Study objectives: We identify key factors affecting out-of-hospital intubation attempts. Methods: This was a retrospective review of consecutive patients transported by the primary ambulance service of a large Midwestern city. Patients were identified as requiring emergency intubation if they were newly unresponsive without a gag reflex, unresponsive with persistent pulse oximetry below 90%, or having a respiratory rate less than 10 breaths/min or greater than 30 breaths/min with persistent pulse oximetry below 90%. Analysis was done using a multiple regression model. Results: From March 2003 to June 2003, 386 transported patients required emergency intubation. Intubation was attempted in 42 (11%) patients and successful in 10 (24%, 95% confidence interval [CI] 11% to 37%), which is consistent with previous studies. Using a multiple regression model, 3 factors were identified that were associated with failure to attempt intubation when indicated: Glasgow Coma Scale (GCS) score of 9 or greater (odds ratio [OR] 18.2, 95% CI 6.5 to 29.9), failure to obtain intravenous access (OR 1.8, 95% CI 0.9 to 2.7), and performing bag-valve-mask or positive pressure ventilation (PPV) (OR 50.4, 95% CI 12.8 to 88.0). Although PPV is a temporizing measure, it does not provide a definitive airway. Whether or not it should preclude out-of-hospital intubation should be addressed prospectively, especially because more than 50% of patients had persistent pulse oximetry between 80% and 90% despite PPV. Out-of-hospital personnel may benefit from further training in optimal techniques for PPV. Likewise, although advanced trauma life support protocols use GCS score as an indication for intubation, it may not be the best indication of the need for intubation, because many patients had GCS score greater than 9 but were in respiratory failure, which suggests an area for further education. Finally, the ability to establish intravenous access was a weak but persistent factor affecting intubation attempts and may be an important area for ongoing training. Conclusion: GCS score of 9 or greater, the ability to obtain intravenous access, and performing PPV were 3 factors affecting intubation attempts and may be important areas for the further training of out-of-hospital personnel.
Read full abstract