate how th muscles propel the bolus of food downward.

Swallowing is a complex coordinated series of movements. From Anyone Can Intubate, 5th Ed.

RECOGNIZING LARYNGOSPASM

Laryngospasm in anesthesia is most likely to occur  when secretions, mucus, blood, or instruments such as a laryngoscope, in the airway stimulate the vocal cords of a patient who is lightly anesthetized. One of the most common times for layrngospasm to occur is after extubation if the endotracheal tube is removed during Stage II when reflexes are hyperactive, instead of while more deeply anesthetized or while awake.

Avoiding vocal cord stimulation when the patient is lightly anesthetized can usually prevent laryngospasm. However, laryngospasm can occur even with the best of care, especially in patients with irritable airways such as those with asthma, COPD, smokers, and with upper or lower respiratory infection.  Laryngospasm can be obvious or subtle, but always has signs of airway obstruction.

If larygospasm is partial, there will be chest movement with stridor but very little air movement. There is very little bag movement with spontaneous ventilation .

If laryngospasm is complete, then there is chest movement but the airway is silent. Without air movement there is no stridor. The bag doesn’t move. No ventilation is possible.

Signs of airway obstruction include rib retraction, tracheal tug, paradoxical breathing movements (chest falls and abdomen rises with inspiration) and possibly stridor. However stridor won’t occur without  some air movement.

MECHANISM OF LARYNGOSPASM

The larynx on the left has relaxed vocal cords (a). The one the right is the same larynx in laryngospasm (b). In between these two images, the endotracheal tube touched the vocal cords in a patient who was too lightly anesthetized, triggering the laryngospasm.

Photo comparing a relaxed larynx with open vocal cords to a photo of laryngospasm in the same larynx.

You can see closure of the larynx occurs by four mechanisms:

  • closure of the vocal cords, both by pulling them together as well as by tensing them
  • closure of the false cords
  • mounding of the paraglottic tissues (lower epiglottis, paraglottic fat, base of tongue) by elevation of the larynx.
  • folding of epiglottis over glottic opening

It’s no wonder it’s hard to ventilate a patient in laryngospasm. Click here for a short video demonstrating these muscle movements and showing active laryngospasm.

BREAKING LARYNGOSPASM

Once the reflex is triggered in a semi-conscious patient, it often persists for a dangerously long time because the part of the brain that would normally  turn it off is “asleep”. Getting the patient out of stage II will break the spasm. This can be done either by deepening the anesthetic (with gas or IV agents) or allowing the patient to awaken to the point where the reflex stops itself. However, hypoxia can develop quickly. If the spasm isn’t broken, this hypoxia can lead to cardiac arrest. Waiting out the spasm usually isn’t an option.

To break laryngospasm, first stop stimulating the vocal cords. Suction the airway. Sometimes simply removing the object that touched the vocal cords or the secretions is enough to break the spasm.

Alert your colleagues and ask for help. Direct all efforts to delivering oxygen. Apply your ventilation mask tightly against the face, and provide a continuous positive pressure breath with your ventilation bag while performing a jaw thrust. The jaw thrust is important. Thrusting the jaw forward:

  • lifts the epiglottis and tongue off the glottic opening
  • rocks the larynx forward, counteracting some of the tension bunching the vocal cords together
  • pulls the aryepiglottic folds connecting the sides of the epiglottis to the back of the arytenoids, opening a small gap between the vocal cords
  • stimulates the patient because it’s painful, perhaps awakening the patient out of Stage II toward consciousness

All of these actions are directed at creating a gap between the vocal cords. Once you have that gap, then the positive pressure breath forces oxygen below the cords, pressurizing the larynx below the cords and forcing the cords further apart, usually breaking the spasm.

If the spasm doesn’t break, a small dose of sedative drug such as propofol may be needed. This deepens the level of anesthesia and usually stops the spasm.

If sedation doesn’t break it, then you may need a small dose of short acting muscle relaxant such as anectine to restore the ability to ventilate. You don’t need a full dose: about 20% the intubating dose will usually break the spasm and allow ventilation. The patient can breathe after this small dose but will be very weak and need ventilatory assistance until it wears off. Just remember, if reversal of muscle relaxant has been given prior to this dose of anectine, that reversal agent will prolong the anectine block, making it long acting. Reassure the awaking patient since such weakness will be frightening.

The time between onset of laryngospasm to hypoxia to bradycardia to cardiac arrest can be a matter of minutes, especially in small children. If laryngospasm is not breaking quickly with positive pressure alone, to not delay further treatment.

AVOID LARYNGOSPASM

Avoid stimulating the vocal cords in a semiconscious patient. Extubate either awake, or in a deep plane of anesthesia – not semiconscious Stage II. Always ensure the pharynx is clear of secretions, especially before extubation. Be vigilant, be prepared and react quickly if it occurs. And never hesitate to ask for help.

May the force be with us

Christine E. Whitten MD,
Author of Anyone Can Intubate 5th edition, and Pediatric Airway Management: a Step by Step guide

Cover of the book Anyone Can Intubate, A Step By Step Guide to Intubation and Airway Management, 5th edition   PedsCover_626x820

Please click on the covers to see inside my books at amazon.com

Further Reading:

D. Hampson-Evans. Pediatric Laryngospasm, Pediatric Anesthesia 2008, 18: 303-307

T Visvanathan, M T Kluger. Crisis management during anaesthesia: laryngospasm. Qual Saf Health Care 2005;14

 

26 thoughts on “Laryngospasm is a Life-Threatening Emergency

  1. I think this happened to me when I went to get my wisdom tooth surgery.

    After he injected me with the pain killers.

    He then stuffed a huge gauze in the corner of my mouth near to my throat, probably to stop the bleeding caused by the needle. I don’t know.

    I think that triggered it

    Because after he took the gauze out, I started to feel like I was choking so bad that i jumped up in the seat and started coughing non stop.

    I remember telling the doctor that I felt like there was something stuck in my throat but he could not see anything . He even used this suction tool they had.

    I coughed repeatedly to the point where I throwed up. I really did feel like someone was choking me.

    Luckily it went away and they continued with the surgery. I strongly believe if i didn’t jump out of the seat it would have gotten worse.

    Scary few seconds.

    • It is certainly possible to get a prolonged episode of laryngospasm in an awake patient, especially if there is still some secretion on the cords. I believe that too have recently experienced this when I had a bad bronchitis and was coughing up thick phlegm. The phlegm lodged in my cords and I suddenly was totally unable to breathe. As my husband jumped up and prepared to do the Heimlich maneuver, I was gradually able to inhale and then I was able to cough out the phlegm. While some of this was undoubtedly due to the mucous plug, I do think there was also some persistent laryngospasm as well, simply because of the way that the episode broke. Scary indeed.

    • Yes. All three can occur in a patient with any tendency toward airway irritability. Laryngospasm, as we discussed, occurs with airway stimulation in stage 2 of anesthesia, when the airway reflexes are heightened and the reflexes arc that tends to turn off or dampen those protective reflexes is not quite restored to normal. Extubating during stage 2 anesthesia is a recipe for inducing laryngospasm in any patient. However, laryngospasm occurs much more commonly in patients with a history of asthma/bronchospasm, those with upper or lower respiratory infections or inflammation, or in the presence of foreign body or secretions. And laryngospasm is going to be more challenging to break in those patients than a patient without those tendencies.

    • Yes. Let me quote an excellent review (reference below). “The overall incidence has been reported by Olsson and Hallen at just under 1% in both adult and paediatric practice.1 The incidence doubles in children and trebles in the very young (birth to 3 months of age). They also report an incidence for laryngospasm of 10% in the very young paediatric patient with reactive airways, either due to upper respiratory infection or asthma. The incidence of laryngospasm has been reported in the literature as high as 25% in patients undergoing tonsillectomy and adenoidectomy.”

      Patients with asthma have reactive airways, and when anesthetizing them care must be taken to avoid stimulating their airways during light planes of anesthesia during induction and emergence.

      Here is the reference too a good review article on laryngospasm.
      http://ceaccp.oxfordjournals.org/content/early/2013/08/23/bjaceaccp.mkt031.full.pdf+html

  2. This has happened to me twice in the middle of the night. Severe airway blockage and my inability to breathe in adequately. Intense stridor, heavy rib cage lifting, and everything as described above. In both instances it took what seemed to be minutes of me squeezing air through, just enough, to allow for the spasm to relax and to return to normal breathing. It just happened, I’m afraid to go back to sleep and was surfing for answers. The first time, 2-3 years ago, I had my wife take me to the ER. They did not diagnose it,but did give me a breathing treatment with albuterol, which set up a whole new event as I had never had that done before and totally went into some type of hyper-shock state or what I termed, “dying agressively”.
    In both instances, I felt I was choking on spittle, but now believe spittle had rolled back onto the vocal chords and triggered the spasms. I wear a mouth appliance now, but not during the first episode. I breathe loudly or snore without it in place. Which is a form of obstructive airway in of itself.
    Any thoughts of how to prevent this while sleeping? Scared now of going back to sleep. Freaks my wife out a bit as well, when I wake up sucking air and seemingly dying before her eyes.

  3. I average about one Laryngospam a year. Its caused by dry air,sickness, or just food irritation. I am 53 and having surgery for the first time in my life. I did note it in my preoperative patient disclosure form. What should I tell my surgeon, or make him aware of? I am very scared it will happen when I’m under anesthesia.

    • You should tell your surgeon and our anesthesiologist that you have a history of laryngospasm. You are at higher risk of laryngospasm during an anesthetic but knowing that you have that tendency there are quite a few things that can be done to help decrease the risk. For example, depending on the type of surgery you may or may not need a general anesthetic. Although there is no way to absolutely prevent laryngospasm, techniques can be used to minimize risk, as well as to treat laryngoscopasm quickly should it occur. We will often modify our anesthetic agents if a patient has cold or other upper respiratory inflammation or injury for example because we know this increases risk. You should ask your surgeon if there is an option of seeing your anesthesiologist in consultation before the surgery date. That way you can discuss any options and be reassured.

  4. Need advice please…my son had to have an emergency appendectomy. What should’ve been a routine surgery turned life threatening due to the Drs trying toextubate during stage II of his surgery causing laryngospasm. Because of this, he developed fluid in his lungs, and It took almost 6 hours working on him in recovery before he was stable enough to go to ICU. He was in ICU for 5 days with continuous oxygen and medications to get the fluid removed enough to move him to a regular room where he spent another 2 days before being released. This happened on Christmas Eve, and there was only 1 surgeon and 1 anesthesiologist in the hospital at that time. I truly feel there was negligence or new Drs working on him because of the holidays. We were told that EVERY person available was working on him (3 nurses, the anesthesiologist and surgeon), but he was not responding because they cold not keep him conscious enough to expell the fluid from his lungs due to being in a semiconscious state. I’m not the type of person to sue people for no reason, but I’m really wondering if I should at least seek legal advice about this. The hospital bill ended up being over $75,000 due to this. Is there anyone that thinks I should take repercussions against the hospital and/or Drs? Thank you for any advice.

  5. This happened to me under anesthesia (or when I was just coming out), when they removed the tube. I remember them calling my name and saying surgery was over, etc…I opened my eyes and couldn’t breath. I hear “why is she making that noise”. I was gasping for air; couldn’t breath at all. I woke up again and they had a mask on my face and 4 people standing over me. I was trying to take a breath, but no air was coming in. I started fighting them and struggling…trying to tell them I couldn’t breath. I hear them yelling to get this, get that, etc… I woke up again, now breathing normally, and I hear “wow that was close. What a way to start a Monday”. Not something a patient wants to hear. Turns out that episode was almost an hour long. They were very vague about the whole thing and acted like everything was fine. Only until my follow up visit did my surgeon say (casually by the way) ” yeah, you were lucky..if we didn’t have Dr so and so there…I’m not sure you would have made it”…and he walked out of the room. I stood there in disbelief and then went to my car and cried. I now wear a bracelet that says I’m susceptible to laryngospasm. To this day, I’m curious as to what they were doing during that hour. He did mention something about giving me something to “paralyze” my body to control the spasm. Anyway, it was the scariest thing I’ve ever been through.

    • I am so sorry you had such a bad experience. Sometimes doctors feel that not giving information (such as what happened to you) is easier on the patient because it would otherwise worry/scare them – or make them think their care was poor. I don’t agree with that and believe the it’s better for the patient to know the full details, than to allow the patient to make up possibly wrong details on their own. Complications can occur even with the best of care. From the description, this could have been laryngospasm. As I mentioned in the discussion, laryngospasm is a protective reflex out of control. To break laryngospasm, we can often apply positive pressure to the airway with a ventilation mask. We also give more sedation to deepen the patient and hopefully cause the spasm to break. However, when these treatments don’t work, we may have to give a muscle relaxant which paralyzes the muscles and allows the larynx to relax. Once relaxed, the provider can help the patient breath again. At this stage, we are helping the patient breath, but must now wait for any sedatives and the muscle relaxant to wear off before waking the patient and allowing the patient to breath on her own. Depending on the patient, the dose of any medications, and the type of muscle relaxant (in combination with any other muscle relaxants given and reversed at the end of the procedure) this can take some time. It does not surprise me that it took an hour for the combination of drugs they most likely used to wear off and it certainly does not imply that you were in danger during that time. It simply takes time for certain combinations to wear off. I would tell any future anesthesiologist that you had the problem but I want to reassure you as well that I think it’s highly unlikely you would have this problem in future if you have surgery again. Patients who have had an experience like yours sometimes are haunted by it and I would encourage you to discuss this with your doctor to seek peace of mind.

  6. Wow this was excellent. Thank you.
    May I ask one very crucial question- It is time sensitive. I am someone who has dysautonomia, postural orthostatic tachycardia syndrome, a mitral valve prolapse with regurgitation, and ehlers danlos type 3- I am 29 and live a healthy lifestyle. My issue is that I suffer a post nasal drip from hayfever and it causes some terrifying laryngeal spasms to occur that almost completely close my throat off- my body kind of over-reacts to everything.
    Anyway, I am training to become a doctor myself and this coming week I am meant to be doing my rounds in the operating theatre- I understand that the staff do have some exposure to the anaesthesia chemicals which make newbies sometimes faint- I wanted to ask if I would be at risk of that dangerous anaesthesia laryngeal spasm if I was to faint or be intoxicated with the gases?

    In general- would the fact I have this disorder make me higher risk if I was to have surgery myself? Or indeed would any of my conditions?

    I am due to start on Monday so am desperately trying to find out so I don’t end up in a bad situation compromising the patients life etc by risking my own.

    Best wishes,
    Ally x

    • Absolutely. We should always document any event that is, as the jargon goes, an unusual occurrence – whether or not it causes a complication. Patient safety comes before ego. Knowing a patient had laryngospasm alerts the postoperative staff to be on the alert for potential problems. One complication of laryngospasm is post obstructive pulmonary edema. This can be obvious with severe oxygen desaturation and frothy sputum requiring reintubation. However, it can also be subtle, with lower than normal oxygen saturations when the patient is on room air. My guess is that at least some of the mild hypoxemia we see in the recovery room is due to unrecognized airway obstruction during wakeup. Knowing a patient had laryngospasm can be very helpful diagnosing such problems.

      • I asked for full op report. Got 2pgs of nothing specific. Patient placed in supine….yatta….patient resting fine. I think I had an airway problem 4hour surgery. How do I get full report and how many pages might lung surgery be?

  7. Very interesting article. I had a larngospasm which was so frightening, but at the time I didn’t know what it was I just couldnt breathe, went to ER of course I was breathing ok by then, but had pulled every muscle in my throat,chest etc. I hurt for weeks afterwards. I thought it was a one off. I then required a parathyroid operation to remove two tumours, during the second stage of the operation during the waking up stage. I had an incident, so severe my jaw locked and the inserted tube broke off my front tooth. The anesthetist was very concerned and lovely. I now know that if I require another operation to let them know I have this. Thank you for this article.

  8. I am not even a DR and I know that to avoid any of this you just need to know how to apply pressure to the Laryngospam notch behind the ear. Every anesthetist should know this. Come on guys what do we pay you for?!

    • There is no specific laryngospasm notch behind the ear. However, when a patient is in laryngospasm it is very common to try to break it by lifting the mandible upwards to open the airway as described. In doing, the fingers are often placed behind the the angle of the jaw below the ear since it’s an effective point of leverage. Because pressing on this spot is painful, it often will help to awaken a patient in stage 2 (the excitement stage of anesthesia) and move them into Stage 1 (the awake/sedated phase). Anything that makes the patient more awake can help to break the laryngospasm. However, simply pressing on that spot is not a cure all for laryngospasm.

  9. What about topical application of lidocaine directly to the glottis? Would that relax the cords long enough to pass an endotracheal tube?

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