Abstract
Introduction: Endotracheal intubation in the prehospital setting poses unique challengeswhere multiple ETI attempts are associated with adverse patient outcomes. Early identificationof difficult ETI cases will allow providers to tailor airway-man agement efforts to minimizecomplications associated with ETI. We sought to derive and validate a prehospital difficult airwayidentification tool based on predictors of difficult ETI in other settings. Methods: We prospectively collected patient and airway data on all airway attempts from 16Advanced Life Support ground emergency medical services agencies from January2011 to October 2014. Cases that required more than two ETI attempts and cases where analternative airway strategy was employed after one unsuccessful ETIattempt were categorized as “difficult.” We used a random allocation sequence to split the datainto derivation and validation subsets. Using backward elimination, factors with a p 3, limited neckmovement, trismus/jaw clenched, inability to palpate thelandmarks of the neck, and fluid in the airwa y such as blood or emesis. This was the most parsimonious model and exhibited good fit with an AUC of 0.68. When applied to the validatio n set,the model had an AUC of 0.63 with high specificity for identifying di fficult ETI if >2factors were present ). Conclusion: We have developed a simple tool using five factors that may aid p rehospitalproviders in the identification of difficult ETI.