Optical and video laryngoscopes for emergency airway management

Systematic Review and Meta-Analysis of Randomized Controlled Trials (RCTs) Revealing the Future of Airway Management: Video Laryngoscopy vs. Macintosh Laryngoscopy for Enhanced Clinical Outcomes

Since the 1940s, Macintosh laryngoscopy (Mac laryngoscopy) has been the gold standard for tracheal intubation, offering visualization of the glottis entrance. However, recent years have witnessed the emergence of various video laryngoscopy (VL) techniques. This systematic review and meta-analysis aims to assess the clinical outcomes of VL versus Mac laryngoscopy in an elective setting. We comprehensively searched five medical databases - PubMed, EMBASE, Medline, Cochrane Library, and Web of Science. All the databases were last searched in January 2023. We only included studies with full texts comparing VL to Mac laryngoscopy clinical outcomes. Studies were excluded if they were non-full text or non-randomized controlled trials (RCTs) and did not compare VL to Mac laryngoscopy. We extracted data comprising author names, publication year, key study outcomes (first-attempt intubation success rate, Cormack and Lehane grade, hypoxia incidence, and glottis view quality), video laryngoscope types, and sample sizes of both VL and Mac laryngoscopy groups. The Cochrane risk of bias tool was used to assess the risk of bias in the included studies. Statistical analysis was performed using Review Manager (RevMan, version 5.4; Cochrane Collaboration, London, UK), presenting results as odds ratio (OR) and risk ratios (RR) at a 95% confidence interval (CI). This facilitated the identification of relevant and appropriate studies of our analysis. The search produced 19 studies that were included in this review. The evaluated sample size ranges from 40 to 802, with 3,238 participants. The rate of success at the first attempt in the use of VL was 1,558/1,890 (82.43%), while the success rate for Mac laryngoscopy was 982/1,348 (72.85%; OR: 1.98 (1.25, 3.12)) at a 95% confidence interval. Pooled analysis indicated no significant difference for hypoxia concerning the type of device used RR (random effects: 1.02; 95% CI: 0.80-1.29). A video laryngoscope had a higher likelihood of visualizing the vocal cords categorized as category 1 in the Cormack-Lehane system of classification (RR: 2.45; 95% CI: 1.43-4.21). Additionally, considerably better glottis views were attained during VL than Mac laryngoscopy (OR: 1.77; 95% CI: 1.19-2.62). In elective tracheal intubation, VL demonstrates superior first-attempt success rates, offers improved glottis visualization, and reduces instances where the glottis cannot be viewed compared to Mac laryngoscopy.

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.

Comparison of two different shapes of stylets for intubation with the McGrath MAC® video laryngoscope: a randomized controlled trial

Objective

This study was performed to compare two different shapes of stylets, 60° and J-shaped stylets, for intubation using the McGrath MAC® video laryngoscope (MVL).

Methods

Two hundred twenty-two patients undergoing surgery under general anesthesia were randomly allocated to Group J (n = 111) or Group 60° (n = 111) and intubated using the MVL with the stylet bent into the allocated shape. The time to intubation (TTI) and other intubating profiles were compared between the groups. Multivariate regression analysis was used to determine the relationship between factors related to difficult intubation and TTI.

Results

The TTI was not different between the two groups. There were also no differences in the intubating profiles between the two groups. In both groups, the TTI was longer with a modified Mallampati score (mMS) of ≥3 and percentage of glottic opening (POGO) score of <50. In Group J, the TTI was longer with a body mass index (BMI) of ≥30 kg/m².

Conclusion

The TTI during tracheal intubation with the MVL was not different between the two groups. The TTI was longer with an mMS of ≥3 and POGO score of <50. In Group J, the TTI was longer with a BMI of ≥30 kg/m².

Video Laryngoscopy or Macintosh Laryngoscopy: Which One Is More Successful in Patients With Bilateral Mandibular Fractures?

PURPOSE

Successful intubation is challenging in patients with bilateral mandibular fractures. The aim of this study was to compare the video laryngoscope (VL) with the Macintosh laryngoscope (ML) for intubation of patients with bilateral mandibular fractures.

MATERIALS AND METHODS

In this randomized controlled trial study, patients who had bilateral mandibular fractures (angle or subcondylar) were studied. Patients were randomly assigned to 1 of 2 groups using computerized randomization. Laryngoscopy was performed by the ML in group 1 and the VL in group 2. Intubation device (ML or VL) was the predictive factor of the study and age, maximum mouth opening (MMO), incisor fracture, and gender were the variables. Intubation time and successful intubation at the first attempt were the study outcomes. Independent t test was applied to compare intubation time, MMO, and age between the 2 groups.

RESULTS

Seventy-eight patients were studied (40 in group 1 and 38 in group 2). Mean intubation time was 33.02 ± 9.68 seconds in group 1 and 39.16 ± 7.40 seconds in group 2. Comparison of the data showed a significant difference between the 2 groups (P = .002). Twenty-four patients in group 1 and 31 in group 2 were successfully intubated at the first attempt. There was a significant difference in the number of successful or failed intubation attempts between the 2 groups (P = .03).

CONCLUSION

According to the present findings, use of the VL increased the first-attempt success rate of intubation in patients with bilateral mandibular fractures. Time of intubation could be longer when using the VL than when using the ML.

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

The C-MAC videolaryngoscope is the first Macintosh-typed videolaryngoscope. Since the advent of its original version video Macintosh system in 1999, this device has been modified several times. A unique feature of C-MAC device is its ability to provide the 2 options of direct and video laryngoscopy with the same device. The available evidence shows that in patients with normal airways, C-MAC videolaryngoscope compared with direct laryngoscopy can provide comparable or better laryngeal views and exerts less force on maxillary incisors, but does not offer conclusive benefits with regard to intubation time, intubation success, number of intubation attempts, the use of adjuncts, and hemodynamic responses to intubation. In patients with predicted or known difficult airways, C-MAC videolaryngoscope can achieve a better laryngeal view, a higher intubation success rate and a shorter intubation time than direct laryngoscopy. Furthermore, the option to perform direct and video laryngoscopy with the same device makes C-MAC videolaryngoscope exceptionally useful for emergency intubation. In addition, the C-MAC videolaryngoscope is a very good tool for tracheal intubation teaching. However, tracheal intubation with C-MAC videolaryngoscope may occasionally fail and introduction of C-MAC videolaryngoscope in clinical practice must be accompanied by formal training programs in normal and difficult airway managements.

Parker Flex-It stylet is as effective as GlideRite Rigid stylet for orotracheal intubation by Glidescope

Objectives:

To evaluate Parker Flex-It stylet as an alternative to GlideRite Rigid stylet to aid tracheal intubation with the Glidescope.

Methods:

This prospective randomized trial was conducted at King Abdulaziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia between May and December 2014. Sixty American Society of Anesthesiologists I-II patients were randomly assigned to one of 2 equal groups receiving intubation by Glidescope using either GlideRite Rigid stylet (Group GS) or Parker Flex-It stylet (Group PS). The total intubation time, ease of intubation, incidences of successful intubation at first attempt, number of intubation attempts, use of optimization maneuvers, and possible complications were recorded.

Results:

No significant differences between both groups regarding the total intubation time (p=0.08) was observed. Intubation was significantly easier in group PS compared with group GS as measured by visual analogue scale (p=0.001) with no significant differences between the groups regarding the rate of successful tracheal intubation from first attempt (p=0.524). However, the number of attempts at intubation and usage of external laryngeal manipulation were similar in both groups (p>0.05). The incidence of sore throat, dysphagia, hoarseness, and trauma were significantly higher in group GS (p<0.05).

Conclusion:

Parker Flex-It stylet is as effective as GlideRite Rigid stylet when used by experienced operators in patients with normal airways using Glidescope; however, it is easier and less traumatic.

Use-Dependent Curvature Changes in the GlideRite® Reusable Intubation Stylet

The Glidescope® is one of the most widely used video laryngoscopes in the market. It is often used with a purpose-built, reusable, "nonmalleable" stainless steel stylet, the GlideRite®. In this study, we investigated whether this stylet retains its original curvature with repeated use and sterilization. To evaluate the shape and curvature of the stylets, high-resolution digital photographs were made of 55 GlideRite stylets (5 new and 50 randomly selected from operating room stock) laid on a grid background and analyzed using Adobe Photoshop®. In a similar fashion, 1 new stylet was inserted into and removed 100 times from an endotracheal tube and photographed every 20 cycles to determine the impact of use on stylet shape. For the 5 new stylets, the handle-to-tip angle was very consistent (23.44° ± 1.04°). The stylets in clinical use varied widely in their configuration. For analysis, they were divided into 3 groups based on the handle-to-tip angle: ±1 SD of the new stylets, those with a shallower angle (straighter), and those with a steeper angle (more curved). The handle-to-tip angles were as follows: 23.07° ± 0.80° (±1 SD), 18.39° ± 2.59° (straighter), and 27.65° ± 2.73° (more curved). Analysis of variance showed that the new and ±1 SD groups were not significantly different, but both the straighter (P = 0.0002) and more curved (P = 0.0048) groups were significantly different from new. The repeated insertion and removal of a new stylet resulted in gradual straightening of the curve of the stylet from 22° at baseline to 19.2° after 100 insertion/removal cycles. Used GlideRite reusable stylets are not reliably equivalent to new ones in terms of their shape or curvature. Given that the repeated insertion and removal of a new stylet from an endotracheal tube resulted in their straightening, it is likely that clinical use has the same effect. Because many used stylets were actually more curved than the new ones, we hypothesize that practitioners likely bend the nonmalleable stylets to improve clinical utility, but often fail to recapture the manufacturer-intended curve. The clinical relevance of the change in shape of the GlideRite stylet remains to be determined; it is that possible intubation may be more difficult than expected compared with the use of new stylets.

Double-lumen tube intubation using video laryngoscopy causes a milder cardiovascular response compared to classic direct laryngoscopy

Objective:

To determine whether there is a clinically relevant difference between the circulatory responses to double-lumen tube intubation (DLTI) with the GlideScope video laryngoscope versus the Macintosh direct laryngoscope.

Methods:

Eighty adult patients requiring double-lumen tubes for thoracic surgery were randomly and equally allocated to either a Macintosh direct laryngoscope group (DL group, n = 40) or a Glide Scope video laryngoscope group (GS group, n = 40). DLTI was performed after airway evaluations and induction of anesthesia. Systolic blood pressure (SBP) and heart rate (HR) were recorded before induction (baseline values), immediately before intubation (post-induction values), at intubation and after intubation. Rate-pressure-product (RPP), and the areas under SBP- and HR-time curves were calculated. All data obtained by the two devices were compared.

Results:

After laryngoscope insertion, SBP of DL and GS groups changed significantly differently (13.1% vs. 4.6%, P< 0.001), while HR changed similarly (17.2% vs. 14.6%, P = 0.074). One minute after intubation, both SBP and HR significantly increased in both groups (SBP: 11.6% vs. 11.9%; HR: 18.4% vs. 10.8%), but there were no significant differences between the two groups. RPP significantly increased in both groups after laryngoscope insertion (32.6%, P=0.001; 18.2%, P=0.002), and there was a significant difference between the two groups (P =0.001). Throughout intubation, the areas under SBP-time curves had a significant difference between the two groups (P = 0.042), while those under HR-time curves did not differ significantly (P=0.06).

Conclusion:

The intubation response was most significant upon laryngoscope insertion during the whole intubation process. The GlideScope video laryngoscope induced milder circulatory fluctuations than the Macintosh direct laryngoscope did, suggesting that DLTI using video laryngoscopy can help reduce the cardiovascular response to intubation.

Comparison of GlideScope video laryngoscopy and Macintosh laryngoscope in ear-nose and throat surgery

AIM

Endotracheal intubation procedure employed during general anaesthesia is the most effective way for keeping the airways and respiration under control and has low risk of complications. We have aimed in this study to compare the first-attempt success and duration of the endotracheal intubation process and its effects on haemodynamics using the Macintosh laryngoscope and the GlideScope video laryngoscope.

METHODS

In this prospective randomized single-centre study, 100 patients of 18-65 years of age, and classified within the American Society of Anaesthesiologists' (ASA) I-II risk groups before elective ear-nose and throat surgery were included. The patients were randomly divided into two groups, designated as Group M, to be intubated using the Macintosh laryngoscope, and as Group G, to be intubated using the GlideScope video laryngoscope. The Mallampati scores, Cormack-Lehane classifications, intubation duration, number of attempts at intubation, the haemodynamic response and the complications were recorded.

RESULTS

There were not intergroup differences with respect to the number of intubation attempts, the Mallampati and Cormack-Lehane classifications. Duration of intubation was found to be longer in group G. The haemodynamic response values of group M were higher than those of group G. Although there was no statistically significant difference between the two groups in the number of intubation attempts, two of the patients in group M were intubated in the second attempt.

CONCLUSION

In our study, despite the longer intubation times in group G, the haemodynamic response was significantly lower in this group. It is believed that especially in cases with vital requirement of haemodynamic stability, the GlideScope video laryngoscope would be safer to employ.

Do emergency medicine residents receive appropriate video laryngoscopy training? A survey to compare the utilization of video laryngoscopy devices in emergency medicine residency programs and community emergency departments

BACKGROUND

Video laryngoscopy (VL) has emerged as a critical tool in the "difficult airway" armamentarium of emergency physicians. The resultant increase in the types of available VL devices has made Emergency Medicine Residency (EMR) training in VL increasingly challenging. Additionally, the prevalence of VL devices in the community is unknown. Because Emergency Medicine (EM) residents go on to work in diverse settings, many in non-EMR emergency departments (EDs), it is preferable that they receive training on the airway modalities they will encounter in practice.

OBJECTIVE

To compare the prevalence and type of VL devices in EMR programs to non-EMR EDs.

METHODS

This was a survey study conducted from July 2012 to October 2012 of Accreditation Council for Graduate Medical Education-accredited, MD EMR programs in the United States and non-EMR EDs in New York State. A chi-squared test was performed to determine whether the difference in VL prevalence was significant.

RESULTS

There were 158 EMR programs and 132 non-EMR EDs surveyed; 97.8% of EMR and 84.3% of non-EMR EDs reported having some form of VL in their departments. The difference in proportion of EMR vs. non-EMR EDs that have VL was χ(2) = 13 (p < 0.001). The Glidescope® device (Verathon Medical, Bothell, WA) was present in 87.7% of EMR programs and 79.3% of non-EMR EDs.

CONCLUSIONS

The majority of EMR programs trained residents in VL. The Glidescope device was used most frequently. Non-EMR EDs in New York State had a lower presence of VL devices, with the Glidescope device again being the most common. These results demonstrate that VL is pervasive in both practice environments.

Influence of clinical experience of the Macintosh laryngoscope on performance with the Pentax-AWS Airway Scope(®), a rigid video-laryngoscope, by paramedics in Japan

PURPOSE

We sought to establish the clinical utility of the Pentax-AWS Airway Scope(®) (AWS) when used by paramedics to intubate the trachea, and to evaluate whether their performance was influenced by previous clinical experience with the Macintosh laryngoscope (ML).

METHODS

Twenty paramedics attempted tracheal intubation using the AWS in five patients each in the operating room. We recorded the success rate, the number of intubation attempts, and the time for intubation and adverse events, and compared these based on the paramedics' previous clinical experience with the ML. Ten paramedics had no prior clinical experience of the ML (group A) and 10 had used it on more than 30 occasions (group B).

RESULTS

The intubation success rate was 99 % (99/100). Notably, 96 % (47/49) of intubations were achieved on the first attempt by the inexperienced paramedics in group A, compared with 64 % (32/50) by the experienced paramedics in group B (p = 0.0001). The time to intubation (mean ± SD) was significantly shorter in group A than in group B (37 ± 24 vs. 48 ± 21 s, p = 0.002). There were marked variations in the times taken to intubate, but no apparent improvement as the intubators gained experience between their first and fifth cases. No complications were encountered in either group.

CONCLUSION

We found that paramedics could achieve a high tracheal intubation success rate using the AWS independent of previous airway management experience. Better intubation performance with the AWS was observed in paramedics without clinical experience with the ML.

Pediatric video laryngoscope versus direct laryngoscope: a meta-analysis of randomized controlled trials

BACKGROUND

We reviewed the updated literature and performed a meta-analysis based on randomized controlled trials in children to compare the clinical efficacy between video laryngoscopes (VLs) and direct laryngoscopes (DLs).

METHODS

We searched articles published in English matching the key words 'video laryngoscope (including Airtraq, GlideScope, Storz, TruView, AWS, Bullard, McGrath)' AND 'direct laryngoscope' AND 'children (including pediatric, infant, neonate)' in PubMed, Ovid, Google Scholar, and the Cochrane Library databases. Only prospective randomized controlled trials (RCTs), which compared the use of VLs and DLs in children, were included. The relative risk (RR), weighted mean difference (WMD), and their corresponding 95% confidence interval (95% CI) were calculated using the quality effects model of the metaxl 1.3 software for outcome data.

RESULTS

Fourteen studies were included in this meta-analysis. Although VLs improved the glottis visualization in most children either with normal airways or with potentially difficult intubations, the time to intubation (TTI) was prolonged in comparison to DLs (WMD: 4.9 s; 95% CI: 2.6-7.1). Subgroup analysis showed the GlideScope (WMD: 5.2 s; 95% CI: 2.0-8.5), TruView (WMD: 5.1 s; 95% CI: 0.7-9.5), Storz (WMD: 6.4 s; 95% CI: 4.8-8.1), and Bullard (WMD: 37.5 s; 95% CI: 21.0-54.0) rather than Airtraq (WMD: 0.6 s; 95% CI: -7.7-8.9) prolonged TTI. Although the success rate of the first attempt (RR: 0.96; 95% CI: 0.92-1.00) and associated complications (RR: 1.11; 95% CI: 0.39-3.16) were similar in both groups, VLs were associated with a higher incidence of failure (RR: 6.70; 95% CI: 1.53-29.39).

CONCLUSION

This meta-analysis demonstrates that although VLs improved glottis visualization in pediatric patients, this was at the expense of prolonged TTI and increased failures. However, further studies are needed to clarify the efficacy and safety of VLs in hands of nonexperts and in children with airway problems.

A comparison of the GlideScope video laryngoscope to the C-MAC video laryngoscope for intubation in the emergency department

STUDY OBJECTIVE

There is growing use of video laryngoscopy in US emergency departments (EDs). This study seeks to compare intubation success between the GlideScope video laryngoscope and the C-MAC video laryngoscope (C-MAC) in ED intubations.

METHODS

This was an analysis of quality improvement data collected during a 3-year period in an academic ED. After each intubation, the operator completed a standardized data form reporting patient demographics, indication for intubation, device(s) used, reason for device selection, difficult airway characteristics, number of attempts, and outcome of each attempt. An attempt was defined as insertion of the device into the mouth regardless of attempt at tube placement. The primary outcomes were first pass and overall intubation success. The study compared success rates between the GlideScope video laryngoscope and the C-MAC groups, using multivariable logistic regression and adjusting for potential confounders.

RESULTS

During the 3-year study period, there were 463 intubations, including 230 with the GlideScope video laryngoscope as the initial device and 233 with the C-MAC as the initial device. The GlideScope video laryngoscope resulted in first-pass success in 189 of 230 intubations (82.2%; 95% confidence interval [CI] 76.6% to 86.9%) and overall success in 221 of 230 intubations (96.1%; 95% CI 92.7% to 98.2%). The C-MAC resulted in first-pass success in 196 of 233 intubations (84.1%; 95% CI 78.8% to 88.6%) and overall success in 225 of 233 intubations (96.6%; 95% CI 93.4% to 98.5%). In a multivariate logistic regression analysis, the type of video laryngoscopic device was not associated with first-pass (odds ratio 1.1; 95% CI 0.6 to 2.1) or overall success (odds ratio 1.2; 95% CI 0.5 to 3.1).

CONCLUSION

In this study of video laryngoscopy in the ED, the GlideScope video laryngoscope and the C-MAC were associated with similar rates of intubation success.

Success rates and endotracheal tube insertion times of experienced emergency physicians using five video laryngoscopes: a randomised trial in a simulated trapped car accident victim

CONTEXT

No randomised controlled trial has yet compared different video laryngoscopes in respect of the success rates and the time taken to achieve endotracheal intubation in trapped car accident victims.

OBJECTIVE

The aim of the present study was to evaluate whether five video laryngoscopes facilitate tracheal intubation more quickly or more securely than conventional laryngoscopy.

DESIGN

Prospective, controlled, randomised crossover trial.

SETTING

An airway manikin was placed on the driver's seat of a compact car. Access was possible only through the opened driver's door.

PARTICIPANTS

Twenty-five experienced anaesthetists.

INTERVENTION

Tracheal intubation in a simulated trapped patient using video laryngoscopes in a typical out-of-hospital setting.

MAIN OUTCOME MEASURES

Times to achievement of a view of the glottis, tracheal intubation, cuff inflation, first ventilation and tracheal tube position were compared using a standard Macintosh laryngoscope or Glidescope Ranger, Storz C-MAC, Ambu-Pentax AWS, Airtraq and McGrath Series 5 video laryngoscopes in a randomised order. Wilcoxon signed-rank test and McNemar test were used for statistical analysis. A P value of less than 0.05 was considered statistically significant.

RESULTS

Twenty-five anaesthetists (35.1 ± 7.3 years; 16 male, nine female) with an intubation experience of 374 ± 96 intubations per year and an experience of 9.1 ± 7.3 years participated. Glottic view, tracheal intubation, cuff inflation and first ventilation were achieved most rapidly with the Macintosh laryngoscope, although the Airtraq and Pentax AWS video laryngoscopes were not significantly slower. Times were significantly longer when the Glidescope Ranger, McGrath Series 5 or Storz C-MAC video laryngoscopes were used (P < 0.05), failure to place the endotracheal tube correctly was significantly commoner with the McGrath Series 5 than with the Macintosh (P = 0.031).

CONCLUSION

When attempting to intubate a trapped car accident victim, video laryngoscopes provide a better view of the glottis, but some delay tracheal intubation significantly. The devices with a tube guide (Airtraq and Ambu Pentax AWS) enable tracheal intubation to be achieved significantly faster and with a lower failure rate than devices without a tube guide. No video laryngoscope outperformed direct laryngoscopy with a Macintosh laryngoscope in this simulation study.

Video Laryngoscopy in the Prehospital Setting

In the prehospital setting, the emergency care provider must anticipate that some patients will manifest with difficult airways. The use of video laryngoscopy to secure an airway in the prehospital setting has not been explored widely, but has the potential to be a useful tool. This article briefly reviews some of the major video laryngoscopes on the market and their usefulness in the prehospital setting. Studies and case reports indicate that the video laryngoscope is a promising device for emergency intubation, and it has been predicted that, in the future, video laryngoscopy will dominate the field of emergency airway management.

Direct laryngoscopy always should be retained as a primary skill; however, the video laryngoscope has the potential to be a good primary choice for the patient with potential cervical spine injuries or limited jaw or spine mobility, and in the difficult-to-access patient.The role of video laryngoscopes in securing an airway in head and neck trauma victims in the prehospital setting has yet to be determined, but offers interesting possibilities. Further clinical studies are necessary to evaluate its role in airway management by prehospital emergency medical services.

Cost-effectiveness analysis of flexible optical scopes for tracheal intubation: a descriptive comparative study of reusable and single-use scopes

STUDY OBJECTIVE

To calculate the costs per intubation of reusable fiberoptic scopes versus single-use intubation scopes.

DESIGN

Open-label retrospective study.

SETTING

University-affiliated hospital.

MEASUREMENTS

The one-year intubation records of intubations performed with reusable intubation scopes, the one-year maintenance costs of these scopes, and their three-year repair cost records were analyzed. A total of 166 intubations were performed with reusable fiberoptic scopes in 2009. Calculations to assess the costs per intubation based on the documented records at our institution were made. The total cost of an intubation, the repair-to-intubation ratio, and the repair cost per intubation were determined.

MAIN RESULTS

The total cost of an intubation at our institution in 2009, using reusable scopes, was $119.75 [US dollars (USD)], which included $20.15 (purchasing), $53.48 (repair), $33.16 (maintenance), and $12.96 (labor). The repair-to-intubation ratio was 1:55. Repair costs were $53.48 per intubation and $2,959.44 per instance of repair.

CONCLUSIONS

The Ambu aScope, a single-use intubation scope, is a new addition to video laryngoscopy. The price should range within 10% of our intubation cost ($120.00 to $132.00 per single-use intubation scope).

Direct endotracheal intubation using a novel detachable optic probe (Sunscope) by emergency medical technicians with various training backgrounds

Objective

Effective airway management requires both proper technique and the appropriate devices. With the widespread implementation of advanced life-support techniques in emergency medical services (EMS), orotracheal intubation is now performed not only by professional practitioners but, in many occasions, nonprofessionals. With extensively diversified skill equipped, we tested whether the Sunscope, a patented tracheal intubation device with a digital display, is able to facilitate tracheal intubation by naïve EMS personnel with various training backgrounds.

Methods

We conducted a study to determine rate of success and time required to insert an orotracheal tube into a mannequin using Sunscope. The participants were placed into the professional group (i.e., anesthesiologists and emergency medical paramedics; EMT-P) or the nonprofessional group (i.e., emergency medical technicians; EMT). Intubation required three steps: equipment preparation, vocal cord exposure, and tube insertion. The time required for each step was recorded by a senior staff member, and the data were analyzed by nonparametric statistics.

Results

Each consecutive step in the operating procedure was significantly shorter for the professional group in comparison with the nonprofessional group during the first trial: equipment preparation, 10.5 ± 2.1 vs. 11.9 ± 4.1 seconds; vocal cord exposure, 7.4 ± 7.7 vs. 12.2 ± 7.7 seconds; tube insertion, 8.8 ± 4.8 vs. 17.6 ± 9.4 seconds; and total time required for intubation, 26.7 ± 8.8 vs. 35.8 ± 19.6 seconds. The professional practitioners showed no significant improvement, in terms of time reduction, on the following three trials. On the other hand, the nonprofessional practitioners showed no significant differences, in terms of time required to expose the vocal cords and total operation time, following the third trial in comparison with the professional practitioners.

Conclusion

Our research demonstrates that professional practitioners are able to use the Sunscope on their first attempt. Despite a lack of training in conventional endotracheal intubation, emergency medical technicians (EMT-I and -II) were able to complete intubation on their first attempt; a significant reduction in the time required to intubate was noted after repeated practice. All levels of naïve EMTs were able to readily visualize the vocal cords through Sunscope and, thereby, reliably insert the endotracheal tube in less than 1 minute, regardless of their skills before testing.

A comparative study on the usefulness of the Glidescope or Macintosh laryngoscope when intubating normal airways

BACKGROUND

The Glidescope Videolaryngoscope (GVL) is a newly developed video laryngoscope. It offers a significantly improved laryngeal view and facilitates endotracheal intubation in difficult airways, but it is controversial in that it offers an improved laryngeal view in normal airways as well. And the price of GVL is expensive. We hypothesized that intubation carried out by fully experienced anesthesiologists using the GVL with appropriate pre-anesthetic preparations offers an improved laryngeal view and shortened intubation time in normal airways. Therefore, the aim of this study was to compare the GVL with the Macintosh laryngoscope in normal airways and to determine whether GVL can substitute the Macintosh laryngoscope.

METHODS

This study included 60 patients with an ASA physical status of class 1 or 2 requiring tracheal intubation for elective surgery. All patients were randomly allocated into two groups, GVL (group G) or Macintosh (group M). ADS (airway difficulty score) was recorded before induction of anesthesia. The anesthesiologist scored vocal cord visualization using the percentage of glottic opening (POGO) visible and the subjective ease of intubation on a visual analogue scale (VAS). The time required to intubate was recorded by an assistant.

RESULTS

There was a significant increase in POGO when using the GVL (P < 0.05). However, there was no difference in the time required for a successful tracheal intubation using the GVL compared with the Macintosh laryngoscope. The VAS score on the ease of intubation was significantly lower for the GVL than for the Macintosh laryngoscope (P < 0.05).

CONCLUSIONS

GVL could be a first-line tool in normal airways.

Pentax-airway scope for tracheal intubation breaks through the limitation of neck motion in an ankylosing spondylitis patient wearing halo vest--a case report

The Airway Scope (AWS) provides better glottic view than the conventional direct laryngoscopy in tracheal intubation. With it, the endotracheal tube can be more easily inserted into the tracheal lumen easily. We hereby presented a 24-year-old ankylosing spondylitis (AS) patient wearing a halo vest who was successfully intubated for undergoing cervical spine surgery involving C1 and C2 under general anesthesia. Pre-operative airway assessment revealed that he was a case of difficult intubation. An AWS was used for oral tracheal intubation which was achieved smoothly in the first attempt. AWS can be an alternative device for airway management in a patient wearing halo vest.

Comparison of the laryngeal view during intubation using Airtraq and Macintosh laryngoscopes in patients with cervical spine immobilization and mouth opening limitation

BACKGROUND

For patients suspicious of cervical spine injury, a Philadelphia cervical collar is usually applied. Application of Philadelphia cervical collar may cause difficult airway. The aim of this study was to evaluate the laryngeal view and the success rate at first intubation attempt of the Airtraq and conventional laryngoscopy in patients with simulated cervical spine injury after application of a Philadelphia cervical collar.

METHODS

Anesthesia was induced with propofol, remifentanil, and rocuronium. After a Philadelphia cervical collar applied, patients were randomly assigned to tracheal intubation with an Airtraq (Group A, n = 25) or with conventional laryngoscopy (Group L, n = 25). Measurements included intubation time, success rate of first intubation attempt, number of intubation attempts, and percentage of glottic opening (POGO) score. Mean blood pressure and heart rate were also recorded at baseline, just before and after intubation.

RESULTS

The success rate of the first attempt in Group A (96%) was significantly greater than with the Group L (40%). POGO score was significantly greater in Group A (84 ± 20%) than in Group L (6 ± 11%). The duration of successful intubation at first tracheal intubation attempt and hemodynamic changes were not significantly different between the two groups.

CONCLUSIONS

The Airtraq offers a better laryngeal view and higher success rate at first intubation attempt in patients who are applied with a Philadelphia cervical collar due to suspicion of cervical spine injury.

Tracheal intubation of a difficult airway using Airway Scope, Airtraq, and Macintosh laryngoscope: a comparative manikin study of inexperienced personnel

BACKGROUND

The Airway Scope (AWS) (Pentax-AWS, Hoya Corp., Tokyo, Japan) and the Airtraq (ATQ) (Prodol, Vizcaya, Spain) have similarities in the novel structures of their blades. In this study, we evaluated the ease of use of the AWS and ATQ compared with the Macintosh laryngoscope (ML) by inexperienced personnel in a simulated manikin difficult airway.

METHODS

Twenty-four fifth-year medical students with no previous experience in tracheal intubation participated in this study. We used an advanced patient simulator (SimMan(R), Laerdal Medical, Stavanger, Norway) to simulate difficult airway scenarios including cervical spine rigidity, limited mouth opening, and pharyngeal obstruction. The sequences in selecting devices and scenarios were randomized. Success rates for tracheal intubation, and the time required for visualization of the glottis, tracheal intubation, and inflation of the lungs, and the number of optimization maneuvers and dental click sounds were analyzed. The 3 different intubation devices were tested in 4 different scenarios by 24 students.

RESULTS

Both the AWS and ATQ had very high success rates of tracheal intubation compared with the ML (AWS 100%*; ATQ 98%*; and ML 89%; *P < 0.05 AWS, ATQ versus ML). The time to intubation with the AWS was significantly shorter than with the ATQ and ML (AWS 11 +/- 6 seconds; ATQ 16 +/- 12 seconds; and ML 16 +/- 11 seconds; *P < 0.05 AWS versus ATQ, ML). The number of optimization maneuvers with the AWS was significantly lower than with the ATQ and ML. There were significantly more audible dental click sounds with the ML than with the AWS and ATQ.

CONCLUSION

Both the AWS and ATQ may be suitable devices for difficult intubation by inexperienced personnel in this manikin simulated scenario. Further studies in a clinical setting are necessary to confirm these findings.