Oxygen desaturation and time burden during tracheobronchial endoscopy for suspected foreign body in toddlers

Tracheobronchial endoscopy with general anaesthesia for suspected foreign body aspiration exposes toddlers to acute hypoxemia. Better quantification of intraoperative hypoxemia could help identify and manage the most severe patients. We explored the hypoxic burden approach to account for both duration and depth of desaturation episodes during the procedure and determined risk factors for high hypoxic burden. We retrospectively analysed tracheobronchial endoscopies performed from September 2015 to September 2018 in children ≤ 36 months for suspected foreign body aspiration, in two French university hospitals. The hypoxic burden (area under 90% of the SpO₂/time curve) was calculated. The median of non-zero burdens was used to delineate a subgroup with high hypoxic burden. Risk factors for high hypoxic burden were identified using multivariable analysis. Of 96 procedures, 56 (58%) were associated with at least one SpO₂ value < 90%. Of them, the median [interquartile] hypoxic burden was 25 [5–87] %.min. Bradycardia < 100 bpm occurred in 11 procedures (11%). Initial admission to general hospitals (OR 0.23, 95% CI 0.06–0.86) and airway anaesthesia with topical lidocaine (OR 0.15, 95% CI 0.03–0.62) were associated with a reduced risk of high hypoxic burden. High hypoxic burden was associated with an increased risk of postoperative invasive ventilation (OR 32, 95% CI 1.7–617) and of hospital stay > 24 h (OR 4.0, 95% CI 1.6–10). No postoperative neurological sequelae were found. The hypoxic burden approach, when applied in tracheobronchial endoscopy for suspected foreign body aspiration in toddlers, enabled the quantification of hypoxemia and the search for specific risk factors.