A Difficult Intubation: Ankylosing Spondylitis

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In this article the authors interview Andrew Bowman, MSN, RN, ACNP-BC, an acute care nurse practitioner and paramedic in Indiana. Andrew recently faced a difficult intubation situation with a patient with CHF complicated by severe kyphosis secondary to ankylosing spondylitis. Patients with ankylosing spondylitis present extremely difficult intubation challenges. Andrew discusses his approach and how he was able to successfully intubate this patient.

Gene: Jason, what is ankylosing spondylitis and what are the difficulties faced when you have to intubate a patient with this condition?

Jason: Ankylosing spondylitis (AS) is one of a group of disorders that are related to rheumatoid arthritis. We have discovered genes that give you a predisposition to it, but it’s not a truly hereditary disease—it seems to be more of a body’s overreaction to an infection.

AS chronically inflames the tendons and joints of the axial skeleton. For whatever reason, it likes to go after the sacroiliac joint first and the spine second. Like other rheumatoid diseases, patients can get flare-ups of AS, and have a greater or lesser degree of symptoms in between flares. Having AS also puts patients at increased risk for stroke.

As the tendons get inflamed, they develop bony growths that make the AS patient’s spine very stiff and painful, making airway positioning difficult. The bones can become weakened and develop compression fractures, to the point where the patients will develop a severe kyphosis, as we will see with Andrew’s patient. The bones are so weak that if this happens even a neck manipulation as innocuous as putting a cervical collar on these patients can be quite dangerous. There is actually a case report of a 59-year-old man’s spine being fractured by application of a rigid cervical collar, which led to spinal cord injury and his eventual death.¹

In other words, you have to intubate these patients with their necks in the position you find, not the position you want.

Gene: Andrew, please describe the patient who presented to you.

Andrew: This was a mid-40s male who lives with his parents and brother at home. I had admitted him to the hospital two weeks prior with pneumonia. He required BiPAP treatment during that hospitalization for hypercapnea (CO₂ retention) secondary to severe restrictive lung disease from his severe kyphosis secondary to his ankylosing spondylitis. He also had a history of hypertension, diabetes, GERD and necrotizing fasciitis.

On this presentation he was awake and complaining of “feeling sick.” He seemed fatigued, would not keep his eyes open and would not elaborate further on his symptoms. His family reported they noticed fever at home and some labored breathing. He was also reportedly hypoxic at home, where he was on supplemental oxygen at 5 lpm via nasal cannula and he reportedly desaturated to 56%, although in ER he was hovering around 90%–91% with his supplemental O₂.

On arrival he was afebrile, with a heart rate of 110, respiratory rate of 22 and slightly labored, and blood pressure elevated to 180/90. Breath sounds were diminished bilaterally without obvious wheezing or rales or rhonchi. JVD could not be well assessed as he could not extend his neck from a chronic flexed position. Heart sounds were heard without murmur. Skin was pink, warm and dry. Abdomen was soft and there was no guarding or tenderness. There was 2+ bilateral pre-tibial edema without calf tenderness. His family reported that his legs had been edematous since last discharge from the hospital.

We established IV access, continued O₂, obtained an EKG, sent off labs and obtained a bedside chest x-ray.

The image below is a slice from his prior admission CT scan that demonstrates his severe kyphosis.

Kelly: That’s some pretty pronounced kyphosis! Andrew, what immediate challenges were you faced with when you first saw this patient?

Andrew: My initial differentials included CHF, recurrent pneumonia, other infectious causes, recurrent hypercapnia, acute intracranial event (bleed or CVA) and metabolic disorders. I had concerns that if he needed an airway intervention, his anatomy would make this a challenge.

Kelly: Half the battle of airway management is anticipating problems and being prepared. So how did you approach this patient initially?

Andrew: His head CT was unremarkable. His chest x-ray was concerning for low lung volumes, CHF and bilateral pleural effusions. He did have an elevated proBNP (a marker for CHF) and an elevated troponin, but his EKG did not show any evidence of ischemia/STEMI, so I was concerned that his hypertensive CHF was causing a troponin leak.

He remained hypertensive and dyspneic, so we drew an arterial blood gas (ABG) and then started BiPAP and nitroglycerin infusion for my working diagnosis of hypertensive CHF. His ABG showed severe hypercapneic respiratory failure with a pH of 6.98, PaCO₂ of 202 mmHg, and PaO₂ 60 mmHg.

I had a discussion with his mother and other family members present about the possible need for intubation and his mother indicated that at his most recent prior hospitalization, the patient had talked about intubation and mechanical ventilation with his pulmonologist and had decided that he did not want this done. However, I could not find that information in the medical record.

I then approached the mother and family again, indicating that it was my concern that if we did not intervene with more aggressive airway and ventilation management, the patient would likely die from his hypercapneic respiratory failure. After 45 minutes, a repeat ABG showed worsening respiratory failure with pH of 6.96 and PaCO₂ of 214 mmHg, but PaO₂ was better at 90 mmHg. It was at this point that the mother requested I proceed with intubation.

My plan was not to chemically paralyze this patient. I wanted to try and preserve his respiratory drive as much as possible since we could not lay him flat to do bag-mask ventilation. My plan was to use ketamine for sedation, with BiPAP continued for ongoing oxygenation, and to add high-flow nasal cannula oxygen using Dr. Richard Levitan’s NO DESAT (nasal oxygen during efforts securing a tube) approach to maintaining oxygenation during the intubation attempt after BiPAP was removed. I was going to use the GlideScope video laryngoscope as again, I would not be able to extend his head and neck to use direct laryngoscopy. In addition, I thought I might try to approach from the front, as he could not lay back, and insert the GlideScope like a tomahawk.

Unfortunately, even though I had a great view of the vocal cords using this approach and his oxygen saturation was well maintained, I could not navigate the tube through the vocal cords.

Jason: Why do you think you had difficulty getting the tube to pass through the cords?

Andrew: I think it comes down to muscle memory. Clearly I have been intubating using direct laryngoscopy for 30+ years and have been using GlideScope video laryngoscopy for five years, so I have great experience with this. However, I have rarely used the tomahawk approach, and I could not flip the technique in my mind to properly rotate the tube where it needed to be.

Jason: What were your thought processes as you formulated the next steps to try to intubate this patient?

Andrew: At this point I had a patient who was sedated and with hypercapneic respiratory failure who clearly needed an airway. As noted earlier, his anatomy would have made any approach such as cricothyrotomy or retrograde intubation difficult. We reapplied the BiPAP and continued his high-flow nasal cannula oxygen as I formulated my back-up plan.

Kelly: Had you ever had to deal with a patient like this before?

Andrew: I have intubated the patient with moderate kyphosis from ankylosing spondylitis before, but not to the degree that this patient was exhibiting.

Gene: Can you describe your GlideScope technique and how it differs from "normal" approaches to intubating?

Andrew: The GlideScope allows us to “see around corners” so that we do not need to have that perfect alignment of multiple airway axes to pass an endotracheal tube. I do follow the recommended approach where I look into the mouth as I advance the GlideScope. I then transfer my attention to the video screen until the glottic opening appears and then bring the endotracheal tube into the right side of the mouth with the tube pointing at the 3 o'clock position. I then rotate the tube as I advance it, so that it is now at the 12 o'clock position, and it is typically perfectly aligned with the glottic opening at this point. It is then just a matter of advancing the tube and removing the stylette.

Jason: Can you discuss how you positioned the patient for your next try and why you did that?

Andrew: As you can see from Figure 2, recreated using one of the excellent emergency nurses I have the pleasure of working with, we elevated the entire bed so that the head could be dropped into a Trendelenburg position, while keeping the head of the patient's bed actually elevated to help support his kyphotic upper body.

While we maintained supplemental oxygen using BiPAP and high-flow nasal cannula oxygen, I positioned myself at the head of the bed and stood on a step stool so that I was above and behind the patient to better visualize placing the GlideScope and tube into the mouth.

Using a hyperangulated GlideScope blade I was able to easily place the GlideScope in the mouth, and as I advanced it, I was afforded a perfect view of the glottic opening.

Since this is typically fairly close to the position I would use for regular intubation, it was just a matter of advancing the tube and it went in very easily. In retrospect, I should have started with this technique and approach.

Gene: Did you consider using a bougie, and why or why not?

Andrew: The typical bougie does not work very well with the GlideScope. However, I did have it available in case a standard approach did not work.

Gene: If you had not been able to get the tube in with the GlideScope, what other measures could you have considered?

Andrew: If we had not been successful, we did have a cricothyrotomy tray and a retrograde intubation kit, as well as a supraglottic airway available to facilitate airway management.

Jason: Obviously this is a rarely occurring presentation. What advice do you have for medics who have never seen this but want to be prepared in case it ever presents to them?

Andrew: Understand that with someone with severe kyphosis from any cause, using a standard direct laryngoscope approach would be very difficult if not nearly impossible. This is a classic scenario where video laryngoscopy is superior to direct laryngoscopy for airway management.

Conclusion

The key to being ready for a patient like this is to practice ahead of time. Set up a manikin with its neck hyperflexed and practice different approaches and techniques. The time to think about these cases is before you are presented with them. At least, if you have practiced a few times and repeat practice at decent intervals, you won't be taken completely by surprise when it happens to you.

Reference

1. Clarke A, James S, Ahuja S. Ankylosing spondylitis: inadvertent application of a rigid collar after cervical fracture, leading to neurological complications and death. Acta Orthop Belg, 2010 Jun; 76(3):413–5.

William E. “Gene” Gandy, JD, LP, has been a paramedic and EMS educator for over 30 years. He has implemented a two-year associate degree paramedic program for a community college, served as both a volunteer and paid paramedic, and practiced in both rural and urban settings and in the offshore oil industry. He lives in Tucson, AZ.

Steven “Kelly” Grayson, NREMT-P, CCEMT-P, is a critical care paramedic for Acadian Ambulance in Louisiana. He has spent the past 22 years as a field paramedic, critical care transport paramedic, field supervisor and educator. He is a frequent EMS conference speaker and author of the book En Route: A Paramedic’s Stories of Life, Death, and Everything In Between and the popular blog A Day in the Life of an Ambulance Driver.

Jason Kodat, MD, EMT-P, has been in EMS for more than 15 years. He has reviewed EMS textbooks and the USFA’s EMS Medical Director Handbook, and lectures at regional EMS conferences regularly. He currently works as an emergency physician and associate EMS medical director at hospitals near Pittsburgh, PA.