Reasons behind failed prehospital intubation attempts while combining C-MAC videolaryngoscope and Frova introducer

Background High first-pass success rate is achieved with the routine use of C-MAC videolaryngoscope and Frova introducer. We aim to identify potential reasons and subgroups associated with failed intubation attempts, analyse actions taken after them and study possible complications. Methods We conducted a retrospective observational study of adult intubated patients at a single helicopter emergency medical service unit in southern Finland between 2016 and 2018. We collected data on patient characteristics, reasons for failed attempts, complications and follow-up measures from a national helicopter emergency medical service database and from prehospital patient records. Results 1011 tracheal intubations were attempted. First attempt was successful in 994 cases (FPS 994/1011, 98.3%), 15 needed a second or third attempt and two a surgical airway (non-FPS 17/1011, 1.7%, 95% CI 1.0-2.7). The failed first attempt group had heterogenous characteristics. The most common cause for a failed first attempt was obstruction of the airway by vomit, food, mucus or blood (10/13, 76%). After the failed first attempt, there were six cases (6/14, 43%) of deviation from the protocol and the most frequent complications were five cases (5/17, 29%) of hypoxia and four cases (4/17, 24%) of hypotension. Conclusions When a protocol combining the C-MAC videolaryngoscope and Frova introducer is used, the most common reason for a failed first attempt is an airway blocked by gastric content, blood or mucus. These findings highlight the importance of effective airway decontamination methods and questions the appropriateness of anatomically focused pre-intubation assessment tools when such protocol is used.