Effects of cervical spine immobilization technique and laryngoscope blade selection on an unstable cervical spine in a cadaver model of intubation

Lack of Association between Cervical Spine Injuries and Prehospital Immobilization: From Tradition to Evidence

Background: Cervical spine (C-spine) trauma usually results from blunt injuries and is traditionally managed by prehospital spinal immobilization using a cervical collar. We sought to examine if prehospital C-spine immobilization is associated with actual C-spine injuries and what factors are associated with the decision to immobilize the C-spine. Methods: We retrospectively analyzed blunt trauma patients treated by Israeli Defense Force (IDF) medical teams from 2015 to 2020. Children, penetrating injuries, and non-threatening injuries were excluded. Demographic data, injury characteristics, and prehospital information were collected from the IDF Trauma Registry's electronic medical records and merged with corresponding hospital data from the Israeli National Trauma Registry. Results: Overall, 220 patients were included, with a mean age of 32 and a predominance of male patients (78%). Most injuries were due to motor vehicle collisions (77%). In total, 40% of the patients received a cervical collar. C-spine injuries were present in 8%, of which 50% were immobilized with a cervical collar. There were no significant differences in the incidences of C-spine injuries or disability outcomes with or without collar immobilization. The use of a collar was significantly associated with backboard immobilization (OR = 14.5, p < 0.001) and oxygen use (OR = 2.5, p = 0.032). Conclusions: Prehospital C-spine immobilization was not associated with C-spine injury or neurological disability incidences. C-spine immobilization by medical providers may be influenced by factors other than the suspected presence of a C-spine injury, such as the use of a backboard. Clear clinical guidelines for inexperienced medical providers are called for.

Airway management in patients with suspected or confirmed cervical spine injury: Guidelines from the Difficult Airway Society (DAS), Association of Anaesthetists (AoA), British Society of Orthopaedic Anaesthetists (BSOA), Intensive Care Society (ICS), Neuro Anaesthesia and Critical Care Society (NACCS), Faculty of Prehospital Care and Royal College of Emergency Medicine (RCEM)

BACKGROUND

There are concerns that airway management in patients with suspected or confirmed cervical spine injury may exacerbate an existing neurological deficit, cause a new spinal cord injury or be hazardous due to precautions to avoid neurological injury. However, there are no evidence-based guidelines for practicing clinicians to support safe and effective airway management in this setting.

METHODS

An expert multidisciplinary, multi-society working party conducted a systematic review of contemporary literature (January 2012-June 2022), followed by a three-round Delphi process to produce guidelines to improve airway management for patients with suspected or confirmed cervical spine injury.

RESULTS

We included 67 articles in the systematic review, and successfully agreed 23 recommendations. Evidence supporting recommendations was generally modest, and only one moderate and two strong recommendations were made. Overall, recommendations highlight key principles and techniques for pre-oxygenation and facemask ventilation; supraglottic airway device use; tracheal intubation; adjuncts during tracheal intubation; cricoid force and external laryngeal manipulation; emergency front-of-neck airway access; awake tracheal intubation; and cervical spine immobilisation. We also signpost to recommendations on pre-hospital care, military settings and principles in human factors.

CONCLUSIONS

It is hoped that the pragmatic approach to airway management made within these guidelines will improve the safety and efficacy of airway management in adult patients with suspected or confirmed cervical spine injury.

Our experience with the surgical management of lower cervical spine fractures: fifty case series

PURPOSE

Trauma to the lower cervical spine is a serious lesion due to its neurological consequences which jeopardize the vital and functional prognosis. They constitute a public health problem due to their frequency and seriousness requiring rapid and adequate treatment. The aim of our study is to (1) describe the epidemiological, clinical, and radiological characteristics of lower cervical spine trauma patients; (2) support the therapeutic management of these patients and show our experience in surgery for lower cervical spine trauma; and (3) analyze the anatomical and functional results and discuss them with literature data.

METHODS

This is a retrospective descriptive study of 50 patients with lower cervical spine trauma treated surgically over a period of five years from January 1, 2016, to December 2020.

RESULTS

The average age of our patients was 34.5 years, with a sex ratio of 1.7. The etiologies are dominated by accidents on public roads (58%). They show neurological disorders such as spinal cord damage in 30% of cases and root damage in 20% of cases. The radiological assessment revealed eight tear drops, ten comminuted fractures, 12 severe sprains, 12 biarticular dislocations, six uniarticular dislocations, and two herniated discs. Treatment was surgical in all patients with an anterolateral approach and anterior arthrodesis. The evolution was favourable in 21 patients and stationary in 29 patients.

CONCLUSION

Our study concluded that dislocations and fracture dislocations were the predominant type of injury in cases of AVP. Tetraplegia was mainly observed with uni- and biarticular dislocations. The variation in consolidation time was not correlated with trauma-to-surgery time. Better neurological recovery was observed with mild initial neurological damage than with initially severe damage. The appearance of an adjacent syndrome is less frequent with monosegmental arthrodesis than with multisegmental arthrodesis. Cage arthrodesis was an alternative to iliac harvesting with similar results.

A novel technique of handling the blade for videolaryngoscopy intubation in patients with a semi-rigid neck collar: a prospective randomized controlled trial

BACKGROUND

Semi-rigid neck collars to protect the cervical spine can limit the extent of neck movement and mouth opening; this may further complicate orotracheal intubation. We aimed to compare intubation environments obtained with videolaryngoscopy using the technique of gliding a blade under the epiglottis and that obtained using the conventional Macintosh blade technique of blade tip placement on the vallecula.

METHODS

This prospective randomized study included patients aged ≥ 20 years with American Society of Anesthesiologists physical status I-III scheduled for cervical spine surgery between October 2020 and August 2021. Patients were divided into two groups according to the placement of the blade of the McGrathTM videolaryngoscope: the gliding and conventional groups. The percentage of glottic opening (POGO) score was the primary endpoint. We also recorded the time to obtain the optimal laryngoscopic view, intubation duration, and ease and satisfaction of the researcher performing intubation.

RESULTS

Among 176 patients, the POGO scores were significantly higher in the gliding group than in the conventional group (88.9 ± 14.7 vs. 63.8 ± 27.4, P < 0.001). The time to achieve the optimal glottic view for intubation and duration of intubation were also shorter, and ease and satisfaction in performing intubation were better in the gliding group than in the conventional group.

CONCLUSION

Our findings demonstrated a superior glottic view and more favorable intubation environments when the blade tip was placed under the epiglottis than using the conventional Macintosh technique in patients with immobilized cervical spine.

Airway Management of Suspected Traumatic Brain Injury Patients in the Emergency Room

The patients of trauma offers a special challenge because of the associated head injury, maxillofacial, neck and spine injuries, which puts the airway at imminent risk. The response time for the emergency team to initiate the airway management determines the outcome of the individual undergoing treatment. A judious implementatin of triage and ATLS guidelines are helpful in the allocation of resources in airway management of trauma patients. One must not get distracted with the severity of other organ systems because cerebral tissue permits a low threshold to the hypoxic insults. Adequate preparedness and a team effort result in better airway management and improved outcomes in trauma patients with variable hemodynamic response to resuscitation. All possible efforts must be made to secure a definitive airway (if required) and should be verified clinically as well as with the available adjuncts. The success of a trauma team depends on the familiarity to the airways devices and their discrete application in various situations.

Intubation during spinal motion restriction using the LuboTM cervical collar - a manikin simulation study

Introduction

The Lubo^TM collar is a cervical motion restriction device featuring a unique external jaw-thrust mechanism designed to provide non-invasive airway patency. In addition, tracheal intubation is facilitated by releasing an anterior chin strap; this allows better mouth opening than the previous generation of semi-rigid cervical collars. This study aimed to compare tracheal intubation using the Lubo^TM collar combined with manual in-line stabilization (MILS) to intubation with MILS alone. The primary outcome was the time to successful intubation. Secondary outcomes compared intubation success rate, Cormack-Lehane grade, ease of intubation and dental trauma.

Methods

A randomized, cross-over, equivalence study was performed. Eighty full-time physician anaesthesia providers were recruited. Participants performed tracheal intubation using direct laryngoscopy on a manikin under two different scenarios: with the Lubo^TM collar and MILS applied, and with MILS and no cervical collar. The time to successful intubation was measured and compared using two-one-sided and paired t-tests.

Results

Intubation times fell well within the a priori equivalence limits of 10 seconds, with a mean difference (95% CI) of 0.52 seconds (-1.30 to 2.56). There was no significant difference in intubation time with the Lubo^TM collar (mean [SD] 19.2 [4.5] seconds) compared to the MILS alone group (19.7 [5.2] seconds). The overall success rate was 98.7% in the Lubo group and 100% in the MILS group. Adequate laryngoscopy views (Cormack-Lehane grades I to IIb) were equivalent between groups (Lubo 92.5% versus MILS alone 93.7%).

Conclusion

In this manikin-based study, the time to intubation with the Lubo^TM collar and MILS applied was equivalent to time to intubation with MILS alone, with similar intubating conditions. Thus, the Lubo^TM collar and MILS may simplify airway management by reducing the number of steps required to perform intubation in patients requiring cervical motion restriction.

Comparison of video-stylet and conventional laryngoscope for endotracheal intubation in adults with cervical spine immobilization: A PRISMA-compliant meta-analysis

BACKGROUND

Although minimization of cervical spine motion by using a neck collar or manual in-line stabilization is recommended for urgent tracheal intubation (TI) in patients with known or suspected cervical spine injury (CSI), it may worsen glottic visualization. The overall performance of video-stylets during TI in patients with neck immobilization remains unclear. The current meta-analysis aimed at comparing the intubation outcomes of different video-stylets with those of conventional laryngoscopes in patients with cervical immobilization.

METHOD

The databases of Embase, Medline, and the Cochrane Central Register of Controlled Trials were searched from inception to June 2021 to identify trials comparing intubation outcomes between video-stylets and conventional laryngoscopes. The primary outcome was first-pass success rate, while secondary outcomes included overall success rate, time to intubation, the risk of intubation-associated sore throat, or tissue damage.

RESULTS

Five randomized controlled trials published between 2007 and 2013 involving 487 participants, all in an operating room setting, were analyzed. The video-stylets investigated included Bonfils intubation fiberscope, Levitan FPS Scope, and Shikani optical stylet. There was no difference in first-pass success rate (risk ratio [RR] =1.08, 95% confidence interval [CI]: 0.89-1.31, P = .46], overall success rate (RR = 1.06, 95% CI: 0.93-1.22, P = .4), intubation time [mean difference = 4.53 seconds, 95% CI: -8.45 to 17.51, P = .49), and risk of tissue damage (RR = 0.46, 95% CI: 0.16-1.3, P = .14) between the 2 groups. The risk of sore throat was lower with video-stylets compared to that with laryngoscopes (RR = 0.45, 95% CI: 0.23-0.9, P = .02).

CONCLUSION

Our results did not support the use of video-stylets as the first choice for patients with neck immobilization. Further studies are required to verify the efficacy of video-stylets in the nonoperating room setting.

The PHOENIX: Design and Development of a Three-Dimensional-Printed Drone Prototype and Corresponding Simulation Scenario Based on the Management of Cardiac Arrest

Sudden cardiac arrest (SCA) remains one of the most prevalent cardiovascular emergencies in the world. The development of international protocols and the use of accessible devices such as automated external defibrillators (AEDs) allowed for the standardization and organization of medical care related to SCA. When defibrillation is performed within five minutes of starting ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT), the victim survival rate has increased considerably. Therefore, training healthcare professionals to use AEDs correctly is essential to improve patient outcomes and response time in the intervention. In this technical report, we advocate simulation-based education as a teaching methodology and an essential component of drone adaptation, novel technology, that can deliver AEDs to the site, as well as a training scenario to teach healthcare professionals how to operate the real-time communication components of drones and AEDs efficiently. Studies have suggested that simulation can be an effective way to train healthcare professionals. Through teaching methodology using simulation, training these audiences has the potential to reduce the response time to intervention, consequently, increasing the patient's chance of surviving.

Effectiveness of intubation devices in patients with cervical spine immobilisation: a systematic review and network meta-analysis

BACKGROUND

Cervical spine immobilisation increases the difficulty of tracheal intubation. Many intubation devices have been evaluated in this setting, but their relative performance remains uncertain.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomised trials comparing two or more intubation devices in adults with cervical spine immobilisation. After critical appraisal, a random-effects network meta-analysis was used to pool and compare device performance. The primary outcome was the probability of first-attempt intubation success (first-pass success). For relative performance, the Macintosh direct laryngoscopy blade was chosen as the reference device.

RESULTS

We included 80 trials (8039 subjects) comparing 26 devices. Compared with the Macintosh, McGrath™ (odds ratio [OR]=11.5; 95% credible interval [CrI] 3.19-46.20), C-MAC D Blade™ (OR=7.44; 95% CrI, 1.06-52.50), Airtraq™ (OR=5.43; 95% CrI, 2.15-14.2), King Vision™ (OR=4.54; 95% CrI, 1.28-16.30), and C-MAC™ (OR=4.20; 95% CrI=1.28-15.10) had a greater probability of first-pass success. This was also true for the GlideScope™ when a tube guide was used (OR=3.54; 95% CrI, 1.05-12.50). Only the Airway Scope™ had a better probability of first-pass success compared with the Macintosh when manual-in-line stabilisation (MILS) was used as the immobilisation technique (OR=7.98; 95% CrI, 1.06-73.00).

CONCLUSIONS

For intubation performed with cervical immobilisation, seven devices had a better probability of first-pass success compared with the Macintosh. However, more studies using MILS (rather than a cervical collar or other alternative) are needed, which more accurately represent clinical practice.

CLINICAL TRIAL REGISTRATION

PROSPERO 2019 CRD42019158067 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=158067).

GlideScope versus D-blade for tracheal intubation in cervical spine patients: A randomised controlled trial

Background and Aims

Airway management in patients with cervical spine pathology is challenging. The aim of the study was to evaluate GlideScope (GVL) and D blade of C-MAC (CMAC-D) using manual inline axial stabilisation (MIAS) for tracheal intubation in patients with cervical spine injury/pathology.

Methods

This is a randomised, single-blind, hospital-based study. After obtaining informed consent, 54 patients with cervical spine pathology/injury were grouped into GVL group or CMAC-D group, (n = 27 each) based on computer-generated random number table. Preoperative airway difficulty score (ADS) was calculated. The primary outcome of the study was intubation difficulty score (IDS) and the secondary outcomes included total time taken to secure airway, failure to intubate, haemodynamic parameters and adverse events. Data was represented in the form of number (%) or mean and standard deviation and median and interquartile range as appropriate. Chi square test was used for analysing IDS.

Results

The mean ± SD of IDS of the CMAC-D and GVL groups were 0.04 ± 0.2 (0.04-0.11) and 0.19 ± 0.40 (0.03-0.34), respectively, (P value = 0.096). The number (%) of patients with IDS > 0 was 1 (3.7) in CMAC-D and 5 (18.5) in GVL group, (P value = 0.192). Demographic data, ADS, Cormack-Lehane grading, success rate, time of tracheal intubation, type of surgeries, haemodynamic parameters and post-operative complications were similar in both the groups.

Conclusion

Both GVL and CMAC-D with MIAS are equally efficacious in tracheal intubation in cervical spine injury/pathology patients without other difficult airway management criteria.

Intubation biomechanics: validation of a finite element model of cervical spine motion during endotracheal intubation in intact and injured conditions

OBJECTIVE

Because of limitations inherent to cadaver models of endotracheal intubation, the authors’ group developed a finite element (FE) model of the human cervical spine and spinal cord. Their aims were to 1) compare FE model predictions of intervertebral motion during intubation with intervertebral motion measured in patients with intact cervical spines and in cadavers with spine injuries at C-2 and C3–4 and 2) estimate spinal cord strains during intubation under these conditions.

METHODS

The FE model was designed to replicate the properties of an intact (stable) spine in patients, C-2 injury (Type II odontoid fracture), and a severe C3–4 distractive-flexion injury from prior cadaver studies. The authors recorded the laryngoscope force values from 2 different laryngoscopes (Macintosh, high intubation force; Airtraq, low intubation force) used during the patient and cadaver intubation studies. FE-modeled motion was compared with experimentally measured motion, and corresponding cord strain values were calculated.

RESULTS

FE model predictions of intact intervertebral motions were comparable to motions measured in patients and in cadavers at occiput–C2. In intact subaxial segments, the FE model more closely predicted patient intervertebral motions than did cadavers. With C-2 injury, FE-predicted motions did not differ from cadaver measurements. With C3–4 injury, however, the FE model predicted greater motions than were measured in cadavers. FE model cord strains during intubation were greater for the Macintosh laryngoscope than the Airtraq laryngoscope but were comparable among the 3 conditions (intact, C-2 injury, and C3–4 injury).

CONCLUSIONS

The FE model is comparable to patients and cadaver models in estimating occiput–C2 motion during intubation in both intact and injured conditions. The FE model may be superior to cadavers in predicting motions of subaxial segments in intact and injured conditions.

Anesthetic considerations for patients with acute cervical spinal cord injury

Anesthesiologists work to prevent or minimize secondary injury of the nervous system and improve the outcome of medical procedures. To this end, anesthesiologists must have a thorough understanding of pathophysiology and optimize their skills and equipment to make an anesthesia plan. Anesthesiologists should conduct careful physical examinations of patients and consider neuroprotection at preoperative interviews, consider cervical spinal cord movement and compression during airway management, and suggest awake fiberoptic bronchoscope intubation for stable patients and direct laryngoscopy with manual in-line immobilization in emergency situations. During induction, anesthesiologists should avoid hypotension and depolarizing muscle relaxants. Mean artery pressure should be maintained within 85-90 mmHg (1 mmHg = 0.133 kPa; vasoactive drug selection and fluid management). Normal arterial carbon dioxide pressure and normal blood glucose levels should be maintained. Intraoperative neurophysiological monitoring is a useful option. Anesthesiologists should be attentive to postoperative respiratory insufficiency (carefully considering postoperative extubation), thrombus, and infection. In conclusion, anesthesiologists should carefully plan the treatment of patients with acute cervical spinal cord injuries to protect the nervous system and improve patient outcome.

Intubation biomechanics: laryngoscope force and cervical spine motion during intubation in cadavers—effect of severe distractive-flexion injury on C3–4 motion

OBJECTIVE

With application of the forces of intubation, injured (unstable) cervical segments may move more than they normally do, which can result in spinal cord injury. The authors tested whether, during endotracheal intubation, intervertebral motion of an injured C3–4 cervical segment 1) is greater than that in the intact (stable) state and 2) differs when a high- or low-force laryngoscope is used.

METHODS

Fourteen cadavers underwent 3 intubations using force-sensing laryngoscopes while simultaneous cervical spine motion was recorded with lateral fluoroscopy. The first intubation was performed with an intact cervical spine and a conventional high-force line-of-sight Macintosh laryngoscope. After creation of a severe C3–4 distractive-flexion injury, 2 additional intubations were performed, one with the Macintosh laryngoscope and the other with a low-force indirect video laryngoscope (Airtraq), used in random order.

RESULTS

During Macintosh intubations, between the intact and the injured conditions, C3–4 extension (0.3° ± 3.0° vs 0.4° ± 2.7°, respectively; p = 0.9515) and anterior-posterior subluxation (−0.1 ± 0.4 mm vs −0.3 ± 0.6 mm, respectively; p = 0.2754) did not differ. During Macintosh and Airtraq intubations with an injured C3–4 segment, despite a large difference in applied force between the 2 laryngoscopes, segmental extension (0.4° ± 2.7° vs 0.3° ± 3.3°, respectively; p = 0.8077) and anterior-posterior subluxation (0.3 ± 0.6 mm vs 0.0 ± 0.7 mm, respectively; p = 0.3203) did not differ.

CONCLUSIONS

The authors' hypotheses regarding the relationship between laryngoscope force and the motion of an injured cervical segment were not confirmed. Motion-force relationships (biomechanics) of injured cervical intervertebral segments during endotracheal intubation in cadavers are not predicted by the in vitro biomechanical behavior of isolated cervical segments. With the limitations inherent to cadaveric studies, the results of this study suggest that not all forms of cervical spine injury are at risk for pathological motion and cervical cord injury during conventional high-force line-of-sight intubation.

Intubation Biomechanics: Laryngoscope Force and Cervical Spine Motion during Intubation in Cadavers-Cadavers versus Patients, the Effect of Repeated Intubations, and the Effect of Type II Odontoid Fracture on C1-C2 Motion

BACKGROUND

The aims of this study are to characterize (1) the cadaver intubation biomechanics, including the effect of repeated intubations, and (2) the relation between intubation force and the motion of an injured cervical segment.

METHODS

Fourteen cadavers were serially intubated using force-sensing Macintosh and Airtraq laryngoscopes in random order, with simultaneous cervical spine motion recorded with lateral fluoroscopy. Motion of the C1-C2 segment was measured in the intact and injured state (type II odontoid fracture). Injured C1-C2 motion was proportionately corrected for changes in intubation forces that occurred with repeated intubations.

RESULTS

Cadaver intubation biomechanics were comparable with those of patients in all parameters other than C2-C5 extension. In cadavers, intubation force (set 2/set 1 force ratio = 0.61; 95% CI, 0.46 to 0.81; P = 0.002) and Oc-C5 extension (set 2 - set 1 difference = -6.1 degrees; 95% CI, -11.4 to -0.9; P = 0.025) decreased with repeated intubations. In cadavers, C1-C2 extension did not differ (1) between intact and injured states; or (2) in the injured state, between laryngoscopes (with and without force correction). With force correction, in the injured state, C1-C2 subluxation was greater with the Airtraq (mean difference 2.8 mm; 95% CI, 0.7 to 4.9 mm; P = 0.004).

CONCLUSIONS

With limitations, cadavers may be clinically relevant models of intubation biomechanics and cervical spine motion. In the setting of a type II odontoid fracture, C1-C2 motion during intubation with either the Macintosh or the Airtraq does not appear to greatly exceed physiologic values or to have a high likelihood of hyperextension or direct cord compression.

Cervical Spine Motion During Airway Management Using Two Manual In-line Immobilization Techniques: A Human Simulator Model Study

OBJECTIVE

The aim of this study is to evaluate cervical spine motion using 2 manual inline immobilization techniques with the use of a human simulator model.

METHODS

Medical students, pediatric and family practice residents, and pediatric emergency medicine fellows were recruited to maintain cervical manual in line immobilization above the head of the bed and across the chest of a human simulator while orotracheal intubation was performed. Participants were then instructed on appropriate holding techniques after the initial session took place. Orotracheal intubation followed. A tilt sensor measured time to intubation and cervical extension and rotation angle.

RESULTS

Seventy-one subjects participated in a total of 284 successful orotracheal intubations. No change in cervical spine movement or time to intubation was observed when using 2 different inline manual immobilization techniques with no training. However, a statistically significant difference with assistants above the head versus across the chest was observed after training in: extension 2.1° (95% confidence interval [95% CI], 1.15 to 3.00; P < 0.0001); rotation 0.7° (95% CI, 0.26 to 1.19; P = 0.003) and intubation time of -1.9 seconds (95% CI, -3.45 to -0.13; P = 0.035) after training.

CONCLUSIONS

Cervical spine movement did not change when maintaining cervical spine immobilization from above the head versus across the chest before training. There was a statistically significant change in extension and rotation when assistants were above the head and in time to intubation when assistants were across the chest after training. The clinical significance of these results is unclear.

Alternative intubation techniques vs Macintosh laryngoscopy in patients with cervical spine immobilization: systematic review and meta-analysis of randomized controlled trials

Background. Immobilization of the cervical spine worsens tracheal intubation conditions. Various intubation devices have been tested in this setting. Their relative usefulness remains unclear.

Methods. We searched MEDLINE, EMBASE, and the Cochrane Library for randomized controlled trials comparing any intubation device with the Macintosh laryngoscope in human subjects with cervical spine immobilization. The primary outcome was the risk of tracheal intubation failure at the first attempt. Secondary outcomes were quality of glottis visualization, time until successful intubation, and risk of oropharyngeal complications.

Results. Twenty-four trials (1866 patients) met inclusion criteria. With alternative intubation devices, the risk of intubation failure was lower compared with Macintosh laryngoscopy [risk ratio (RR) 0.53; 95% confidence interval (CI) 0.35–0.80]. Meta-analyses could be performed for five intubation devices (Airtraq, Airwayscope, C-Mac, Glidescope, and McGrath). The Airtraq was associated with a statistically significant reduction of the risk of intubation failure at the first attempt (RR 0.14; 95% CI 0.06–0.33), a higher rate of Cormack–Lehane grade 1 (RR 2.98; 95% CI 1.94–4.56), a reduction of time until successful intubation (weighted mean difference −10.1 s; 95% CI −3.2 to −17.0), and a reduction of oropharyngeal complications (RR 0.24; 95% CI 0.06–0.93). Other devices were associated with improved glottis visualization but no statistically significant differences in intubation failure or time to intubation compared with conventional laryngoscopy.

Conclusions. In situations where the spine is immobilized, the Airtraq device reduces the risk of intubation failure. There is a lack of evidence for the usefulness of other intubation devices.

Clinical evaluation and airway management for adults with cervical spine instability

Airway management of patients with cervical spine instability may be difficult as a result of immobilization, and may be associated with secondary neurologic injury related to cervical spine motion. Spinal cord instability is most common in patients with trauma, but there are additional congenital and acquired conditions that predispose to subacute cervical spine instability. Patients with suspected instability should receive immobilization during airway management with manual in-line stabilization. The best strategy for airway management is one that applies the technique with the highest likelihood of success on the first attempt and the lowest biomechanical influence on a potentially unstable spine.

Airway management of patients with traumatic brain injury/C-spine injury

Traumatic brain injury (TBI) is usually combined with cervical spine (C-spine) injury. The possibility of C-spine injury is always considered when performing endotracheal intubation in these patients. Rapid sequence intubation is recommended with adequate sedative or analgesics and a muscle relaxant to prevent an increase in intracranial pressure during intubation in TBI patients. Normocapnia and mild hyperoxemia should be maintained to prevent secondary brain injury. The manual-in-line-stabilization (MILS) technique effectively lessens C-spine movement during intubation. However, the MILS technique can reduce mouth opening and lead to a poor laryngoscopic view. The newly introduced video laryngoscope can manage these problems. The AirWay Scope® (AWS) and AirTraq laryngoscope decreased the extension movement of C-spines at the occiput-C1 and C2-C4 levels, improving intubation conditions and shortening the time to complete tracheal intubation compared with a direct laryngoscope. The Glidescope® also decreased cervical movement in the C2-C5 levels during intubation and improved vocal cord visualization, but a longer duration was required to complete intubation compared with other devices. A lightwand also reduced cervical motion across all segments. A fiberoptic bronchoscope-guided nasal intubation is the best method to reduce cervical movement, but a skilled operator is required. In conclusion, a video laryngoscope assists airway management in TBI patients with C-spine injury.

Catastrophic neurological complications of emergent endotracheal intubation: report of 2 cases

Although exceedingly rare, catastrophic neurological decline may result from endotracheal intubation of patients with preexisting cervical spine disease. The authors report on 2 cases of quadriplegia resulting from emergent endotracheal intubation in the intensive care unit. A 68-year-old man with ankylosing spondylitis became quadriplegic after emergent intubation. A new C6-7 fracturedislocation was identified, and the patient underwent emergent open reduction and C4-T2 posterior fixation and fusion. The patient remained quadriplegic and ultimately died of pneumonia 1 year later. This is the first report with radiographic documentation of a cervical fracture-dislocation resulting from intubation in a patient with ankylosing spondylitis. A 73-year-old man underwent posterior C6-T1 decompression and fixation for a C6-7 fracture. On postoperative Day 12, emergent intubation for respiratory distress resulted in C6-level quadriplegia. Imaging revealed acute spondyloptosis at C6-7, and the patient underwent emergent open reduction with revision and extension of posterior fusion from C-3 to T-2. He remained quadriplegic and ventilator dependent. Five days after the second operation, care was withdrawn. This is the first report of intubation as a cause of significant neurological decline related to disruption of a recently fixated cervical fracture. Risk factors are identified and pertinent literature is reviewed for cases of catastrophic neurological complications after emergent endotracheal intubation. Strategies for obtaining airway control in patients with cervical spine pathology are also identified. Awareness of the potential dangers of airway management in patients with cervical spine pathology is critical for all involved subspecialty team members.

Neurological deterioration during intubation in cervical spine disorders

Anaesthesiologists are often involved in the management of patients with cervical spine disorders. Airway management is often implicated in the deterioration of spinal cord function. Most evidence on neurological deterioration resulting from intubation is from case reports which suggest only association, but not causation. Most anaesthesiologists and surgeons probably believe that the risk of spinal cord injury (SCI) during intubation is largely due to mechanical compression produced by movement of the cervical spine. But it is questionable that the small and brief deformations produced during intubation can produce SCI. Difficult intubation, more frequently encountered in patients with cervical spine disorders, is likely to produce greater movement of spine. Several alternative intubation techniques are shown to improve ease and success, and reduce cervical spine movement but their role in limiting SCI is not studied. The current opinion is that most neurological injuries during anaesthesia are the result of prolonged deformation, impaired perfusion of the cord, or both. To prevent further neurological injury to the spinal cord and preserve spinal cord function, minimizing movement during intubation and positioning for surgery are essential. The features that diagnose laryngoscopy induced SCI are myelopathy present on recovery, short period of unconsciousness, autonomic disturbances following laryngoscopy, cranio-cervical junction disease or gross instability below C3. It is difficult to accept or refute the claim that neurological deterioration was induced by intubation. Hence, a record of adequate care at laryngoscopy and also perioperative period are important in the event of later medico-legal proceedings.

Airway management in cervical spine injury

To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury.

[Cervical spine instability in the surgical patient]

Many congenital and acquired diseases, including trauma, may result in cervical spine instability. Given that airway management is closely related to the movement of the cervical spine, it is important that the anesthesiologist has detailed knowledge of the anatomy, the mechanisms of cervical spine instability, and of the effects that the different airway maneuvers have on the cervical spine. We first review the normal anatomy and biomechanics of the cervical spine in the context of airway management and the concept of cervical spine instability. In the second part, we review the protocols for the management of cervical spine instability in trauma victims and some of the airway management options for these patients.

Nuances in pediatric trauma

Pediatric trauma evaluation mimics adult stabilization in that it is best accomplished with a focused and systematic approach. Attention to developmental differences, anatomic and physiologic nuances, and patterns of injury equip emergency physicians to stabilize and manage pediatric injury.

[Cervical spine instability: point of view of the anesthesiologist]

The experience in airway management permits the anesthesiologist to participate in cases of cervical spine instability in the operating room when the patient is subjected to surgical procedures, or in cases of difficulty to access or keep the airway open in emergencies. This article reviews the epidemiology, definition, etiology, diagnostic criteria, methods of approach to airway management, and current recommendations on handling cervical instability in different scenarios. There is no approach to the airway that ensures complete immobility of the cervical spine, but there are methods that are better adapted to specific contexts; at the end, the reader will be able to identify the virtues and defects of the various options that the anesthesiologists have to address the airway in cases of cervical instability.

Upper cervical spine movement during intubation with different airway devices

Prevention of secondary neurologic injury is critical during the airway management of a trauma patient. Trauma patients are assumed to have an unstable cervical spine (C-spine) until proven otherwise: orotracheal intubation during airway management may result in a certain amount of C-spine movement. This study, therefore, aimed to compare C-spine movement within different advanced airway devices (Macintosh blade, McCoy Blade, LMA, I-LMA, and Combitube) during airway management.

MATERIALS AND METHODS

A total of 3 fresh frozen cadavers were used. The cadavers were consecutively intubated by 4 different postgraduate year residents with LMA4, I-LMA5, Combitube (37F), Macintosh 3, and McCoy blades. The cinefluoroscopic view of the entire intubation process was recorded, and vertebral body angles were calculated.

RESULTS

At the C0C1 level, compared with the McCoy laryngoscope (median, 7°), the LMA (median, 2.5°) and the Combitube (median, 1.5°) caused less extension of the cervical vertebra. In addition, the Combitube (median, -1°) and the I-LMA (median, -2°) caused less extension of the C2C3 region when compared with the Macintosh laryngoscope (median, 3°). There was no significant difference between groups at the C1C2, C3C4, and C4C5 segments.

CONCLUSION

Supraglottic devices used during airway management cause C-spine movement less or equal to conventional laryngoscopes. Furthermore, because of ease of training and blind insertion, supraglottic devices can be safely used with trauma patients when C-spine integrity is a concern.

[Traumatic neurogenic shock]

Traumatic neurogenic shock is a rare but serious complication of spinal cord injury. It associates bradycardia and hypotension caused by a medullary trauma. It is life-threatening for the patient and it aggravates the neurological deficit. Strict immobilization and a quick assessment of the gravity of cord injury are necessary as soon as prehospital care has begun. Initial treatment requires vasopressors associated with fluid resuscitation. Steroids are not recommended. Early decompression is recommended for incomplete deficit seen in the first 6 hours. We relate the case of secondary spinal shock to a luxation C6/C7 treated in prehospital care.

Use of video-assisted intubation devices in the management of patients with trauma

Patients with trauma may have airways that are difficult to manage. Patients with blunt trauma are at increased risk of unrecognized cervical spine injury, especially patients with head trauma. Manual in-line stabilization reduces cervical motion and should be applied whenever a cervical collar is removed. All airway interventions cause some degree of cervical spine motion. Flexible fiberoptic intubation causes the least cervical motion of all intubation approaches, and rigid video laryngoscopy provides a good laryngeal view and eases intubation difficulty. In emergency medicine departments, video laryngoscopy use is growing and observational data suggest an improved success rate compared with direct laryngoscopy.

Comparison of the use of McCoy and TruView EVO2 laryngoscopes in patients with cervical spine immobilization

CONTEXT

The cervical spine has to be stabilized in patients with suspected cervical spine injury during laryngoscopy and intubation by manual in-line axial stabilization. This has the propensity to increase the difficulty of intubation. An attempt has been made to compare TruView EVO2 and McCoy with cervical spine immobilization, which will aid the clinician in choosing an appropriate device for securing the airway with an endotracheal tube (ETT) in the clinical scenario of trauma.

AIMS

To compare the effectiveness of TruView EVO2 and McCoy laryngoscopes when performing tracheal intubation in patients with neck immobilization using manual in-line axial cervical spine stabilization.

SETTINGS AND DESIGN

K. M. C. Hospital, Mangalore, This was a randomized control clinical trial.

METHODS

Sixty adult patients of either sex of ASA physical status 1 and 2 who were scheduled to undergo general anesthesia with endotracheal intubation were studied. Comparison of intubation difficulty score (IDS), hemodynamic response, Cormack and Lehane grade, duration of the tracheal intubation and rate of successful placement of the ETT in the trachea between TruView EVO2 and McCoy laryngoscopes was performed.

RESULTS

The results demonstrated that TruView has a statistically significant less IDS of 0.33 compared with an IDS of 1.2 for McCoy. TruView also had a better Cormack and Lehane glottic view (CL 1 of 77% versus 40%) and less hemodynamic response.

CONCLUSIONS

The TruView blade is a useful option for tracheal intubation in patients with suspected cervical spine injury.

Airway management in trauma

Trauma has assumed epidemic proportion. 10% of global road accident deaths occur in India. Hypoxia and airway mismanagement are known to contribute up to 34% of pre-hospital deaths in these patients. A high degree of suspicion for actual or impending airway obstruction should be assumed in all trauma patients. Objective signs of airway compromise include agitation, obtundation, cyanosis, abnormal breath sound and deviated trachea. If time permits, one should carry out a brief airway assessment prior to undertaking definitive airway management in these patients. Simple techniques for establishing and maintaining airway patency include jaw thrust maneuver and/or use of oro- and nas-opharyngeal airways. All attempts must be made to perform definitive airway management whenever airway is compromised that is not amenable to simple strategies. The selection of airway device and route- oral or -nasal, for tracheal intubation should be based on nature of patient injury, experience and skill level.

Airway management in neuroanesthesiology

Airway management for neuroanesthesiology brings together some key principles that are shared throughout neuroanesthesiology. This article appropriately targets the cervical spine with associated injury and the challenges surrounding airway management. The primary focus of this article is on the unique airway management obstacles encountered with cervical spine injury or cervical spine surgery, and unique considerations regarding functional neurosurgery are addressed. Furthermore, topics related to difficult airway management for those with rheumatoid arthritis or pituitary surgery are reviewed.

National athletic trainers' association position statement: preventing sudden death in sports

OBJECTIVE

To present recommendations for the prevention and screening, recognition, and treatment of the most common conditions resulting in sudden death in organized sports.

BACKGROUND

Cardiac conditions, head injuries, neck injuries, exertional heat stroke, exertional sickling, asthma, and other factors (eg, lightning, diabetes) are the most common causes of death in athletes.

RECOMMENDATIONS

These guidelines are intended to provide relevant information on preventing sudden death in sports and to give specific recommendations for certified athletic trainers and others participating in athletic health care.

Cervical spine trauma in children and adults: perioperative considerations

A wide spectrum of cervical spine injuries, including stable and unstable injuries with and without neurologic compromise, account for a large percentage of emergency department visits. Effective treatment of the polytrauma patient with cervical spine injury requires knowledge of cervical spine anatomy and the pathophysiology of spinal cord injury, as well as techniques for cervical spine stabilization, intraoperative positioning, and airway management. The orthopaedic surgeon must oversee patient care and coordinate treatment with emergency department physicians and anesthesia services in both the acute and subacute settings. Children are particularly susceptible to substantial destabilizing cervical injuries and must be treated with a high degree of caution. The surgeon must understand the unique anatomic and biomechanical properties associated with the pediatric cervical spine as well as injury patterns and stabilization techniques specific to this patient population.

Motion within the unstable cervical spine during patient maneuvering: the neck pivot-shift phenomenon

BACKGROUND

Cervical extrication collars are applied to millions of blunt trauma victims despite the lack of any evidence that a collar can protect against secondary injuries to the cervical spine. Cadaver studies support that in the presence of a dissociative injury, substantial motion can occur within the occipitocervical spine with collar application or during patient transfers. Little is known about the biomechanics of cervical stabilization; hence, it is difficult to develop and test improved immobilization strategies.

MATERIALS

Severe unstable injuries were created in seven fresh whole human cadavers. Rigid collars were applied with the body in a neutral position. Computed tomographic examinations were obtained before and after tilting the body or backboard as would be done during patient transport or to inspect the back. Relative displacements between vertebrae at the site of the injury were measured from the Computed tomographic examinations. The overall relative alignment between body and collar was assessed to understand the mechanisms that may facilitate motion at the injury site.

RESULTS

Intervertebral motion averaged 7.7 mm±6.8 mm in the axial plain and 2.9 mm±2.5 mm in the cranial-caudal direction. The rigid collars appeared to create pivot points where the collar contacts the head in the region under the ear and where the collar contacts the shoulders.

DISCUSSION

Rigid cervical collars appear to create pivot points that shift the center of rotation lateral to the spine and contribute to the intervertebral motions that were measured. Immobilization strategies that avoid these neck pivot-shift phenomena may help to reduce secondary injuries to the cervical spine. The whole cadaver model with simulation of patient maneuvers may provide an effective test method for cervical immobilization.

Comparison of the laryngeal view during intubation using Airtraq and Macintosh laryngoscopes in patients with cervical spine immobilization and mouth opening limitation

BACKGROUND

For patients suspicious of cervical spine injury, a Philadelphia cervical collar is usually applied. Application of Philadelphia cervical collar may cause difficult airway. The aim of this study was to evaluate the laryngeal view and the success rate at first intubation attempt of the Airtraq and conventional laryngoscopy in patients with simulated cervical spine injury after application of a Philadelphia cervical collar.

METHODS

Anesthesia was induced with propofol, remifentanil, and rocuronium. After a Philadelphia cervical collar applied, patients were randomly assigned to tracheal intubation with an Airtraq (Group A, n = 25) or with conventional laryngoscopy (Group L, n = 25). Measurements included intubation time, success rate of first intubation attempt, number of intubation attempts, and percentage of glottic opening (POGO) score. Mean blood pressure and heart rate were also recorded at baseline, just before and after intubation.

RESULTS

The success rate of the first attempt in Group A (96%) was significantly greater than with the Group L (40%). POGO score was significantly greater in Group A (84 ± 20%) than in Group L (6 ± 11%). The duration of successful intubation at first tracheal intubation attempt and hemodynamic changes were not significantly different between the two groups.

CONCLUSIONS

The Airtraq offers a better laryngeal view and higher success rate at first intubation attempt in patients who are applied with a Philadelphia cervical collar due to suspicion of cervical spine injury.

Pre-hospital care management of a potential spinal cord injured patient: a systematic review of the literature and evidence-based guidelines

An interdisciplinary expert panel of medical and surgical specialists involved in the management of patients with potential spinal cord injuries (SCI) was assembled. Four key questions were created that were of significant interest. These were: (1) what is the optimal type and duration of pre-hospital spinal immobilization in patients with acute SCI?; (2) during airway manipulation in the pre-hospital setting, what is the ideal method of spinal immobilization?; (3) what is the impact of pre-hospital transport time to definitive care on the outcomes of patients with acute spinal cord injury?; and (4) what is the role of pre-hospital care providers in cervical spine clearance and immobilization? A systematic review utilizing multiple databases was performed to determine the current evidence about the specific questions, and each article was independently reviewed and assessed by two reviewers based on inclusion and exclusion criteria. Guidelines were then created related to the questions by a national Canadian expert panel using the Delphi method for reviewing the evidence-based guidelines about each question. Recommendations about the key questions included: the pre-hospital immobilization of patients using a cervical collar, head immobilization, and a spinal board; utilization of padded boards or inflatable bean bag boards to reduce pressure; transfer of patients off of spine boards as soon as feasible, including transfer of patients off spinal boards while awaiting transfer from one hospital institution to another hospital center for definitive care; inclusion of manual in-line cervical spine traction for airway management in patients requiring intubation in the pre-hospital setting; transport of patients with acute traumatic SCI to the definitive hospital center for care within 24 h of injury; and training of emergency medical personnel in the pre-hospital setting to apply criteria to clear patients of cervical spinal injuries, and immobilize patients suspected of having cervical spinal injury.

National athletic trainers' association position statement: acute management of the cervical spine-injured athlete

OBJECTIVE

To provide certified athletic trainers, team physicians, emergency responders, and other health care professionals with recommendations on how to best manage a catastrophic cervical spine injury in the athlete.

BACKGROUND

The relative incidence of catastrophic cervical spine injury in sports is low compared with other injuries. However, cervical spine injuries necessitate delicate and precise management, often involving the combined efforts of a variety of health care providers. The outcome of a catastrophic cervical spine injury depends on the efficiency of this management process and the timeliness of transfer to a controlled environment for diagnosis and treatment.

RECOMMENDATIONS

Recommendations are based on current evidence pertaining to prevention strategies to reduce the incidence of cervical spine injuries in sport; emergency planning and preparation to increase management efficiency; maintaining or creating neutral alignment in the cervical spine; accessing and maintaining the airway; stabilizing and transferring the athlete with a suspected cervical spine injury; managing the athlete participating in an equipment-laden sport, such as football, hockey, or lacrosse; and considerations in the emergency department.

Summary of the National Athletic Trainers' Association position statement on the acute management of the cervical spine-injured athlete

The incidence of catastrophic cervical spine injury in sports is low compared with other injuries. However, cervical spine injuries necessitate delicate and precise management, often involving the combined efforts of a variety of health care providers. The outcome of a catastrophic cervical spine injury depends on the efficiency of this management process and timeliness of transfer to a controlled environment for diagnosis and treatment. The objective of the National Athletic Trainers' Association (NATA) position statement on the acute care of the cervical spine-injured athlete is to provide the certified athletic trainer, team physician, emergency responder, and other health care professionals with recommendations on how to best manage a catastrophic cervical spine injury in an athlete. Recommendations are based on current evidence pertaining to prevention strategies to reduce the incidence of cervical spine injuries in sport; emergency planning and preparation to increase management efficiency; maintaining or creating neutral alignment in the cervical spine; accessing and maintaining the airway; stabilizing and transferring the athlete with a suspected cervical spine injury; managing the athlete participating in an equipment-laden sport such as football, hockey, or lacrosse; and imaging considerations in the emergency department.

Motion of a cadaver model of cervical injury during endotracheal intubation with a Bullard laryngoscope or a Macintosh blade with and without in-line stabilization

BACKGROUND

Endotracheal intubation in patients with potential cervical injury is a common dilemma in trauma. Although direct laryngoscopy (DL) with manual in-line stabilization (MILS) is a standard technique there is little data on the effect of MILS on cervical motion. Likewise there is little data available regarding alternative airway techniques in this setting. This study compared intubations with and without MILS in a cadaver model of cervical instability. We also used this model to compare intubations using DL with a Macintosh blade versus a Bullard laryngoscope (BL).

METHODS

Complete C4-C5 disarticulations were surgically created in 10 fresh human cadavers. The cadavers were then intubated in a random order with either BL or DL with and without MILS. The motion at the unstable interspace was measured for subluxation, angulation, and distraction.

RESULTS

MILS did not significantly affect maximal motion of this model in any of the three measures using either DL or BL. There were no clinically significant differences in maximal median motion in any of the three measures when comparing the two blades. However, there was significantly more variance in the subluxation caused by DL than by BL.

CONCLUSIONS

We were unable to demonstrate any significant effect of MILS on the motion of an unstable cervical spine in this cadaver model. The BL appears to be a viable alternative to DL in the setting of an unstable lower cervical spine.