Tracheal intubation using the ILMA, C-TrachTM or McCoy laryngoscope in patients with simulated cervical spine injury

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).

Comparison of Videolaryngoscope and Intubating Laryngeal Mask Airway for Tracheal Intubation with Manual-in-line Stabilization in Patients Undergoing Cervical Spine Surgery

Background:

This prospective, randomized study compared CMAC^® videolaryngoscope with intubating laryngeal mask airway (ILMA) for intubation under manual-in-line-stabilization (MILS) in patients undergoing cervical spine surgery. Settings and Design: Sixty-five ASA Physical Status Classes I and II patients aged 18–65 years undergoing elective cervical spine surgery were randomly allocated into two groups: group CM-intubation with CMAC^® videolaryngoscope (n = 33) and Group IL-intubation using ILMA (n = 32).

Materials and Methods:

Intubation was performed in all patients after the application of MILS. The primary outcomes included first attempt and overall intubation success rate, intubation time, and apnea time. The secondary objectives were degree of head movement, hemodynamic response, incidence of desaturation, sore throat, and tissue injury.

Statistical Analysis:

Normality of data was tested by the Kolmogorov–Smirnov test. Quantitative variables were compared using the unpaired t-test or Wilcoxon Mann–Whitney test and qualitative variables were compared using the Chi-square test/Fisher's exact test. P < 0.05 was considered statistically significant.

Results:

CM group had a higher first attempt (96.97%, P = 0.054) and overall (100%, P = 0.053) intubation success rate than IL group (81.25% and 87.5%, respectively). Group CM had a significantly shorter (P < 0.0001) intubation time (33.13 ± 11.82 s) than IL group (55.71 ± 19.28 s), but group CM had significantly longer (P < 0.0001) apnea time (33.13 ± 11.82 s) than IL group (22.03 ± 7.14 s). The incidence of head movement was significantly lower in IL group (P = 0.011). Hypoxemia did not occur. Postintubation hemodynamic changes and tissue injury were significantly higher in ILMA group.

Conclusion:

CMAC group had higher intubation success rate and significantly shorter intubation time. However, ILMA group had a significantly shorter apnea time and significantly lower incidence of head movements.

Radiographic comparison of cervical spine motion using LMA Fastrach, LMA CTrach, and the Macintosh laryngoscope

Background/aim

The optimal technique for airway management in patients with cervical pathology remains unclear. Intubating laryngeal mask airway devices such as LMA CTrach and LMA Fastrach have not been compared for cervical spine (C-spine) movements in the context of cervical pathology. The present study aimed to determine upper C-spine movements by radiography during intubation with different devices as well as comparing the duration and success of intubation in cervical surgery.

Materials and methods

Sixty patients scheduled for elective cervical surgery were registered in this prospective, randomized study. Patients with cervical trauma/injury, previous neck surgery, and body mass index (BMI) of >35 kg/m² were excluded. Participants were randomized to one of the 3 groups: LMA CTrach, LMA Fastrach, or the Macintosh laryngoscope. C-spine motion was evaluated by measuring angles created by bordering vertebrae at cervical 1/2 and 2/3 (C1/2, C2/3) segments on 2 lateral cervical radiographs for each patient. Intubation time, ease of intubation, number of attempts, and success rate were also documented.

Results

Demographic data were similar in all the groups. The cervical movement with LMA CTrach and LMA Fastrach compared to the Macintosh laryngoscope were similar at C1/2. However, LMA CTrach significantly reduced extension compared to LMA Fastrach and Macintosh laryngoscopes at C2/3. Duration of intubation was significantly shorter with the Macintosh laryngoscope. The rate of successful intubation was 80% with LMA Fastrach and 100% with both LMA CTrach and the Macintosh laryngoscopes.

Conclusion

The LMA CTrach laryngoscopy involves less upper C-spine movement than the LMA Fastrach and does not increase the duration of the intubation period.

Tracheal intubation through laryngeal mask airway CTrach™ with polyvinyl chloride tube: Comparison between two orientations of the tracheal tube

Background and Aims:

Higher success rate of intubation is observed with the reverse orientation of polyvinyl chloride (PVC) tracheal tube while intubating through laryngeal mask airway (LMA) Fastrach™. It is not clear whether the same is true during intubation through LMA CTrach™ visualizing the process of intubation. The primary aim of this study was to compare the influence of the PVC tracheal tube orientation on the success rate of intubation while intubating through LMA CTrach™.

Material and Methods:

One-hundred and fifty patients belonging to American Society of Anesthesiologists status I–II, undergoing elective surgery under general anesthesia were randomized to either group normal orientation or group reverse orientation. A maximum of 3 intubation attempts within a span of 3 min was allowed in each group before the change over to the other group. If intubation failed with the other orientation of the tube also, then intubation through LMA CTrach™ was abandoned and intubation done by direct laryngoscopy. The success of intubation, time, maneuvers, postoperative sore throat, and hoarseness were recorded.

Results:

Tracheal intubation through LMA CTrach™ with PVC tube was successful in 94.5% of patients in group normal orientation and in 98.6% of patients in group reverse orientation. The first attempt success rate was 75.3% and 86.3% in group normal and group reverse orientation, respectively. The incidence of a sore throat was higher in the group normal orientation than in the reverse orientation (31.8% and 26.5%, respectively).

Conclusions:

Overall success rate of intubation was comparable between the two groups. Though statistically insignificant, the first attempt success rate was higher in group reverse orientation.

Endotracheal intubation in elective cervical surgery: A randomized, controlled, assessor-blinded study

BACKGROUND

We compared the effectiveness and safety of endotracheal intubation using the GlideScope (GS) video laryngoscope, CTrach laryngeal mask airway (LMA), or Shikani optical stylet rigid laryngoscope (SOS) during elective cervical surgery.

METHODS

Forty-five patients undergoing elective cervical surgery were randomly and equally assigned to endotracheal intubation via GS, LMA, or SOS airway management.

RESULTS

Endotracheal intubation was successfully completed in all patients. The mean intubation times of the groups differed significantly (P < .01): GS, 17.9 ± 3.1 s; SOS, 40.4 ± 13.7 s; and LMA, 80.5 ± 22.5 s. The groups had similar heart rates and mean arterial pressures throughout the intubation, except that at 2 minutes after intubation the mean arterial pressure of the GS group (106.1 ± 18.5 mm Hg) was significantly higher than that of the LMA (89.7 ± 18.5 mm Hg) or SOS (89.7 ± 18.5 mm Hg; P < .01). The change in C2-5 Cobb angle from baseline was significantly higher in the GS group (GS, 34.2° ± 7.3°) than the LMA (24.4° ± 5.8°) or SOS (25.5° ± 6.4°); P < .01).

CONCLUSIONS

The CTrach LMA and SOS rigid laryngoscope are effective, safe alternatives to the GS video laryngoscope for patients undergoing elective cervical surgery.

Comparison of Macintosh, McCoy and C-MAC D-Blade video laryngoscope intubation by prehospital emergency health workers: a simulation study

The aim of the this study is to evaluate the intubation success rates of emergency medical technicians using a Macintosh laryngoscope (ML), McCoy laryngoscope (MCL), and C MAC D-Blade (CMDB) video laryngoscope on manikin models with immobilized cervical spines. This randomized crossover study included 40 EMTs with at least 2 years' active service in ambulances. All participating technicians completed intubations in three scenarios-a normal airway model, a rigid cervical collar model, and a manual in-line cervical stabilization model-with three different laryngoscopes. The scenario and laryngoscope model were determined randomly. We recorded the scenario, laryngoscope method, intubation time in seconds, tooth pressure, and intubation on a previously prepared study form. We performed Friedman tests to determine whether there is a significant change in the intubation success rate, duration of tracheal intubation, tooth pressure, and visual analog scale scores due to violations of parametric test assumptions. We performed the Wilcoxon test to determine the significance of pairwise differences for multiple comparisons. An overall 5 % type I error level was used to infer statistical significance. We considered a p value of less than 0.05 statistically significant. The CMDB and MCL success rates were significantly higher than the ML rates in all scenario models (p < 0.05). The CMDB intubation duration was significantly shorter when compared with ML and MCL in all models. CMDB and MCL may provide an easier, faster intubation by prehospital emergency health care workers in patients with immobilized cervical spines.

Hemodynamic response to endotracheal intubation using C-Trach assembly and direct laryngoscopy

Purpose:

Our objective was to study the pressor response to endotracheal intubation through laryngeal mask airway C-Trach and compare it to the hemodynamic response to intubation with direct laryngoscopy (DL).

Materials and Methods:

After obtained approval from institutional ethical committee, 100 patients of American Society of Anesthesiologists physical Status I, aged 14-65 years, posted for elective surgery were enrolled in the trial. They were randomly divided into two groups of each 50 patients. Anesthesia technique was standardized and patients of Group I were intubated using DL, while patients of Group II were intubated with the help of C-Trach assembly. Hemodynamic parameters, systemic blood pressure (systolic and diastolic) and heart rate were recorded before and after induction of anesthesia and every minute up to 5 min after intubation.

Results:

Patients of Group II recorded a minimal rise in peak systolic blood pressure (SBP) (1.8%) and diastolic blood pressure (10.6%). In comparison patients of Group I recorded a significant sustained rise in peak SBP (20.3%) and diastolic blood pressure (21.4%). However heart rate changes recorded in the two groups were of equal measure (peak rise of 22.9% in Group I vs. 22.4% in Group II).

Conclusion:

We conclude that intubation through C-Trach generates a lower pressor response to intubation in comparison to intubation using DL.

A comparison of McCoy, TruView, and Macintosh laryngoscopes for tracheal intubation in patients with immobilized cervical spine

BACKGROUND

Cervical spine immobilization results in a poor laryngeal view on direct laryngoscopy leading to difficulty in intubation. This randomized prospective study was designed to compare the laryngeal view and ease of intubation with the Macintosh, McCoy, and TruView laryngoscopes in patients with immobilized cervical spine.

MATERIALS AND METHODS

60 adult patients of ASA grade I-II with immobilized cervical spine undergoing elective cervical spine surgery were enrolled. Anesthesia was induced with propofol, fentanyl, and vecuronium and maintained with isoflurane and nitrous oxide in oxygen. The patients were randomly allocated into three groups to achieve tracheal intubation with Macintosh, McCoy, or TruView laryngoscopes. When the best possible view of the glottis was obtained, the Cormack-Lehane laryngoscopy grade and the percentage of glottic opening (POGO) score were assessed. Other measurements included the intubation time, the intubation difficulty score, and the intubation success rate. Hemodynamic parameters and any airway complications were also recorded.

RESULTS

TruView reduced the intubation difficulty score, improved the Cormack and Lehane glottic view, and the POGO score compared with the McCoy and Macintosh laryngoscopes. The first attempt intubation success rate was also high in the TruView laryngoscope group. However, there were no differences in the time required for successful intubation and the overall success rates between the devices tested. No dental injury or hypoxia occurred with either device.

CONCLUSION

The use of a TruView laryngoscope resulted in better glottis visualization, easier tracheal intubation, and higher first attempt success rate as compared to Macintosh and McCoy laryngoscopes in immobilized cervical spine patients.

LMA C Trach aided endotracheal intubation in simulated cases of cervical spine injury: A series of 30 cases

Background:

Laryngeal mask airway (LMA) C Trach is a novel device designed to intubate trachea without conventional laryngoscopy. The aim of the study was to evaluate the clinical efficacy of C trach in the simulated scenario of cervical spine injury where conventional laryngoscopy is not desirable.

Methods:

This prospective pilot study was carried out in 30 consenting adults of either gender, ASAPS I or II, scheduled for surgery requiring endotracheal intubation. An appropriate sized rigid cervical collar was positioned around the patient's neck to restrict the neck movements and simulate the scenario of cervical spine injury. After induction of anesthesia, various technical aspects of C Trach facilitated endotracheal intubation, changes in hemodynamic variables, and complications were recorded.

Results:

Mask ventilation was easy in all the patients. Successful insertion of C Trach was achieved in 27 patients at first attempt, while 3 patients required second attempt. Majority of patients required one of the adjusting maneuvers to obtain acceptable view of glottis (POGO score >50%). Intubation success rate was 100% with 26 patients intubated at first attempt and the rest required second attempt. Mean intubation time was 69.8±27.40 sec. With experience, significant decrease in mean intubation time was observed in last 10 patients as compared to first 10 (46±15.77 sec vs. 101.3±22.91 sec). Minor mucosal injury was noted in four patients.

Conclusion:

LMA C Trach facilitates endotracheal intubation under direct vision and can be a useful technique in patients with cervical spine injury with cervical collar in situ.

Comparison of Flexiblade and Macintosh laryngoscopes: cervical extension angles during orotracheal intubation

SUMMARY

The Flexiblade(TM) is a new laryngoscope with a flexible blade, a handle and a lever, allowing gradual flexion over the distal half of the blade. In this study, we aimed to compare cervical vertebral movements during tracheal intubation with the Flexiblade and Macintosh laryngoscope in 32 patients undergoing elective surgery requiring general anaesthesia (n = 16 per group). Fluoroscopic images of cervical movement were captured before, during and after intubation and evaluated by a radiologist. C1-C2 cervical vertebral movement was significantly reduced during the intubation in the Flexiblade group (p < 0.0001). C2-C3 cervical movement was similar in both groups (p = 0.81). No significant differences were noted in success rates for intubation, oxygen saturation levels, haemodynamic variables or intubation-related injury. The decreased extension angle between C1-C2 during Flexiblade laryngoscopy compared with Macintosh laryngoscopy may be an advantage where neurological damage with cervical movement is a concern.

The impact of manual in-line stabilisation on ventilation and visualisation of the glottis with the LMA CTrach: a randomised crossover trial

The LMA CTrach (CTrach) enables ventilation, glottis visualisation and tracheal intubation via a laryngeal mask conduit. The CTrach has been successfully used in patients with cervical spine pathology, but it is unclear if cervical spine immobilisation affects its ease of use. In this randomised crossover trial, the CTrach was used once with and once without manual in-line stabilisation of the cervical spine in every patient. With manual in-line stabilisation, the median [IQR] time to achieve ventilation was 22 [16-32] s, compared with 19 [13-30] s without stabilisation (p = 0.065). With manual in-line stabilisation, the time to achieving a glottic views was 42 [30-63] s compared with 39 [25-53] s without stabilisation (p = 0.019). There was no difference in the success rates of achieving ventilation and glottic views. These results suggest that manual in-line stabilisation does not affect use of the CTrach.

Airway Management in Trauma: An Update

This article reviews the more recent theoretic and practical information that pertains to airway management in the trauma setting. This is followed by a presentation of the newer airway devices that may be advantageous in the management of the airway in trauma as well as a discussion of other devices, techniques, or maneuvers that are useful in the trauma setting but may be underused. Each clinician needs to be knowledgeable about the various airway options and then, based on one's own particular skills and resources, construct an airway management algorithm that works best for him or her. Each clinician needs to be knowledgeable about the various airway options, and then, based on the clinician's particular skills and resources, construct an airway management algorithm that works best.

Endotracheal Intubation in Patients with Cervical Spine Immobilization

Background:

The Airtraq laryngoscope (Prodol Ltd., Vizcaya, Spain) is a novel single-use tracheal intubation device. The authors compared ease of intubation with the Airtraq and Macintosh laryngoscopes in patients with cervical spine immobilization in a randomized, controlled clinical trial.

Methods:

Forty consenting patients presenting for surgery requiring tracheal intubation were randomly assigned to undergo intubation using a Macintosh (n = 20) or Airtraq (n = 20) laryngoscope. All patients were intubated by one of four anesthesiologists experienced in the use of both laryngoscopes.

Results:

No significant differences in demographic or airway variables were observed between the groups. All but one patient, in the Macintosh group, were successfully intubated on the first attempt. The Airtraq reduced the duration of intubation attempts (mean ± SD: 13.2 ± 5.5 vs. 20.3 ± 12.2 s), the need for additional maneuvers, and the intubation difficulty scale score (0.1 ± 0.5 vs. 2.7 ± 2.5). Tracheal intubation with the Airtraq caused fewer alterations in blood pressure and heart rate.

Conclusions:

These findings demonstrate the utility of the Airtraq laryngoscope for tracheal intubation in patients with cervical spine immobilization.

Comparison of the GlideScope video laryngoscope vs. the intubating laryngeal mask for females with normal airways

BACKGROUND AND OBJECTIVE

In this randomized clinical study, we compared the intubation success rates of the intubating laryngeal mask airway with the GlideScope in patients with normal airways. The primary hypothesis was that the intubating laryngeal mask airway was equally effective as the GlideScope in terms of successful intubation times.

METHODS

Sixty ASA I and II adult patients undergoing elective gynaecological surgery were randomly allocated into either the intubating laryngeal mask airway group or the GlideScope group. After a standard anaesthetic intravenous induction, orotracheal intubation was performed. Time taken for successful tracheal intubation, ease of device insertion, difficulty of tracheal intubation, manoeuvres needed to aid tracheal intubation, number of intubation attempts, haemodynamic changes every 2.5 min interval for 5 min and complications during tracheal intubation were recorded.

RESULTS

Time to successful intubation was longer (mean 68.4 s +/- 23.5 vs. 35.7 s +/- 10.7; P < 0.05), mean difficulty score was higher (mean 16.7 +/- 16.3 vs. 7.3 +/- 13.1; P < 0.05) and more intubation attempts were required in the intubating laryngeal mask airway group.

CONCLUSION

The GlideScope improved intubation time and difficulty score for tracheal intubation when compared with the intubating laryngeal mask airway in our patients. Blind intubation through the intubating laryngeal mask airway offers no advantages over the GlideScope in patients with normal airways. Despite its limitations, the intubating laryngeal mask airway is a valuable adjunct, especially in cases of difficult airway management when it can provide ventilation in between intubation attempts.