Journal article
Intubation biomechanics: Computational modeling to identify methods to minimize cervical spine motion and spinal cord strain during laryngoscopy and tracheal intubation in an intact cervical spine
Journal of clinical anesthesia, Vol.81, pp.110909-110909
10/2022
DOI: 10.1016/j.jclinane.2022.110909
PMID: 35738028
Abstract
To minimize the risk of cervical spinal cord injury in patients who have cervical spine pathology, minimizing cervical spine motion during laryngoscopy and tracheal intubation is commonly recommended. However, clinicians may better aim to reduce cervical spinal cord strain during airway management of their patients. The aim of this study was to predict laryngoscope force characteristics (location, magnitude, and direction) that would minimize cervical spine motions and cord strains.
We utilized a computational model of the adult human cervical spine and spinal cord to predict intervertebral motions (rotation [flexion/extension] and translation [subluxation]) and cord strains (stretch and compression) during laryngoscopy.
Routine direct (Macintosh) laryngoscopy conditions were defined by a specific force application location (mid-C3 vertebral body), magnitude (48.8 N), and direction (70 degrees). Sixty laryngoscope force conditions were simulated using 4 force locations (cephalad and caudad of routine), 5 magnitudes (25–200% of routine), and 3 directions (50, 70, 90 degrees).
Under all conditions, extension at Oc-C1 and C1-C2 were greater than in all other cervical segments. Decreasing force magnitude to values reported for indirect laryngoscopes (8–17 N) decreased cervical extension to ~50% of routine values. The cervical cord was most likely to experience potentially injurious compressive strain at C3, but force magnitudes ≤50% of routine (≤24.4 N) decreased strain in C3 and all other cord regions to non-injurious values. Changing laryngoscope force locations and directions had minor effects on motion and strain.
The model predicts clinicians can most effectively minimize cervical spine motion and cord strain during laryngoscopy by decreasing laryngoscope force magnitude. Very low force magnitudes (<5 N, ~10% of routine) are necessary to decrease overall cervical extension to <50% of routine values. Force magnitudes ≤24.4 N (≤50% of routine) are predicted to help prevent potentially injurious compressive cord strain.
•A computational model of the intact (normal) cervical spine and cord was used.•Spine motion and cord strain are mostly determined by laryngoscope force magnitude.•Indirect laryngoscopes are predicted to decrease cervical spine extension by ~50%.•Fiberoptic intubation is necessary to decrease extension to <50% of routine values.•Potentially injurious spinal cord strain is unlikely with indirect laryngoscopes.
Details
- Title: Subtitle
- Intubation biomechanics: Computational modeling to identify methods to minimize cervical spine motion and spinal cord strain during laryngoscopy and tracheal intubation in an intact cervical spine
- Creators
- Benjamin C. Gadomski - Colorado State UniversityBradley J. Hindman - Department of Anesthesia, University of Iowa Roy J. and Lucille A. Carver College of Medicine, 451 Newton Road, 200 Medicine Administration Building, Iowa City, IA 52242, United StatesMichael J. Poland - Colorado State UniversityMitchell I. Page - Colorado State UniversityFranklin Dexter - Department of Anesthesia, University of Iowa Roy J. and Lucille A. Carver College of Medicine, 451 Newton Road, 200 Medicine Administration Building, Iowa City, IA 52242, United StatesChristian M. Puttlitz - Colorado State University
- Resource Type
- Journal article
- Publication Details
- Journal of clinical anesthesia, Vol.81, pp.110909-110909
- Publisher
- Elsevier Inc
- DOI
- 10.1016/j.jclinane.2022.110909
- PMID
- 35738028
- ISSN
- 0952-8180
- eISSN
- 1873-4529
- Language
- English
- Date published
- 10/2022
- Academic Unit
- Health Management and Policy; Anesthesia
- Record Identifier
- 9984269060102771
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