Mohammad Abboud, MD EM1
Article
S, Baydoun J, Bailey J, et al. A Prospective Evaluation of Transverse Tracheal Sonography During Emergent Intubation by Emergency Medicine Resident Physicians. J Ultrasound Med. 2017;36(10):2079-2085.
Takeaway (TRDL)
This study measured the sensitivity and specificity of transverse tracheal ultrasound in detecting successful intubation the hands of EM residents. This prospective cohort study demonstrated a sensitivity of 98.5% and a specificity of 75% of detecting successful endotracheal intubation. The differences of these outcomes was not statistically significant between training years 1-3. Of the 72 patients enrolled in this study, only 4 were interpreted as esophageal intubations, one of which was actually in the trachea. While an interesting study, this is not practice changing- we need a specificity of 100% when securing airways as anything less is unacceptable when dealing with life or death.
Background
Direct visualization of the ET tube passing through the vocal cords is currently the gold standard of intubation. ETCO2, breath sounds, ET tube condensation and chest wall rise are all reassuring signs of intubation. This is the first study to elucidate US utility in intubation among EM residents. Can ultrasound be used by EM residents to help confirm tube placement?
The Study
Type: Prospective Cohort
Population: County Hospital Patients requiring intubation via EM residents over the course of 2 years
Clinical Setting: Emergency Department, county teaching hospital with EM residents years 1-3
Exclusion Criteria: <18 yo patients, pregnant patients, patients with cervical spine immobilization or suspected c-spine injury, patients with anterior neck lesions, masses or lacerations. Patients who needed cricothyroid pressure or laryngeal manipulation were also excluded. Any patient undergoing CPR was also excluded.
Inclusion Criteria: All other patients who were in need of emergent intubation between December 2013 - December 2015.
Methods: Each resident received a 30 minute lecture on transverse ultrasonography during intubation and then had a hands on session afterward. During intubations, one resident was responsible for tube placement while another was responsible for managing the ultrasound. They were each blinded to each other by having the US screen turned away from the intubating resident and the US resident being turned away from the ETO2 monitor used as the gold standard. An intubation was considered endotracheal if there was the presence of hyper-echoic comet tail artifacts with posterior shadowing in the trachea. An intubation was considered esophageal if there was presence of a "second airway" adjacent to the trachea with hyper-echoic artifact.
Primary Endpoints: Accuracy of realtime bedside resident performed ultrasound in detecting endotracheal or esophageal intubation.
Secondary Endpoints: Comparing EM residents with different levels of training to determine whether greater experience had improved accuracy in determining tube placement.
Results: Of the 72 patients that were intubated, 68 were interpreted as correct tracheal placement and 4 were interpreted as esophageal (one of which was a false negative finding). The sensitivity and specificity were 98.5% (95% CI, 92.1%-99.9%) and 75% (95% CI, 19.4-99.4%), respectively. There was not any statistical difference between level of residency training and accuracy of tube placement using the ultrasound.