Prophylactic corticosteroids for prevention of post-extubation stridor and reintubation in adults: a systematic review and meta-analysis, by Akira Kuriyama et al .
Few things piss me off more than extubation failure. Not because of the failure itself, as an intensivists, you start to see failure as an undesired companion that every now and then comes at you to have a little chat. What really piss me off about extubation failure is that doesn’t matter what you do, it will happen. The only way to avoid it is to keep your patient under mechanical ventilation forever, which might seems a good idea at first, but I don’t think it’s feasible. Can you imagine a guy next to you on a plane with his snorkel? the smell of dry spit, and the feeling that you are in fact seated next to Darth Vader. Anyway…Of course there are lot of things you can do to decrease your rates of extubation failure, and the recently published meta-analysys by Kuriyama et al might bring new perspectives and consolidate an old practice to a common entity.
Post-extubation stridor (PES). You all heard it and heard of it! To have a tube placed on your throat is not the most physiological thing you can do to a body, and although we could spend hours here discussing the disadvantages of endotracheal intubation, today we’re gonna focus on a specific one, and probably the easiest to explain. The intubation act itself, specially those 2 attempts by the intern and the resident, can cause damage to the larynx and trachea, and having a tube for days in close contact with such noble structures only increases this damage, resulting in laryngeal edema. Fortunately, most of the time, this edema is self-limited and transient. However, some poor souls are not that lucky. One good thing is that we can identify the population with increased risk of laryngeal edema, naming : duration of intubation, gender (female), high cuff pressure, trauma patients, difficult intubation, tube to trachea ratio, excessive airway manipulation, among others. So, the incidence of PES varies depending on your population, but generally speaking, might be something around 15%.
Well, but does this really matter? I think it does. The reintubation rates for patients experiencing PES varies from 18 to 69%, and as I said, extubation failure sucks! OK. We know it sucks and we know the risk factors. Just one more little thing before moving on. The cuff leak test! For those unfamiliar with the subject: is a test used to predict the risk PES. Below there is a table adapted from Miller’s article  on how to perform the test:
If you have a difference in expiratory tidal volume grater than 110ml before x after the cuff deflation (positive test) you practically rule out PES (specificity=99% and negative predictive value=98%). However, you cannot rule in PES with a negative test. After all this jibber-jabber, we are left with the possibility of predicting who will face the apocalyptic horns of PES, and finally, here comes the recently published Chest meta-analysis.
The authors conducted a systematic review and meta-analysis to assess the efficacy of prophylactic corticosteroids in PES prevention. They searched for randomized controlled trials where steroids were given prior to elective extubation. Heterogeneity was assessed and the data was pooled using random effects model. Eleven trials were included (2472 patients), the most used drugs were dexamethasone and methylprednisolone (with all sorts of dosage). Unfortunately, only two trials were graded as ow risk of bias, and worse than that, the most common bias source among the trials was selective outcome reporting!
Post-extubation airway events (airway obstruction, laryngeal edema or stridor that occurred following extubation), reintubation and adverse effects were the primary outcomes. The forest plot for post-extubation airway events is seen below, showing a reduced incidence of events in patients treated with steroids (RR 0.43; 95% CI 0.29–0.66). This difference was mostly driven by trials of high risk patients (negative cuff leak test).
But, what we are really looking for is reintubation! Again, steroids were associated with reduced incidence of reintubation (RR 0.42; 95% CI 0.25–0.71), and the difference was again driven by trials of high risk patients (forest plot below). There was no difference in adverse effects.
Another interesting information: the meta-regression analysis showed an inverse relation between duration of mechanical ventilation and post-extubation airway events/reintubation, meaning, the shorter the duration of mechanical ventilation, greater the benefit of prophylactic steroids. The authors also threw up the number necessary to treat (NNT) during the discussion, but I won’t give’em to you. Why? Because I don’t think you should ever calculate the NNT in a meta analysis.
Was this an amazing-practice-changing meta-analysis? No, it was not. But I think they did what they could, and now, instead of being around with a dick in your hand while watching your patients failing due PES, you could do a few things. All right, I might have been too dramatic in the sense of painting PES as a nazi ICU bastard, but try to look at this way: PES is real, you know the risk factors, there is a test that practically rule it out, the treatment seems to have no severe adverse effects (ok, they were not scrutinized), most of the protocols use a short regimen of steroids, and the treatment seems to work. So, for a selected group of patients I really think it with trying. Besides, don’t lie to me, I know you all do it, even before this study! The only difference now is that you can vomit some meta-analysis data and impress some sleepless residents.
1. Kuriyama A, Umakoshi N, Sun R. Prophylactic corticosteroids for prevention of post-extubation stridor and reintubation in adults: a systematic review and meta-analysis. Chest. 2017.
2. Wittekamp BH, van Mook WN, Tjan DH, Zwaveling JH, Bergmans DC. Clinical review: post-extubation laryngeal edema and extubation failure in critically ill adult patients. Crit Care. 2009;13(6):233.
3. Miller RL, Cole RP. Association between reduced cuff leak volume and postextubation stridor. Chest. 1996;110(4):1035-1040.
4. Altman DG, Deeks JJ. Meta-analysis, Simpson’s paradox, and the number needed to treat. BMC Medical Research Methodology. 2002;2:3.