Pre-Hospital Factors Predicting First-Attempt Intubation Success

Background: Effective pre-hospital endotracheal intubation is crucial in management of severe emergencies such as respiratory failure, cardiac arrest, and trauma, where first-pass success (FPS) markedly reduces complications such as hypoxia and cardiovascular instability. Objective: To identify critical predictors of FPS and evaluate the utility and limitations of the HEAVEN criteria within the authors’ prehospital setting. Materials and Methods: A retrospective analysis of 90 patients who underwent pre-hospital endotracheal intubation at the Narenthorn EMS Center, Rajavithi Hospital, was conducted between August and November 2023. Demographic data, the HEAVEN criteria, Cormack-Lehane classifications, sedative drugs, laryngoscopic equipment, and types of operator were analyzed using logistic regression to evaluate predictors of FPS. Results: FPS was achieved in 80% of cases. The patients, predominantly male, at 66.7%, had a mean age of 59.30±16.56 years. The primary indication for intubation was cardiac arrest, for 43.3% of the cases. Analysis highlighted the absence of anatomical challenges and a Cormack-Lehane classification Grade I as significant predictors of FPS (OR for Grade I 6.60, 95% CI 1.39 to 31.28, p=0.017). However, in multivariable analysis, no factors remained statistically significant. The HEAVEN criteria showed an AUROC of 0.549 (p=0.519). Conclusion: The present study found that the absence of anatomical challenges in the HEAVEN criteria together with laryngeal visualization grades significantly influenced FPS in pre-hospital endotracheal intubation in univariable analysis. However, in multivariable analysis, no factors remained statistically significant. The poor predictive performance of the HEAVEN criteria suggests the need for improved predictive models and specialized EMS training to effectively manage challenging airways.