Direct laryngoscopy and endotracheal intubation is an indispensable procedure in contemporary healthcare, with millions of patients being intubated each year. Because intubation invariably results in cervical spine movement, it is considered to be hazardous in patients with cervical spine instability, carrying a risk of catastrophic spinal cord injury (quadriplegia or death). Our long-term goal is to increase the safety of endotracheal intubation in patients with cervical spine instability. Current clinical standards for intubation in the presence of cervical spine instability are not evidence-based because, in large part, previous studies have not studied intubation from a biomechanical perspective. The relationships between forces applied to the peri-airway tissues and cervical spine during intubation and the resulting motion are not known. Consequently, it is not known (1) which forms of cervical spine instability present the greatest risk of neurologic sequelae, and (2) which intubation techniques and devices minimize cervical spine movement and the possibility of spinal cord compression. To fill this knowledge gap, the aims of this project are to quantify the pattern of cervical spine motion that results from the specific forces applied to the peri-airway tissues during intubation. We will simultaneously measure cervical spine motion (lateral x-rays), applied forces (force-sensing laryngoscopes), and view of the airway (video) during intubation. These measurements will be made in (1) living anesthetized humans with stable spines and (2) in cadavers with stable and unstable spines. We will then utilize all of the information derived from these studies to complete and verify a three-dimensional model of the human cervical spine. The model will be used to (1) indentify which types of cervical spine instability are most dangerous in terms of intubation, (2) determine how current and future intubation devices can be most safely used to accomplish intubation while minimizing dangerous motion, and (3) develop new protocols that ultimately lead to safer patients intubations in the presence of unstable cervical spines.

Public Health Relevance

Endotracheal intubation is an essential procedure, however, when the cervical spine is unstable, it can sometimes cause permanent paralysis. The goal of this research is to better understand how the stable and unstable spine moves during intubation using both physical experiments and computational modeling. The acquired information and new protocols developed in this study will help physicians to more safely accomplish intubation in patients with an unstable cervical spine.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB012048-03
Application #
8440797
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Peng, Grace
Project Start
2011-05-15
Project End
2015-02-28
Budget Start
2013-03-01
Budget End
2014-02-28
Support Year
3
Fiscal Year
2013
Total Cost
$202,949
Indirect Cost
$43,507
Name
Colorado State University-Fort Collins
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
785979618
City
Fort Collins
State
CO
Country
United States
Zip Code
80523
Shetye, Snehal S; Troyer, Kevin L; Streijger, Femke et al. (2014) Nonlinear viscoelastic characterization of the porcine spinal cord. Acta Biomater 10:792-7
Hindman, Bradley J; Santoni, Brandon G; Puttlitz, Christian M et al. (2014) Intubation biomechanics: laryngoscope force and cervical spine motion during intubation with Macintosh and Airtraq laryngoscopes. Anesthesiology 121:260-71
Shetye, Snehal S; Deault, Matthew M; Puttlitz, Christian M (2014) Biaxial response of ovine spinal cord dura mater. J Mech Behav Biomed Mater 34:146-53
Santoni, Brandon G; Ehrhart, Nicole; Betancourt-Benitez, Ricardo et al. (2012) Quantifying massive allograft healing of the canine femur in vivo and ex vivo: a pilot study. Clin Orthop Relat Res 470:2478-87