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BACKGROUND: The Paediatric Difficult Intubation Collaborative identified multiple attempts and persistence with direct laryngoscopy as risk factors for complications in children with difficult tracheal intubations and subsequently engaged in initiatives to reduce repeated attempts and persistence with direct laryngoscopy in children. We hypothesised these efforts would lead to fewer attempts, fewer direct laryngoscopy attempts and decrease complications.

METHODS: Paediatric patients less than 18 years of age with difficult direct laryngoscopy were enrolled in the Paediatric Difficult Intubation Registry. We define patients with difficult direct laryngoscopy as those in whom (1) an attending or consultant obtained a Cormack Lehane Grade 3 or 4 view on direct laryngoscopy, (2) limited mouth opening makes direct laryngoscopy impossible, (3) direct laryngoscopy failed in the preceding 6 months, and (4) direct laryngoscopy was deferred due to perceived risk of harm or poor chance of success. We used a 5:1 propensity score match to compare an early cohort from the initial Paediatric Difficult Intubation Registry analysis (August 6, 2012-January 31, 2015, 785 patients, 13 centres) and a current cohort from the Registry (March 4, 2017-March 31, 2023, 3925 patients, 43 centres). The primary outcome was first attempt success rate between cohorts. Success was defined as confirmed endotracheal intubation and assessed by the treating clinician. Secondary outcomes were eventual success rate, number of attempts at intubation, number of attempts with direct laryngoscopy, the incidence of persistence with direct laryngoscopy, use of supplemental oxygen, all complications, and severe complications.

FINDINGS: First-attempt success rate was higher in the current cohort (42% vs 32%, OR 1.5 95% CI 1.3-1.8, p < 0.001). In the current cohort, there were fewer attempts (2.2 current vs 2.7 early, regression coefficient -0.5 95% CI -0.6 to -0.4, p < 0.001), fewer attempts with direct laryngoscopy (0.6 current vs 1.0 early, regression coefficient -0.4 95% CI -0.4 to 0.3, p < 0.001), and reduced persistence with direct laryngoscopy beyond two attempts (7.3% current vs 14.1% early, OR 0.5 95% CI 0.4-0.6, p < 0.001). Overall complication rates were similar between cohorts (19% current vs 20% early). Severe complications decreased to 1.8% in the current cohort from 3.2% in the early cohort (OR 0.55 95% CI 0.35-0.87, p = 0.011). Cardiac arrests decreased to 0.8% in the current cohort from 1.8% in the early cohort. We identified persistence with direct laryngoscopy as a potentially modifiable factor associated with severe complications.

INTERPRETATION: In the current cohort, children with difficult tracheal intubations underwent fewer intubation attempts, fewer attempts with direct laryngoscopy, and had a nearly 50% reduction in severe complications. As persistence with direct laryngoscopy continues to be associated with severe complications, efforts to limit direct laryngoscopy and promote rapid transition to advanced techniques may enhance patient safety.



Complications, Difficult airway, Intubation, Outcomes, Paediatric airway, Video laryngoscopy



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