Current evidence for the use of C-MAC videolaryngoscope in adult airway management: a review of the literature

A Comparison of the Effectiveness of the McCoy Laryngoscope and the C-MAC D-Blade Video Laryngoscope in Obese Patients

Background and Objective: Obesity is associated with difficult or failed intubation attempts, making general anesthesia challenging for anesthesiologists to perform. The purpose of this study was to evaluate and compare the efficacy of a McCoy laryngoscope and a C-MAC D-blade video laryngoscope for intubation in obese patients with a body mass index (BMI) ≥ 35 kg/m2. Methods: In total, 104 patients were randomly assigned to be intubated with a McCoy (McCoy group) or C-MAC D-blade video laryngoscope (C-MAC group). The primary outcome was intubation time. The secondary outcomes were vocal cord exposure time, vocal cord passage time, proportion of successful intubation, mask ventilation scale, intubation difficulty scale (IDS), percentage of glottis opening (POGO) score, and hemodynamic variables. Results: Although the intubation time did not significantly differ, the C-MAC group showed shorter vocal cord exposure times and a higher rate of successful vocal cord exposure within 5 s. The IDS value was significantly lower in the C-MAC group than in the McCoy group. The proportion of patients who required an increase in lifting force during laryngoscopy was higher in the McCoy group than in the C-MAC group, which may explain the difference in MAP between the groups. Conclusions: Both the McCoy laryngoscope and the C-MAC D-blade video laryngoscope were useful during the intubation of obese patients. The C-MAC D-blade video laryngoscope might be more useful for obese patients in terms of hemodynamic stability.

A Comparative Study Between Video Laryngoscope and Video Stylet for Tracheal Intubation in Patients With Simulated Cervical Fracture Injury: A Prospective Randomised Controlled Study

Purpose Video laryngoscopes were being used more often in cases of potentially difficult airways. The Karl Storz video stylet offered clear advantages over conventional laryngoscopes for patients with cervical spine fractures. This study aimed to compare the performance of the C-MAC video laryngoscope with the new Karl Storz video stylet in patients with simulated cervical fracture injuries. Material and methods The study, approved by the Board of Studies and the Ethical Committee of Jawaharlal Nehru Medical College and Hospital in Aligarh, involved 50 patients undergoing operative procedures under general anaesthesia. It was a prospective randomised controlled study on patients aged 20-60, weighing 30-80 kg, and classified as American Society of Anesthesiologists (ASA) Grades I and II, admitted for elective operative procedures. Patients were randomly assigned to two groups for intubation using different devices: the control group (N = 25) was intubated with the C-MAC (Mac blade) video laryngoscope (CM), and the study group (N = 25) was intubated with the Karl Storz video stylet (VS). The anaesthetic procedure involved a detailed pre-anesthetic check-up for all patients, including a medical history review, physical examination, and necessary tests based on age. Standard monitoring and pre-medication were administered uniformly. Anesthesia was induced and intubation was attempted using appropriate devices, following manual stabilisation of the neck. Parameters such as intubation attempts, time taken, failures, hemodynamic changes, and complications were recorded throughout the procedure. If intubation was unsuccessful, alternative measures were taken, and the operative procedure proceeded. Results The intubation success rates were compared between the two groups, CM and VS. In the CM group, all 25 patients (100%) were successfully intubated on the first attempt, while in the VS group, 23 patients (92%) were successfully intubated on the first attempt, and two patients (8%) required two attempts. The difference in the distribution of the number of attempts between the two groups was not statistically significant (p = 0.4915). The mean intubation time in the CM group was 27.24 ± 2.16 seconds, while in the VS group, the mean intubation time was significantly longer at 30.84 ± 6.81 seconds, with a statistically significant difference (p = 0.0105). Adjustment manoeuvres were required in only 4% of patients in the CM group compared to 0% in the VS group, although this difference was not statistically significant. The occurrence of blood on the device during intubation was recorded, and the distribution of patients with blood on the device among the two groups did not show a statistically significant difference (p = 0.617). Conclusion This study compared the effectiveness of two intubation devices. The C-MAC video laryngoscope showed a significantly higher rate of first-attempt successful intubations and required fewer attempts compared to the Karl Storz video stylet. The C-MAC also had shorter intubation times compared to the Karl Storz device. However, the Karl Storz video stylet demonstrated comparable performance to the C-MAC video laryngoscope in clinical settings, with both devices having similar safety profiles and minimal complications.

A comparative evaluation of fibreoptic bronchoscopy versus C-MAC® D-BLADE-guided videolaryngoscopy for nasotracheal intubation under general anesthesia in oropharyngeal carcinoma surgery patients

PURPOSE

Nasotracheal intubation (NTI) is required for surgery in oropharyngeal (OP) carcinoma patients, but it may be challenging because of distorted anatomy, mucosal congestion, and increased risk of bleeding. Flexible bronchoscopy (FB)-guided NTI is preferred in these cases but has limitations. In this randomized controlled study, we sought to compare C-MAC® D-BLADE-guided videolaryngoscopy (VL) (Karl Storz SE & Co. KG, Tuttlingen, Germany) with FB for NTI under general anesthesia in patients with OP carcinomas.

METHODS

We randomized a total of 100 patients with OP carcinoma and El-Ganzouri's risk index (EGRI) < 7 to undergo NTI under general anesthesia with FB (n = 50) or C-MAC D-BLADE-guided VL (n = 50). The primary outcome was the total intubation time. We also recorded the time to glottis view, nasal intubation difficulty scale (NIDS) score, best percentage of glottis opening score, and complications.

RESULTS

The median [interquartile range (IQR)] total intubation time was shorter with VL than with FB (total intubation time, 38 [26-43] sec vs 60 [52-65] sec; difference, -20 sec [95% confidence interval (CI), -27 to -11]; P < 0.001). Similarly, the median [IQR] time to glottis view was shorter with VL compared to FB (8 [6-9] sec vs 22 [14-25] sec; difference, -13 sec [95% CI, -17 to -10]; P < 0.001). The median NIDS score was higher with VL (difference, 2 [95% CI, 2 to 3]; P < 0.001). The incidences of airway trauma (two cases with FB vs seven with VL; P = 0.30) and postoperative sore throat (ten cases in both groups; P = 0.56) were similar.

CONCLUSION

Compared to FB, C-MAC D-BLADE-based VL reduced the total time for nasal intubation oropharyngeal carcinoma patients, potentially representing an acceptable alternative in selected cases.

TRIAL REGISTRATION

CTRI.nic.in (2018/11/0162830); first submitted 8 November 2018.

Comparison of video laryngoscope, video stylet, and flexible videoscope for transoral endotracheal intubation in patients with difficult airways: a randomized, parallel-group study

BACKGROUND

The 2022 ASA guidelines recommend the video laryngoscope, video stylet, and flexible videoscope as airway management tools. This study aims to compare the efficacy of three airway devices in intubating patients with difficult airways.

METHODS

A total of 177 patients were selected and randomized into the following three groups: the video laryngoscope group (Group VL, n = 59), video stylet group (Group VS, n = 59), and flexible videoscope group (Group FV, n = 59). The success rate of the first-pass intubation, time of tracheal intubation, level of glottic exposure, and occurrence of intubation-related adverse events were recorded and analyzed.

RESULTS

All patients were successfully intubated with three devices. The first-pass intubation success rate was significantly higher in Groups VS and FV than in Group VL (96.61% vs. 93.22% vs. 83.05%, P < 0.01), but it was similar in the first-pass intubation success rate between Groups VS and FV(P > 0.05). The number of patients categorized as Wilson-Cormack-Lehane grade I-II was fewer in Group VL than in Groups VS and FV (77.97% vs. 98.30% vs. 100%, P = 0.0281). The time to tracheal intubation was significantly longer in Group FV(95.20 ± 4.01) than in Groups VL(44.56 ± 4.42) and VS(26.88 ± 4.51) (P < 0.01). No significant differences were found among the three groups in terms of adverse intubation reactions (P > 0.05).

CONCLUSIONS

In patients with difficult airways requiring intubation, use of the video stylet has the advantage of a relatively shorter intubation time, and the flexible videoscope and video stylet yield a higher first-pass intubation success rate and clearer glottic exposure than the use of the video laryngoscope.

TRIAL REGISTRATION

Chinese Clinical Trial Registry. No: ChiCTR2200061560, June 29, 2022.

Comparison of haemodynamic response to tracheal intubation with two different videolaryngoscopes: A randomized clinical trial

BACKGROUND

Endotracheal intubation (ETI), which is the gold standard in coronary artery bypass grafting (CABG), may cause myocardial ischaemia by disturbing the balance between haemodynamic changes and oxygen supply and consumption of the myocardium as a result of sympathetic stimulation. In this study, we aimed to compare two different videolaryngoscopes (C-MAC and Airtraq) in the hemodynamic response to ETI.

METHODS

Fifty ASA II...III CABG surgery patients were randomly assigned to C-MAC or Airtraq. The hemodynamic data included arterial blood pressure [systolic (SAP), diastolic (DAP) and mean (MAP)] and heart rate (HR) and were recorded at six different points in time: before laryngoscopy-T1, during laryngoscopy-T2, immediately after intubation-T3, and 3 (T4), 5 (T5) and 10 (T6) minutes after intubation. Intraoperative complications were recorded. Patients were questioned about postoperative complications 2 and 24...hours following extubation.

RESULTS

The hemodynamic response to ETI was significantly greater with C-MAC. The increase in HR started with the laryngoscopy procedure, whereas increases in SAP, DAP, and MAP started immediately after ETI (p...=...0.024; p...=...0.012; p...=...0.030; p...=...0.009, respectively). In group analyses, T1...T2, T2...T3 and T1...T3 comparisons did not show any significant differences in HR with Airtraq. However, with C-MAC, HR after intubation increased significantly compared to the pre-laryngoscopy values (T1...T3) (p...=...0.004). The duration of laryngoscopy was significantly reduced with C-MAC (p...<...0.001), but the duration of intubation and total intubation were similar (p...=...0.36; p...=...0.79).

CONCLUSIONS

Compared to C-MAC, the hemodynamic response to ETI was less with Airtraq. Thus, Airtraq may be preferred in CABG patients for ETI.

Does videolaryngoscopy improve tracheal intubation first attempt success in the NICUs? A report from the NEAR4NEOS

OBJECTIVE

We hypothesized that videolaryngoscope use for tracheal intubations would differ across NICUs, be associated with higher first attempt success and lower adverse events.

STUDY DESIGN

Data from the National Emergency Airway Registry for Neonates (01/2015 to 12/2017) included intubation with direct laryngoscope or videolaryngoscope. Primary outcome was first attempt success. Secondary outcomes were adverse tracheal intubation associated events and severe desaturation.

RESULTS

Of 2730 encounters (13 NICUs), 626 (23%) utilized a videolaryngoscope (3% to 64% per site). Videolaryngoscope use was associated with higher first attempt success (p < 0.001), lower adverse tracheal intubation associated events (p < 0.001), but no difference in severe desaturation. After adjustment, videolaryngoscope use was not associated with higher first attempt success (OR:1.18, p = 0.136), but was associated with lower tracheal intubation associated events (OR:0.45, p < 0.001).

CONCLUSION

Videolaryngoscope use is variable, not independently associated with higher first attempt success but associated with fewer tracheal intubation associated events.

Awake videolaryngoscopic orotracheal intubation in patients with laryngeal tumour using the C-MAC D-Blade

Background and Aims:

This study assessed the applicability of C-MAC videolaryngoscope (VL) D-blade for awake intubation in patients with laryngeal tumour. The primary study objective was to determine the rate of successful intubation in the first attempt. The other parameters recorded were number of attempts required for intubation, duration of different stages of intubation, haemodynamics, ease of intubation and patient comfort on visual analogue scale (VAS) postoperatively.

Methods:

Thirty patients were studied. Patients were sedated with dexmedetomidine and fentanyl as a slow bolus (over 20 min) and Ramsay sedation score was assessed. Topicalisation of the oropharynx, tonsillar pillars and base of the tongue was done with lignocaine 10% spray. Four ml of 4% lignocaine using MADgic atomiser was used for anaesthetising the glottis and the tracheal lumen.

Results:

Successful intubation was achieved in 86.6% patients in first attempt and 13.3% in two attempts. Total time for all intubations was less than 30 seconds. Fremantle score was F-1-C-MAC D-blade (easy intubation with full view) in 60% patients, while 23.3% had F-2-C-MAC D-blade (full view and either required more than one attempt or a modified technique), 13.3% had P-1-C-MAC D-blade (partial view with easy intubation) and 3.3% had P-2-C-MAC D-blade (partial view and required more than one attempt or a modified technique). The VAS score for anaesthesiologist’s ease and for patient’s experience was 85.83 ± 7.20 and 86.66 ± 14.46, respectively.

Conclusion:

C-MAC VL D-blade-assisted awake intubation is an effective and safe method to manage the airway of patients with laryngeal tumour once adequate topicalisation is ensured before the procedure.

Comparison of the effects of the McGRATH MAC, C-MAC, and Macintosh laryngoscopes on the intraocular pressures of non-ophthalmic patients: A prospective, randomised, clinical trial

INTRODUCTION

In this prospective, randomised study, we compared the effects of the Macintosh, McGRATH MAC, and C-MAC laryngoscopes on intraocular pressure (IOP) and haemodynamics of non-ophthalmic patients during endotracheal intubation.

METHODS

One hundred and twenty adult patients undergoing non-ophthalmic surgeries performed in the supine position under general anaesthesia requiring orotracheal intubation were included in this study. The patients were separated randomly and prospectively into 3 groups: Macintosh group (n = 40), McGRATH MAC group (n = 40), and C-MAC group (n = 40). Mean arterial pressure (MAP), heart rate (HR) and IOP of left and right eye were measured at specified times.

RESULTS

There were no significant differences with regard to patients characteristics. After intubation, the HR increased significantly in the Macintosh group when compared to the other groups (p = 0.001) and the MAP increased significantly in the Macintosh group when compared to the McGRATH MAC group (p = 0.001) and the C-MAC group (p < 0.001). The IOP values increased in the Macintosh group when compared to the McGRATH MAC group (p < 0.001) and the C-MAC group (p < 0.001) after intubation. Additionally, there was a significant difference between the McGRATH MAC group and C-MAC group in the IOP values of the eyes after intubation (p < 0.001). According to the evaluation within the groups, there were significant differences in all of the groups at all times when compared with the baseline values (p < 0.001).

CONCLUSIONS

In this study, we concluded that the C-MAC VL may be preferable when compared to the Macintosh and McGRATH MAC laryngoscopes for use in ophthalmic patients in whom a rise in the IOP is undesirable.

A comparison of intubating conditions for nasotracheal intubation with standard direct Macintosh laryngoscope versus C-MAC® video laryngoscope employing cuff inflation technique in adult patients

Background and Aims:

While performing laryngoscopy during nasotracheal intubation (NTI), the tip of the advancing endotracheal tube (ETT) generally lies along the posterior pharyngeal wall. The inflation of the ETT cuff brings it anterior towards the glottis. The present study was planned to compare the intubating conditions for NTI with standard direct Macintosh laryngoscope versus C-MAC^® video laryngoscope (VL) employing ETT cuff inflation technique.

Methods:

This prospective randomised study was carried out on 50 patients, American Society of Anesthesiologists physical status I–II, age 18–60 years of either sex with an indication for NTI under general anaesthesia. They were randomly divided into two groups: group VL (n = 25): C-MAC^® VL and group ML (n = 25): Macintosh laryngoscope. The primary outcome was to compare the total duration of NTI (T), while the secondary outcomes were to compare the need for cuff inflation or assistance with Magill forceps for successful NTI, the total number of attempts to achieve successful NTI, haemodynamic effects and complications.

Results:

T was significantly higher in group ML than group VL (P < 0.001). The intubation was successful with cuff inflation in all the patients in group VL, however, six patients of group ML required assistance with Magill forceps (P = 0.022). The haemodynamic parameters were all significantly higher at 3 min in group ML in comparison to group VL.

Conclusion:

The cuff inflation technique when used along with C-MAC^® VL had more success rate, required lesser time and had minimal postoperative complications in comparison to the Macintosh laryngoscope.

A randomized control led study comparing CMAC video laryngoscope and Macintosh laryngoscope for insertion of double lumen tube in patients undergoing elective thoracotomy

Background and Aims

Double lumen tube (DLT) insertion for isolation of lung during thoracic surgery is challenging and is associated with considerable airway trauma. The advent of video laryngoscopy has revolutionized the management of difficult airway. Use of video laryngoscopy may reduce the time to intubate for DLTs even in patients with normal airway.

Material and Methods

A total of 87 ASA 1-3 adults, scheduled to undergo elective thoracotomy, requiring a DLT were randomly allocated to videolaryngoscope (CMAC) arm or Macintosh laryngoscope arm. It was on open label study, and only the patient was blinded. The primary objective of this study was to compare the mean time taken for DLT intubation with CMAC (Mac 3) and Macintosh laryngoscope blade and the secondary objectives included the hemodynamic response to intubation, the level of difficulty using the intubation difficulty scale (IDS), and complications associated with intubation. Data was analysed using the statistical software SPSS (version 18.0).

Results

The time taken for intubation was not significantly different (42.8 ± 14.8 s for CMAC and 42.5 ± 11.5 s for Macintosh laryngoscope P -0.908). The CMAC video laryngoscope was associated with an improved laryngoscopy grade (Grade I in 81.8% with CMAC and in 46.5% with Macintosh), less pressure applied on the tongue, and less external laryngeal pressure required. Hemodynamic responses to intubation were similar in both groups.

Conclusion

Macintosh blade is as good as CMAC (mac 3) blade to facilitate DLT intubation in adult patients with no anticipated airway difficulty, however CMAC was superior as it offers better laryngoscopic view, needed less force, and fewer external laryngeal manipulations.

Comparison of aerosol box intubation with C-MAC video laryngoscope and direct laryngoscopy-A randomised controlled trial

Background and Aims:

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is a highly infectious disease and healthcare workers are at constant risk for contracting it. Nowadays, aerosol box is used in conjunction with WHO-recommended safety kits, to avoid health workers from getting SARS-CoV-2 infection during aerosol-generating procedures. In our study, we compared the ease of oral intubation with C-MAC video laryngoscope and direct laryngoscopy, when the aerosol box was used. The secondary objectives were to compare the incidence of airway loss, haemodynamic changes, number of attempts, and time required for intubation between these two techniques.

Methods:

This prospective randomised controlled study was conducted on 60 non-coronavirus disease (COVID) patients presenting for elective surgery under general anaesthesia. Patients were randomly assigned into two groups:C and D using a computer-generated random sequence of numbers by closed envelope technique. In group D, laryngoscopy was performed with Macintosh blade and in group C, with Storz® C-MAC video laryngoscope.

Results:

The ease of intubation was better (grade 1) in group C than D (68.6% vs. 31.4% respectively) with a P value of < 0.001. 10% of patients required more than one intubation attempt in group D compared to none in group C, but this difference was not statistically significant. The intubation time was comparable between the two groups. There were no incidences of loss of airway or failure to intubate in both groups.

Conclusion:

The use of C-MAC video-laryngoscopy resulted in easier orotracheal intubation as compared to intubation with direct laryngoscopy when the aerosol box was used.

Comparison of conventional C-MAC video laryngoscope guided intubation by anesthesia trainees with and without Frova endotracheal introducer: A randomized clinical trial

BACKGROUND AND AIMS

Successful intubation with video laryngoscopes necessitates good hand-eye coordination and the use of intubation adjuncts like bougie and stylet. We proposed this study to find whether using Frova introducer with C-MAC video laryngoscope will reduce the intubation time in trainee anesthesiologists.

MATERIAL AND METHODS

We enrolled 140 adults without any difficult airway predictors. They were randomly assigned to undergo C-MAC video laryngoscope guided intubation by anesthesia residents using tracheal tube preloaded over Frova introducer (n = 70) or without Frova introducer (n = 70). Primary outcome was the intubation time. Secondary outcomes were the number of redirections of tracheal tube or Frova introducer toward glottis, need for external laryngeal maneuvers (ELMs), first attempt intubation success rate, and ease of intubation.

RESULTS

The median actual intubation time (IQR) in Frova and non-Frova group, respectively, were 25.46 (28.11-19.80) and 19.96 (26.59-15.52) s (P = 0.001). The number of redirections of TT or Frova introducer toward glottis, first attempt success rate, and ease of intubation were comparable. The need for ELMs [n (%)] was 15 (21.4) and 26 (37.1) in Frova and non-Frova group, respectively (P = 0.04).

CONCLUSION

Frova introducer guided endotracheal intubation with C-MAC videolaryngoscope in patients with normal airways had a marginally prolonged intubation time with a significant reduction in the need of external laryngeal manoeuvres but with a comparable number of redirections and attempts. Further research is needed to generalize these findings to patients with difficult airways.

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.

Comparison of videolaryngoscope-guided versus standard digital insertion techniques of the ProSeal™ laryngeal mask airway: a prospective randomized study

Background

This study were designed to investigate the usefulness of the videolaryngoscope-guided insertion technique compared with the standard digital technique for the insertion success rate and insertion conditions of the Proseal™ laryngeal mask airway (PLMA).

Methods

Prospective, one hundred and nineteen patients (ASA I–II, aged 18–65 yr) were randomly divided for PLMA insertion using the videolaryngoscope-guided technique or the standard digital technique. The PLMA was inserted according to the manufacturer’s instructions in the standard digital technique group. The videolaryngoscope-guided technique was performed a C-MAC® videolaryngoscope with D-Blade, under gentle videolaryngoscope guidance, the epiglottis was lifted, and the PLMA was advanced until the tip of the distal cuff reached the oesophagus inlet. The number of insertion attempts, insertion time, oropharyngeal leak pressure, leak volume, fiberoptic bronchoscopic view, peak inspiratory pressure, ease of gastric tube placement, hemodynamic changes, visible blood on PLMA and postoperative airway morbidity were recorded.

Results

The first-attempt success rate (the primary outcome) was higher in the videolaryngoscope-guided technique than in the standard digital technique (p = 0.029). The effect size values with 95% confidence interval were 0.19 (0.01–0.36) for the first and second attempts, 0.09 (− 0.08–0.27) for the first and third attempts, and not computed for the second and third attempts by the groups, respectively.

Conclusion

Videolaryngoscope-guided insertion technique can be a help in case of difficult positioning of a PLMA and can improve the PLMA performance in some conditions. We suggest that the videolaryngoscope-guided technique may be a useful technique if the digital technique fails.

Trial registration

ClinicalTrials.gov NCT03852589 date of registration: February 22th 2019.

Comparison of Laryngoscopic Views betweenC-MAC™ and Conventional Laryngoscopy in Patients with Multiple Preoperative Prognostic Criteria of Difficult Intubation. An Observational Cross-Sectional Study

Background and Objectives: Video laryngoscopy has been proven useful under difficult airway scenarios, but it is unclear whether anticipated improvement of visualization is related to specific difficult intubation prognostic factors. The present study evaluated the change in laryngoscopic view between conventional and C-MAC^® laryngoscopy and the presence of multiple difficult intubation risk factors. Materials and Methods: Patients scheduled for elective surgery with >2 difficult intubation factors, (Mallampati, thyromental distance (TMD), interinscisor gap, buck teeth, upper lip bite test, cervical motility, body mass index (BMI)) were eligible. Patients underwent direct laryngoscopy (DL) followed by C-MAC™ laryngoscopy (VL) and intubation. Change of view between DL and VL, time for best view, intubation difficulty scale (IDS) and correlation between prognostic factors, laryngoscopic view improvement, and IDS were measured. Results: One-hundred and seventy-six patients completed the study. VL lead to fewer Cormarck–Lehane (C/L) III-IV, compared to DL (13.6% versus 54.6%, p < 0.001). The time to best view was also shorter (VL: 10.82 s, DL: 12.08 s, p = 0.19). Mallampati III-IV and TMD ≤ 6 cm were related to improvement of C/L between DL and VL. Logistic regression showed these two factors to be a significant risk factor of the glottis view change (p = 0.006, AUC-ROC = 0.57, 95% CI: 0.47–0.66). 175/176 patients were intubated with VL. 108/176 were graded as 0 < IDS ≤ 5 and 12/176 as IDS > 5. IDS was only correlated to the VL view (p < 0.0001). Conclusion: VL improved laryngoscopic view in patients with multiple factors of difficult intubation. Mallampati and TMD were related to the improved view. However, intubation difficulty was only related to the VL view and not to prognostic factors.

The midline approach for endotracheal intubation using GlideScope video laryngoscopy could provide better glottis exposure in adults: a randomized controlled trial

Background

Previous studies have demonstrated that the common laryngoscopic approach (right-sided) and midline approach are both used for endotracheal intubation by direct laryngoscopy. Although the midline approach is commonly recommended for video laryngoscopy (VL) in the clinic, there is a lack of published evidences to support this practice. This study aimed to evaluate the effects of different video laryngoscopic approaches on intubation.

Methods

Two hundred sixty-two patients aged 18 years who underwent elective surgery under general anaesthesia and required endotracheal intubation were included in the present prospective, randomized, controlled study. The participants were randomly and equally allocated to the right approach (Group R) or midline approach (Group M). All the intubations were conducted by experienced anaesthetists using GlideScope video laryngoscopy. The primary outcomes were Cormack-Lehane laryngoscopic views (CLVs) and first-pass success (FPS) rates. The secondary outcomes were the time to glottis exposure, time to tracheal intubation, haemodynamic responses and other adverse events. Comparative analysis was performed between the groups.

Results

Finally, 262 patients completed the study, and all the tracheas were successfully intubated. No significant differences were observed in the patient characteristics and airway assessments (P > 0.05). Compared with Group R, Group M had a better CLV (χ2 = 14.706, P = 0.001) and shorter times to glottis exposure (8.82 ± 2.04 vs 12.38 ± 1.81; t = 14.94; P < 0.001) and tracheal intubation (37.19 ± 5.01 vs 45.23 ± 4.81; t = 13.25; P < 0.001), but no difference was found in the FPS rate (70.2% vs 71.8%; χ2 = 0.074; P = 0.446) and intubation procedure time (29.86 ± 2.56 vs 30.46 ± 2.97, t = 1.75, P = 0.081). Between the groups, the rates of hoarseness or sore throat, minor injury, hypoxemia and changes in SBP and HR showed no significant difference (P > 0.05).

Conclusion

Although the FPS rate did not differ based on the laryngoscopic approach, the midline approach could provide better glottis exposure and shorter times to glottis exposure and intubation. The midline approach should be recommended for teaching in VL-assisted endotracheal intubation.

Trial registration

The study was registered on May 18, 2019 in the Chinese Clinical Trial Registry (ChiCTR1900023252).

A Synopsis of Contemporary Anesthesia Airway Management

New airway equipment has recently become available that has reduced morbidity and mortality. However, airway disasters still occur. This article discusses the prudent escalation of the use of advanced airway equipment to prevent these disasters. We illustrate when and how to use a gum elastic bougie and a video-laryngoscope (VL). We also strongly recommend the combined use of the VL together with a flexible intubation scope (FIS) for both asleep and awake intubation when dealing with a genuinely difficult airway. Blind intubations should no longer be performed today. When an airway has been recognized as difficult it is the safest to aim for an awake or at least a spontaneously breathing intubation if circumstances do not allow for an awake intubation. Emergency cricothyroidotomy needs to be prepared for so that it can be executed rapidly in case the attempted awake intubation leads to complete airway obstruction.

The use of the C-MAC videolaryngoscope for awake intubation in patients with a predicted extremely difficult airway: case series

The C-MAC videolaryngoscope was evaluated for intubation in patients with predicted extremely difficult airway. The presented cases are patients with neoplasm tumors in larynx. In all cases, awake intubation using C-MAC videolaryngoscope was performed in patients breathing spontaneously, under local anaesthesia, with oxygen administered via nasal catheter. All intubations were successful and uneventful. The pre-surgery examination (CT scans and fiberscope laryngeal examination) was compared with view of larynx obtained during laryngoscopy. Based on my experience, I assume that C-MAC videolaryngoscope is a very useful tool for anaesthesiologists and can be applied not only for unexpected difficult intubation but also for predicted difficult airway. Moreover, it could be used as an additional diagnosis tool before larynx surgery. The view obtained with the C-MAC videlaryngoscope corresponds with larynx examination performed before surgery, and could potentially reveal more details.

Video laryngoscopy does not improve the intubation outcomes in emergency and critical patients - a systematic review and meta-analysis of randomized controlled trials

Background

There is significant controversy regarding the influence of video laryngoscopy on the intubation outcomes in emergency and critical patients. This systematic review and meta-analysis was designed to determine whether video laryngoscopy could improve the intubation outcomes in emergency and critical patients.

Methods

We searched the Cochrane Central Register of Controlled Trials, PubMed, Embase, and Scopus databases from database inception until 15 February 2017. Only randomized controlled trials comparing video and direct laryngoscopy for tracheal intubation in emergency department, intensive care unit, and prehospital settings were selected. The primary outcome was the first-attempt success rate. Review Manager 5.3 software was used to perform the pooled analysis and assess the risk of bias for each eligible study. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to assess the quality of evidence for all outcomes.

Results

Twelve studies (2583 patients) were included in the review for data extraction. Pooled analysis did not show an improved first-attempt success rate using video laryngoscopy (relative risk [RR], 0.93; P = 0.28; low-quality evidence). There was significant heterogeneity among studies (I² = 91%). Subgroup analyses showed that, in the prehospital setting, video laryngoscopy decreased the first-attempt success rate (RR, 0.57; P < 0.01; high-quality evidence) and overall success rate (RR, 0.58; 95% CI, 0.48–0.69; moderate-quality evidence) by experienced operators, whereas in the in-hospital setting, no significant difference between two devices was identified for the first-attempt success rate (RR, 1.06; P = 0.14; moderate-quality evidence), regardless of the experience of the operators or the types of video laryngoscopes used (P > 0.05), although a slightly higher overall success rate was shown (RR, 1.11; P = 0.03; moderate-quality evidence). There were no differences between devices for other outcomes (P > 0.05), except for a lower rate of esophageal intubation (P = 0.01) and a higher rate of Cormack and Lehane grade 1 (P < 0.01) when using video laryngoscopy.

Conclusions

On the basis of the results of this study, we conclude that, compared with direct laryngoscopy, video laryngoscopy does not improve intubation outcomes in emergency and critical patients. Prehospital intubation is even worsened by use of video laryngoscopy when performed by experienced operators.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1885-9) contains supplementary material, which is available to authorized users.