A novel scale for predicting delayed intubation in patients with inhalation injury

•PDI score was developed to predict the need for delayed intubation after inhalation injury.•The score was validated to have higher discriminatory power than other scales.•4 of PDI score (0–6) was practical cut-off point with high negative predictive value. Strategies to predict delayed airway obstruction in patients with inhalation injury have not been extensively studied. This study aimed to develop a novel scale, predicting the need for Delayed Intubation after inhalation injury (PDI) score. We retrospectively identified patients with inhalation injury at four tertiary care centers in Japan between 2012 and 2018. We included patients aged 15 or older and excluded those intubated within 30 min after hospital arrival. Predictors for delayed intubation were identified with univariate analyses and scored on the basis of odds ratios. The PDI score was evaluated with the area under the receiver operating characteristic (AUROC) curve and compared with other scaling systems for burn injuries. Data from 158 patients were analyzed; of these patients, 18 (11.4%) were intubated during the delayed phase. Signs of respiratory distress, facial burn, and pharyngolaryngeal swelling observed on laryngoscopy, were identified as predictors for delayed intubation. The discriminatory power of the PDI (AUROC curve = 0.90; 95% confidence interval, 0.83 to 0.97; p < 0.01) was higher than that of the other scaling systems. We developed a novel scale for predicting delayed intubation in inhalation injury. The score should be further validated with other population.