Cervical Spine Motion with Direct Laryngoscopy and Orotracheal Intubation

Background Cervical spine kinetics during airway manipulation are poorly understood. This study was undertaken to quantify the extent and distribution of segmental cervical motion produced by direct laryngoscopy and orotracheal intubation in human subjects without cervical abnormality. Methods Ten patients without clinical or radiographic evidence of cervical spine abnormality underwent laryngoscopy using a #3 Macintosh blade while under general anesthesia and neuromuscular blockade. Cervical motion was recorded with continuous lateral fluoroscopy. The intubation sequence was divided into distinct stages and the corresponding fluoroscopic images were digitized. Segmental motion, occiput through C5, was calculated for each stage using the digitized data. Results During exposure and laryngoscope blade insertion, minimal displacement of the skull base and rostral cervical vertebral bodies was observed. Visualization of the larynx created superior rotation of the occiput and C1 in the sagittal plane, and mild inferior rotation of C3-C5. C2 maintained nearneutral posture. This pattern of displacement resulted in extension at each motion segment, with the most significant motion produced at the occipitoatlantal and atlantoaxial joints (mean = 6.8 degrees and 4.7 degrees, respectively). Intubation created slight additional superior rotation at the occiput and C1, without substantial alteration in the posture of C2-C5. After laryngoscope removal, position trended toward baseline at all levels, although exact neutral posture was not regained. Conclusions This investigation quantifies the behavior of the normal cervical spine during direct laryngoscopy with a Macintosh blade. With this maneuver, the vast majority of cervical motion is produced at the occipitoatlantal and atlantoaxial joints. The subaxial cervical segments (C2-C5) are displaced only minimally. This study establishes a highly reliable and reproducible method for analyzing cervical motion in real time.

Download Full-text

Craniocervical Motion during Direct Laryngoscopy and Orotracheal Intubation with the Macintosh and Miller Blades

Anesthesiology ◽

10.1097/01.anes.0000291461.62404.46 ◽

2007 ◽

Vol 107 (6) ◽

pp. 884-891 ◽

Cited By ~ 24

Author(s):

Scott A. LeGrand ◽

Bradley J. Hindman ◽

Franklin Dexter ◽

Julie B. Weeks ◽

Michael M. Todd

Keyword(s):

Direct Laryngoscopy ◽

Sagittal Plane ◽

Macintosh Laryngoscope ◽

Cervical Vertebra ◽

Random Order ◽

Orotracheal Intubation ◽

Mean Difference ◽

Routine Practice ◽

Macintosh Blade ◽

Cervical Motion

Background Previous studies have characterized segmental craniocervical motion that occurs during direct laryngoscopy and intubation with a Macintosh laryngoscope blade. Comparable studies with the Miller blade have not been performed. The aim of this study was to compare maximal segmental craniocervical motion occurring during direct laryngoscopy and orotracheal intubation with Macintosh and Miller blades. Methods Eleven anesthetized and pharmacologically paralyzed patients underwent two sequential orotracheal intubations, one with a Macintosh blade and another with a Miller in random order. During each intubation, segmental craniocervical motion from the occiput to the fifth cervical vertebra (C5) was recorded using continuous lateral cinefluoroscopy. Single-frame images corresponding to the point of maximal cervical motion for both blade types were compared with a preintubation image. Using image analysis software, angular change in the sagittal plane at each of five intervertebral segments was compared between the Macintosh and Miller blades. Results Extension at occiput-C1 was greater with the Macintosh blade compared with the Miller (12.1 degrees +/- 4.9 degrees vs. 9.5 degrees +/- 3.8 degrees, respectively; mean difference = 2.7 degrees +/- 3.0 degrees; P = 0.012). Total craniocervical extension (occiput-C5) was also greater with the Macintosh blade compared with the Miller (28.1 degrees +/- 9.5 degrees vs. 23.2 degrees +/- 8.4 degrees, respectively; mean difference = 4.8 degrees +/- 4.4 degrees; P = 0.008). Conclusions Compared with the Macintosh, the Miller blade was associated with a statistically significant, but quantitatively small, decrease in cervical extension. This difference is likely too small to be important in routine practice.

Download Full-text

Cervical spine motion with direct laryngoscopy and orotracheal intubation

Journal of Emergency Medicine ◽

10.1016/s0736-4679(97)80815-3 ◽

1997 ◽

Vol 15 (2) ◽

pp. 263

Author(s):

Kenneth J Bramwell

Keyword(s):

Cervical Spine ◽

Direct Laryngoscopy ◽

Orotracheal Intubation ◽

Spine Motion

Download Full-text

Segmental cervical spine motion during orotracheal intubation of the intact and injured spine with and without external stabilization

Journal of Neurosurgery Spine ◽

10.3171/spi.2000.92.2.0201 ◽

2000 ◽

Vol 92 (2) ◽

pp. 201-206 ◽

Cited By ~ 17

Author(s):

Peter J. Lennarson ◽

Darin Smith ◽

Michael M. Todd ◽

Douglas Carras ◽

Paul D. Sawin ◽

...

Keyword(s):

Cervical Spine ◽

Orotracheal Intubation ◽

Segmental Motion ◽

Content Type ◽

Spine Motion ◽

Human Cadavers ◽

External Stabilization ◽

Caudal Level ◽

Video Fluoroscopy ◽

Fine Print

Object. The purpose of this study was to establish a cadaveric model for evaluating cervical spine motion in both the intact and injured states and to examine the efficacy of commonly used stabilization techniques in limiting that motion. Methods. Intubation was performed in fresh human cadavers with intact cervical spines, following the creation of a C4–5 posterior ligamentous injury. Movement of the cervical spine during direct laryngoscopy and intubation was recorded using video fluoroscopy and examined under the following conditions: 1) without external stabilization; 2) with manual in-line cervical immobilization; and 3) with Gardner—Wells traction. Subsequently, segmental motion of the occiput through C-5 (Oc—C5) was measured from digitized frames of the recorded video fluoroscopy. The predominant motion, at all levels measured in the intact spine, was extension. The greatest degree of motion occurred at the atlantooccipital (Oc—C1) junction, followed by the C1–2 junction, with progressively less motion at each more caudal level. After posterior destabilization was induced, the predominant direction of motion at C4–5 changed from extension to flexion, but the degree of motion remained among the least of all levels measured. Traction limited but did not prevent motion at the Oc—C1 junction, but neither traction nor immobilization limited motion at the destabilized C4–5 level. Conclusions. Cadaveric cervical spine motion accurately reflected previously reported motion in living, anesthetized patients. Traction was the most effective method of reducing motion at the occipitocervical junction, but none of the interventions significantly reduced movement at the subaxial site of injury. These findings should be considered when treating injured patients requiring orotracheal intubation.

Download Full-text

Manual In-line Stabilization Increases Pressures Applied by the Laryngoscope Blade during Direct Laryngoscopy and Orotracheal Intubation

Anesthesiology ◽

10.1097/aln.0b013e318190b556 ◽

2009 ◽

Vol 110 (1) ◽

pp. 24-31 ◽

Cited By ~ 71

Author(s):

Brandon G. Santoni ◽

Bradley J. Hindman ◽

Christian M. Puttlitz ◽

Julie B. Weeks ◽

Nathaniel Johnson ◽

...

Keyword(s):

Cervical Spine ◽

Direct Laryngoscopy ◽

Random Order ◽

Orotracheal Intubation ◽

Laryngoscope Blade ◽

Cervical Instability ◽

Cervical Spine Instability ◽

Pressure Application ◽

Glottic View ◽

Cervical Motion

Background Manual in-line stabilization (MILS) is recommended during direct laryngoscopy and intubation in patients with known or suspected cervical spine instability. Because MILS impairs glottic visualization, the authors hypothesized that anesthesiologists would apply greater pressure during intubations with MILS than without. Methods Nine anesthetized and pharmacologically paralyzed patients underwent two sequential laryngoscopies and intubations, one with MILS and one without, in random order. A transducer array along a Macintosh 3 laryngoscope blade continuously measured applied pressures, and glottic view was characterized. Results With MILS, glottic visualization was worse in six patients, and intubation failure occurred in two of these six patients. Maximum laryngoscope pressure at best glottic view was greater with MILS than without (717 +/- 339 mmHg vs. 363 +/- 121 mmHg, respectively; n = 8; P = 0.023). Other measures of pressure application also indicated comparable increases with MILS. Conclusion Pressures applied to airway tissues by the laryngoscope blade are secondarily transmitted to the cervical spine and result in cranio-cervical motion. In the presence of cervical instability, impaired glottic visualization and secondary increases in pressure application with MILS have the potential to increase pathologic cranio-cervical motion.

Download Full-text

Faculty Opinions recommendation of Cervical spine motion during tracheal intubation with manual in-line stabilization: direct laryngoscopy versus GlideScope videolaryngoscopy.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.7186957.7428055 ◽

2010 ◽

Author(s):

Miguel Arango

Keyword(s):

Cervical Spine ◽

Tracheal Intubation ◽

Direct Laryngoscopy ◽

Spine Motion

Download Full-text

Cervical Spine Motion in the Sagittal Plane II

Spine ◽

10.1097/00007632-199205000-00001 ◽

1992 ◽

Vol 17 (5) ◽

pp. 467-474 ◽

Cited By ~ 82

Author(s):

H. van Mameren ◽

H. Sanches ◽

J. Beursgens ◽

J. Drukker

Keyword(s):

Cervical Spine ◽

Sagittal Plane ◽

Spine Motion

Download Full-text

Increased Sagittal Plane Segmental Motion in the Lower Cervical Spine in Women With Chronic Whiplash-Associated Disorders, Grades I–II

Spine ◽

10.1097/01.brs.0000089525.59684.49 ◽

2003 ◽

Vol 28 (19) ◽

pp. 2215-2221 ◽

Cited By ~ 50

Author(s):

Eythor Kristjansson ◽

Gunnar Leivseth ◽

Paul Brinckmann ◽

Wolfgang Frobin

Keyword(s):

Cervical Spine ◽

Sagittal Plane ◽

Segmental Motion ◽

Lower Cervical Spine ◽

Whiplash Associated Disorders ◽

Chronic Whiplash

Download Full-text

Intertester Reliability and Validity of Motion Assessments During Lumbar Spine Accessory Motion Testing

Physical Therapy ◽

10.2522/ptj.20060179 ◽

2008 ◽

Vol 88 (1) ◽

pp. 43-49 ◽

Cited By ~ 32

Author(s):

Rob Landel ◽

Kornelia Kulig ◽

Michael Fredericson ◽

Bernard Li ◽

Christopher M Powers

Keyword(s):

Lumbar Spine ◽

Magnetic Resonance ◽

Sagittal Plane ◽

Magnetic Resonance Images ◽

Segmental Motion ◽

Segmental Mobility ◽

Spine Motion ◽

Mobile Segment ◽

Good Agreement

Background and PurposePosterior-anterior (PA) assessment of the lumbar spine correlates with radiographic signs of instability and can guide treatment choices, yet studies of the validity of lumbar PA assessments have not been conducted in vivo. The purposes of this study were to determine the intertester reliability of the PA examination in assessing intersegmental lumbar spine motion and to evaluate the validity of this procedure in vivo with dynamic magnetic resonance imaging (MRI).SubjectsTwenty-nine subjects with central lumbar pain participated in this study.MethodsTwo physical therapists independently identified each subject's most and least mobile lumbar segments using the PA procedure. Midsagittal lumbar images were obtained simultaneously during one examiner's assessment. Lumbar segmental mobility was quantified from magnetic resonance images as the change in the intervertebral angle between the resting position and the end range of the PA force application. For each vertebral level tested, maximal sagittal-plane segmental motion was determined.ResultsThe intertester reliability for identifying the least mobile segment was good (agreement=82.8%, kappa=.71, 95% confidence interval [CI]=.48 to .94), but it was poor for identifying the most mobile segment (kappa=.29, 95% CI=−.13 to .71), despite good agreement (79.3%). The level of agreement between the PA assessments and intervertebral motion measured by MRI was poor (kappa=.04, 95% CI=−.16 to .24, and kappa=.00, 95% CI=−.09 to .08, for the least and most mobile segments, respectively).Discussion and ConclusionDespite good intertester reliability for identifying the least mobile segment, PA assessments of lumbar segmental mobility did not agree with sagittal-plane motion measured by dynamic MRI. This finding calls into question the validity of the PA procedure for assessing intervertebral lumbar spine motion.

Download Full-text