Laryngospasm is a life-threatening emergency the airway jedi anoxia definicion

Larynx in laryngospasm from anyone can intubate, 5th edition by C. Whitten MD

One of the more frightening events in anesthesia is laryngospasm: 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.

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.Anoxia definicion


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

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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.Anoxia definicion 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).Anoxia definicion 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.

Laryngospasm: involuntary reflex closure of the vocal cords is seen on the right in b. From anyone can intubate, 5th edition

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.Anoxia definicion 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.Anoxia definicion 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

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• 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.Anoxia definicion 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.Anoxia definicion 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

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

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.Anoxia definicion 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?Anoxia definicion 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.

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.Anoxia definicion 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.

This happened to me under anesthesia (or when I was just coming out), when they removed the tube.Anoxia definicion 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.Anoxia definicion 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.Anoxia definicion 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.Anoxia definicion 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.Anoxia definicion 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.