Study Design. Human cadaveric study using various intubation devices in a cervical spine instability model.
Objective. We sought to evaluate various intubation techniques and determine which device results in the least cervical motion in the setting of a global ligamentous instability model.
Summary of Background Data. Many patients presenting with a cervical spine injury have other injuries that may require rapid airway management with endotracheal intubation. Secondary neurologic injuries may occur in these patients because of further displacement at the level of injury, vascular insult, or systemic decrease in oxygen delivery. The most appropriate technique for achieving endotracheal intubation in the patient with a cervical spine injury remains controversial.
Methods. A global ligamentous instability at the C5–C6 vertebral level was created in lightly embalmed cadavers. An electromagnetic motion analysis device (Liberty; Polhemus, Colchester, VT) was used to assess the amount of angular and linear translation in 3 planes during intubation trials with each of 4 devices (Airtraq laryngoscope, lighted stylet, intubating LMA, and Macintosh laryngoscope). The angular motions measured were flexion-extension, axial rotation, and lateral bending. Linear translation was measured in the medial-lateral (ML), axial, and anteroposterior planes. Intubation was performed by either an emergency medical technician or by a board-certified attending anesthesiologist. Both time to intubate as well as failure to intubate (after 3 attempts) were recorded.
Results. There was no significant difference shown with regards to time to successfully intubate using the various devices. It was shown that the highest failure-to-intubate rate occurred with use of the intubating LMA (ILMA) (23%) versus 0% for the others. In flexion/extension, we were able to demonstrate that the Lightwand (P = 0.005) and Airtraq (P = 0.019) resulted in significantly less angular motion than the Macintosh blade. In anterior/posterior translation, the Lightwand (P = 0.005), Airtraq (P = 0.024), and ILMA (P = 0.021) all caused significantly less linear motion than the Macintosh blade. In axial rotation, the Lightwand (P = 0.017) and Airtraq (P = 0.022) resulted in significantly less angular motion than the Macintosh blade. In axial translation (P = 0.037) and lateral bending (P = 0.003), the Lightwand caused significantly less motion than the Macintosh blade.
Conclusion. In a cadaver model of C5–C6 instability, the greatest amount of motion was caused by the most commonly used intubation device, the Macintosh blade. Intubation with the Lightwand resulted in significantly less motion in all tested parameters (other than ML translation) as compared with the Macintosh blade. It should also be noted that the Airtraq caused less motion than the Macintoshblade in 3 of the 6 tested planes. There were no significant differences in failure rate or the amount of time it took to successfully intubate in comparing these techniques. We therefore recommend the use of the Lightwand, followed by the Airtraq, in the setting of a presumed unstable cervical spine injury over the Macintosh laryngoscope.
Trauma patients are commonly intubated using a blade laryngoscope device. We were able to demonstrate that a Lightwand resulted in significantly less motion in all tested parameters (except ML plane translation) when compared with the Macintosh blade in an unstable C5–C6 injury model. The Airtraq Laryngoscope showed improvement over the Macintosh blade as well. There were no observed differences in either the failure to intubate rate or the time to intubate between these devices.
*University of Rochester/Strong Memorial Hospital, Rochester, NY
†University of Florida, Gainesville, FL
‡Hacettepe University, Ankara, Turkey
Address correspondence and reprint requests to Mark L. Prasarn, MD, 59 Lac Kine Dr, Rochester, NY 14618; E-mail: firstname.lastname@example.org
Acknowledgment date: December 9, 2010. Revision date: February 17, 2011. Acceptance date: May 2, 2011.
The device(s)/drug(s) is/are FDA approved or approved by the corresponding national agency for this indication.
Foundation funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.