Logo image
Back
Intubation Biomechanics: Clinical Implications of Computational Modeling of Intervertebral Motion and Spinal Cord Strain during Tracheal Intubation in an Intact Cervical Spine
Journal article   Open access   Peer reviewed

Intubation Biomechanics: Clinical Implications of Computational Modeling of Intervertebral Motion and Spinal Cord Strain during Tracheal Intubation in an Intact Cervical Spine

Benjamin C Gadomski, Bradley J Hindman, Mitchell I Page, Franklin Dexter and Christian M Puttlitz
Anesthesiology (Philadelphia), Vol.135(6), pp.1055-1065
12/01/2021
DOI: 10.1097/ALN.0000000000004024
PMCID: PMC8578403
PMID: 34731240
url
https://doi.org/10.1097/ALN.0000000000004024View
Published (Version of record) Open Access

Abstract

In a closed claims study, most patients experiencing cervical spinal cord injury had stable cervical spines. This raises two questions. First, in the presence of an intact (stable) cervical spine, are there tracheal intubation conditions in which cervical intervertebral motions exceed physiologically normal maximum values? Second, with an intact spine, are there tracheal intubation conditions in which potentially injurious cervical cord strains can occur? This study utilized a computational model of the cervical spine and cord to predict intervertebral motions (rotation, translation) and cord strains (stretch, compression). Routine (Macintosh) intubation force conditions were defined by a specific application location (mid-C3 vertebral body), magnitude (48.8 N), and direction (70 degrees). A total of 48 intubation conditions were modeled: all combinations of 4 force locations (cephalad and caudad of routine), 4 magnitudes (50 to 200% of routine), and 3 directions (50, 70, and 90 degrees). Modeled maximum intervertebral motions were compared to motions reported in previous clinical studies of the range of voluntary cervical motion. Modeled peak cord strains were compared to potential strain injury thresholds. Modeled maximum intervertebral motions occurred with maximum force magnitude (97.6 N) and did not differ from physiologically normal maximum motion values. Peak tensile cord strains (stretch) did not exceed the potential injury threshold (0.14) in any of the 48 force conditions. Peak compressive strains exceeded the potential injury threshold (-0.20) in 3 of 48 conditions, all with maximum force magnitude applied in a nonroutine location. With an intact cervical spine, even with application of twice the routine value of force magnitude, intervertebral motions during intubation did not exceed physiologically normal maximum values. However, under nonroutine high-force conditions, compressive strains exceeded potentially injurious values. In patients whose cords have less than normal tolerance to acute strain, compressive strains occurring with routine intubation forces may reach potentially injurious values.
 Biomechanical Phenomena - physiology Cervical Vertebrae - injuries Cervical Vertebrae - physiology Computer Simulation Humans Intubation, Intratracheal - adverse effects Intubation, Intratracheal - methods Laryngoscopy - adverse effects Laryngoscopy - methods Range of Motion, Articular - physiology Spinal Cord - physiology Spinal Cord Injuries - etiology Spinal Cord Injuries - physiopathology Spinal Cord Injuries - prevention & control Sprains and Strains - etiology Sprains and Strains - physiopathology Sprains and Strains - prevention & control

Details

Metrics

14 Record Views
8 Times Cited - Web of Science
Logo image