Predictors of laryngospasm during 276,832 episodes of pediatric procedural sedation
Cosgrove P, Krauss BS, Cravero JP, et al. Ann Emerg Med. Published online June 22, 2022. doi:10.1016/j.annemergmed.2022.05.002
Of all the potential complications of pediatric procedural sedation, laryngospasm is arguably the most serious, because it introduces risks of hypoxemia, intubation, bradycardia, aspiration, and cardiac arrest.
Essentially all previous publications on the topic have been underpowered, and meta-analyses are limited by differences in the medications used, patients enrolled, and outcome definitions.
In this study, the authors analyzed a large database of pediatric sedation, to quantify the prevalence of laryngospasm and identify biologically plausible predictors of laryngospasm.
This was a secondary analysis of the Pediatric Sedation Research Consortium (PSRC) multicenter database from 64 sites of various types, including academic hospitals, community hospitals, freestanding imaging centers, and even dental offices.
In this study, similarly to the National Emergency Airway Registry (NEAR) study, sites were mandated to submit data from more than 90% of pediatric procedural sedations performed in the selected area, to minimize selection bias.
Laryngospasm was defined as “complete or nearly complete lack of air movement with respiratory effort and with or without stridor, not relieved by chin repositioning or oral/nasal airway.”
As the title states, more than a quarter million sedations over a 7-year period are reported.
Overall, 913 children had laryngospasm, indicating an overall unadjusted prevalence of 3.3/1,000. The most common interventions were jaw thrust (73.9%) and bag-valve mask (54.3%); only 49 children (5.4%) received endotracheal intubation, and 7 (0.8%) received nasotracheal intubation; cardiac arrest occurred in 0.2%.
The authors performed a multivariable regression with laryngospasm as the dependent variable and many independent variables including age, American Society of Anesthesiologists category, presence of an upper respiratory infection, location of procedure, grouping of procedure (airway, painful, or other), and medication regimen.
The authors found that younger age, a higher American Society of Anesthesiologists category, a concurrent upper respiratory infection (aOR 3.94, 2.57-6.03; predicted probability 12.2/1,000, 6.3/1,000 to 18.0/1,000), and airway procedures (aOR 3.73, 2.33-5.98; predicted probability 9.6/1,000, 5.2/1,000 to 13.9/1,000) were associated with greater risk of laryngospasm.
Interestingly, propofol combination regimens were associated with greater risk than propofol alone (propofol plus ketamine: aOR 2.52, 1.41-4.50; propofol plus dexmedetomidine: aOR 2.10, 1.25-3.52).
The authors conducted several sensitivity analyses including limiting the population to ED patients, and ketofol remained a predictor of laryngospasm.
In terms of location, the ED had the lowest aOR for laryngospasm, and the endoscopy suite had the highest. By provider type, ED physicians had the lowest unadjusted laryngospasm prevalence (0 in their study), and anesthesiologists and intensivists had the highest.
This study used a large data set and excellent statistical methods. However, limitations include that the data are observational, so the findings might possibly have been due to unmeasured confounders; why certain medications were chosen for each instance is unclear; no controlling for site was performed; dosing data are not reported; and nearly half the sedations occurred in radiology departments.
Another consideration is that, although the identified high-risk features generated statistically significant increases in the odds, the absolute differences were very small, and laryngospasm was rare, thus making the clinical importance of the differences somewhat questionable.
EDITOR’S COMMENTARY: In this massive report of more than a quarter million pediatric sedations, the authors report statically higher odds of laryngospasm in younger kids and those with higher American Society of Anesthesiologists scores, respiratory infections, airway procedures, and treatment with combinations of sedation agents including ketofol. But the absolute differences were very small, bringing into question the magnitude of the clinical impact. Still, it’s good to be aware of these high-risk features before starting a sedation. I would be curious to know if other more common adverse events were also associated with sedation—such associations might really change the way I practice and the medications I choose.
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Sean R. - October 5, 2022 6:00 AM
One of the frequent EM:RAP contributors has noted that true laryngospasm occurs on the level of being case reportable and that the vast vast majority are not actual spasm but rather glottic closure that impedes breathing as well as BVM use and there is not VL documentation of seeing the cords slapping together in actual spasm. Listening to the episode their definition of laryngospasm seemed to focus on lack of air movement not relieved by chin repositioning or an OPA/NPA. I struggle a bit connecting the dots as to how this is by definition actual laryngospasm or how this combination of criteria is by default laryngospasm (obviously one has to make the leap that laryngospasm in the true sense of spasm exists) and not another etiology causing the symptoms.
Rosy K. - October 22, 2022 12:35 PM
With the N of this prospective study, and the 3/1000 rate, with ED prevalence being much lower ( underreporting, others biases , ?)
I think the clinical significance is not of absolute risk reduction but of how safe this procedure is. Kudos to the 1000s of authors and teachers who furthered the research , quality , and safety of this procedure.
Mike M. - November 16, 2022 2:42 PM
Totally agree with both above comments. The literature demonstrates overwhelmingly that laryngospasm, even using an extraordinarily generous definition, is even more extraordinarily rare.