EMS Intubation Improves with King Vision Video Laryngoscopy

Predictive and protective factors for failing first pass intubation in prehospital rapid sequence intubation: an aetiology and risk systematic review with meta-analysis

BACKGROUND

Prehospital rapid sequence intubation first pass success rates vary between 59% and 98%. Patient morbidity is associated with repeat intubation attempts. Understanding what influences first pass success can guide improvements in practice. We performed an aetiology and risk systematic review to answer the research question 'what factors are associated with success or failure at first attempt laryngoscopy in prehospital rapid sequence intubation?'.

METHODS

MEDLINE, EMBASE, CINAHL, and Cochrane Library were searched on March 3, 2023 for studies examining first pass success rates for rapid sequence intubation of prehospital live patients. Screening was performed via Covidence, and data synthesised by meta-analysis. The review was registered with PROSPERO and performed and reported as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Reasonable evidence was discovered for predictive and protective factors for failure of first pass intubation. Predictive factors included age younger than 1 yr, the presence of blood or fluid in the airway, restricted jaw or neck movement, trauma patients, nighttime procedures, chronic or acute distortions of normal face/upper airway anatomy, and equipment issues. Protective factors included an experienced intubator, adequate training, use of certain videolaryngoscopes, elevating the patient on a stretcher in an inclined position, use of a bougie, and laryngeal manoeuvres.

CONCLUSIONS

Managing bloody airways, positioning well, using videolaryngoscopes with bougies, and appropriate training should be further explored as opportunities for prehospital services to increase first pass success. Heterogeneity of studies limits stronger conclusions.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42022353609).

Evidence-Based Guideline for Prehospital Airway Management

Airway management is a cornerstone of emergency medical care. This project aimed to create evidence-based guidelines based on the systematic review recently conducted by the Agency for Healthcare Research and Quality (AHRQ). A technical expert panel was assembled to review the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The panel made specific recommendations on the different PICO (population, intervention, comparison, outcome) questions reviewed in the AHRQ review and created good practice statements that summarize and operationalize these recommendations. The recommendations address the use of ventilation with bag-valve mask ventilation alone vs. supraglottic airways vs. endotracheal intubation for adults and children with cardiac arrest, medical emergencies, and trauma. Additional recommendations address the use of video laryngoscopy and drug-assisted airway management. These recommendations, and the associated good practice statements, offer EMS agencies and clinicians an opportunity to review the available evidence and incorporate it into their airway management strategies.

Video Laryngoscopy versus Direct Laryngoscopy for Orotracheal Intubation in the Out-of-Hospital Environment: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the effect of video and direct laryngoscopy on first-pass success rates for out-of-hospital orotracheal intubation.

METHODS

MEDLINE, Embase, and Cochrane databases were searched from inception to January 2023. Out-of-hospital studies comparing video and direct laryngoscopy on either first-pass or overall intubation success were included. A random effects meta-analysis was performed with a primary outcome of first-pass success stratified by clinician type and laryngoscope blade geometry. The secondary outcomes were overall intubation success stratified by clinician type, and intubation time. All hypotheses and subgroup analyses were determined a priori.

RESULTS

Twenty-five studies involving 35,489 intubations met inclusion criteria. Substantial heterogeneity (>75%) precluded reporting point estimates for nearly all analyses. For our primary outcome, video laryngoscopy was associated with improved first-pass success in 3/5 physician studies, 4/6 critical care paramedic/registered nurse studies, and 7/10 paramedic studies. Video laryngoscope devices with Macintosh blade geometry were associated with improved first-pass success in 7/10 studies, while devices with hyperangulated geometry were associated with improved first-pass success in 3/7 studies. Overall intubation success was greater with video laryngoscopy in 2/6 studies in the physician subgroup and 9/10 studies in the paramedic subgroup. Video laryngoscopy was not associated with overall intubation success among critical care paramedics/nurses (OR = 1.89, 0.96 to 3.72, I2 = 34%). Lastly, 4/5 studies found video laryngoscopy to be associated with longer intubation times.

CONCLUSIONS

We found substantial heterogeneity among out-of-hospital studies comparing video laryngoscopy to direct laryngoscopy on first-pass success, overall success, or intubation time. This heterogeneity was not explained with stratification by study design, clinician type, video laryngoscope blade geometry, or leave-one-out meta-analysis. A majority of studies showed that video laryngoscopy was associated with improved first pass success in all subgroups, but only for paramedics and not physicians when looking at overall success. This improvement was more common in studies that used Macintosh blades than those that used hyperangulated blades. Future research should explore the heterogeneity identified in our analysis with an emphasis on differences in training, clinical milieu, and specific video laryngoscope devices.

Transitioning from Direct to Video Laryngoscopy during the COVID-19 Pandemic Was Associated with a Higher Endotracheal Intubation Success Rate

OBJECTIVE

The objective of this study was to determine the effect of transitioning from direct laryngoscopy (DL) to video laryngoscopy (VL) on endotracheal intubation success overall and with enhanced precautions implemented during the COVID-19 pandemic.

METHODS

We examined electronic transport records from Mayo Clinic Ambulance Service, a large advanced life support (ALS) provider serving rural, suburban, and urban areas in Minnesota and Wisconsin, USA. We determined the success of intubation attempts when using DL (March 10, 2018 to December 19, 2019), VL (December 20, 2019 to September 29, 2021), and VL with an enhanced COVID-19 guideline that restricted intubation to one attempt, performed by the most experienced clinician, who wore enhanced personal protective equipment (April 1 to December 18, 2020). Success rates at first attempt and after any attempt were assessed for association with type of laryngoscopy (VL vs DL) after adjusting for patient age group, patient weight, use of enhanced COVID-19 guideline, medical vs trauma patient, and ALS vs critical care clinician. A secondary analysis further adjusted for degree of glottic visualization.

RESULTS

We identified 895 intubation attempts using DL and 893 intubation attempts using VL, which included 382 VL intubation attempts using the enhanced COVID-19 guideline. Success on first intubation attempt was 69.2% for encounters with DL, 82.9% overall with VL, and 83.2% with VL and enhanced COVID-19 protocols (DL vs overall VL: p < 0.001; COVID-19 vs non-COVID VL: p = 0.86). In multivariable analysis, use of VL was associate with higher odds of successful intubation on first attempt (odds ratio, 2.28; 95%CI, 1.73-3.01; p < 0.001) and on any attempt (odds ratio, 2.16; 95%CI, 1.58-2.96; p < 0.001) compared with DL. Inclusion of glottic visualization in the model resulted in a nonsignificant association between laryngoscopy type and successful first intubation (p = 0.41) and a significant association with the degree of glottic visualization (p < 0.001).

CONCLUSIONS

VL is designed to improve glottic visualization. The use of VL by a large, U.S. multistate ALS ambulance service was associated with increased odds of successful first-pass and overall attempted intubation, which was mediated by better visualization of the glottis. COVID-19 protocols were not associated with success rates.

Efficacy of Video Laryngoscopy versus Direct Laryngoscopy in the Prehospital Setting: A Systematic Review and Meta-Analysis

INTRODUCTION

Placing an endotracheal tube is a life-saving measure. Direct laryngoscopy (DL) is traditionally the default method. Video laryngoscopy (VL) has been shown to improve efficiency, but there is insufficient evidence comparing VL versus DL in the prehospital settings. This study, comprising a systematic review and random-effects meta-analysis, assesses current literature for the efficacy of VL in prehospital settings.

METHODS

PubMed and Scopus databases were searched from their beginnings through March 1, 2022 for eligible studies. Outcomes were the first successful intubation, overall success rate, and number of total DL versus VL attempts in real-life clinical situations. Cochrane's Risk of Bias (RoB) tool and the Newcastle-Ottawa Scale (NOS) were applied to assess risk of bias and study quality; Q-statistics and I2 values were used to assess heterogeneity.

RESULTS

The search yielded seven studies involving 23,953 patients, 6,674 (28%) of whom underwent intubation via VL. Compared to DL, VL was associated with a statistically higher risk ratio for first-pass success (Risk Ratio [RR] = 1.116; 95% CI, 1.005-1.239; P = .041; I2 = 87%). The I2 value for the subgroup of prospective studies was 0% compared to 89% for retrospective studies. In addition, VL was associated with higher likelihood of overall success rate (RR = 1.097; 95% CI, 1.01-1.18; P = .021; I2 = 85%) and lower mean number of attempts (Mean Difference = -0.529; 95% CI, -0.922 to -0.137; P = .008).

CONCLUSION

The meta-analysis suggested that VL was associated with higher likelihood of achieving first-pass success, greater overall success rate, and lower number of intubation attempts for adults in the prehospital settings. This study had high heterogeneity, likely presenced by the inclusion of retrospective observational studies. Further studies with more rigorous methodology are needed to confirm these results.

Out-of-Hospital Intubation Success Rates Vary Based on Transport Environment

BACKGROUND

Oral endotracheal intubation is a procedure performed by emergency medical services (EMS) providers-who are stationed on ground ambulances, rotor-wing air ambulances (helicopter), and fixed-wing air ambulances (airplane)-for the purpose of securing a patient's airway.

OBJECTIVE

Historically, intubation success rates have depended on human factors, such as provider familiarity with intubation. There has been relatively little literature examining intubation success rates as a factor of EMS transport environment, despite there being important human factors differences between the different environments.

METHODS

We queried a national database of EMS calls in the United States. Inclusion criteria were oral endotracheal intubations performed in 2019 where providers documented whether or not the intubation was successful and what mode of transport they were assigned to.

RESULTS

A total of 98,048 intubations met inclusion criteria. The majority of intubations were performed by providers stationed to ground ambulances (95.38%), followed by rotor-wing air ambulances (4.35%) and fixed-wing air ambulances (0.27%). Intubation success rates were comparable between fixed-wing air ambulances (89.66%) and rotor-wing air ambulances (89.17%)-however, they were significantly lower on ground ambulances (75.69%) (p < .001).

CONCLUSIONS

Our data show that flight crew members-either on fixed-wing or rotor-wing air ambulances-are associated with significantly higher rates of intubation success than ground ambulance providers. There are a number of possible explanations for this trend, including more opportunities to intubate in the air medical setting, increased clinical education focused on airway management in the air medical setting, or assistive technologies being more commonly used in the air medical setting.

Prehospital Drug Assisted Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical intervention for patients with airway compromise, respiratory failure, and cardiac arrest. Many EMS agencies use drug-assisted airway management (DAAM) - the administration of sedatives alone or in combination with neuromuscular blockers - to facilitate advanced airway placement in patients with airway compromise or impending respiratory failure who also have altered mental status, agitation, or intact protective airway reflexes. While DAAM provides several benefits including improving laryngoscopy and making insertion of endotracheal tubes and supraglottic airways easier, DAAM also carries important risks. NAEMSP recommends:DAAM is an appropriate tool for EMS clinicians in systems with clear guidelines, sufficient training, and close EMS physician oversight. DAAM should not be used in settings without adequate resources.EMS physicians should develop clinical guidelines informed by evidence and oversee the training and credentialing for safe and effective DAAM.DAAM programs should include best practices of airway management including patient selection, assessmenct and positioning, preoxygenation strategies including apneic oxygenation, monitoring and management of physiologic abnormalities, selection of medications, post-intubation analgesia and sedation, equipment selection, airway confirmation and monitoring, and rescue airway techniques.Post-DAAM airway placement must be confirmed and continually monitored with waveform capnography.EMS clinicians must have the necessary equipment and training to manage patients with failed DAAM, including bag mask ventilation, supraglottic airway devices and surgical airway approaches.Continuous quality improvement for DAAM must include assessment of individual and aggregate performance metrics. Where available for review, continuous physiologic recordings (vital signs, pulse oximetry, and capnography), audio and video recordings, and assessment of patient outcomes should be part of DAAM continuous quality improvement.

Comparison of Hyperangulated and Standard Geometry Video Laryngoscopy Tracheal Intubation for Prehospital Care in a Manikin: A Randomized Controlled Crossover Trial

OBJECTIVE

The purpose of this study was to investigate the efficacy of hyperangulated video laryngoscopy (HAVL) versus standard geometry video laryngoscopy (SGVL) in the simulated prehospital environment using a manikin. There is consensus that video laryngoscopy (VL) can be very useful in the emergency department when difficult intubations are predicted. Emergency medical service (EMS) providers are also often faced with difficult, rapidly deteriorating airway management situations that not only involve patient and operator factors but also include challenging unique environmental factors, such as nonoptimized positions in transport vehicles (eg, helicopters and ambulances) or at ground level or entrapped positions. To our knowledge, there has never been a study purposefully investigating the efficacy of hyperangulated geometry versus standard geometry VL techniques in the prehospital environment.

METHODS

A single-center, randomized controlled crossover trial was performed using attending physician helicopter EMS providers. Physicians were randomized to perform 5 HAVL or SGVL intubations followed by the subsequent technique. Intubations were performed on ground level and then repeated in the helicopter with the first location also randomized. A manikin airway management trainer was used to simulate intubation in each environment. The time to intubation (primary outcome) as well as first-pass success and the Cormack-Lehane view were recorded for each attempt. Qualitative data were also obtained for physician preference and perceived difficulty.

RESULTS

There was no statistically significant difference in the time to intubation with HAVL versus SGVL (ground: 15.02 vs. 14.88 seconds, P = .86; helicopter: 16.11 vs. 16.14 seconds, P = .93). First-pass success was 100% for both techniques in both scenarios. More Grade 1 views were obtained with HAVL (147/150 vs. 134/150). Moreover, most physicians preferred HAVL overall and felt that HAVL required less force (9/15 grounded manikin and 10/15 helicopter manikin) and led to the best chance for first-pass success (11/15 grounded manikin and 10/15 helicopter manikin).

CONCLUSION

The results of this study are limited because of the static and highly favorable anatomy of a manikin versus the variability and often difficult anatomy of individual patients. Our results suggest that both techniques are efficacious when the patient is both on the ground or in the helicopter, although provider preference does seem to vary.

Video laryngoscopy for out of hospital cardiac arrest

INTRODUCTION

Endotracheal intubation is an import component of out-of-hospital cardiac arrest (OHCA) resuscitation. In this analysis, we evaluate the association of video laryngoscopy (VL) with first pass success and return of spontaneous circulation (ROSC) using a national OHCA cohort.

METHODS

We analyzed 2018 data from ESO Inc. (Austin, TX), a national prehospital electronic health record. We included all adult, non-traumatic cardiac arrests undergoing endotracheal intubation. We defined VL and direct laryngoscopy (DL) based on paramedic recorded intubation device. The primary outcomes were first pass success, ROSC, and sustained ROSC. Using multivariable, mixed models, we determined the association between VL and first pass success rate, ROSC, and sustained ROSC (survival to ED or ROSC in the field for greater than 20 min), fitting agency as a random intercept and adjusting for confounders.

RESULTS

We included 22,132 patients cared for by 914 EMS agencies, including 5702 (25.7%) VL and 16,430 (74.2%) DL. Compared to DL, VL had a lower rate of bystander CPR, but other characteristics were similar between the groups. VL exhibited higher first pass success than DL (75.1% v 69.5%, p < .001). On mixed model analysis, VL was associated with a higher first pass success (OR 1.5, CI 1.3-1.6) but not ROSC (OR 1.1, CI 0.97-1.2) or sustained ROSC (OR 1.1, CI 0.9-1.2).

CONCLUSION

While associated with higher FPS, VL was not associated with increased rate of ROSC. The role of VL in OHCA remains unclear.

Comparison of Video Versus Direct Laryngoscopy: A Prospective Prehospital Air Medical Services Study

OBJECTIVE

Videolaryngoscopy (VL) in the prehospital setting remains controversial, with conflicting data on its utility. We compared C-MAC VL (Karl Storz, Tuttlingen, Germany) versus direct laryngoscopy (DL) in the prehospital setting, recording the grade of the glottic view, first pass success (FPS), overall success, and equipment functionality.

METHODS

We conducted a prospective observational study with a convenience sample of 49 adult patients who were intubated by flight crew nurses and paramedics using the C-MAC videolaryngoscope from April to November 2013. We compared Cormack-Lehane (CL) grades of view for DL and VL, intubation success rates, and equipment functionality.

RESULTS

CL grades 1 or 2 were obtained with 24 patients (49%) with DL and 45 patients (92%) with VL. Of the 25 patients (51%) who had a CL grade 3 or 4 view on DL, 22 of those patients (88%) converted to a CL grade 1 or 2 with VL (P < .001). There was an overall success rate of 96% and an FPS rate of 71%. The C-MAC videolaryngoscope was functional during intubation 100% of the time.

CONCLUSION

VL improved glottic visualization compared with DL. The FPS and overall intubation success rates were similar to other published prehospital studies using VL. The C-MAC provided reliable, high-quality video despite demanding prehospital conditions.

Evolution of videolaryngoscopy in pediatric population

Direct laryngoscopy has remained the sole method for securing airway ever since the inception of endotracheal intubation. The recent introduction of video-laryngoscopes has brought a paradigm shift in the pratice of airway management. It is claimed that they improve the glottic view and first pass success rates in adult population. The airway management in children is more challenging than adults. The role of videolaryngoscopy for routine intubation in children is not clearly proven. This review attempts to discuss various videolaryngosocpes available for use in pediatric patients.

Proficiencies of military medical officers in intubating difficult airways

Background

This study sheds light on the proficiency of military medical officers who had received between 2 and 3 years of post-graduate training, in the handling of the difficult airway in a trauma manikin simulator using direct and video laryngoscopes.

Method

One hundred thirty-three doctors from the Singapore Armed Forces Medical Officer Cadet Course were assessed using high-fidelity simulator models with standardised difficult airways (simulator with tongue-swelling and cervical collar). They used the Macintosh direct laryngoscope (DL), King Vision channelled-blade laryngoscope (KVC), King Vision non-channelled blade laryngoscope (KVNC), and the McGrath (MG) laryngoscope on the same model in a randomised sequence. The intubation success rates and time to intubation were recorded and analysed for the study.

Results

The medical officers had a 71.4% intubation success rate with the DL on the difficult airway trauma simulator model and the mean time to intubation of 40.1 s. With the KVC, the success rate is 86.5% with mean intubation time of 40.4 s. The KVNC produced 24.8% success rate, with mean time to intubation of 53.2 s. The MG laryngoscope produced 85.0% success rate, with a mean time of intubation of 37.4 s.

Conclusion

Military medical officers with 2–3 years of post-graduate training had a success rate of 71.4% success rate intubating a simulated difficult airway in a trauma setting using a DL. Success rates were improved with the use of KVC and the MG laryngoscope, but was worse with the KVNC.

Comparison of the time to successful endotracheal intubation using the Macintosh laryngoscope or KingVision video laryngoscope in the emergency department: A prospective observational study

OBJECTIVE:

Intubation is a skill that must be mastered by the emergency physician (EP). Today, we have a host of video laryngoscopes which have been developed to make intubations easier and faster. It may seem that in a busy emergency department (ED), a video laryngoscope (VL) in the hands of an EP would help him intubate patients faster compared to the traditional direct laryngoscope (DL). Our goal was to compare the time taken to successfully intubate patients coming in ED using King Vision VL (KVVL) and DL.

MATERIALS AND METHODS:

This was a prospective observational study on patients coming to the ED requiring emergent intubation. They were allocated one to one alternatively into two groups – KVVL and DL. Accordingly, KVVL or DL intubations were carried out by the EPs. Time taken to intubate, first-pass success, and crossover between laryngoscopes were recorded.

RESULTS:

A total of 350 patients were enrolled in the study. Overall, mean time to intubate patients using the DL was 15.85 s (95% confidence interval [CI] 14.05–17.65), while the meantime with KVVL was 13.75 s (95% CI 12.32–15.18) (P = 0.084). The overall first-pass success rates with DL and KVVL were 89.94% and 85.16%, respectively (P = 0.076). A total of 7.43% (95% CI 5.12–10.66) patients had crossover between laryngoscopes.

CONCLUSION:

We found the KVVL to have a similar performance to the DL in terms of time for intubations and ease in difficult airways. We consider the KVVL a useful device for EDs to equip themselves with.

Video Laryngoscopic Intubation Using the King VisionTM Laryngoscope in a Simulated Cervical Spine Trauma: A Comparison Between Non-Channeled and Channeled Disposable Blades

Videolaryngoscopes may reduce cervical spine movement during tracheal intubation in patients with neck trauma. This manikin study aimed to compare the performance of disposable non-channeled and channeled blades of the King Vision™ videolaryngoscope in simulated cervical spine injury. Fifty-eight anesthesiologists in training intubated the TruMan manikin with the neck immobilized using each blade in a randomized order. The primary outcome was the time needed for tracheal intubation, secondary aims included total success rate, the time required for visualization of the larynx, number of attempts, view of the vocal cords, and subjective assessment of both methods. Intubation time with the channeled blade was shorter, with a median time of 13 s (IQR 9-19) vs. 23 s (14.5-37.5), p < 0.001, while times to visualization of the larynx were similar in both groups (p = 0.54). Success rates were similar in both groups, but intubation with the non-channeled blade required more attempts (1.52 vs. 1.05; p < 0.001). The participants scored the intubation features of the channeled blade significantly higher, while visualization features were scored similarly in both groups. Both blades of the King Vision™ videolaryngoscope are reliable intubation devices in a simulated cervical spine injury in a manikin model when inserted by non-experienced operators. The channeled blade allowed faster intubation of the trachea.

First attempt success of video versus direct laryngoscopy for endotracheal intubation by ambulance nurses: a prospective observational study

Purpose

The aim of this study was to compare the rate of first attempt success of endotracheal intubation performed by ambulance nurses in patients with a Glasgow Coma Scale (GCS)  of 3 using video laryngoscopy versus direct laryngoscopy.

Methods

A prospective cohort study was conducted in a single, independent ambulance service. Twenty of a total of 65 nurse-staffed ambulances were equipped with a video laryngoscope; a classic direct laryngoscope (Macintosh) was available on all 65 ambulances. The primary outcome was first attempt success of the intubation. Secondary outcomes were overall success, time needed for intubation, adverse events, technical or environmental issues encountered, and return of spontaneous circulation (ROSC). Ambulance nurses were asked if the intubation device had affected the outcome of the intubation.

Results

The first attempt success rate in the video laryngoscopy group [53 of 93 attempts (57%)] did not differ from that in the direct laryngoscopy group [61 of 126 (48%); p = 0.221]. However, the second attempt success rate was higher in the video laryngoscopy group [77/93 (83%) versus 80/126 (63%), p = 0.002]. The median time needed for the intubation (53 versus 56 s) was similar in both groups. Ambulance nurses more often expected a positive effect when performing endotracheal intubation with a video laryngoscope (n = 72, 81%) compared with a direct laryngoscope (n = 49, 52%; p < 0.001).

Conclusion

Although no significant effect on the first attempt success was found, video laryngoscopy did increase the overall success rate. Ambulance nurses had a more positive valuation of the video laryngoscope with respect to success chances.

Comparison of King Vision video laryngoscope and Macintosh laryngoscope: a prospective randomized controlled clinical trial

Background and objectives

We compared the efficiency of the King Vision video laryngoscope and the Macintosh laryngoscope, when used by experienced anesthesiologists on adult patients with varying intubating conditions, in a prospective randomized controlled clinical trial.

Methods

A total of 388 patients with an American Society of Anesthesiologists physical status of I or II, scheduled for general anesthesia with endotracheal intubation. Each patient was intubated with both laryngoscopes successively, in a randomized order. Intubation success rate, time to best glottic view, time to intubation, time to ventilation, Cormack–Lehane laryngoscopy grades, and complications related to the laryngoscopy and intubation were analyzed.

Results and conclusions

First pass intubation success rates were similar for the King Vision and the Macintosh (96.6% vs. 94.3%, respectively, p > 0.05). King Vision resulted in a longer average time to glottic view (95% CI 0.5–1.4 s, p < 0.001), and time to intubation (95% CI 3–4.6 s, p < 0.001). The difference in time to intubation was similar when unsuccessful intubation attempts were excluded (95% CI 2.8–4.4 s, p < 0.001). Based on the modified Mallampati class at the preoperative visit, the King Vision improved the glottic view in significantly more patients (220 patients, 56.7%) compared with the Macintosh (180 patients, 46.4%) (p < 0.001). None of the patients had peripheral oxygen desaturation below 94%. Experienced anesthesiologists may obtain similar rates of first pass intubation success and airway trauma with both laryngoscopes. King Vision requires longer times to visualize the glottis and to intubate the trachea, but does not cause additional desaturation.

Video laryngoscopy versus direct laryngoscopy for first-attempt tracheal intubation in the general ward

Background

Recent trials showed that video laryngoscopy (VL) did not yield higher first-attempt tracheal intubation success rate than direct laryngoscopy (DL) and was associated with higher rates of complications. Tracheal intubation can be more challenging in the general ward than in the intensive care unit. This study aimed to investigate which laryngoscopy mode is associated with higher first-attempt intubation success in a general ward.

Methods

This is a retrospective study of tracheal intubations conducted at a tertiary academic hospital. This analysis included all intubations performed by the medical emergency team in the general ward during a 48-month period.

Results

For the 958 included patients, the initial laryngoscopy mode was video laryngoscopy in 493 (52%) and direct laryngoscopy in 465 patients (48%). The overall first-attempt success rate was 69% (664 patients). The first-attempt success rate was higher with VL (79%; 391/493) than with DL (59%; 273/465, p < 0.001). The first-attempt intubation success rate was higher among experienced operators (83%; 266/319) than among inexperienced operators (62%; 398/639, p < 0.001). In multivariate logistic regression analyses, VL, pre-intubation heart rate, pre-intubation SpO₂ > 80%, a non-predicted difficult airway, experienced operator, and Cormack–Lehane grade were associated with first-attempt intubation success in the general ward. Over all intubation-related complications were not different between two groups (27% for VL vs. 25% for DL). However, incidence of a post-intubation SpO₂ < 80% was higher with VL than with DL (4% vs. 1%, p = 0.005), and in-hospital mortality was also higher (53.8% vs. 43%, p = 0.001).

Conclusion

In a general ward setting, the first-attempt intubation success rate was higher with video laryngoscopy than with direct laryngoscopy. However, video laryngoscopy did not reduce intubation-related complications. Furthers trials on best way to perform intubation in the emergency settings are required.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0428-0) contains supplementary material, which is available to authorized users.

[Comparison of King Vision video laryngoscope and Macintosh laryngoscope: a prospective randomized controlled clinical trial]

BACKGROUND AND OBJECTIVES

We compared the efficiency of the King Vision video laryngoscope and the Macintosh laryngoscope, when used by experienced anesthesiologists on adult patients with varying intubating conditions, in a prospective randomized controlled clinical trial.

METHODS

A total of 388 patients with an American Society of Anesthesiologists physical status of I or II, scheduled for general anesthesia with endotracheal intubation. Each patient was intubated with both laryngoscopes successively, in a randomized order. Intubation success rate, time to best glottic view, time to intubation, time to ventilation, Cormack-Lehane laryngoscopy grades, and complications related to the laryngoscopy and intubation were analyzed.

RESULTS AND CONCLUSIONS

First pass intubation success rates were similar for the King Vision and the Macintosh (96.6% vs. 94.3%, respectively, p>0.05). King Vision resulted in a longer average time to glottic view (95% CI 0.5-1.4s, p<0.001), and time to intubation (95% CI 3-4.6s, p<0.001). The difference in time to intubation was similar when unsuccessful intubation attempts were excluded (95% CI 2.8-4.4s, p<0.001). Based on the modified Mallampati class at the preoperative visit, the King Vision improved the glottic view in significantly more patients (220 patients, 56.7%) compared with the Macintosh (180 patients, 46.4%) (p<0.001). None of the patients had peripheral oxygen desaturation below 94%. Experienced anesthesiologists may obtain similar rates of first pass intubation success and airway trauma with both laryngoscopes. King Vision requires longer times to visualize the glottis and to intubate the trachea, but does not cause additional desaturation.

Implementation of a Clinical Bundle to Reduce Out-of-Hospital Peri-intubation Hypoxia

STUDY OBJECTIVE

Peri-intubation hypoxia is an important adverse event of out-of-hospital rapid sequence intubation. The aim of this project is to determine whether a clinical bundle encompassing positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation is associated with decreased peri-intubation hypoxia compared with standard out-of-hospital rapid sequence intubation.

METHODS

We conducted a retrospective, before-after study using data from a suburban emergency medical services (EMS) system in central Texas. The study population included all adults undergoing out-of-hospital intubation efforts, excluding those in cardiac arrest. The before-period intervention was standard rapid sequence intubation using apneic oxygenation at flush flow, ketamine, and a paralytic. The after-period intervention was a care bundle including patient positioning (elevated head, sniffing position), apneic oxygenation, delayed sequence intubation (administration of ketamine to facilitate patient relaxation and preoxygenation with a delayed administration of paralytics), and goal-directed preoxygenation. The primary outcome was the rate of peri-intubation hypoxia, defined as the percentage of patients with a saturation less than 90% during the intubation attempt.

RESULTS

The before group (October 2, 2013, to December 13, 2015) included 104 patients and the after group (August 8, 2015, to July 14, 2017) included 87 patients. The 2 groups were similar in regard to sex, age, weight, ethnicity, rate of trauma, initial oxygen saturation, rates of initial hypoxia, peri-intubation peak SpO₂, preintubation pulse rate and systolic blood pressure, peri-intubation cardiac arrest, and first-pass and overall success rates. Compared with the before group, the after group experienced less peri-intubation hypoxia (44.2% versus 3.5%; difference -40.7% [95% confidence interval -49.5% to -32.1%]) and higher peri-intubation nadir SpO₂ values (100% versus 93%; difference 5% [95% confidence interval 2% to 10%]).

CONCLUSION

In this single EMS system, a care bundle encompassing patient positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation was associated with lower rates of peri-intubation hypoxia than standard out-of-hospital rapid sequence intubation.

A comparison of direct laryngoscopy to video laryngoscopy by paramedic students in manikin-simulated airway management scenarios

INTRODUCTION

We compare the effectiveness of direct laryngoscopy (DL) to video laryngoscopy (VL) in simulated, difficult airway scenarios in a cohort of novice, prehospital, emergency care providers.

METHODS

Forty-five (45) students were randomised to DL or VL groups and then tasked to perform intubation on a manikin in three simulated airway scenarios. The scenarios included an uncomplicated intubation, intubation with manual in-line neck stabilisation (MILNS), and a simulated motor vehicle entrapment, with C-Spine held from behind, using a face-to-face intubation technique. The primary outcome was time taken to intubate, with secondary outcomes including first pass success rate, number of intubation attempts, Cormack-Lehane (CL) view grade obtained, adverse event rate, and self-reported laryngoscopist comfort.

RESULTS

Twenty-seven participants (VL n = 15, DL n = 12) completed the study. Mean time to intubate was not statistically different between VL and DL groups in any scenario. VL was associated with an increased frequency of intubation attempts (p = 0.043) and failed intubations (RR 6.4, 95% CI 0.92-44.33, p = 0.0175) in the face-to-face intubation scenario, VL was associated with a reduced incidence of poor CL view (RR 0.06, 95% CI 0.004-0.997, p = 0.0497) in the face-to-face intubation scenario, and a reduction in the frequency of dental damage (RR 0.13, 95% CI 0.02-0.96, p = 0.0165) in the supine MILNS scenario.

DISCUSSION

In our small sample, we found DL to be superior to VL in relation to a reduced risk of failed intubation and frequency of intubation attempts despite VL being superior in obtaining a good view of the vocal cords in a face-to-face intubation scenario. We found no statistically significant difference in the time taken to intubate in any scenarios. A larger study is required to inform practice and education around prehospital use of VL.

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

A Comparison of Paramedic First Pass Endotracheal Intubation Success Rate of the VividTrac VT-A 100, GlideScope Ranger, and Direct Laryngoscopy Under Simulated Prehospital Cervical Spinal Immobilization Conditions in a Cadaveric Model

OBJECTIVE

The primary goal of this study was to compare paramedic first pass success rate between two different video laryngoscopes and direct laryngoscopy (DL) under simulated prehospital conditions in a cadaveric model.

METHODS

This was a non-randomized, group-controlled trial in which five non-embalmed, non-frozen cadavers were intubated under prehospital spinal immobilization conditions using DL and with both the GlideScope Ranger (GL; Verathon Inc, Bothell, Washington USA) and the VividTrac VT-A100 (VT; Vivid Medical, Palo Alto, California USA). Participants had to intubate each cadaver with each of the three devices (DL, GL, or VT) in a randomly assigned order. Paramedics were given 31 seconds for an intubation attempt and a maximum of three attempts per device to successfully intubate each cadaver. Confirmation of successful endotracheal intubation (ETI) was confirmed by one of the six on-site physicians.

RESULTS

Successful ETI within three attempts across all devices occurred 99.5% of the time overall and individually 98.5% of the time for VT, 100.0% of the time for GL, and 100.0% of the time for DL. First pass success overall was 64.4%. Individually, first pass success was 60.0% for VT, 68.8% for GL, and 64.5% for DL. A chi-square test revealed no statistically significant difference amongst the three devices for first pass success rates (P=.583). Average time to successful intubation was 42.2 seconds for VT, 38.0 seconds for GL, and 33.7 for seconds for DL. The average number of intubation attempts for each device were as follows: 1.48 for VT, 1.40 for GL, and 1.42 for DL.

CONCLUSION

The was no statistically significant difference in first pass or overall successful ETI rates between DL and video laryngoscopy (VL) with either the GL or VT (adult). Hodnick R , Zitek T , Galster K , Johnson S , Bledsoe B , Ebbs D . A comparison of paramedic first pass endotracheal intubation success rate of the VividTrac VT-A 100, GlideScope Ranger, and direct laryngoscopy under simulated prehospital cervical spinal immobilization conditions in a cadaveric model. Prehosp Disaster Med. 2017;32(6):621-624.

Direct Versus Video Laryngoscopy for Prehospital Intubation: A Systematic Review and Meta-analysis

OBJECTIVES

The use of video laryngoscopy (VL) for intubation has gained recent popularity. In the prehospital setting, it is unclear if VL increases intubation success rates compared to direct laryngoscopy (DL). We sought to conduct a systematic review and meta-analysis of studies comparing VL to DL in the prehospital setting to determine whether the use of VL increases overall and first-pass endotracheal intubation success rates compared to DL.

METHODS

A systematic search was performed of the PubMed, Embase, and SCOPUS databases through May 2016 to include studies comparing overall and first-pass success for VL versus DL in patients requiring intubation in the prehospital setting. Data were abstracted by two reviewers. A meta-analysis was performed using a random-effects model.

RESULTS

Of a potential 472 articles, eight eligible studies were included. Considerable heterogeneity (I²  > 90%) precluded reporting an overall pooled estimate across all studies. When stratified by provider type, the pooled estimates for overall intubation success using VL versus DL were a risk ratio (RR) of 0.05 (95% confidence interval [CI] = 0.01-0.18) in studies of physicians and RR = 2.28 (95% CI = 1.00-5.20) in nonphysicians. For first-pass intubation success the pooled RR estimates for using VL versus DL were 0.32 (95% CI = 0.23-0.44) and 1.83 (95% CI = 1.18-2.84) among studies using physicians and nonphysicians, respectively. There was moderate to significant heterogeneity between studies when stratified by provider.

CONCLUSIONS

Among physician intubators with significant DL experience, VL does not increase overall or first-pass success rates and may lead to worsening performance. However, among nonphysician intubators with less experience with DL, VL may provide benefit in the prehospital setting.

Advanced Airway Type and Its Association with Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation Attempts

OBJECTIVE

To assess interruptions in chest compressions associated with advanced airway placement during cardiopulmonary resuscitation (CPR) of out-of-hospital cardiac arrest (OHCA) victims.

METHODS

The method used was observational analysis of prospectively collected clinical and defibrillator data from 339 adult OHCA victims, excluding victims with <5 minutes of CPR. Interruptions in CPR, summarized by chest compression fraction (CCF), longest pause, and the number of pauses greater than 10 seconds, were compared between patients receiving bag valve mask (BVM), supraglottic airway (SGA), endotracheal intubation (ETI) via direct laryngoscopy (DL), and ETI via video laryngoscopy (VL). Secondary outcomes included first pass success and the effect of multiple airway attempts on CPR interruptions.

RESULTS

During the study period, paramedics managed 23 cases with BVM, 43 cases with SGA, 148 with DL, and 125 with VL. There were no statistically significant differences between the airway groups with regard to longest compression pause (BVM 18 sec [IQR 11-33], SGA 29 sec [IQR 15-65], DL 26 sec [IQR 12-59], VL 22 sec [IQR 14-41]), median number of pauses greater than 10 seconds (BVM 2 [IQR 1-3], SGA 2 [IQR 1-3], DL 2 [IQR 1-4], VL 2 [IQR 1-3]), or CCF (0.92 for all groups). However, each additional attempt following failed initial DL was associated with an increase in the risk of additional chest compression pauses (relative risk 1.29, 95% confidence interval 1.02-1.64). Such an association was not observed with additional attempts using VL or SGA. First pass success was highest with SGA (77%), followed by between DL (68%) and VL (67%); these differences were not statistically significant.

CONCLUSIONS

While summary measures of chest compression delivery did not differ significantly between airway classes in this observational study, repeated attempts following failed initial DL during cardiopulmonary resuscitation were associated with an increase in the number of pauses in chest compression delivery observed.

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

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

Transfer of skills and comparison of performance between king vision® video laryngoscope and macintosh blade following an AHA airway management course

Background

To potentially optimize intubation skill teaching in an American Heart Association® Airway Management Course® for novices, we investigated the transfer of skills from video laryngoscopy to direct laryngoscopy and vice versa using King Vision® and Macintosh blade laryngoscopes respectively.

Methods

Ninety volunteers (medical students, residents and staff physicians) without prior intubation experience were randomized into three groups to receive intubation training with either King Vision® or Macintosh blade or both. Afterwards they attempted intubation on two human cadavers with both tools. The primary outcome was skill transfer from video laryngoscopy to direct laryngoscopy assessed by first attempt success rates within 60 s. Secondary outcomes were skill transfer in the opposite direction, the efficacy of teaching both tools, and the success rates and esophageal intubation rates of Macintosh blade versus King Vision®.

Results

Performance with the Macintosh blade was identical following training with either Macintosh blade or King Vision® (unadjusted odds ratio [OR] 1.09, 95% confidence interval [95% CI] 0.5–2.6). Performance with the King Vision® was significantly better in the group that was trained on it (OR 2.7, 95% CI 1.2–5.9). Success rate within 60 s with Macintosh blade was 48% compared to 52% with King Vision® (OR 0.85, 95% CI 0.4–2.0). Rate of esophageal intubations with Macintosh blade was significantly higher (17% versus 4%, OR 5.0, 95% CI 1.1–23).

Conclusions

We found better skill transfer from King Vision® to Macintosh blade than vice versa and fewer esophageal intubations with video laryngoscopy. For global skill improvement in an airway management course for novices, teaching only video laryngoscopy may be sufficient. However, success rates were low for both devices.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0296-9) contains supplementary material, which is available to authorized users.

Advances in Laryngoscopy

Recent technological advances have made airway management safer. Because difficult intubation remains challenging to predict, having tools readily available that can be used to manage a difficult airway in any setting is critical. Fortunately, video technology has resulted in improvements for intubation performance while using laryngoscopy by various means. These technologies have been applied to rigid optical stylets, flexible intubation scopes, and, most notably, rigid laryngoscopes. These tools have proven effective for the anticipated difficult airway as well as the unanticipated difficult airway.

Direct Versus Video Laryngoscopy for Intubating Adult Patients with Gastrointestinal Bleeding

Introduction

Video laryngoscopy (VL) has been advocated for several aspects of emergency airway management; however, there are still concerns over its use in select patient populations such as those with large volume hematemesis secondary to gastrointestinal (GI) bleeds. Given the relatively infrequent nature of this disease process, we sought to compare intubation outcomes between VL and traditional direct laryngoscopy (DL) in patients intubated with GI bleeding, using the third iteration of the National Emergency Airway Registry (NEARIII).

Methods

We performed a retrospective analysis of a prospectively collected national database (NEARIII) of intubations performed in United States emergency departments (EDs) from July 1, 2002, through December 31, 2012. All cases where the indication for intubation was “GI bleed” were analyzed. We included patient, provider and intubation characteristics. We compared data between intubation attempts initiated as DL and VL using parametric and non-parametric tests when appropriate.

Results

We identified 325 intubations, 295 DL and 30 VL. DL and VL cases were similar in terms of age, sex, weight, difficult airway predictors, operator specialty (emergency medicine, anesthesia or other) and level of operator training (post-graduate year 1, 2, etc). Proportion of successful first attempts (DL 261/295 (88.5%) vs. VL 28/30 (93.3%) p=0.58) and Cormack-Lehane grade views (p=0.89) were similar between devices. The need for device change was similar between DL [2/295 (0.7%) and VL 1/30 (3.3%); p=0.15].

Conclusion

In this national registry of intubations performed in the ED for patients with GI bleeds, both DL and VL had similar rates of success, glottic views and need to change devices.