Title: Laryngeal Injury and Upper Airway Symptoms after Oral Endotracheal Intubation with Mechanical Ventilation During Critical Care: A Systematic Review
Author: Brodsky, Levy, Jedlanek, et al.
Journal: Critical Care Medicine
Year of Publication: 2018
Design Type: Systematic Review
Purpose: “The purposes of this systematic review are to (1) evaluate the nature and severity of laryngeal injury after endotracheal intubation in ICU patients and (2) identify areas of inquiry for mitigation strategies and future intervention.”
Population: extubated adults in ICU (mechanically ventilated) with laryngeal evaluations
Inclusion criteria: Studies: English only text; Population: adults> 18 years; direct/indirect visualization of larynx; reported sufficient laryngeal data
Exclusion criteria: Studies: pediatric-focused/animal-only research; case study/retrospective designs; patients <18 years old; pre-existing laryngeal injury/disease; patients with history of surgeries with risk of recurrent laryngeal nerve injury; gray literature; non-focal neurologically impaired patients (e.g. stroke) resulting in difficulty determining post-intubation dysphonia/dysphagia; no evaluation/reporting of visualization of larynx; (See Figure 1 for additional criteria)
“I have a patient X. What should I do?”
That’s basically what our brain automatically defaults to when we cannot come up with a solution or rationale immediately, right? There are many more steps that should be taken when finding ourselves asking this question, of course always running back to our favorite famous triangle:
“What do I already know about this population/disorder/anatomy etc?”
“What does the best evidence suggest?”
“What does the patient want? Do they even think there’s a problem?”
These are just some of the questions we can find ourselves asking after that initial big one above. Right now, we’re probably asking ourselves many more questions and unfortunately finding fewer answers than we’d like. But…the good news is we can still go back to the basics to help us come up with possibly more updated answers in order to create the best assessment and treatment plan for our patients.
This article is NOT like one of those pizzas where you have to pick things apart to get what you actually want (or is that just me with pineapple??😅). Instead, it’s much more like a beautifully delicious and authentic margherita pizza, with those basic ingredients that make it OH SO GOOD.🤤👍👍
By focusing on one specific setting, the authors could narrow their search and criteria while making it a bit more difficult to generalize to other environments like surgical settings.
“Laryngeal injuries from intubation during surgery are believed to be confined to minor injuries. By comparison, critically ill patients intubated in ICU generally experience longer intubation resulting in laryngeal injuries that are more prevalent, potentially more severe, frequently overlooked, and often result in voice dysfunction (i.e., dysphonia) and/or swallowing dysfunction (i.e., dysphagia).” p.2
Have you ever been to the doctor, complaining of something, and then getting told to “wait ‘n see?” Maybe it was the right advice, but maybe it wasn’t. Either way, it probably didn’t a) make you feel more assured and b) make you feel ‘heard.’ Imagine having to wait, see if it gets better, but continually having the same or worsening symptoms after the fact?
With their two main goals, the authors were able to group types of laryngeal injuries and look at other variables below:
- Prevalence of laryngeal injury grade (average intubation duration)
- Grade of Severity for laryngeal injury post-extubation (See Table 2)
- Timing of laryngeal injury post-extubation (plus by severity grade)
- Symptoms reported post-extubation
Arguably more important to know is across how many studies did they look for the above info? In other words, their sample size for studies. If you’re thinking going from 4,530 articles across 4 major databases/sources, then to 126….then down to 9 studies would take F-O-R-E-V-E-R, you are definitely right!! But this is the kind of quality analysis that can be SO valuable to us clinicians, so while time might not be on their side, hopefully, eager clinicians will be🙂. The authors are also nice enough to point out the strengths and weaknesses (e.g. lack of reproducibility, attrition, detection) of the quality of the studies they ended up with.
Even MORE important is the quality of those studies (this is where the under-rated magic can be🔮💫!) because of those final 9 studies:
- 7 were Cohort Studies (663 subjects total; ranging from 16-209 patients)
- 2 were Cross-sectional Studies (112 subjects total; 51 and 61 patients)
- = 775 patients TOTAL
(For a quick recap to help you actually understand just what those terms mean, make sure to Subscribe to SLP R&R to download your ‘Research Cheat Sheet‘ !!🤓)
The authors give some really great comprehensive information about what they found from the above studies so I would without a doubt recommend perusing their article to find some great data including but not limited to:
- laryngeal injury (how many of the studies actually focused on this)
- average age of patient
- endotracheal tube (ETT) size (and the differences used between men/women)
- ETT manufacturers
- duration of intubation
That last one is of crucial importance if some may not know already (don’t spill the beans!!), but if not keep reading. . .
I was actually surprised a little to find that only 2 studies used direct visualization via laryngoscope vs 8 studies using indirect visualization methods (i.e., laryngeal mirror, rigid endoscope, flexible nasoendoscopy, flexible bronchoscopy). Luckily, 7 of the studies collaborated with our dear Otolaryngologist friends to interpret and confirm results.
My most favorite part😊:
“After extubation, assessment was completed within 6 hours, within 24 hours, within 72 hours, and at 2 weeks post-extubation.” p.4
What a range!!!! (and might I say pretty dang relatable! #generalizable)
Here’s also a quick glimpse into how they graded the severity of the laryngeal injuries that were being reported, along with the most common symptoms (See Table 2 for full data):
0= No injury
1= Self-limited/soft tissue (e.g., edema, erythema)
2=Hematoma, granulation, mass lesion, etc.
3=stenosis, immobility of vocal folds, etc.
Symptoms (in order of prevalence):
- Laryngeal dyspnea
So what were some of the results they found???
“Many injuries were self-limiting, Grade 1 injuries. Overall, erythema was most frequent, with a prevalence of 82% (252/307 patients), followed closely by edema with a prevalence of 70% (583/828 patients).” (my emphasis added)
“The interarytenoid space, the area through which the ETT passes and remains present in situ, had a 95%(106/112 patients) to 96%(108/112 patients)prevalence of edema and erythema, respectively.” p.4
“Ulcerations, with a 31% (174/524 patients) prevalence, were the most frequently reported moderate (i.e., Grade 2) injury.”
“Intubation granulomas/granulation tissue, the only other injury type reported, had a 27% (86/318 patients) prevalence.” p.5
“Vocal fold immobility was the most frequently reported and most common of the severe (i.e., Grade 3) injuries, with a 21% (105/508 patients) prevalence.”
“There was a 6% (12/200 patients) prevalence of glottic stenosis and 13% (15/112 patients) prevalence of subglottic stenosis. A prevalence of 5% or less for both subglottic mucosa edema and arytenoid(s) dislocation were reported.” p.5
And if THAT wasn’t good enough. . . .
The authors also looked at all the above results to see if the length of intubation for:
(1) <5 days
(2) 5-10 days
(3) >10 days
impacted any of this at all:
“There was increased prevalence and increased severity of injury observed in patients intubated 5–10 days compared with those intubated <5 days. Specifically, there was a 37% and 38% increased prevalence of injury in Grades 1 and 2, respectively. Grade 3 had a 125% increase in prevalence between the same two periods.” p.5
Such unique injuries even happened in 2 studies for patients that were intubated >10 days that they couldn’t even summarize!
Just in case you missed a largely important point🧐:
“Laryngeal injury prevalence may change with longer durations of intubation.” p.5
Wondering if it matters when you go in to assess for any of this??
The authors were just as curious as you were (but have all the means to answer our questions!)
They looked at different timeframes for when direct/indirect assessments were completed from time post-extubation:
- <6 hours
- <24 hours
- < 72 hours
- 2 weeks
I feel like this is a perfect place to take the time to think about where YOU and YOUR facility fall within those windows (or, maybe where you would like to fall?🤔).
Do you know why you fall where you are? Have you been given any rationale as to why you’re at that range? Maybe it makes much more sense for your facility, or there may be some miscommunication going on. Either way, without trying to argue or play the #blamegame or “#guiltgame, asking these “why” questions should always be encouraged, at any time, any place, because it is not only to benefit our patients but also that’s how we keep moving forward and onward on our SLP elevator versus staying stagnant on a wet doormat🙂 (jumping off a soapbox now…..)
“Compared with overall prevalence and considering variability in the reporting of data, timing of assessment resulted in little change in laryngeal injury prevalence within grade. This finding suggests that the injuries observed vary little within 3 days post-extubation.” p.5
Yeah, that was my face too. As I thought about it, understood this as explaining how timing of evaluation didn’t necessarily affect the severity of the injury. So if it’s a Grade 1, it’ll likely still stay a Grade 1 a day later (versus getting more severe). Anyone else as surprised as I was by this?!? 😀
“Despite frequent complaints of dysphonia and pain after extubation, identifying which patients are at high risk for moderate to severe laryngeal injury and the best time for assessment is less clear. Moreover, there are no screening tools or published guidelines offering direction on this issue, a large gap in critical care patient populations and their long-term outcomes” p.7
Ughhh not again😩😩! While knowing there are no clear guidelines for what we should be doing specifically for post-extubation and laryngeal evaluation can be frustrating (guys, I get it😉), the silver lining (if you want to see it) is that it can also be very liberalizing so each specific facility, each specific team, each clinician, can determine what may be best for their facility, their department, and their patient…
BUT WAIT–we’re not done with the Results just yet!!
“One finding worth highlighting is that approximately half of all patients experienced dysphagia after extubation and that 1 in 5 patients had vocal fold immobility.” p.6
*Hopefully* we all know that post-extubation dysphagia IS A THING (if not, check out some of these resources [1, 2, 3, 4, 5] to learn more!). This review goes further to make the connection between laryngeal injury and compromised airways, which can lead to more of an increase in swallowing safety impairment (i.e., risk of aspiration/pneumonia).
“There are several potential contributing etiologies that might increase aspiration risk in this population, including compromised cognition, sensory impairment, reduced laryngeal adductor reflex, and reduced strength in muscles involved in swallowing.”
“Moreover, the risk of pneumonia doubles in patients with unilateral vocal fold paralysis. Early recognition of vocal fold paralysis may mitigate risks for pneumonia or pneumonitis with a timely vocal fold medialization procedure, for example.” p.6
So, while the “wait and see” approach is what’s pondered by the authors’ review, is this really the best we can come up with as clinicians? Does this really demonstrate being at the top of our practices?? Is “wait and see” really worth it, if not for the HIGH RISK for dysphagia and pneumonias?
Before planting your stake on whichever side of the fence, some long-term consequences and results to sit on first:
“Our findings encourage more routine, timely and consistent use of a laryngeal assessment and dysphagia screening post-extubation, especially in the wake of payment reform and a national focus on patient safety”
“On average, more than twice as many patients will sustain moderate or severe injuries that impact airway, voice, and/or swallowing than will have no injury”
“Moderate to severe laryngeal injuries may result in more than 2 days and $6000 in costs with readmission for repair”
“Hospital-acquired pneumonia can increase length of stay in the ICU by more than 8 days.” p.7
Those numbers can be much harder to swallow for those managers and higher-ups (I mean, $6,000 for your voice!?!?).
Wouldn’t it be super swell if we could formulate some type of standardized screen post-extubation to assess the likelihood for laryngeal injury?? Even if there are some false positives, better to continue to see ‘n assess versus wait, see, ‘n hope🤞?? Clinicians and researchers unite for this guys!!😃🤓👩🏿🔬👨🔬🙆🏽♀️ [**Dr. Brodsky shared to stay tuned because he’s actually working on this very thing now!!😮🤯)
A quick bit on some limitations to consider because life’s just not perfect, right?😐:
- high risk of bias >50% of rating parameters
- detection biasº (e.g. those able to communicate pain versus those who are unable to do so)
- attrition biasº (people drop out so you might never really know if they had any injuries later on)
- reporting biasº (e.g. only sharing the positive results, failing to disclose conflicts of interests)
- Unclear description for future replication of studies
- >19-year gap between 3 studies in/before 1987 (the next study was published in 2006!!😱)
Obviously, the saddest part is that we can’t give a handout just yet stating “This is what we are supposed to do.” But, we can start individually evaluating and thinking critically about the who, what, when, why, and how parts NOW in order to avoid major problems later on.🤓
How can you use this article?!?
First off, who wants to come meet Dr. Brodsky and I for a virtual coffee to chat and nerd out about this article🤓?!?
Did anything surprise you from this article?!
Are you finding anything consistent at your facility or in your practice with the findings??
What do you think we can do to improve these findings or at least advocate for them???
- “Laryngeal injury prevalence may change with longer durations of intubation”
- “Symptoms of laryngeal injury identified after extubation were common, with voice dysfunction (i.e., dysphonia), dysphagia, and pain being the most frequent”
- “Although less severe injuries are more common, Grades 2 and Grade 3 injuries occur with a remarkable frequency of 31% and 13%, respectively”
- “It is well-recognized that intubation duration more than 2 days places patients at high risk for both acute and chronic dysphagia that may result in aspiration, possibly leading to aspiration pneumonia or pneumonitis
- “No conclusions can be made concerning laryngeal injury, ETT size, and/or materials/manufacturing due to the large variability within and between studies”
Article Referenced: [FREE ACCESS]
Brodsky MB, Levy MJ, Jedlanek E, et al. Laryngeal Injury and Upper Airway Symptoms After Oral Endotracheal Intubation With Mechanical Ventilation During Critical Care: A Systematic Review. Crit Care Med. 2018;46(12):2010‐2017. doi:10.1097/CCM.0000000000003368