The adult cervical spine: implications for airway management

Spinal Backboard-Necessity or Hazard? The IDF Clinical Practice Guidelines and Policy

INTRODUCTION

Prehospital spinal immobilization using a cervical collar and a backboard has been standard practice for suspected spinal cord injuries (SCIs) since the 1960s. Multiple studies have shown that the disadvantages of the spinal backboard outweigh its advantages. This report aims to present a review of the current literature along with the revised IDF protocol regarding patients with suspected SCI.

METHODS

In 2019, the IDF Medical Corps (IDFMC) convened a multidisciplinary expert committee to revise the IDFMC protocols regarding the use of spinal backboards. Prior to convening the committee, a review of the pertinent literature was done by conducting a thorough clinical evaluation in "PubMed" and "Google Scholar" databases to identify recent studies investigating traumatic SCI and the prehospital military use of spinal backboards.

RESULTS

There were no documented studies that have managed to prove the efficacy of spinal backboards to prevent exacerbation of spinal injuries during mobilization. Despite being a good tool for extraction from vehicles and combat arenas, more than 11 studies have shown that backboards may even result in adverse outcomes such as pain due to the contact between board and skin, the formation of decubitus ulcers, hypothermia, and inadequate ventilation.

CONCLUSION

In light of the evidence showing the potential harmful effects of the routine use of spinal backboards, the IDF guidelines have been revised and now recommends avoiding the routine use of spinal backboards and using a standard stretcher for transporting potential SCI patients. Current IDF guidelines recommend using a backboard for the extraction of an entrapped patient and for obtunded or unconscious patients with obvious deformity or mechanism for spinal trauma.

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.

Perioperative care of adults with Down syndrome: a narrative review

Because of enhanced life expectancy due to medical and surgical therapeutic advances, it is estimated that there are more adults than children living with Down syndrome (DS), or trisomy 21, in the United States. Therefore, DS can no longer be considered a syndrome limited to the pediatric population. These patients are presenting for surgery and anesthesia in adult care settings, where anesthesiologists will encounter these patients more frequently. As these patients age, their commonly associated co-morbidities not only progress, but they also develop other cardiac, respiratory, gastrointestinal, and neurologic conditions. The manifestations and consequences of chronic disease can present new challenges for the anesthesiologist and require expertise and judgement to minimize patient risk. The purpose of this narrative review is to describe the common pediatric co-morbidities associated with DS and discuss the age-acquired manifestations. Additionally, considerations for anesthetic care of the adult with DS will be presented, including the preoperative assessment, intraoperative management, and postoperative care.

Comparison of C-MAC D-blade videolaryngoscope and McCoy laryngoscope efficacy for nasotracheal intubation in simulated cervical spinal injury: a prospective randomized comparative study

BACKGROUND

Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries.

METHODS

This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications.

RESULTS

Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P <  0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups.

CONCLUSION

The C-MAC D-Blade videolaryngoscope is an effective tool for NTI in a simulated difficult airway, which improves glottic visualization and shortens intubation time relative to those with McCoy laryngoscope.

TRIAL REGISTRATION

Clinical Research Information Service of the Korea National Institute of Health, Identification number: KCT 0004535, Registered December 10, 2019, Retrospectively registered, http://cris.nih.go.kr.

Oxygen insufflation via working channel in a fiberscope is a useful method: A case report and review of literature

BACKGROUND

Fiberoptic bronchoscopic intubation is the gold standard for endotracheal intubation in difficult or compromised airway situations. However, oxygen insufflation through the working channel of a fiberscope is a controversial method because of the possibility of gastric distention and rupture during an awake fiberoptic bronchoscopic intubation, despite the advantages of preventing fogging of the fiberoptic bronchoscopic lens, blowing oral secretions away, and oxygenation of patients.

CASE SUMMARY

Here, we describe a case of cervical instability where we rapidly performed fiberoptic bronchoscopic intubation using oxygen insufflation through working channel of the broncoscopy to administer general anesthesia after two previous failures due to low visibility. A 50-year-old man with a non-specific medical history underwent emergency cervical spine surgery for posterior fusion of the C2 and C3 vertebrae. After two unsuccessful attempts at intubation using the fiberoptic broncoscopy, we performed it successfully using the oxygen insufflation via the working channel, instead of using suction to remove the secretion from the lens.

CONCLUSION

Oxygen insufflation via the working channel of the broncoscopy is a useful method for assisting with difficult intubation cases.

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.

Comparative effectiveness of McCoy laryngoscope and CMAC(®) videolaryngoscope in simulated cervical spine injuries

Background:

Videolaryngoscopes are increasingly being used in potentially difficult airway. McCoy laryngoscope provides definitive advantage over conventional laryngoscopes in cervical spine patients. The aim of this study was to compare the performance of the CMAC^® videolaryngoscope with the McCoy Laryngoscope in patients with a cervical collar.

Material and Methods:

Sample size of at least 22 patients in each group was calculated using Intubation Difficulty Scale (IDS) score as the primary outcome. 60 American Society of Anesthesiologists I and II patients requiring tracheal intubation for elective surgery were randomly allocated into the McCoy group (n = 30) and the CMAC^® videolaryngoscope group (n = 30). Anesthesia was induced with fentanyl 2 mcg/kg, propofol 2-3 mg/kg and rocuronium 0.6 mg/kg. A rigid collar was applied to immobilize the cervical spine. Comparative data on the IDS scale, Cormack-Lehane (CL) laryngoscopic view, time taken for glottis visualization, time taken to pass endotracheal tube, total time to intubate, number of optimizing maneuvers and hemodynamic variables were recorded in the two groups.

Results:

IDS score was significantly less in the CMAC^® group compared to the McCoy group (median [interquartile range (IQR)], 1 [0-1] vs. 4 [3-6], P < 0.05). CMAC^® videolaryngoscope required significantly less time for glottic visualization with median (IQR), 5 (5-7) versus 14 (8-15), P = 0.000 in McCoy laryngoscope, 29 (96.7%) patients in the CMAC^® group had Modified CL Grade I compared with 16 (53.3%) patients in McCoy group. The hemodynamic variables, number of optimizing maneuvers and incidence of side effects were comparable in the two groups.

Conclusion:

CMAC^® videolaryngoscope forms an effective tool for the airway management of cervical spine patients with a cervical collar.

Comparison of intubation times using a manikin with an immobilized cervical spine: Macintosh laryngoscope vs. GlideScope vs. fiberoptic bronchoscope

Objective

Airway management in patients with suspected cervical spine injury is classified as a “difficult airway.” The best device for managing difficult airways is not known. Therefore, we conducted an intubation study simulating patients with cervical spine injury using three devices: a conventional Macintosh laryngoscope, a video laryngoscope (GlideScope), and a fiberoptic bronchoscope (MAF-TM). Success rates, intubation time, and complication rates were compared.

Methods

Nine physician experts in airway management participated in this study. Cervical immobilization was used to simulate a difficult airway. Each participant performed intubation using airway devices in a randomly chosen order. We measured the time to vocal cord visualization, time to endotracheal tube insertion, and total tracheal intubation time. Success rates and dental injury rates were compared between devices.

Results

Total tracheal intubation time using the Macintosh laryngoscope, GlideScope, and fiberoptic bronchoscope was 13.3 (range, 11.1 to 20.1), 14.9 (range, 12.7 to 22.3), and 19.4 seconds (range, 14.1 to 32.5), respectively. Total tracheal intubation time differed significantly among the devices (P=0.009). Success rates for the Macintosh laryngoscope, GlideScope, and fiberoptic bronchoscope were 98%, 96%, and 100%, respectively, and dental injury rates were 5%, 19%, and 0%, respectively.

Conclusion

The fiberoptic bronchoscope required longer intubation times than the other devices. However, this device had the best success rate with the least incidence of dental injury.

The Effect of Cricoid Pressure on the Unstable Cervical Spine

BACKGROUND

It has been proposed that cricoid pressure can exacerbate an unstable cervical injury and lead to neurologic deterioration.

OBJECTIVE

We sought to examine the amount of motion cricoid pressure could cause at an unstable subaxial cervical spine injury, and whether posterior manual support is of any benefit.

METHODS

Five fresh, whole cadavers had complete segmental instability at C5-C6 surgically created by a fellowship-trained spine surgeon. Cricoid pressure was applied to the anterior cricoid by an attending anesthesiologist. In addition, the effect of posterior cervical support was tested during the trials. The amount of angular and linear motion between C5 and C6 was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT).

RESULTS

When cricoid pressure is applied, the largest angular motion was 3 degrees and occurred in flexion-extension at C5-C6. The largest linear displacement was 1.36 mm and was in anterior-posterior displacement of C5-C6. When manual posterior cervical support was applied, the flexion-extension was improved to less than half this value (1.43 degrees), and this reached statistical significance (p = 0.001). No other differences were observed to be significant in the other planes of motion with the applications of support.

CONCLUSIONS

Based on the evidence presented, we believe that the application of cricoid pressure to a patient with a globally unstable subaxial cervical spine injury causes small displacements. There may be some benefit to the use of manual posterior cervical spine support for reducing motion at such an injured segment.

Intubation techniques: preferences of maxillofacial trauma surgeons

OBJECTIVE

To evaluate the clinical outcomes of alternative techniques of intubation in patients sustaining maxillofacial injuries, where nasotracheal intubation (NTI) is best avoided.

MATERIAL AND METHODS

Alternative techniques to standard naso-tracheal intubation like submental intubation, orotracheal intubation-retrotuberosity/retromolar and missing dentition were used and variables of clinical outcome recorded.

RESULTS

Submental intubation provides an unobstructed intraoral surgical field, avoids intraoperative and postoperative complications of tracheostomy, and overcomes the disadvantages of NTI. In our experience with submental intubation (6 cases), we only had complication related to tube apparatus like damage to pilot balloon. With retrotuberosity intubation (5 cases) we did not encounter any complications and the only limitations were bulbous maxillary tuberosity. Retromolar intubation (4 cases) a safe noninvasive technique has disadvantages like tube interference within the surgical field and not feasible in case of limited retromolar space. Orotracheal-missing dentition intubation (4 cases) is of great advantage i.e. it can be used in cases where NTI is contraindicated, no specialized skill required, no added cost, avoids the need for tracheostomy, no extra-oral procedures required and does not interfere with occlusion/MMF; with disadvantage of occasional tube interference within the surgical field.

CONCLUSION

Preferred techniques of securing an airway like orotracheal, nasotracheal may not always be applicable, thus a trauma surgeon-anesthesist team should always have alternative techniques in their armamentarium to reduce the morbidity associated with these patients without interference with occlusion, which is prime goal in jaw fracture reduction. We have used these techniques in a country with limited resources and found them equally effective and convenient to use.

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.

Novel 2 radiographical measurements for atlantoaxial instability in children with Down syndrome

STUDY DESIGN

A retrospective case-control study.

OBJECTIVE

To assess the usefulness and reproducibility of 2 novel safe and simple radiographical measurements for atlantoaxial instability in children with Down syndrome.

SUMMARY OF BACKGROUND DATA

In pediatric atlantoaxial instability, early diagnosis is important for improved outcomes because of poor postoperative recovery in progressed neurological symptoms. Conventional dynamic radiography of the cervical spine is associated with a potential risk of worsening neurological symptoms.

METHODS

We retrospectively reviewed the medical records of 50 patients (24 boys and 26 girls) with atlantoaxial instability associated with Down syndrome. Of the 50 children, 11 had undergone and 4 had been scheduled for surgery (surgical group). In this investigation, in addition to the atlas-dens interval (ADI) and space available for spinal cord (SAC), we measured C1 inclination angle and C1/4 SAC ratio on lateral radiographs of the cervical spine in the neutral position. To assess the diagnostic abilities of these indices to determine indication for surgery, receiver operating characteristic analysis of each index was performed, and their diagnostic abilities were compared using the area under the receiver operating characteristic curve. Moreover, we assessed reproducibility of our 2 proposed indices.

RESULTS

The discriminatory abilities of C1/4 SAC ratio (area under the receiver operating characteristic curve, 1.00) and C1 inclination angle (0.91) were comparable with those of ADI (0.98) and SAC (0.95). For the interobserver and intraobserver reliability of the novel indices, the correlation coefficients were in the range from 0.88 to 0.99. Correlation was observed between the ADI and C1/4 SAC ratio (r = 0.507, P < 0.01) and between the ADI and C1 inclination angle (r = 0.407, P < 0.01).

CONCLUSION

The diagnostic abilities of the 2 novel radiographical measurements were comparable with those of ADI and SAC. Moreover, these novel measurements can be obtained safely on lateral radiographs of the cervical spine in the neutral position.

LEVEL OF EVIDENCE

4.

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.

Perioperative management of patients with rheumatic diseases

This paper aims to explore the assessment of patients with rheumatologic diseases, especially rheumatoid arthritis (RA), before undergoing orthopedic surgery. Perioperative assessment ensures an early diagnosis of the patient's medical condition, overall health, medical co-morbidities, and the assessment of the risk factors associated with the proposed procedures. Perioperative assessment allows for proper postoperative management of complications and of the management of drugs such as disease-modifying anti-rheumatic drugs (DMARD) and anti-platelets, and corticosteroids. The assessment also supports follow up plans, and patient education. Perioperative assessment enables the discussion of the proposed treatment plans and the factors associated with them in each case among the different specialists involved to facilitate an appropriate early decision-making about the assessment and treatment of patients with rheumatologic diseases. It also enables the discussion of both condition and procedure with the patient to ensure a good postoperative care. The article identifies the components of perioperative medical evaluation, discusses perioperative management of co-morbidities and the management of specific clinical problems related to RA, systemic lupus erythematosus, the management of DMARDs, like methotrexate (MTX) and biologic therapies, prophylactic antibiotics, and postoperative follow up, including patient education and rehabilitation.

Anesthetic considerations in acute spinal cord trauma

Patients with actual or potential spinal cord injury (SCI) are frequently seen at adult trauma centers, and a large number of these patients require operative intervention. All polytrauma patients should be assumed to have an SCI until proven otherwise. Pre-hospital providers should take adequate measures to immobilize the spine for all trauma patients at the site of the accident. Stabilization of the spine facilitates the treatment of other major injuries both in and outside the hospital. The presiding goal of perioperative management is to prevent iatrogenic deterioration of existing injury and limit the development of secondary injury whilst providing overall organ support, which may be adversely affected by the injury. This review article explores the anesthetic implications of the patient with acute SCI. A comprehensive literature search of Medline, Embase, Cochrane database of systematic reviews, conference proceedings and internet sites for relevant literature was performed. Reference lists of relevant published articles were also examined. Searches were carried out in October 2010 and there were no restrictions by study design or country of origin. Publication date of included studies was limited to 1990–2010.

[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.

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.

A comparison of 4 airway devices on cervical spine alignment in cadaver models of global ligamentous instability at c1-2

BACKGROUND

The effects of advanced airway management on cervical spine alignment in patients with upper cervical spine instability are uncertain.

METHODS

To examine the potential for mechanical disruption during endotracheal intubation in cadavers with unstable cervical spines, we performed a prospective observational cohort study with 3 cadaver subjects. We created an unstable, type II odontoid fracture with global ligamentous instability at C1-2 in lightly embalmed cadavers, followed by repetitive intubations with 4 different airway devices (Airtraq laryngoscope, Lightwand, intubating laryngeal mask airway [LMA], and Macintosh laryngoscope) while manual in-line stabilization was applied. Motion analysis data were collected using an electromagnetic device to assess the degree of angular movement in 3 axes (flexion-extension, axial rotation, and lateral bending) during the intubation trials with each device. Intubation was performed by either an emergency medical technician or attending anesthesiologist.

RESULTS

Overall, 153 intubations were recorded with the 4 devices. The Lightwand technique resulted in significantly less flexion-extension and axial rotation at C1-2 than with the intubating LMA (mean difference in flexion-extension 3.2° [95% confidence interval {CI}, 0.9°-5.5°], P = 0.003; mean difference in axial rotation 1.6° [95% CI, 0.3°-2.8°], P = 0.01) and Macintosh laryngoscope (mean difference in flexion-extension 3.1° [95% CI, 0.8°-5.4°], P = 0.005; mean difference in axial rotation 1.4° [95% CI 0.1°-2.6°], P = 0.03).

CONCLUSIONS

In cadavers with instability at C1-2, the Lightwand technique produced less motion than the Macintosh and intubating LMA.

Quadriplegia in a child following adenotonsillectomy

Neurological deterioration in a child following routine surgery, although rare, has potentially life threatening consequences. We report the case of a child who, following adentonsillectomy, developed quadriplegia and acute respiratory distress due to previously undetected atlanto-axial instability. Patients with atlanto-axial instability often have mild or non-specific symptoms, despite severe cervical cord compression. Subtle manifestations may be ignored or attributed to other disease processes, which render patients with undiagnosed atlanto-axial instability at risk of serious neurological injury during general anaesthesia, particularly at the time of laryngoscopy and tracheal intubation.

Motion generated in the unstable cervical spine during the application and removal of cervical immobilization collars

BACKGROUND

Many studies have compared the restriction of motion that immobilization collars provide to the injured victim. No previous investigation has assessed the amount of motion that is generated during the fitting and removal process. The purpose of this study was to compare the three-dimensional motion generated when one-piece and two-piece cervical collars are applied and removed from cadavers intact and with unstable cervical spine injuries.

METHODS

Five fresh, lightly embalmed cadavers were tested three times each with either a one-piece or two-piece cervical collar in the supine position. Testing was performed in the intact state, following creation of a global ligamentous instability at C5-C6. The amount of angular motion resulting from the collar application and removal was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). The measurements recorded in this investigation included maximum values for flexion/extension, axial rotation, medial/lateral flexion, anterior/posterior displacement, axial distraction, and medial/lateral displacement at the level of instability.

RESULTS

There was statistically more motion observed with application or removal of either collar following the creation of a global instability. During application, there was a statistically significant difference in flexion/extension between the one-piece (1.8 degrees) and two-piece (2.6 degrees) collars, p = 0.009. There was also a statistically significant difference in anterior/posterior translation between the one-piece (3.6 mm) and two-piece (3.4 mm) collars, p = 0.015. The maximum angulation and displacement during the application of either collar was 3.4 degrees and 4.4 mm. Statistical analysis revealed no significant differences between the one-piece and two-piece collars during the removal process. The maximum angulation and displacement during removal of either collar type was 1.6 degrees and 2.9 mm.

CONCLUSIONS

There were statistically significant differences in motion between the one-piece and two-piece collars during the application process, but it was only 1.2 degrees in flexion/extension and 0.2 mm in anterior/posterior translation. Overall, the greatest amount of angulation and displacement observed during collar application was 3.4 degrees and 4.4 mm. Although the exact amount of motion that could be deleterious to a cervical spine-injured patient is unknown, collars can be placed and removed with manual in-line stabilization without large displacements. Only trained practitioners should do so and with great care given that some motion in all planes does occur during the process.

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.

Comparison of 4 airway devices on cervical spine alignment in a cadaver model with global ligamentous instability at C5-C6

STUDY DESIGN

Human cadaveric study using various intubation devices in a cervical spine instability model.

OBJECTIVE

We sought to evaluate various intubation techniques and determine which device results in the least cervical motion in the setting of a global ligamentous instability model.

SUMMARY OF BACKGROUND DATA

Many patients presenting with a cervical spine injury have other injuries that may require rapid airway management with endotracheal intubation. Secondary neurologic injuries may occur in these patients because of further displacement at the level of injury, vascular insult, or systemic decrease in oxygen delivery. The most appropriate technique for achieving endotracheal intubation in the patient with a cervical spine injury remains controversial.

METHODS

A global ligamentous instability at the C5-C6 vertebral level was created in lightly embalmed cadavers. An electromagnetic motion analysis device (Liberty; Polhemus, Colchester, VT) was used to assess the amount of angular and linear translation in 3 planes during intubation trials with each of 4 devices (Airtraq laryngoscope, lighted stylet, intubating LMA, and Macintosh laryngoscope). The angular motions measured were flexion-extension, axial rotation, and lateral bending. Linear translation was measured in the medial-lateral (ML), axial, and anteroposterior planes. Intubation was performed by either an emergency medical technician or by a board-certified attending anesthesiologist. Both time to intubate as well as failure to intubate (after 3 attempts) were recorded.

RESULTS

There was no significant difference shown with regards to time to successfully intubate using the various devices. It was shown that the highest failure-to-intubate rate occurred with use of the intubating LMA (ILMA) (23%) versus 0% for the others. In flexion/extension, we were able to demonstrate that the Lightwand (P = 0.005) and Airtraq (P = 0.019) resulted in significantly less angular motion than the Macintosh blade. In anterior/posterior translation, the Lightwand (P = 0.005), Airtraq (P = 0.024), and ILMA (P = 0.021) all caused significantly less linear motion than the Macintosh blade. In axial rotation, the Lightwand (P = 0.017) and Airtraq (P = 0.022) resulted in significantly less angular motion than the Macintosh blade. In axial translation (P = 0.037) and lateral bending (P = 0.003), the Lightwand caused significantly less motion than the Macintosh blade.

CONCLUSION

In a cadaver model of C5-C6 instability, the greatest amount of motion was caused by the most commonly used intubation device, the Macintosh blade. Intubation with the Lightwand resulted in significantly less motion in all tested parameters (other than ML translation) as compared with the Macintosh blade. It should also be noted that the Airtraq caused less motion than the Macintoshblade in 3 of the 6 tested planes. There were no significant differences in failure rate or the amount of time it took to successfully intubate in comparing these techniques. We therefore recommend the use of the Lightwand, followed by the Airtraq, in the setting of a presumed unstable cervical spine injury over the Macintosh laryngoscope.

Cervical spine radiographs in patients with rheumatoid arthritis undergoing anesthesia

BACKGROUND

There is no consensus on the role of preoperative cervical spine radiographs to screen for instability in patients with rheumatoid arthritis (RA).

OBJECTIVES

This study aimed to evaluate the preoperative use of cervical spine radiographs in patients with RA undergoing preoperative anesthesia assessment and to determine whether preoperative radiographic findings influenced anesthesia delivery techniques.

METHODS

We reviewed all medical records of RA patients who underwent surgical procedures requiring general anesthesia with airway intubation or monitored anesthesia care without airway intubation. We examined cervical spine radiographs obtained up to 2 years before surgery and determined airway management techniques used during surgery.

RESULTS

Overall, 215 patients with RA underwent 217 individual surgeries requiring anesthesia; of these, 176 (82%) underwent general anesthesia with airway management with direct laryngoscopy in 83%, fiber-optic intubation in 10%, and laryngeal mask in 7%. Ninety-two (52%) of the patients receiving airway management had radiographs available for cervical spine evaluation; of these, only 7 (8%) had complete radiographic examinations with which to evaluate possible atlantoaxial subluxation. Eighteen (20%) of the 92 patients receiving airway management had radiographic evidence of cervical spine abnormality. Multiple regression models were conducted to evaluate the association of patient demographics and airway management technique used and showed that the use of fiber-optic intubation or laryngeal mask was not influenced by radiographic results. A difficult oropharyngeal class/glottic visualization grade (3 or 4) as determined by the anesthesiologist was the only statistically significant predictor of fiber-optic intubation or laryngeal mask use.

CONCLUSIONS

Cervical spine abnormalities were frequently noted in patients who underwent general surgery but did not influence the choice of airway management. Future prospective studies evaluating the utility of cervical spine radiographs in patients with RA and practice guidelines are needed to ensure appropriate and cost-effective perioperative cervical evaluation and management of patients with RA.

Cervical spine motion during flexible bronchoscopy compared with the Lo-Pro GlideScope

BACKGROUND

The most appropriate device for tracheal intubation in patients with potential cervical spine injury remains controversial. We hypothesized that the Lo-Pro GlideScope (LP-G) videolaryngoscope would not cause significantly greater cervical spine movement than fibreoptic bronchoscopy even in the non-immobilized spine.

METHODS

Twenty-eight healthy adults requiring intubation for radiographic procedures were randomized to either the LP-G or the flexible bronchoscope (FB) devices. Continuous fluoroscopy was used to assess cervical spine movement during tracheal intubation. The point of maximum movement was compared with baseline for change in angulation between Occiput (Occ)-C1, Occ-C2, Occ-C4, Occ-C5, C1-2, C2-4, and C4-5. Measurements were made by two independent observers. The change in angulation was also measured for tongue pull and jaw thrust, manoeuvres for enlarging the pharyngeal space, before FB intubation.

RESULTS

LP-G resulted in greater cervical extension compared with FB for every angle calculated, statistically significant between Occ-C1 (P<0.05), Occ-C2 (P<0.05), and Occ-C4 (P<0.01). Tongue pull resulted in significantly less cervical spine motion than FB intubation at Occ-C1, Occ-C2, Occ-C4, and Occ-C5 (P<0.05). When jaw thrust was added to tongue pull, there was a tendency for greater movement than FB intubation at Occ-C1, Occ-C2, and Occ-C3. This was statistically significant at Occ-C1 and Occ-C3 (P<0.05) for one of the two observers.

CONCLUSIONS

During intubation under general anaesthesia, LP-G resulted in greater cervical movement than FB when no cervical immobilization was used in adults without cervical disease. Airway manoeuvres performed before FB, especially jaw thrust, also resulted in cervical spine movement.

Management of the Airway in Patients Undergoing Cervical Spine Surgery

The perioperative management of the airway in patients with cervical spine disease requires careful consideration. In an observational prospective cohort study, we assessed the preoperative factors that may have influenced the anesthesiologists' choice for the technique of intubation and the incidence of postoperative airway complications. We recorded information from 327 patients: mean (+/-SD) age 51+/-15 year, 138 females and 189 males, for anterior surgical approach (n=195) and posterior (n=132). The technique of intubation used was awake fiberoptic bronchoscopy (FOB) in 39% (n=128), asleep FOB 32% (n=103), asleep laryngoscopy 22% (n=72), and other asleep 7% (n=24). Awake FOB was predominately chosen for intubating patients with myelopathy (45%), unstable/fractured spine (73%), and spinal stenosis (55%) but patients with radiculopathy had more asleep FOB (49%) (P<0.001). There was no association between method of intubation and postoperative airway complications. Acute postoperative airway obstruction occurred in 4 (1.2%) patients requiring reintubation. The technique of management of the airway for cervical spine surgery varied considerably among the anesthesiologists, although the choice was not associated with postoperative airway complications.

Cervical complications following routine tonsillectomy and adenoidectomy

PURPOSE OF REVIEW

Fortunately, patients undergoing adenotonsillectomies have far more complaints than complications. Sore throats, dysphagia, and neck pain are frequent and expected symptoms after surgery. Differentiating these symptoms from early signs of severe cervical complications can be difficult. Such complications are rare but include atlanto-axial subluxation (Grisel's syndrome), cervical necrotizing fasciitis, cervical emphysema and cervical oseteomyelitis. Due to the frequency with which adenotonsillectomies are performed, most otolaryngologists will encounter these events during their career. This article is thereby intended to elucidate the early warnings, appropriate diagnostic workup, and therapeutic modalities for cervical complications following adenotonsillectomies.

RECENT FINDINGS

Early recognition and intervention can prevent devastating morbidity and mortality described with cervical complications. Computed tomography scanning remains the gold standard for diagnosing cervical complications after adenotonsillectomy. Although a range of severity exists in cervical complications, most cases can be managed conservatively with broad spectrum antibiotics, observation, bedrest and immobilization in cases of Grisel's syndrome. Cervical necrotizing fasciitis requires a high index of suspicion and urgent management to avoid fatal consequences.

SUMMARY

This is a review of the most frequently encountered, although rare, cervical complications following adenotonsillectomies. It gives the reader an insight into the efficient diagnosis and management of these complications.

Cervical spine abnormalities associated with Down syndrome

Atlantoaxial instability (AAI) affects 10-20% of individuals with Down syndrome (DS). The condition is mostly asymptomatic and diagnosed on radiography by an enlarged anterior atlanto-odontoid distance. Symptomatic AAI, which affects 1-2% of individuals with DS, manifests with spinal cord compression. Cervical spondylosis, which is common in DS, also has the potential for cord damage but it has received less attention because paediatric populations were mostly studied. Forty-four Kuwaiti subjects with DS, whose ages were > or = 15 years, were evaluated clinically and radiographically. Lateral neck radiographs were taken in the neutral and flexion positions. Asymptomatic AAI was diagnosed in eight subjects (18%) and congenital anomalies of C1-2 were found in five (12%). Five patients had AAI in flexion only while three patients had it in both views. Three patients with AAI had odontoid anomalies contributing to the condition. When assessing AAI, the posterior atlanto-odontoid distance has to be considered because it indicates the space available for the cord. Cervical spondylosis was noted in 16 (36%) subjects. Degenerative changes increased with age, occurred earlier than in the normal population, and affected mostly the lower cervical levels. Half the patients with AAI had cervical spondylosis, a comorbidity that puts the cord at increased risk.

Emergency department intubation of trauma patients with undiagnosed cervical spine injury

OBJECTIVES

Some trauma patients have an undiagnosed cervical spine injury but require immediate airway control. This paper reports an emergency department's (ED) experience with these patients. In particular, is there a worse neurological outcome?

METHODS

A retrospective study over 6.5 years, based on prospectively collected data from the Royal Perth Hospital trauma registry. Patients with a cervical spine injury were identified and clinical data were abstracted. The primary outcome measure was evidence of exacerbation of cervical spine injury as a result of intubation by ED medical staff.

RESULTS

308 patients (1.9%) of the 15 747 trauma patients were intubated by ED medical staff. Thirty seven (12%) were subsequently verified to have a cervical spine injury, of which 36 were managed with orotracheal intubation. Twenty five (69%) survived to have a meaningful post-intubation neurological examination. Fourteen (56%) of these 25 patients had an unstable cervical spine injury. Ninety per cent of all ED intubations were by ED medical staff. No worsening of neurological outcomes occurred.

CONCLUSIONS

Every ninth trauma patient that this ED intubates has a cervical spine injury. Intubation by ED medical staff did not worsen neurological outcome. In the controlled setting of an ED staffed by senior practitioners, patients with undiagnosed cervical spine injury can be safely intubated.

Acute complications of artificial airways

In conclusion, though there has been a dramatic reduction in the acute complications of artificial airways in the last hundred years, it remains crucial for the intensivist/anesthesiologist to have an implicit understanding of the anatomy and physiology of the process of ETI. As new techniques such as PDT are introduced, we must investigate their utility compared with the current standard of care in the most rigorous fashion. Additionally, as many of the complications of ETI can lead to increases in morbidity and mortality, prompt diagnosis and management are essential.

Rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic, debilitating disease characterized by chronic polyarticular inflammation that leads to erosion of joint and bones and to significant extra-articular, systemic, and cardiopulmonary manifestations. RA affects the patient's psychologic and social well-being as well as physical activity. The economical burden is high. Patients with RA may be admitted to the ICU for a variety of problems and present unique challenges to all physicians, including intensivists. This article discusses the basic pathophysiology and clinical manifestations of RA and the extra-articular disorders that bring these patients to an ICU. The management of these patients in ICU is discussed, with emphasis on airway management and outcome.

A comparison of two tracheal intubation techniques with Trachlight and Fastrach in patients with cervical spine disorders

Optimal airway management strategies in patients with an unstable cervical spine remain controversial. A newly designed lightwand device (Trachlight) or an intubating laryngeal mask (Fastrach) may avoid hyperextension of the neck. However, there are few objective data that guide us in selecting the appropriate devices. We conducted a prospective randomized study in 148 patients who received general anesthesia for whom the operations were related to the clinical and/or radiographic evidence of cervical abnormality. Trachlight or Fastrach was used for tracheal intubation with the head and neck held in a neutral position. In the Trachlight group, intubation was successful at the first attempt in 67 of 74 (90.5%) cases and at the second attempt in 5 (6.8%) cases. In contrast, in the Fastrach group, 54 of 74 (73.0%) patients were intubated within our protocol. The mean time for successful tracheal intubation at the first attempt was significantly shorter in the Trachlight group than in the Fastrach group. The Trachlight may be more advantageous for orotracheal intubation in patients with cervical spine disorders than the Fastrach with respect to reliability, rapidity, and safety.

IMPLICATIONS

The Trachlight may be more advantageous for orotracheal intubation in patients with cervical spine disorders than the Fastrach with respect to reliability, rapidity and safety.

Pharyngeal abscess presenting with upper airway obstruction and atlanto-axial subluxation in a small infant

We describe an infant who presented with a combination of upper airway obstruction and atlanto-axial subluxation, secondary to a pharyngeal abscess resulting from cosmetic ear piercing. This combination posed a number of difficulties for the anasthetist and a detailed plan was formulated to prepare the child for anasthesia.

Recognition and management of preoperative risk

Internists are frequently asked to do preoperative consultations and to manage perioperative complications. Realistic goals are to identify patient factors that increase the risk of surgery, to quantify this risk in order to make decisions about the appropriateness of and timing of the surgery, to provide recommendations on how to minimize the risk, to identify and manage coexisting medical conditions and their associated medication requirements, to monitor the patient for perioperative problems, and to make recommendations to deal with these problems when they occur. With few exceptions, nonselective imaging and laboratory screening tests have repeatedly been shown to be of little value when the history and physical do not suggest a problem. The risk associated with the planned surgery can be estimated, with the most common serious complications being cardiac events. Updated versions of Goldman's risk indices are particularly helpful for this. Clinical variables are optimally combined with selective stress testing to discern which patients will benefit from preoperative revascularization. This has been studied best in the setting of vascular surgery. A critical guiding principle is that the value of revascularization must be judged in terms of long term gains rather than just immediate perioperative benefit. Other interventions include the selective use of beta blockers, adequate analgesia for all, control of hypertension, and appropriate volume management, especially in the settings of preexisting CHF or valvular disease. It must also be recognized that perioperative ischemia and CHF often present atypically. An approach that combines aspects of both the ACC/AHA and the ACP guidelines seems optimal. A variety of noncardiac issues must also be addressed. Postoperative pulmonary complications are common, especially with preexisting pulmonary disease, thoracic and upper abdominal surgery, and obesity. PFTs and ABGs are indicated in selected patients. Stopping smoking, incentive spirometry, and selective use of bronchodilators and antibiotics are helpful. Patients with rheumatologic diseases have specific concerns based on systemic manifestations of disease including anemia, thrombocytopenia, pulmonary fibrosis, pericarditis, and hypercoagulability; medication effects particularly from steroids and nonsteroidal anti-inflammatory drugs; and specific joint problems including contractures and atlantoaxial joint instability. Diabetes increases the risk of infection and cardiac complications. Prevention of ketoacidosis and glucose control are necessary and can be achieved through a variety of approaches, depending on whether the patient suffers from Type 1 or Type 2 diabetes. The threshold for transfusion has increased in recent years, as has the use of erythropoietin and autologous blood donation. There is no longer an absolute hemoglobin that requires transfusion, although most require transfusion for hemoglobins less than 8 mg/dL, especially in the setting of cardiac disease and bloody surgery. The elderly require surgery at an increased rate and often do not do as well as younger patients. The primary issues are, however, not their age but their increased frequency of underlying disease and diminished reserve. The latter makes them prone to postoperative delirium, sensitivity to medications, and cardiac and pulmonary problems. Despite the many diseases that patients often have and the stresses of surgery itself, modern anesthetic and surgical techniques allow almost all patients to undergo necessary procedures at acceptable risk. The internist plays a critical role in minimizing this risk even further.