Randomized controlled trial of the Pentax AWS, Glidescope, and Macintosh laryngoscopes in predicted difficult intubation

Pro-Con Debate: Videolaryngoscopy Should Be Standard of Care for Tracheal Intubation

In this Pro-Con commentary article, we discuss whether videolaryngoscopy (VL) should be the standard of care for tracheal intubation. Dr Aziz makes the case that VL should be the standard of care, while Dr Berkow follows with a challenge of that assertion. In this debate, we explore not only the various benefits of VL, but also its limitations. There is compelling evidence that VL improves first-pass success rates, reduces the risk of intubation failure and esophageal intubation, and has benefits in the difficult airway patient. But VL is not without complications and does not possess a 100% success rate. In the case of failure, it is important to have back-up plans for airway management. While transition of care from direct laryngoscopy (DL) to VL may result in improved airway management outcomes, the reliance on VL may degrade other important clinical skills when they are needed most. If VL is adapted as the standard of care, airway managers may no longer practice and retain competency in other airway techniques that may be required in the event of VL failure. While cost is a barrier to broad implementation of VL, those costs are normalizing. However, it may still be challenging for institutions to secure purchase of VL for every intubating location, as well as back-up airway devices. As airway management care increasingly transitions from DL to VL, providers should be aware of the benefits and risks to this practice change.

Hemodynamic response related to the Airway Scope versus the Macintosh laryngoscope: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

It is important to reduce the hemodynamic response during tracheal intubation. We performed a systematic review and meta-analysis of the Airway Scope and Macintosh laryngoscope to determine whether they reduce the hemodynamic responses of heart rate (HR) and mean blood pressure (MBP) after tracheal intubation under general anesthesia.

METHODS

We performed a comprehensive literature search of electronic databases for clinical trials comparing hemodynamic response to tracheal intubation. The primary aim of our meta-analyst is to determine if the Airway Scope reduces hemodynamic responses (HR and mean MBP) 60 seconds after tracheal intubation compared to the Macintosh laryngoscope. We expressed pooled differences in hemodynamic responses between the 2 devices as weighted mean differences with 95% confidence intervals. We conducted trial sequential analysis. Secondarily, we investigated the ability of the Airway Scope and Macintosh laryngoscope to reduce hemodynamic responses at 120 seconds, 180 seconds, and 300 seconds after tracheal intubation.

RESULTS

We identified clinical trials comparing hemodynamic response via a comprehensive literature search. Of 185 articles found in the search, we selected 8. In comparison to the Macintosh laryngoscope, the Airway Scope significantly reduced HR and MBP at 60 seconds after tracheal intubation (HR; weighted mean difference = -7.29; 95% confidence interval, -10.9 to -3.62; P < .0001; I2 = 57%, MBP; weighted mean difference = -11.5; 95% confidence interval, -20.4 to -2.65; P = .01; I2 = 91%). At the secondary outcome, the Airway Scope significantly reduced the fluctuation of HR after 120 seconds and 180 seconds of tracheal intubation. However, the Airway Scope did not significantly reduce MBP 120 seconds, 180 seconds, and 300 seconds after tracheal intubation. Trial sequential analysis suggested that the total sample size reached the required information size for heart rate.

CONCLUSIONS

Our finding suggested that the Airway Scope attenuated hemodynamic responses at 60 seconds after tracheal intubation in comparison with that of the Macintosh laryngoscope. However, the MBP sample size is small and further research is needed.

Standard and flexible tip bougie for tracheal intubation using a non-channelled hyperangulated videolaryngoscope: a randomised comparison. Anaesthesia 2022;77:1368-1375. [PMID: 36066179 DOI: 10.1111/anae.15854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Bougie impingement during tracheal intubation can increases the likelihood of prolonged intubation time, failed intubation and airway trauma. A flexible tip bougie may overcome this problem, which can occur when using a non-channelled, hyperangulated videolaryngoscope with a standard bougie. This randomised controlled study compared standard and flexible tip bougies using a non-channelled videolaryngoscope (C-MAC® D-blade) in 160 patients. The primary outcome measure was the modified intubation difficulty scale score. Secondary outcome measures were: laryngoscopy time; total tracheal intubation time; first attempt success rate; and postoperative sore throat verbal rating score. The median (IQR [range]) modified intubation difficulty scale scores for standard bougie and flexible tip bougie were 1 (0-2[0-5]) and 0 (0-1[0-3]), respectively (p = 0.001). There was no significant differences in laryngoscopy time, total tracheal intubation time, first attempt success rate and postoperative sore throat between the two groups. Both the flexible tip and standard bougies can be used with a high first attempt success rate for tracheal intubation using a C-MAC D-blade videolaryngoscope. The flexible tip bougie demonstrated a significantly better modified intubation difficulty scale score and lower incidence of bougie impingement.

Videolaryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation

BACKGROUND

Tracheal intubation is a common procedure performed to secure the airway in adults undergoing surgery or those who are critically ill. Intubation is sometimes associated with difficulties and complications that may result in patient harm. While it is traditionally achieved by performing direct laryngoscopy, the past three decades have seen the advent of rigid indirect videolaryngoscopes (VLs). A mounting body of evidence comparing the two approaches to tracheal intubation has been acquired over this period of time. This is an update of a Cochrane Review first published in 2016.

OBJECTIVES

To assess whether use of different designs of VLs in adults requiring tracheal intubation reduces the failure rate compared with direct laryngoscopy, and assess the benefits and risks of these devices in selected population groups, users and settings.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and Web of Science on 27 February 2021. We also searched clinical trials databases, conference proceedings and conducted forward and backward citation searches.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs with adults undergoing laryngoscopy performed with either a VL or a Macintosh direct laryngoscope (DL) in any clinical setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We collected data for the following outcomes: failed intubation, hypoxaemia, successful first attempt at tracheal intubation, oesophageal intubation, dental trauma, Cormack-Lehane grade, and time for tracheal intubation.

MAIN RESULTS

We included 222 studies (219 RCTs, three quasi-RCTs) with 26,149 participants undergoing tracheal intubation. Most studies recruited adults undergoing elective surgery requiring tracheal intubation. Twenty-one studies recruited participants with a known or predicted difficult airway, and an additional 25 studies simulated a difficult airway. Twenty-one studies were conducted outside the operating theatre environment; of these, six were in the prehospital setting, seven in the emergency department and eight in the intensive care unit.  We report here the findings of the three main comparisons according to videolaryngoscopy device type. We downgraded the certainty of the outcomes for imprecision, study limitations (e.g. high or unclear risks of bias), inconsistency when we noted substantial levels of statistical heterogeneity and publication bias. Macintosh-style videolaryngoscopy versus direct laryngoscopy (61 studies, 9883 participants) We found moderate-certainty evidence that a Macintosh-style VL probably reduces rates of failed intubation (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.26 to 0.65; 41 studies, 4615 participants) and hypoxaemia (RR 0.72, 95% CI 0.52 to 0.99; 16 studies, 2127 participants). These devices may also increase rates of success on the first intubation attempt (RR 1.05, 95% CI 1.02 to 1.09; 42 studies, 7311 participants; low-certainty evidence) and probably improve glottic view when assessed as Cormack-Lehane grade 3 and 4 (RR 0.38, 95% CI 0.29 to 0.48; 38 studies, 4368 participants; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.51, 95% CI 0.22 to 1.21; 14 studies, 2404 participants) but this finding was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of this evidence was very low (RR 0.68, 95% CI 0.16 to 2.89; 18 studies, 2297 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 96%). Hyperangulated videolaryngoscopy versus direct laryngoscopy (96 studies, 11,438 participants) We found moderate-certainty evidence that hyperangulated VLs probably reduce rates of failed intubation (RR 0.51, 95% CI 0.34 to 0.76; 63 studies, 7146 participants) and oesophageal intubation (RR 0.39, 95% CI 0.18 to 0.81; 14 studies, 1968 participants). In subgroup analysis, we noted that hyperangulated VLs were more likely to reduce failed intubation when used on known or predicted difficult airways (RR 0.29, 95% CI 0.17 to 0.48; P = 0.03 for subgroup differences; 15 studies, 1520 participants). We also found that these devices may increase rates of success on the first intubation attempt (RR 1.03, 95% CI 1.00 to 1.05; 66 studies, 8086 participants; low-certainty evidence) and the glottic view is probably also improved (RR 0.15, 95% CI 0.10 to 0.24; 54 studies, 6058 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). However, we found low-certainty evidence of little or no clear difference in rates of hypoxaemia (RR 0.49, 95% CI 0.22 to 1.11; 15 studies, 1691 participants), and the findings for dental trauma were unclear because the certainty of this evidence was very low (RR 0.51, 95% CI 0.16 to 1.59; 30 studies, 3497 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 99%). Channelled videolaryngoscopy versus direct laryngoscopy (73 studies, 7165 participants) We found moderate-certainty evidence that channelled VLs probably reduce rates of failed intubation (RR 0.43, 95% CI 0.30 to 0.61; 53 studies, 5367 participants) and hypoxaemia (RR 0.25, 95% CI 0.12 to 0.50; 15 studies, 1966 participants). They may also increase rates of success on the first intubation attempt (RR 1.10, 95% CI 1.05 to 1.15; 47 studies, 5210 participants; very low-certainty evidence) and probably improve glottic view (RR 0.14, 95% CI 0.09 to 0.21; 40 studies, 3955 participants; data for Cormack-Lehane grade 3/4 views; moderate-certainty evidence). We found little or no clear difference in rates of oesophageal intubation (RR 0.54, 95% CI 0.17 to 1.75; 16 studies, 1756 participants) but this was supported by low-certainty evidence. We were unsure of the findings for dental trauma because the certainty of the evidence was very low (RR 0.52, 95% CI 0.13 to 2.12; 29 studies, 2375 participants). We were not able to pool data for time required for tracheal intubation owing to considerable heterogeneity (I2 = 98%).

AUTHORS' CONCLUSIONS

VLs of all designs likely reduce rates of failed intubation and result in higher rates of successful intubation on the first attempt with improved glottic views. Macintosh-style and channelled VLs likely reduce rates of hypoxaemic events, while hyperangulated VLs probably reduce rates of oesophageal intubation. We conclude that videolaryngoscopy likely provides a safer risk profile compared to direct laryngoscopy for all adults undergoing tracheal intubation.

Optimization of Intraoperative Neural Monitoring of the Recurrent Laryngeal Nerve in Thyroid Surgery

The application of intraoperative neural monitoring (IONM) has been widely accepted to improve surgical outcomes after thyroid surgery. The malfunction of an IONM system might interfere with surgical procedures. Thus, the development of anesthesia modalities aimed at ensuring functional neuromonitoring is essential. Two key issues should be taken into consideration for anesthetic management. Firstly, most patients undergo recurrent laryngeal nerve monitoring via surface electrodes embedded in an endotracheal tube. Thus, advanced video-assisted devices might optimize surface electrode positioning for improved neuromonitoring signaling accuracy. Secondly, neuromuscular blocking agents are routinely used during thyroid surgery. The ideal neuromuscular block should be deep enough for surgical relaxation at excision and recovered enough for an adequate signal f nerve stimulation. Proper neuromuscular block management could be achieved by titration doses of muscle relaxants and reversal agents.

Comparisons of Videolaryngoscopes for Intubation Undergoing General Anesthesia: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: The efficacy and safety of videolaryngoscopes (VLs) for tracheal intubation is still conflicting and changeable according to airway circumstances. This study aimed to compare the efficacy and safety of several VLs in patients undergoing general anesthesia. Methods: Medline, EMBASE, and the Cochrane Library were searched until 13 January 2020. The following VLs were evaluated compared to the Macintosh laryngoscope (MCL) by network meta-analysis for randomized controlled trials (RCTs): Airtraq, Airwayscope, C-MAC, C-MAC D-blade (CMD), GlideScope, King Vision, and McGrath. Outcome measures were the success and time (speed) of intubation, glottic view, and sore throat (safety). Results: A total of 9315 patients in 96 RCTs were included. The highest-ranked VLs for first-pass intubation success were CMD (90.6 % in all airway; 92.7% in difficult airway) and King Vision (92% in normal airway). In the rank analysis for secondary outcomes, the following VLs showed the highest efficacy or safety: Airtraq (safety), Airwayscope (speed and view), C-MAC (speed), CMD (safety), and McGrath (view). These VLs, except McGrath, were more effective or safer than MCL in moderate evidence level, whereas there was low certainty of evidence in the intercomparisons of VLs. Conclusions: CMD and King Vision could be relatively successful than MCL and other VLs for tracheal intubation under general anesthesia. The comparisons of intubation success between VLs and MCL showed moderate certainty of evidence level, whereas the intercomparisons of VLs showed low certainty evidence.

Comparison of Vie Scope® and Macintosh laryngoscopes for intubation during resuscitation by paramedics wearing personal protective equipment

Background

Endotracheal intubation (ETI) is still the gold standard of airway management, but in cases of sudden cardiac arrest in patients with suspected SARS-CoV-2 infection, ETI is associated with risks for both the patient and the medical personnel. We hypothesized that the Vie Scope® is more useful for endotracheal intubation of suspected or confirmed COVID-19 cardiac arrest patients than the conventional laryngoscope with Macintosh blade when operators are wearing personal protective equipment (PPE).

Methods

Study was designed as a prospective, multicenter, randomized clinical trial performed by Emergency Medical Services in Poland. Patients with suspected or confirmed COVID-19 diagnosis who needed cardiopulmonary resuscitation in prehospital setting were included. Patients under 18 years old or with criteria predictive of impossible intubation under direct laryngoscopy, were excluded.

Patients were randomly allocated 1:1 to Vie Scope® versus direct laryngoscopy with a Macintosh blade. Study groups were compared on success of intubation attempts, time to intubation, glottis visualization and number of optimization maneuvers.

Results

We enrolled 90 out-of-hospital cardiac arrest (OHCA) patients, aged 43–92 years. Compared to the VieScope® laryngoscope, use of the Macintosh laryngoscope required longer times for tracheal intubation with an estimated mean difference of −48 s (95%CI confidence interval [CI], −60.23, −35.77; p < 0.001). Moreover VieScope® improved first attempt success rate, 93.3% vs. 51.1% respectively (odds ratio [OR] = 13.39; 95%CI: 3.62, 49.58; p < 0.001).

Conclusions

The use of the Vie Scope® laryngoscope in OHCA patients improved the first attempt success rate, and reduced intubation time compared to Macintosh laryngoscope in paramedics wearing PPE for against aerosol generating procedures.

Trial registration: ClinicalTrials registration number NCT04365608

Success rate and duration of orotracheal intubation of premature infants by healthcare providers with different levels of experience using a video laryngoscope as compared to direct laryngoscopy in a simulation-based setting

BACKGROUND

Endotracheal intubation of very low birth weight infants (VLBWI) is an essential procedure in NICUs, but intubation experience is often limited. Video laryngoscopy (VL) has been described as a tool to improve intubation skills, but studies in high-risk neonatal populations are limited.

OBJECTIVE

The aim of this study was to investigate whether VL is a useful tool to support airway management in high-risk premature infants with inexperienced operators.

METHODS

In this crossover study predominantly inexperienced participants were exposed in random sequence to VL and conventional direct laryngoscopy (DL) for endotracheal intubation of a VLBWI simulation manikin to measure total time, number of attempts, success rate on first attempt, view of the vocal cords and perceived subjective safety until successful intubation.

RESULTS

In our study group of 94 participants there was no significant difference in the total time (mean VL: 34 s (±24 s); DL: 37 s (±28 s), p = 0.246), while the number of intubation attempts using VL was significantly lower (mean VL: 1.22 (±0.53); DL: 1.37 (±0.60), p = 0.023). Success rate of VL during the first attempt was significantly higher (VL: 84%; DL 69%, p = 0.016), view of the vocal cords was significantly better and perceived subjective safety was increased using VL.

CONCLUSIONS

Our study results suggest that with rather inexperienced operators, VL can be a useful tool to increase rate of successful endotracheal intubation of VLBWI and to improve their perceived safety during the procedure, which may have an impact on mortality and/or morbidity.

2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway

The American Society of Anesthesiologists; All India Difficult Airway Association; European Airway Management Society; European Society of Anaesthesiology and Intensive Care; Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care; Learning, Teaching and Investigation Difficult Airway Group; Society for Airway Management; Society for Ambulatory Anesthesia; Society for Head and Neck Anesthesia; Society for Pediatric Anesthesia; Society of Critical Care Anesthesiologists; and the Trauma Anesthesiology Society present an updated report of the Practice Guidelines for Management of the Difficult Airway.

A comparative study of the efficacy of Glidescope versus Macintosh direct laryngoscopy for intubation in pediatric patients undergoing cardiac surgery

Background:

The Glidescope is a novel, portable, reusable video laryngoscope that has provided superior laryngeal visualization to facilitate tracheal intubation, especially in the management of difficult airways. In this study, we aimed to compare the efficacy of the Glidescope (video-laryngoscope) against the Macintosh direct laryngoscope.

Methods:

Fifty patients were randomly selected via simple randomization using computer-generated random numbers, and sorted into two groups of 25 patients: the Glidescope group and the Macintosh group. We included pediatric patients undergoing cardiac surgery for the repair of congenital heart disease. Those with suspected difficult intubation, preterm babies with low body weight, and patients at risk of aspiration were all excluded.

Results:

Patients’ baseline demographic and clinical characteristics were found to be comparable in the two groups. The mean intubation time was 24.1 ± 13.6 s in the Glidescope group, as compared to 18.1 ± 5.9 s in the Macintosh group. Blade insertion was easy in 92% and 96% of the patients in the Glidescope and Macintosh groups, respectively. Tracheal intubation was considered easy in 84% of the Glidescope group, compared to 92% of the Macintosh group. There was a statistically significant correlation between the ease of tracheal intubation and the used intubation method (rho = –0.35; P = 0.014).

Conclusion:

Our findings indicate that the Glidescope can be used as an efficient modality for obtaining successful intubations with no complications. Ease of tracheal intubation was the only outcome that was found to be affected by the used modality. Further investigations with proper sample sizes are needed.

Effects of tip-manipulated stylet angle on intubation using the GlideScope® videolaryngoscope in children: A prospective randomized controlled trial

BACKGROUND

An optimal endotracheal tube curve can be a key factor in successful intubation using the GlideScope videolaryngoscope.

AIMS

This study aimed to evaluate the effects of tube tip-modified stylet curve on the intubation time in children.

METHODS

Children aged 1-5 years were randomly assigned to either the standard curve (group S, n = 60) or tip-modified curve (group T, n = 60) groups. In group S, the endotracheal tube curve was similar to that in the GlideScope. In group T, a point approximately 1.5 cm from the tube tip was additionally angled to the left by 15°-20°. The primary outcome was the total intubation time, and the secondary outcomes were incidence of successful intubation in the first attempt, number of additional manipulations of the stylet curve, and visual analog scale (VAS) score for the easiness of intubation.

RESULTS

The mean total intubation time was significantly longer in group S than that in group T (13.9 [10.8] vs. 9.0 [3.4] sec, mean difference, 4.9 s; 95% confidence interval [CI], 2.0-7.8; p = .001). All patients in group T were successfully intubated in the first attempt, whereas those in group S were not (100% vs. 93.3%, relative risk [RR], 0.11; 95% CI, 0.01-2.02; p = .1376). Three patients in group S could be intubated after modifying the ETT curve similar to that in group T. Operators reported that tracheal intubation was easier in group T than in group S (median [interquartile range] for VAS; 1 [1-2] vs. 2 [1-3]; p < .001).

CONCLUSIONS

Having additional angle of the endotracheal tube tip to the left could be a useful technique to facilitate directing and advancing endotracheal tube into the vocal cords.

Difficult Airway Management in Adult COVID-19 Patients: Statement by the Society of Airway Management

The COVID-19 disease, caused by Coronavirus SARS-CoV-2, often results in severe hypoxemia requiring airway management. Because SARS CoV-2 virus is spread via respiratory droplets, bag-mask ventilation, intubation, and extubation may place health care workers (HCW) at risk. While existing recommendations address airway management in patients with COVID-19, no guidance exists specifically for difficult airway management. Some strategies normally recommended for difficult airway management may not be ideal in the setting of COVID-19 infection. To address this issue the Society for Airway Management (SAM) created a task force to review existing literature and current Practice Guidelines for management of the difficult airway by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. SAM task force created recommendations for management of known or suspected difficult airway in the setting of known or suspected COVID-19 infection. The goal of the task force was to optimize successful airway management while minimizing exposure risk. Each member conducted a literature review on specific clinical practice section utilizing standard search engines (PubMed, Ovid, Google Scholar). Existing recommendations and evidence for difficult airway management in COVID-19 context were developed. Each specific recommendation was discussed among task force members and modified until unanimously approved by all task force members. Elements of AGREE Reporting Checklist for dissemination of clinical practice guidelines were utilized to develop this statement. Airway management in the COVID-19 patient increases HCW exposure risk. and difficult airway management often takes longer, may involve multiple procedures with aerosolization potential, strict adherence to personal protective equipment (PPE) protocols is mandatory to reduce risk to providers. When patient's airway risk assessment suggests awake tracheal intubation is an appropriate choice of technique, procedures that may cause increased aerosolization of secretions should be avoided. Optimal preoxygenation before induction with tight seal facemask may be performed to reduce risk of hypoxemia. Unless the patient is experiencing oxygen desaturation, positive pressure bag-mask ventilation after induction may be avoided to reduce aerosolization. For optimal intubating conditions, patients should be anesthetized with full muscle relaxation. Videolaryngoscopy is recommended as first-line strategy for airway management. If emergent invasive airway access is indicated, we recommend a surgical technique such as scalpel-bougie-tube, rather than an aerosolizing generating procedure, such as transtracheal jet ventilation. This statement represents recommendations by SAM task force for the difficult airway management of adults with COVID-19 with the goal to optimize successful airway management while minimizing the risk of clinician exposure.

Evaluation of transmitted glow point at a priori chosen depth (1 cm below vocal cords) for lightwand intubation: a prospective observational study

Objective

When performing lightwand intubation, an improper transmitted glow position before tube advancement can cause intubation failure or laryngeal injury. This study was performed to explore the transmitted glow point corresponding to a priori chosen depth for lightwand intubation.

Methods

Before lightwand intubation, we marked the transmitted glow point from a bronchoscope on the neck when it reached 1 cm below the vocal cords. Lightwand intubation was then performed using this marking point. The distances from the mark to the upper border of the thyroid cartilage, upper border of the cricoid cartilage, and suprasternal notch were measured.

Results

In total, 107 patients were enrolled. The success rate of lightwand intubation using the mark was 93.5% (95% confidence interval, 88.7%–99.2%) at the first attempt. The marking point was placed 12.0 mm (95% confidence interval, 10.6–13.4 mm) below the upper border of the cricoid cartilage.

Conclusion

Anaesthesiologists should be aware of the appropriate point of the transmitted glow on the patient’s neck when performing lightwand intubation. We suggest that this point is approximately 1 cm below the upper border of the cricoid cartilage.

Trial registration: ClinicalTrials.gov NCT03480035

Use of the GlideScope does not lower the hemodynamic response to tracheal intubation more than the Macintosh laryngoscope: a systematic review and meta-analysis

BACKGROUND

It is presently unclear whether the hemodynamic response to intubation is less marked with indirect laryngoscopy using the GlideScope (GlideScope) than with direct laryngoscopy using the Macintosh laryngoscope. Thus, the aim of this study was to determine whether using the GlideScope lowers the hemodynamic response to tracheal intubation more than using the Macintosh laryngoscope.

METHODS

We performed a comprehensive literature search of electronic databases for clinical trials comparing hemodynamic response to tracheal intubation. The primary aim was to determine whether the heart rate (HR) and mean blood pressure (MBP) 60 s after tracheal intubation with the GlideScope were lower than after intubation with the Macintosh laryngoscope. We expressed pooled differences in HR and MBP between the devices as the weighted mean difference with 95% confidence interval and also performed trial sequential analysis (TSA). Second, we examined whether use of the GlideScope resulted in lower post-intubation hemodynamic responses at 120, 180, and 300 s compared with use of the Macintosh laryngoscope. For sensitivity analysis, we used a multivariate random effects model that accounted for within-study correlation of the longitudinal data.

RESULTS

The literature search identified 13 articles. HR and MBP at 60 seconds post-intubation was not significantly lower with the GlideScope than with the Macintosh (HR vs MBP: weighted mean difference = 0.22 vs 2.56; 95% confidence interval -3.43 to 3.88 vs -0.82 to 5.93; P = .90 vs 0.14; I = 77% vs 63%: Cochran Q, 52.7 vs 27.2). Use of the GlideScope was not associated with a significantly lower HR or MBP at 120, 180, or 300 s post-intubation. TSA indicated that the total sample size was over the futility boundary for HR and MBP. Sensitivity analysis indicated no significant association between use of the GlideScope and a lower HR or MBP at any measurement point.

CONCLUSIONS

Compared with the Macintosh laryngoscope, the GlideScope did not lower the hemodynamic response after tracheal intubation. Sensitivity analysis results supported this finding, and the results of TSA suggest that the total sample size exceeded the TSA monitoring boundary for HR and MBP.

Is video laryngoscopy easier than direct laryngoscopy for intubation in patients with contracture neck?

Background and Objective:

Postburn contracture (PBC) of the neck is commonly seen after acute burn in the face and neck region. Managing the airway is a challenge due to functional and anatomical deformities. We compared the ease of intubation using video and direct laryngoscopes.

Material and Methods:

Eighty patients, 18–60 years of age with ASA physical status I/II with Onah's types 1 and 2 contracture of the neck were randomized in this study. Group DL were intubated by direct laryngoscopy (DL) using Macintosh blade and Group VL by video laryngoscopy (VL) using King Vision. The outcome measures were ease of intubation (EOI), Cormack-Lehane (CL) grading, and associated complications if any.

Results:

EOI score was significantly lower in group VL (0.42 ± 0.84) as compared to group DL (0.85 ± 1.21) (P = 0.048) as was the use of external maneuvers (group VL: 17.5%; group DL: 42.5%; P = 0.015), and the use of stylet (group VL: 0%; group DL: 20%, P = 0.005). CL grading improved significantly in group VL (P < 0.001). Occurrence of complications was negligible in both the groups. A single failure in group DL needed rescue intubation.

Conclusion:

Intubation with a video laryngoscope was easier than with DL in patients with mild-to-moderate contracture neck with mouth opening >3 cm and MPG I/II.

A randomized controlled comparison of non-channeled king vision, McGrath MAC video laryngoscope and Macintosh direct laryngoscope for nasotracheal intubation in patients with predicted difficult intubations

BACKGROUND

King Vision and McGrath MAC video laryngoscopes (VLs) are increasingly used. The purpose of this study was to evaluate the performance of nasotracheal intubation in patients with predicted difficult intubations using non-channeled King Vision VL, McGrath MAC VL or Macintosh laryngoscope by experienced intubators.

METHODS

Ninety nine ASA I or II adult patients, scheduled for oral maxillofacial surgeries with El-Ganzouri risk index 1-7 were enrolled. Patients were randomly allocated to intubate with one of three laryngoscopes (non-channeled King Vision, McGrath MAC and Macintosh). The intubators were experienced with more than 100 successful nasotracheal intubations using each device. The primary outcome was intubation time. The secondary outcomes included first success rate, time required for viewing the glottis, Cormack-Lehane grade of glottis view, the number of assist maneuvers, hemodynamic responses, the subjective evaluating of sensations of performances and associated complications.

RESULTS

The intubation time of King Vision and McGrath group was comparable (37.6 ± 7.3 s vs. 35.4 ± 8.8 s) and both were shorter than Macintosh group (46.8 ± 10.4 s, p < 0.001). Both King Vision and McGrath groups had a 100% first attempt success rate, significantly higher than Macintosh group (85%, p < 0.05). The laryngoscopy time was comparable between King Vision and McGrath group (16.7 ± 5.5 s vs. 15.6 ± 6.3 s) and was shorter than Macintosh group (22.8 ± 7.2 s, p < 0.05) also. Compared with Macintosh laryngoscope, Glottis view was obviously improved when exposed with either non-channeled King Vision or McGrath MAC VL (p < 0.001), and assist maneuvers required were reduced (p < 0.001). The maximum fluctuations of MAP were significantly attenuated in VL groups (47.7 ± 12.5 mmHg and 45.1 ± 10.3 mmHg vs. 54.9 ± 10.2 mmHg, p < 0.05 and p < 0.01). Most device insertions were graded as excellent in McGrath group, followed by Macintosh and King Vision group (p = 0.0014). The tube advancements were easier in VLs compared with the Macintosh laryngoscope (p < 0.001). Sore throat was found more frequent in Macintosh group compared with King Vision group (p < 0.05).

CONCLUSIONS

Non-channeled King Vision and McGrath MAC VLs were comparable and both devices facilitated nasotracheal intubation in managing predicted difficult intubations compared with Macintosh laryngoscope.

TRIAL REGISTRATION

ClinicalTrials registration number NCT03126344 . Registered on April 24, 2017.

Comparison of Pentax Airway Scope and Macintosh laryngoscope for orotracheal intubation in children: A randomised non-inferiority trial

BACKGROUND

Pentax Airway Scope (AWS) is a recently developed videolaryngoscope for use in both normal and difficult airways, yet its use in paediatric patients has not been established. The purpose of this study was to evaluate the efficacy of the Pentax AWS regarding intubation time, laryngeal view and ease of intubation in paediatric patients with normal airway, compared to Macintosh laryngoscope.

METHOD

A total of 136 paediatric patients aged 1-10 with American Society of Anaesthesiologists physical status I or II undergoing general anaesthesia were randomly allocated into two groups: Macintosh laryngoscope (n = 68) and Pentax Airway Scope (n = 68). Primary outcome was intubation time. Cormack-Lehane laryngeal view grade, application of optimal laryngeal external manipulation, intubation difficulty scale, intubation failure rate and adverse events were also measured.

RESULT

No significant difference was observed between the two groups regarding intubation time (P = 0.713). As for the laryngeal view grade, the Pentax group resulted in lower graded cases compared to the Macintosh group (P = 0.000). No optimal laryngeal external manipulation application was required in the Pentax group. Intubation difficulty scale resulted in lower values for Pentax group (P = 0.001). Failure rate was not different between the two groups (P = 0.619). There were significantly more teeth injury cases in the Pentax group than Macintosh group (P = 0.042).

CONCLUSION

Pentax Airway Scope provided similar intubation time and success rate, while improving laryngeal view, compared to Macintosh laryngoscopy in children with normal airway. When using Pentax AWS in children, however, the risk of teeth injury may increase.

A single-centre, randomised controlled feasibility pilot trial comparing performance of direct laryngoscopy versus videolaryngoscopy for endotracheal intubation in surgical patients

Introduction

Most trials comparing effectiveness of laryngoscopy technique use surrogate endpoints. Intubation success is a more appropriate endpoint for comparing effectiveness of techniques or devices. A large pragmatic clinical trial powered for intubation success has not yet been performed.

Methods

We tested the feasibility of a randomised controlled trial to compare the performance of direct laryngoscopy versus videolaryngoscopy for endotracheal intubation. The trial was conducted in the Department of Adult and Emergency Anaesthesia at the Auckland City Hospital, New Zealand. Patients over 18 years who required endotracheal intubation and were not known or predicted to be difficult to bag-mask ventilate were eligible for the study. Patients were excluded if they required rapid sequence induction, fibreoptic intubation or were unable to consent due to language barriers or cognitive impairment.

Patients were permuted block randomised in groups of 8 to either direct laryngoscopy (DL) or videolaryngoscopy (VL) for the technique of endotracheal intubation. Patients were blinded to laryngoscopic technique; the duty anaesthetist, outcome assessors and statistician were unblinded.

Feasibility was assessed on recruitment rate, adherence to group assignment and data completeness. Primary outcome was first-pass success rate, with secondary outcomes of time to intubation (seconds), Intubation Difficulty Score and complication rate.

Results

One hundred and six patients were randomised and 100 patient results were analysed. Completed data from patients randomised to the DL group (n = 49) was compared with those in the VL group (n = 51). Group adherence and data completeness were 100% and 97%, respectively. First-pass success rate was 83.7% in the direct laryngoscopy group and 72.5% in the videolaryngoscopy group (p = 0.18). Median time to intubation was significantly shorter for direct laryngoscopy when compared to videolaryngoscopy (34 s v 43 s, p = 0.038). Complications included mucosal trauma and airway bleeding which are recognised complications of endotracheal intubation.

Conclusion

A large, pragmatic, multicentre, randomised controlled trial comparing the relative effectiveness of direct laryngoscopy and indirect videolaryngoscopy is feasible.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12615001267549

A comparative randomized trial of intubation success in difficult intubation cases: the use of a Frova intubation catheter versus a Bonfils intubation fiberoscope

Introduction

A difficult airway is one of the main causes of morbidity and mortality in patients who undergo surgical interventions. Therefore, many devices and algorithms have been developed for the management of a difficult airway. However no study has been conducted comparing Frova catheter (FC) and a Bonfils fiberoscope (BF) to date.

Aim

To compare the effectiveness and success of two devices, a FC and BF, in difficult intubation cases.

Material and methods

Design: Single-centre randomized controlled trial in patients with difficult airways. The assignment order was created by unplanned number charts, and the assignment was hidden in closed covers, which were not unlocked until case permission had been provided. Setting: The trial was undertaken in a university hospital in Turkey. The primary analysis was based on 60 participants (n = 30, n = 30) with difficult intubation. The main outcomes were the success rates of placement of the tracheal tube in the trachea and the duration of the tracheal intubation process.

Results

In the BF group, successful intubation was carried out in 25 of the 30 (83.3%) patients, whereas intubation was successful in 28 of the 30 patients (93.3%) in the FC group. Patients who could not be intubated with the first device were intubated with the other device. The mean duration of intubation was 109 (85–140) s in the BF group, whereas it was 38.8 (26–60) s in the FC group.

Conclusions

Both devices were successful in difficult intubation cases. However, given the shorter duration of intubation using the FC and its lower cost as compared with that of the BF, the FC can be considered superior to the BF in difficult intubation cases.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation: a Cochrane Systematic Review

Difficulties with tracheal intubation commonly arise and impact patient safety. This systematic review evaluates whether videolaryngoscopes reduce intubation failure and complications compared with direct laryngoscopy in adults. We searched CENTRAL, MEDLINE, Embase and clinicaltrials.gov up to February 2015, and conducted forward and backward citation tracking. We included randomized controlled trials that compared adult patients undergoing laryngoscopy with videolaryngoscopy or Macintosh laryngoscopy. We did not primarily intend to compare individual videolaryngoscopes. Sixty-four studies (7044 participants) were included. Moderate quality evidence showed that videolaryngoscopy reduced failed intubations (Odds Ratio (OR) 0.35, 95% Confidence Interval (CI) 0.19-0.65) including in participants with anticipated difficult airways (OR 0.28, 95% CI 0.15-0.55). There was no evidence of reduction in hypoxia or mortality, but few studies reported these outcomes. Videolaryngoscopes reduced laryngeal/airway trauma (OR 0.68, 95% CI 0.48-0.96) and hoarseness (OR 0.57, 95% CI 0.36-0.88). Videolaryngoscopy increased easy laryngeal views (OR 6.77, 95% CI 4.17-10.98) and reduced difficult views (OR 0.18, 95% CI 0.13-0.27) and intubation difficulty, typically using an 'intubation difficulty score' (OR 7.13, 95% CI 3.12-16.31). Failed intubations were reduced with experienced operators (OR 0.32, 95% CI 0.13-0.75) but not with inexperienced users. We identified no difference in number of first attempts and incidence of sore throat. Heterogeneity around time for intubation data prevented meta-analysis. We found evidence of differential performance between different videolaryngoscope designs. Lack of data prevented analysis of impact of obesity or clinical location on failed intubation rates. Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a videolaryngoscope reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a videolaryngoscope affects time required for intubation.

The Difficult Airway after Endoscopic Endonasal Skull Base Surgery: A Case Series and Management Algorithm

OBJECTIVES

To analyze difficult airway situations affecting patients after endoscopic endonasal surgery (EES) for skull base tumors and to develop an airway management algorithm.

STUDY DESIGN

Case series with chart review.

SETTING

Single tertiary care center.

SUBJECTS AND METHODS

Eleven difficult airway events occurred among patients after EES for skull base tumors, as identified through a retrospective review of our institutional Difficult Airway Management Team registry from January 2008 to March 2016. Data from these events included patient demographics, event characteristics, airway management techniques, and outcomes. Results were used to design a difficult airway protocol.

RESULTS

The majority of patients were obese (63.6%) and had a dural defect (90.9%), each of which was repaired with a vascularized flap. The most common reasons for the difficult airway call were concern for using mask ventilation in a patient with a dural defect (27.3%) and difficult airway anatomy (27.3%). Two patients did not require airway intervention; 8 were intubated; and 1 underwent cricothyroidotomy. Videolaryngoscopy was the most common first-attempt intubation technique, followed by conventional direct laryngoscopy. Effective adjunctive techniques included intubation through a laryngeal mask airway and bougie-guided intubation. As compared with simple mask ventilation, laryngeal mask airway-assisted ventilation was associated with a decreased incidence of postevent cerebrospinal fluid leak. There were no incidences of postevent pneumocephalus, cardiopulmonary arrest, or mortality.

CONCLUSIONS

We propose a difficult airway algorithm for patients following EES of the skull base, with sequential recommendations for airway management methods and commentary on adjunctive techniques.

Predictors of difficult videolaryngoscopy with GlideScope® or C-MAC® with D-blade: secondary analysis from a large comparative videolaryngoscopy trial

BACKGROUND

Tracheal intubation using acute-angle videolaryngoscopy achieves high success rates, but is not without difficulty. We aimed to determine predictors of 'difficult videolaryngoscopy'.

METHODS

We performed a secondary analysis of a data set (n=1100) gathered from a multicentre prospective randomized controlled trial of patients for whom difficult direct laryngoscopy was anticipated and who were intubated with one of two videolaryngoscopy devices (GlideScope(®) or C-MAC(®) with D-blade). 'Difficult videolaryngoscopy' was defined as 'first intubation time >60 s' or 'first attempt intubation failure'. A multivariate logistic regression model along with stepwise model selection techniques was performed to determine independent predictors of difficult videolaryngoscopy.

RESULTS

Of 1100 patients, 301 were identified as difficult videolaryngoscopies. By univariate analysis, head and neck position, provider, type of surgery, and mouth opening were associated with difficult videolaryngoscopy (P<0.05). According to the multivariate logistic regression model, characteristics associated with greater risk for difficult videolaryngoscopy were as follows: (i) head and neck position of 'supine sniffing' vs 'supine neutral' {odds ratio (OR) 1.63, 95% confidence interval (CI) [1.14, 2.31]}; (ii) undergoing otolaryngologic or cardiac surgery vs general surgery (OR 1.89, 95% CI [1.19, 3.01] and OR 6.13, 95% CI [1.85, 20.37], respectively); (iii) intubation performed by an attending anaesthestist vs a supervised resident (OR 1.83, 95% CI [1.14, 2.92]); and (iv) small mouth opening (OR 1.18, 95% CI [1.02, 1.36]).

CONCLUSION

This secondary analysis of an existing data set indicates four covariates associated with difficult acute-angle videolaryngoscopy, of which patient position and provider level are modifiable.

Comparison of hemodynamic responses to endotracheal intubation with the GlideScope video laryngoscope and Macintosh laryngoscope in patients undergoing cardiovascular surgery

Background

This study aimed to compare hemodynamic response to endotracheal intubation using GlideScope and Macintosh laryngoscopes in patients who underwent cardiovascular surgery.

Methods

A total of 74 patients were enrolled in the study. Patients were randomly assigned into two groups either a GlideScope (n=37) or a Macintosh laryngoscope (n=37). Laryngoscopy time, heart rate, invasive arterial pressure and rate pressure product were compared during induction and until five minutes after laryngoscopy at 11 time points.

Results

Seventy patients completed the study. The intubation time was similar in both groups (14.1±4.0 sec vs. 13.2±4.2 sec; p=0.22). Hemodynamic values including heart rate, systolic, diastolic and mean arterial pressure and rate pressure product were similar at all-time points. The laryngoscopy time was also similar between groups.

Conclusion

The GlideScope video laryngoscope did not show any advantage on hemodynamic response in patients undergoing cardiovascular surgery when compared to Macintosh laryngoscope.

A prospective randomized controlled study to evaluate and compare GlideScope with Macintosh laryngoscope for ease of endotracheal intubation in adult patients undergoing elective surgery under general anesthesia

Background:

The aim of the study was to compare the ease the intubation using GlideScope video laryngoscope and Macintosh laryngoscope in adult patients undergoing elective surgery under general anesthesia.

Materials and Methods:

A total of 200 American Society of Anesthesiologists I–II patients of either sex, in the age group of 18–60 years were included in the study. Patients were randomly allocated to two groups. We assessed ease of intubation depending on time to tracheal intubation, number of attempts, glottic view (Cormack–Lehane grade [CL grade] and percentage of glottis opening [POGO]) and intubation difficulty score (IDS), hemodynamic variables and any intra- and post-operative adverse events.

Results:

The rate of successful endotracheal intubation (ETI) in both groups was 100% in the first attempt. The time required for successful ETI was 24.89 ± 5.574 in Group G and 20.68 ± 3.637 in Group M (P < 0.001) found to be statistically significant. There was significant improvement in glottic view with GlideScope (as assessed by POGO score 66.71 ± 29.929 and 94.40 ± 10.476 in group G and 75.85 ± 26.969 and 74.20 ± 29.514 Group M and CL grading [P < 0.001]). A comparison of mean IDS between two groups revealed intubation was easier with the use of GlideScope. The hemodynamic response to intubation was significantly lesser with the use of GlideScope when compared with Macintosh laryngoscope. The incidence of adverse events, though minor like superficial lip or tongue bleed, was similar in two groups.

Conclusions:

GlideScope offers superiority over Macintosh laryngoscope in terms of laryngeal views and the difficulty encountered at ETI in an unselected population.

Change in management of predicted difficult airways following introduction of video laryngoscopes

AIM

To determine if video laryngoscopy (VL) has significantly impacted management of difficult airways by decreasing the rate of awake fiberoptic intubation (FOI).

METHODS

Anesthetic records of 3723 patients who underwent general anesthesia at Rush University Medical Center were reviewed over a 2-mo period prior to the introduction of VLs in 2009 (“pre-VL” group) and over the same 2-mo period after the introduction of VLs in 2012 (“post-VL” group). Patient records with predicted difficult airways based on pre-operative airway examination were analyzed. The primary outcome was rate of awake FOI.

RESULTS

To control for possible factors that may influence the FOI rate, a logistic regression was performed with these factors included as covariates. The rate of awake FOI was 13.1% in pre-VL group compared to 9.0% in post-VL group. Although this decrease was not statistically significant individually (P = 0.1768), it showed a trend toward significance when covariates were accounted for (P = 0.0910). Several factors predicting a higher likelihood of awake FOI were found to be statistically significant: Morbid obesity (larger BMI P = 0.0154, OR = 1.5 per 10 point BMI increase), male gender (P = 0.0026, OR = 3.0) and a higher el-Ganzouri airway score (P = 0.0007, OR = 1.5). Although VLs were seen to be used to intubate 51% of predicted difficult airways, the rate of awake FOI has not significantly changed.

CONCLUSION

Although VL may continue to grow in popularity, the most difficult airways are still managed using awake FOI.

A Continuous Quality Improvement Airway Program Results in Sustained Increases in Intubation Success

INTRODUCTION

Airway management is a critical skill for air medical providers, including the use of rapid sequence intubation (RSI) medications. Mediocre success rates and a high incidence of complications has challenged air medical providers to improve training and performance improvement efforts to improve clinical performance.

OBJECTIVES

The aim of this research was to describe the experience with a novel, integrated advanced airway management program across a large air medical company and explore the impact of the program on improvement in RSI success.

METHODS

The Helicopter Advanced Resuscitation Training (HeART) program was implemented across 160 bases in 2015. The HeART program includes a novel conceptual framework based on thorough understanding of physiology, critical thinking using a novel algorithm, difficult airway predictive tools, training in the optimal use of specific airway techniques and devices, and integrated performance improvement efforts to address opportunities for improvement. The C-MAC video/direct laryngoscope and high-fidelity human patient simulation laboratories were implemented during the study period. Chi-square test for trend was used to evaluate for improvements in airway management and RSI success (overall intubation success, first-attempt success, first-attempt success without desaturation) over the 25-month study period following HeART implementation.

RESULTS

A total of 5,132 patients underwent RSI during the study period. Improvements in first-attempt intubation success (85% to 95%, p < 0.01) and first-attempt success without desaturation (84% to 94%, p < 0.01) were observed. Overall intubation success increased from 95% to 99% over the study period, but the trend was not statistically significant (p = 0.311).

CONCLUSIONS

An integrated advanced airway management program was successful in improving RSI intubation performance in a large air medical company.

Semiprone position is superior to supine position for paediatric endotracheal intubation during massive regurgitation, a randomized crossover simulation trial

BACKGROUND

Endotracheal intubation of patients with massive regurgitation represents a challenge in emergency airway management. Gastric contents tend to block suction catheters, and few treatment alternatives exist. Based on a technique that was successfully applied in our district, we wanted to examine if endotracheal intubation would be easier and quicker to perform when the patient is turned over to a semiprone position, as compared to the supine position.

METHODS

In a randomized crossover simulation trial, a child manikin with on-going regurgitation was intubated both in the supine and semiprone positions. Endpoints were experienced difficulty with the procedure and time to intubation, as well as visually confirmed intubation and first-pass success rate.

RESULTS

Intubation in the semiprone position was significantly easier and faster compared to the supine position; the median experienced difficulty on a visual analogue scale was 27 and 65, respectively (p = 0.004), and the median time to intubation was 26 and 45 s, respectively (p = 0.001). There were no significant differences in frequency of visually confirmed intubation (16 and 18, p = 0.490) of first-pass success rate (17 and 18, p = 1.000).

CONCLUSION

In this experiment, endotracheal intubation during massive regurgitation with the patient in the semiprone position was significantly easier and quicker to perform than in the supine position. Endotracheal intubation in the semiprone position can provide a quick rescue method in situations where airway management is hindered by massive regurgitation, and it represents a possible supplement to current airway management training.

The pressure exerted on the tongue during intubation with simultaneous cervical spine immobilisation: a comparison between four videolaryngoscopes and the Macintosh laryngoscope-a manikin study

Excessive pressures exerted on the tongue during intubation may be associated with serious complications and may make intubation more difficult. The aim of this study was to evaluate five different intubating devices in the hands of experienced anaesthetists during simulated conditions of reduced cervical spine mobility. Forty senior anaesthetists participated in the study (female = 18, male = 22). The mean pressure exerted on the tongue during intubation was recorded with a standard manometer. The overall intubation success rate as well as the difference in exerted pressures between female and male anaesthetists were also assessed. The five studied devices were used by each participant and they were randomly chosen. Each anaesthetists participating in the study had over 15 years of clinical anaesthetic practice. The mean pressure exerted on the tongue during intubation was significantly lower when the videolaryngoscopes (VLs) were used (p < 0.0001 for each of the studied VL). There were failed intubation attempts with all of the studied devices, the highest failure rate was in the Airtraq® group, 10 in 40 (25%). Female anaesthetists exerted lower pressures during intubation with all studied devices (except the Airtraq®). However, the difference was only significant for the Macintosh laryngoscope (p = 0.0083). The blades of VLs exerted lower pressures on the tongue during intubation than the Macintosh laryngoscope blade. Their use may be associated with less complications. Furthermore, male anaesthetists exerted higher pressures on the soft tissues although this was neither statistically nor clinically significant. There was higher failed intubation rate in the male anaesthetist group.

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.

Using King Vision video laryngoscope with a channeled blade prolongs time for tracheal intubation in different training levels, compared to non-channeled blade

Purpose

It is generally accepted that using a video laryngoscope is associated with an improved visualization of the glottis. However, correctly placing the endotracheal tube might be challenging. Channeled video laryngoscopic blades have an endotracheal tube already pre-loaded, allowing to advance the tube once the glottis is visualized. We hypothesized that use of a channel blade with pre-loaded endotracheal tube results in a faster intubation, compared to a curved Macintosh blade video laryngoscope.

Methods

After ethical approval and informed consent, patients were randomized to receive endotracheal Intubation with either the King Vision^® video laryngoscope with curved blade (control) or channeled blade (channeled). Success rate, evaluation of the glottis view (percentage of glottic opening (POGO), Cormack&Lehane (C&L)) and intubating time were evaluated.

Results

Over a two-month period, a total of 46 patients (control n = 23; channeled n = 23) were examined. The first attempt success rates were comparable between groups (control 100% (23/23) vs. channeled 96% (22/23); p = 0.31). Overall intubation time was significantly shorter with control (median 40 sec; IQR [24–58]), compared to channeled (59 sec [40–74]; p = 0.03). There were no differences in glottis visualization between groups.

Conclusion

Compared with the King Vision channeled blade, time for tracheal intubation was shorter with the control group using a non-channeled blade. First attempt success and visualization of the glottis were comparable. These data do not support the hypothesis that a channeled blade is superior to a curved video laryngoscopic blade without tube guidance.

Trial registration

ClinicalTrials.gov NCT02344030

Efficacy of Pentax airway scope versus Macintosh laryngoscope when used by novice personnel: A prospective randomized controlled study

Objective

To determine whether intubation education using the Pentax Airway Scope (AWS) in normal airways is more useful than direct laryngoscopy (Macintosh laryngoscope) in novice personnel.

Methods

Eleven intern doctors without intubation experience performed 60 sequential intubations with each device on a manikin and 10 sequential intubations in adult patients. The time required for successful intubation, percentage of glottic opening (POGO) score, number of intubation attempts, and number of dental injuries were analyzed for each intubation technique.

Results

The mean (standard deviation) time required for successful intubation decreased as the number of intubations increased and was significantly shorter with the Pentax AWS than direct laryngoscope [22.6 (7.3) vs. 29.6 (10.0) and 33.0 (8.0) vs. 44.7 (5.6) s, respectively] in both the manikin and clinical studies. The Pentax AWS was also associated with higher POGO scores than the direct laryngoscope [81.7 (8.9) vs. 55.1 (13.2) and 80.9 (9.7) vs. 49.6 (16.5), respectively] and fewer intubation attempts. Fewer dental injuries occurred with the Pentax AWS in the manikin study.

Conclusions

Novices performed intubation more rapidly and easily with an improved laryngeal view using the Pentax AWS. We suggest that intubation education with video laryngoscopy should be mandatory along with direct laryngoscope training.

Recent trends in airway management

Tracheal intubation remains a life-saving procedure that is typically not difficult for experienced providers in routine conditions. Unfortunately, difficult intubation remains challenging to predict and intubation conditions may make the event life threatening. Recent technological advances aim to further improve the ease, speed, safety, and success of intubation but have not been fully investigated. Video laryngoscopy, though proven effective in the difficult airway, may result in different intubation success rates in various settings and in different providers’ hands. The rescue surgical airway remains a rarely used but critical skill, and research continues to investigate optimal techniques. This review highlights some of the new thoughts and research on these important topics.

A comparison of videolaryngoscopes for tracheal intubation in predicted difficult airway: a feasibility study

Background

Videolaryngoscopy has become increasingly attractive for the routine management of the difficult airway. Glidescope® is well studied in the literature while imago V-Blade® is a recent videolaryngoscope. This is a feasibility study with 1:1 case-control sequential allocation comparing Imago V-Blade ® and Glidescope® in predicted difficult airway settings.

Methods

Two senior anesthesiologists with no clinical experience in video assisted intubation but previously trained in a simulated scenario, performed the endotracheal intubations with Imago V-Blade® and Glidescope®. A third experienced anesthesiologist supervised the procedures. Forty-two patients, 21 for each group, with the presence of predicted difficult airway according to the Italian guideline were included. The primary end point is the feasibility of intubation. The secondary end-points are the success to intubate in the first attempt, the intubation time, the Cormack and Lehane score view, the comparison of the intubation difficulty scale (IDS) score and the need for maneuvers to aid the endotracheal intubation comparing Imago V-Blade® and Glidescope®.

Results

The intubation was achieved in 100% of cases in both groups. No differences were found in the first-attempt success rate (p = 0.383), intubation time (p = 0.280), Cormack and Lehane score view (p = 0.799) and IDS score (p = 0.252). Statistical differences were found in external laryngeal pressure (p = 0.005), advancement of the blade (p = 0.024) and use of increasing lifting force (p = 0.048).

Conclusions

This feasibility study showed that the intubation with the newly introduced Imago V-Blade® is feasible. Further randomized and/or non-inferiority trials are needed to evaluate the benefit of Imago V-Blade® in this procedure.

Trial registration

Clinicaltrials.gov NCT02897518. Retrospectively registered 25 August 2016

Video Laryngoscopy Improves Odds of First-Attempt Success at Intubation in the Intensive Care Unit. A Propensity-matched Analysis

RATIONALE

Urgent tracheal intubation is performed frequently in intensive care units and incurs higher risk than when intubation is performed under more controlled circumstances. Video laryngoscopy may improve the chances of successful tracheal intubation on the first attempt; however, existing comparative data on outcomes are limited.

OBJECTIVES

To compare first-attempt success and complication rates during intubation when using video laryngoscopy compared with traditional direct laryngoscopy in a tertiary academic medical intensive care unit.

METHODS

We prospectively collected and analyzed data from a continuous quality improvement database of all intubations in one medical intensive care unit between January 1, 2012, and December 31, 2014. Propensity matching and multivariable logistic regression were used to reduce the risk of bias and control for confounding.

MEASUREMENTS AND MAIN RESULTS

A total of 809 intubations took place over the study period. Of these, 673 (83.2%) were performed using video laryngoscopy and 136 (16.8%) using direct laryngoscopy. First-attempt success with video laryngoscopy was 80.4% (95% confidence interval [CI], 77.2-83.3%) compared with 65.4% (95% CI, 56.8-73.4%) for intubations performed with direct laryngoscopy (P < 0.001). In a propensity-matched analysis, the odds ratio for first-attempt success with video laryngoscopy versus direct laryngoscopy was 2.81 (95% CI, 2.27-3.59). The rate of arterial oxygen desaturation events during the first intubation attempt was significantly lower for video laryngoscopy than for direct laryngoscopy (18.3% vs. 25.9%; P = 0.04). The rate of esophageal intubation during any attempt was also significantly lower for video laryngoscopy (2.1% vs. 6.6%; P = 0.008).

CONCLUSIONS

Video laryngoscopy was associated with significantly improved odds of first-attempt success at tracheal intubation by nonanesthesiologists in a medical intensive care unit. Esophageal intubation and oxygen desaturation occurred less frequently with the use of video laryngoscopy. Randomized clinical trials are needed to confirm these findings.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation

BACKGROUND

Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.

OBJECTIVES

Our primary objective was to assess whether use of videolaryngoscopy for tracheal intubation in adults requiring general anaesthesia reduces risks of complications and failure compared with direct laryngoscopy. Our secondary aim was to assess the benefits and risks of these devices in selected population groups, such as adults with obesity and those with a known or predicted difficult airway.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase on 10 February 2015. Our search terms were relevant to the review question and were not limited by outcomes. We carried out clinical trials register searches and forward and backward citation tracking. We reran the search on 12 January 2016; we added potential new studies of interest from the 2016 search to a list of 'Studies awaiting classification', and we will incorporate these studies into the formal review during the review update.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized studies with adult patients undergoing laryngoscopy performed with a VLS or a Macintosh laryngoscope in a clinical, emergency or out-of-hospital setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting a third review author to resolve disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias.

MAIN RESULTS

We included 64 studies identified during the 2015 search that enrolled 7044 adult participants and compared a VLS of one or more designs with a Macintosh laryngoscope. We identified 38 studies awaiting classification and seven ongoing studies. Of the 64 included studies, 61 included elective surgical patients, and three were conducted in an emergency setting. Among 48 studies that included participants without a predicted difficult airway, 15 used techniques to simulate a difficult airway. Seven recruited participants with a known or predicted difficult airway, and the remaining studies did not specify or included both predicted and not predicted difficult airways. Only two studies specifically recruited obese participants. It was not possible to blind the intubator to the device, and we noted a high level of inevitable heterogeneity, given the large number of studies.Statistically significantly fewer failed intubations were reported when a VLS was used (Mantel-Haenszel (M-H) odds ratio (OR), random-effects 0.35, 95% confidence Interval (CI) 0.19 to 0.65; 38 studies; 4127 participants), and fewer failed intubations occurred when a VLS was used in participants with an anticipated difficult airway (M-H OR, random-effects 0.28, 95% CI 0.15 to 0.55; six studies; 830 participants). We graded the quality of this evidence as moderate on the basis of the GRADE system. Failed intubations were fewer when a VLS was used in participants with a simulated difficult airway (M-H OR, random-effects 0.18, 95% CI 0.04 to 0.77; nine studies; 810 participants), but groups with no predicted difficult airway provided no significant results (M-H OR, random-effects 0.61, 95% CI 0.22 to 1.67; 19 studies; 1743 participants).Eight studies reported on hypoxia, and only three of these described any events; results showed no differences between devices for this outcome (M-H OR, random-effects 0.39, 95% CI 0.10 to 1.44; 1319 participants). Similarly, few studies reported on mortality, noting no differences between devices (M-H OR, fixed-effect 1.09, 95% CI 0.65 to 1.82; two studies; 663 participants), and only one study reporting on the occurrence of respiratory complications (78 participants); we graded these three outcomes as very low quality owing to lack of data. We found no statistically significant differences between devices in the proportion of successful first attempts (M-H OR, random-effects 1.27, 95% CI 0.77 to 2.09; 36 studies; 4731 participants) nor in those needing more than one attempt. We graded the quality of this evidence as moderate. Studies reported no statistically significant differences in the incidence of sore throat in the postanaesthesia care unit (PACU) (M-H OR, random-effects 1.00 (95% CI 0.73 to 1.38); 10 studies; 1548 participants) nor at 24 hours postoperatively (M-H OR random-effects 0.54, 95% CI 0.27 to 1.07; eight studies; 844 participants); we graded the quality of this evidence as moderate. Data combined to include studies of cross-over design revealed statistically significantly fewer laryngeal or airway traumas (M-H OR, random-effects 0.68, 95% CI 0.48 to 0.96; 29 studies; 3110 participants) and fewer incidences of postoperative hoarseness (M-H OR, fixed-effect 0.57, 95% CI 0.36 to 0.88; six studies; 527 participants) when a VLS was used. A greater number of laryngoscopies performed with a VLS achieved a view of most of the glottis (M-H OR, random-effects 6.77, 95% CI 4.17 to 10.98; 22 studies; 2240 participants), fewer laryngoscopies performed with a VLS achieved no view of the glottis (M-H OR, random-effects 0.18, 95% CI 0.13 to 0.27; 22 studies; 2240 participants) and the VLS was easier to use (M-H OR, random-effects 7.13, 95% CI 3.12 to 16.31; seven studies; 568 participants).Although a large number of studies reported time required for tracheal intubation (55 studies; 6249 participants), we did not present an effects estimate for this outcome owing to the extremely high level of statistical heterogeneity (I2 = 96%).

AUTHORS' CONCLUSIONS

Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a VLS affects time required for intubation.