Assessment of cervical spine movement during laryngoscopy with Macintosh and Truview laryngoscopes

A comparative study to evaluate the cervical spine movements during laryngoscopy using Macintosh and Airtraq laryngoscopes

Background and Aim

Intubation with Macintosh requires flexing the lower cervical spine and extending the atlanto-occipital joint to create a "line of sight." Primary aim of study was to compare the extent of cervical spine movement during laryngoscopy using conventional Macintosh laryngoscope and Airtraq.

Material and Methods

A total of 25 patients of either sex between the age group of 18 and 60 years, having American Society of Anesthesiologists (ASA) physical status of Grade-I and Grade-II, scheduled for elective surgery under image control requiring general anesthesia and intubation were enrolled. A baseline image of the lateral cervical spine including the first four cervical vertebrae was taken by an image intensifier. After administration of general anesthesia, laryngoscopy was first performed using a Macintosh laryngoscope and a second X-ray image of the lateral cervical spine was taken. The second laryngoscopy using a Airtraq laryngoscope was done and the third image of the lateral cervical spine was taken. Angles between occiput and C1; C1 and C2; C2 and C3; C3 and C4; and occiput and C4 were calculated. Atlanto-occipital distance (AOD) was calculated as the distance between occiput and C1.

Results

Macintosh showed greater cervical movement as compared with Airtraq but a significant difference in the movement was observed at C2-C3 and C0-C4. Baseline mean AOD was 2.21 ± 1.25 mm, after Macintosh and Airtraq laryngoscopy was found to be 1.13 ± 0.60 and 1.6 ± 0.78 mm, respectively, and was found to be significant (P < 0.05).

Conclusion

We conclude that Airtraq allows intubation with less movement of the upper cervical spine makes Airtraq preferred equipment for intubation in patients with a potential cervical spine injury.

Cervical spine movements during laryngoscopy and orotracheal intubation: a systematic review and meta-analysis

BACKGROUND

Airway management is challenging in trauma patients because of the fear of worsening cervical spinal cord damage. Video-integrated and optic-integrated devices and intubation laryngeal mask airways have been proposed as alternatives to direct laryngoscopy with the Macintosh laryngoscope (MAC). We performed a meta-analysis to clarify which devices cause less cervical movement during airway management.

METHODS

We searched MEDLINE, Cochrane Central, Embase and LILACS from inception to January 2022. We selected randomised controlled trials comparing alternative devices with the MAC for cervical movement from C0 to C5 in adult patients, evaluated by radiological examination. Additionally, cervical spine immobilisation (CSI) techniques were evaluated. We used the Cochrane Risk of Bias Tool to evaluate the risk of bias, and the principles of the Grading of Recommendations, Assessment, Development, and Evaluations system to assess the quality of the body of evidence.

RESULTS

Twenty-one studies (530 patients) were included. Alternative devices caused statistically significantly less cervical movement than MAC during laryngoscopy with mean differences of -3.43 (95% CI -4.93 to -1.92) at C0-C1, -3.19 (-4.04 to -2.35) at C1-C2, -1.35 (-2.19 to -0.51) at C2-C3, and -2.61 (-3.62 to -1.60) at C3-C4; and during intubation: -3.60 (-5.08 to -2.12) at C0-C1, -2.38 (-3.17 to -1.58) at C1-C2, -1.20 (-2.09 to -0.31) at C2-C3. The Airtraq and the Intubation Laryngeal Mask Airway caused statistically significant less movement than MAC restricted to some cervical segments, as well as CSI. Heterogeneity was low to moderate in most results. The quality of the body of evidence was 'low' and 'very low'.

CONCLUSIONS

Compared with the MAC, alternative devices caused less movement during laryngoscopy (C0-C4) and intubation (C0-C3). Due to the high risk of bias and the very low grade of evidence of the studies, further research is necessary to clarify the benefit of each device and to determine the efficacy of cervical immobilisation during airway management.

Perioperative management of spinal cord injury: the anesthesiologist's point of view

BACKGROUND

Traumatic spinal cord injury (SCI) is one of the most devastating events a person can experience. It may be life-threatening or result in long-term disability. This narrative review aims to delineate a systematic step-wise airways, breathing, circulation and disability (ABCD) approach to perioperative patient management during spinal cord surgery in order to fill some of the gaps in our current knowledge.

METHODS

We performed a comprehensive review of the literature regarding the perioperative management of traumatic spinal injuries from May 15, 2020, to December 13, 2020. We consulted the PubMed and Embase database libraries.

RESULTS

Videolaryngoscopy supplements the armamentarium available for airway management. Optical fiberscope use should be evaluated when intubating awake patients. Respiratory complications are frequent in the acute phase of traumatic spinal injury, with an estimated incidence of 36-83%. Early tracheostomy can be considered for expected difficult weaning from mechanical ventilation. Careful intraoperative management of administered fluids should be pursued to avoid complications from volume overload. Neuromonitoring requires investments in staff training and cooperation, but better outcomes have been obtained in centers where it is routinely applied. The prone position can cause rare but devastating complications, such as ischemic optic neuropathy; thus, the anesthetist should take the utmost care in positioning the patient.

CONCLUSIONS

A one-size fit all approach to spinal surgery patients is not applicable due to patient heterogeneity and the complexity of the procedures involved. The neurologic outcome of spinal surgery can be improved, and the incidence of complications reduced with better knowledge of patient-specific aspects and individualized perioperative management.

Comparison of TruView and King Vision video laryngoscopes in subaxial cervical spine injury: A randomized controlled trial

Background:

Airway management with cervical spine immobilization poses a particular challenge for intubation in the absence of neck extension and risks neurological damage in cases of unstable cervical spine injuries. Here, with manual inline stabilization (MILS) in patients with cervical spine injuries, we compared the safety/efficacy of intubation utilizing the TruView versus King Vision video laryngoscopes.

Methods:

This prospective, single-blind, comparative study was conducted over a 3-year period. The study population included 60 American Society of Anesthesiologists (ASA) Grade I-III patients, aged 18–65 years, who underwent subaxial cervical spine surgery utilizing two intubation techniques; TruView (TV) versus King Vision (KV). For both groups, relative intubation difficulty scores (IDS), total duration of intubation, hemodynamic changes, and other complications (e.g., soft-tissue injury and neurological deterioration) were recorded.

Results:

With MILS, patients in the KV group had statistically significant lower IDS (0.70 ± 1.02) and significantly shorter duration of intubation as compared to the TV group (1.67 ± 1.27) with MILS (P = 0.0010); notably, the glottic exposure was similar in both groups. The complication rate (e.g., soft-tissue injury) was lower for the KV group, but this was not statistically significant. Interestingly, no patient from either group exhibited increased neurological deterioration attributable to the method of intubation.

Conclusion:

King Vision has several advantages over TruView for intubating patients who have sustained cervical spine trauma. Nevertheless, both laryngoscopes afford comparable glottic views and safety profiles with similar alterations in hemodynamics.

Comparison of the Laryngoscopic View using Macintosh and Miller Blades in Children Less than Four Years Old

This study aimed to compare Miller and Macintosh laryngoscopes in zero to 4-year-old children. A total of 72 children with a score of I and II, according to the American Society of Anesthesiologists (ASA) physical status classification, who were candidates for elective surgery with general anesthesia and tracheal intubation were enrolled in the study. The children were divided into two equal groups (36 persons) according to used laryngoscope: Miller laryngoscope (group 1) and Macintosh laryngoscope (group 2). Observations and all laryngoscopies were performed by a single experienced anesthesiologist. Heart rate, systolic blood pressure, non-invasive arterial blood pressure, and hemoglobin saturation were measured and recorded. The number of endotracheal intubation attempts and complications were also recorded for both groups. In terms of gender, the first group consisted of 88.9% boys and 11.1% girls, and the second group consisted of 66.6% boys and 33.3% girls (p-value=0.05). The mean age was 16.7 months in the first group and 17.7 months in the second group (p-value=0.5). The mean weight of the children was 16988.5 g and 16300 g in the Miller and Macintosh groups, respectively (p-value=0.9). Regarding the Cormack-Lehane classification system, 5 patients were classified as grade 1 (13.9%), 14 patients as grade 2 (38.9%), 15 patients as grade 3 (41.7%), and 2 patients as grade 4 (5.6%) in the Macintosh group. In contrast, in the Miller group, 5 patients were classified as grade 1 (13.9%), 27 patients as grade 2 (75%), and 4 patients as grade 3 (11.1%) (p-value=0.004). These results can provide more data about the tracheal intubation method with the Macintosh and Miller laryngoscopes, the ease of intubation, and the best laryngoscopic view with each blade.

Comparison of cervical spine motion during intubation with a C‑MAC D‑Blade® and an LMA Fastrach®

BACKGROUND

This prospective randomized study compared cervical motion during intubation with a C‑MAC D‑Blade® and with a laryngeal mask airway LMA Fastrach®.

MATERIAL AND METHODS

The participants in this study were 52 ASA I-III patients aged 18-70 years and assigned for elective cervical discectomy. The patients were randomly selected for intubation with a C‑MAC D‑Blade® (group V) or an LMA Fastrach® laryngeal airway (group F). Both groups received the same induction of anaesthesia. The first lateral view was X‑rayed while the head and neck were in a neutral supine position and the second exposure was taken during the passage of the endotracheal tube through the vocal cords for group V and during the advance of the endotracheal tube for group F. The occiput-C1 (C0-C1), C1-C2 and C2-5 angles were measured. The angle formed by the line between the occipital protuberance and anterior process of the foramen magnum and the line between the central point of C1 spinous process and the anterior process of the foramen magnum was defined as angle A. The differences between the angles were calculated. Overall intubation success and first-pass success (success at the first attempt) were recorded.

RESULTS

The change in angulations between C0-C1 during intubation was significantly lower in group F than in group V (2.78⁰ ± 2.1⁰ vs. 6.04⁰ ± 4.1⁰, p = 0.007). Before intubation, angle A was 14.4⁰ ± 3.9⁰ in group V and 13.8⁰ ± 3.7⁰ in group F (p = 0.627). During intubation, angle A was significantly smaller for group V than for group F (9.1⁰ ± 2.4⁰ vs. 10.7⁰ ± 2.9⁰, p = 0.04). The number of successful intubations were significantly higher in group V (100% of intubations were successful on the first attempt for group V, vs. 80% for group F, p = 0.023).

CONCLUSION

Intubation with both a C‑MAC D‑Blade and a Fastrach LMA resulted in cervical motion but within safe ranges. Intubation with a C-mac D blade might be preferred because the Fastrach LMA may result in more failed intubation attempts in patients with cervical spine disorders.

Management of Anaesthesia

Surgical treatment of the craniovertebral junction (CVJ) requires excellent management by the anaesthetist. Patients undergoing this type of surgery have a wide range of concomitant diseases. Therefore, before proceeding to CVJ surgery, it is recommended to analyse the clinical aspects of the patient that could complicate the outcome of the surgical procedure.In this paper we aim to establish what constitutes the best surgical and anaesthesia management of these patients. We consider airway management, trying to identify the gold standard for the patient. We also consider the most appropriate intraoperative approach to guarantee the best management of the patient.

Airway Management of the Patient with Maxillofacial Trauma: Review of the Literature and Suggested Clinical Approach

According to the Advanced Trauma Life Support recommendations for managing patients with life-threatening injuries, securing the airway is the first task of a primary caregiver. Airway management of patients with maxillofacial trauma is complex and crucial because it can dictate a patient's survival. Securing the airway of patients with maxillofacial trauma is often extremely difficult because the trauma involves the patient's airway and their breathing is compromised. In these patients, mask ventilation and endotracheal intubation are anticipated to be difficult. Additionally, some of these patients may not yet have been cleared of a cervical spine injury, and all are regarded as having a full stomach and having an increased risk of regurgitation and pulmonary aspiration. The requirements of the intended maxillofacial operation may often preclude the use of an oral intubation tube, and alternative methods for securing the airway should be considered before the start of the surgery. In order to improve the clinical outcome of patients with maxillofacial trauma, cooperation between maxillofacial surgeons, anesthesiologists, and trauma specialists is needed. In this review, we discuss the complexity and difficulties of securing the airway of patients with maxillofacial trauma and present our approach for airway management of such patients.

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.