Ultrasound is a readily-available technique used to identify accurate placement of an endotracheal tube (ETT) after an intubation attempt. There is limited research on using manipulation of the ETT to improve the diagnostic accuracy of ETT location confirmation. Our study sought to directly assess whether ETT twisting during the standard grayscale technique influenced the accuracy of intubation confirmation by ultrasound.
The study was performed using two different fresh cadavers. During each trial, the cadavers were randomized to either tracheal or esophageal intubation. Three blinded, ultrasound fellowship-trained sonographers assessed the location of the ETT post-intubation alternating between using either a technique with no ETT movement or a technique with ETT twisting. In the latter technique, the sonographers manipulated the ETT in using a side-to-side, twisting motion while performing the ultrasound exam. The study measured the accuracy of ETT location identification, time to identification, and sonographer confidence.
540 assessments were performed with equal numbers of tracheal and esophageal intubations. The accuracy of ultrasound using the static technique was 97.8% (95% CI 95.2% to 99.0%) and the accuracy using the ETT twisting technique was 100% (95% CI 98.6% to 100%). The ETT twisting group showed a faster time to identification with a mean time to identification of 4.97 s (95% CI 4.36 to 5.57 s) compared to 6.87 s (95% CI 6.30 to 7.44 s) for the static ETT group. Operator confidence was also higher in the ETT twisting group at 4.84/5.0 (95% CI 4.79 to 4.90) compared to 4.71/5.0 (95% CI 4.63 to 4.78) in the static ETT group.
There was no statistically significant difference in the accuracy of ETT location identification between the two groups. However, utilizing the ETT twisting technique showed a statistically significant improvement in the time to identification and sonographer confidence.