Difficult prehospital endotracheal intubation - predisposing factors in a physician based EMS

Evaluating the Impact of Direct, Direct Video, and Indirect Video Laryngoscopy Training on the Proficiency of Medical Students in Performing Direct Laryngoscopy: A High-Fidelity Manikin-Based Assessment

Endotracheal intubation (ETI), a potentially lifesaving intervention employed frequently in the emergent setting, is a manual skill that improves with repetitive practice and high-quality feedback. Classically, ETI centered around Direct Laryngoscopy (DL); however, with the advent and recent availability of Indirect Video Laryngoscopy (IVL) and Direct Video Laryngoscopy (DVL), studies have demonstrated varying results on the benefit of Video Laryngoscopy (VL) in training. We hypothesize that a training program centered on DVL, allowing students to visualize the anatomy and simultaneously receive instructor feedback via a real-time video feed, will practically improve student performance in DL. Our study of first-year medical students from the Edward Via College of Osteopathic Medicine (n = 21) randomized participants to one of three cohorts: DL, IVL, and DVL in a manikin-based simulation laboratory evaluated on successful intubation, time to successful intubation, dental injury, Numeric Rating Scale (NRS) to assess the trainee's perception of their performance and confidence level of performing intubation in a real-life scenario. Our results did not demonstrate a statistically significant difference between the three training modalities based on the outcomes assessed. Although IVL and DVL cohorts achieved 100% success following training, compared to 71% in the DL cohort, the results were not statistically significant. This is potentially due to our limited sample size, as our sample did not meet the calculated 162 participants for 80% power. These findings suggest that a larger sample size may be required to determine if there is a significant difference in outcomes for these training modalities.

The Impact of Location and Asset Type on the Success of Advanced Airway Management in a Critical Care Transport Environment

OBJECTIVE

Advanced airway management (AAM) is a critical component of prehospital critical care. Airway management in flight can be more challenging because of spatial, ergonomic, and environmental factors. This study examines the frequency of in-flight intubation (IFI), first-pass success (FPS) rates, and definitive airway sans hypoxia/hypotension on first attempt (DASH-1A) across different locations of airway management.

METHODS

We conducted a retrospective database analysis of all patients transported between January 2016 and July 2021 who received AAM from a single air medical service. Patient records were reviewed for location of intubation, patient characteristics, and FPS and DASH-1A rates. The primary outcome was the frequency of IFI. The secondary outcomes included FPS and DASH-1A rates by location and type of transport asset.

RESULTS

During the study period, 473 patients required AAM. Three percent (15/473) of patients were intubated in an in-flight setting, 28% (130/473) were intubated on scene, and 70% (328/473) were intubated in a health care facility. The primary reason for IFI was unanticipated cardiac arrest or clinical deterioration. The overall FPS rate was 69% (328/473), and the DASH-1A rate was 49% (194/399). Based on the location of AAM, the FPS and DASH-1A rates were the lowest for on-scene intubations (56% [74/130] and 27% [20/74], respectively). Most of the on-scene AAM took place with rotor wing flight crews.

CONCLUSION

Airway management occurs infrequently in an in-flight setting and is necessary because of patient deterioration or cardiac arrest. Based on our results, we identified opportunities for targeted AAM quality improvement and clinical governance.

Influence of Patient Weight on Prehospital Advanced Airway Procedure Success Rates

OBJECTIVE

Previous investigations of the relationship between obesity and difficult airway management have provided mixed results. Almost universally, these studies were conducted in the hospital setting, and the influence of patient body weight on successful prehospital airway management remains unclear. Because patient weight could be one readily identifiable risk factor for problematic airway interventions, we sought to evaluate this relationship.

METHODS

We conducted a retrospective analysis using the 2020 ESO Data Collaborative dataset. The inclusion criteria consisted of adult patients weighing >30kg with an attempted orotracheal intubation (OTI) and/or blind insertion airway device (BIAD) placement. Separate logistic regression models were developed to determine the influence of weight (dichotomized at 100 kg) on cumulative procedure success for OTI and BIAD, and linear regression models were used to identify trends for each across weight strata.

RESULTS

A total of 45,344 patients met inclusionary criteria, among which 40,668(89.7%) suffered from a medical emergency, followed by 3,130(6.9%) with traumatic injuries, and 1,546(3.4%) attributable to a combined medical-trauma etiology. Cardiac arrest occurred either prior to EMS arrival or at some point during EMS care in 38,210(84.3%) patients. OTI was attempted in 18,153(40.0%) patients, while 21,597(47.6%) had a BIAD attempt and 5,594(12.3%) had both airway types attempted. The overall cumulative insertion success rates for OTI and BIAD were 79.5% and 92.7%, respectively. Altogether, 2,711(6.0%) had no advanced airway of any type successfully placed, which represents the overall failed advanced airway rate. After controlling for patient age, sex, minority status, and call type (medical vs. trauma), weight >100kg was associated with decreased likelihood of cumulative OTI success (OR = 0.64, p < 0.001), but higher likelihood of cumulative BIAD success (OR = 1.31, p < 0.001). Cumulative OTI success was associated with a negative 0.6% linear trend per 5 kg of body weight (p < 0.001) while cumulative BIAD success had a 0.2% positive trend (p < 0.001).

CONCLUSION

This retrospective analysis of a national EMS database revealed that increasing patient weight was negatively associated with intubation success. A positive, but smaller, linear trend was observed for BIAD placement. Patient weight may be an easily identifiable predictor of difficult oral intubation and may be a consideration when selecting an airway management strategy.

[Airwaymangement in Emergencies]

Emergency airway management is a rare but essential emergency medical intervention directly impacting morbidity and mortality of emergency patients. The success of airway management depends on various factors such as patient anatomy, environmental aspects and the provider performing the procedure. Therefore, the use of a clearly structured algorithm for anticipating the difficult airway in emergency situations is strongly recommended. Our article explains different ways of securing the airway as part of a structured algorithm as well as pitfalls and helpful tips.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Tick-tock: Prehospital intubation is associated with longer field time without any survival benefit

BACKGROUND

Prehospital endotracheal intubation is a debated topic, and few studies have found it beneficial after trauma. A growing body of evidence suggests that prehospital endotracheal intubation is associated with increased morbidity and mortality. Our study was designed to compare patients with attempted prehospital endotracheal intubation to those intubated promptly upon emergency department arrival.

METHODS

A retrospective review of a single-center trauma research data repository was utilized. Inclusion criteria included age ≥15 years, transport from the scene by ground ambulance, and undergoing prehospital endotracheal intubation attempts or intubation within 10 minutes of emergency department arrival without prior prehospital endotracheal intubation attempt. Propensity score matching was used to minimize differences in baseline characteristics between groups. Standard mean differences are also presented for pre- and post-matching datasets to evaluate for covariate balance.

RESULTS

In total, 208 patients met the inclusion criteria. Of these, 95 patients (46%) underwent prehospital endotracheal intubation, which was successful in 47% of cases. A control group of 113 patients (54%) were intubated within 10 minutes of emergency department arrival. We performed propensity score matching between cohorts based on observed differences after univariate analysis and used standard mean differences to estimate covariate balance. After propensity score matching, patients who underwent prehospital endotracheal intubation experienced a longer time on scene as compared with those intubated in the emergency department (9 minutes [interquartile range 6-12] vs 6 minutes [interquartile range 5-9], P < .01) without difference in overall mortality (67% vs 65%, P = 1.00). Rapid sequence intubation was not used in the field; however, it was used for 58% of patients intubated within 10 minutes of emergency department arrival. After matched analysis, patients with a failed prehospital intubation attempt were equally likely to receive rapid sequence intubation during re-intubation in the emergency department as compared with those undergoing a first attempt (n = 13/28, 46% vs n = 28/63, 44%, P = 1.00, standard mean differences 0.04). Among patients with prehospital arrest (n = 98), prehospital endotracheal intubation was associated with shorter time to death (8 minutes [interquartile range 3-17] vs 14 minutes [interquartile range 8-45], P = .008) and longer total transport time (23 minutes [interquartile range 19-31] vs 19 minutes [interquartile range 16-24], P = .006), but there was no difference in observed mortality (n = 29/31, 94% vs n = 30/31, 97%, P = 1.00, standard mean differences = 0.15) after propensity score matching.

CONCLUSION

Prehospital providers should prioritize expeditious transport over attempting prehospital endotracheal intubation, as prehospital endotracheal intubation is inconsistently successful, may delay definitive care, and appears to have no survival benefit.

Association between out-of-hospital cardiac arrest and survival in paediatric traumatic population: results from the French national registry

Trauma is an important cause of paediatric out-of-hospital cardiac arrest (OHCA) with a high mortality rate. The first aim of this study was to compare the survival rate at day 30 and at hospital discharge following paediatric traumatic and medical OHCA. The second aim was to compare the rates of return of spontaneous circulation and survival rates at hospital admission (Day 0). This multicentre comparative post-hoc study was conducted between July 2011 and February 2022 based on the French National Cardiac Arrest Registry data. All patients aged <18 years with OHCA were included in the study. Patients with traumatic aetiology were matched with those with medical aetiology using propensity score matching. Endpoint was the survival rate at day 30. There were 398 traumatic and 1061 medical OHCAs. Matching yielded 227 pairs. In non-adjusted comparisons, days 0 and 30 survival rates were lower in the traumatic aetiology group than in the medical aetiology group [19.1% vs. 24.0%, odds ratio (OR) 0.75, 95% confidence interval (CI) 0.56-0.99, and 2.0% vs. 4.5%, OR 0.43, 95% CI, 0.20-0.92, respectively]. In adjusted comparisons, day 30 survival rate was lower in the traumatic aetiology group than in the medical aetiology group (2.2% vs. 6.2%, OR 0.36, 95% CI, 0.13-0.99). In this post-hoc analysis, paediatric traumatic OHCA was associated with a lower survival rate than medical cardiac arrest.

The Prehospital Emergency Anaesthetic in 2022

Prehospital emergency anesthesia (PHEA) is a commonly performed prehospital procedure with inherent risks. The processes and drug regimens behind PHEA are continually updated by prehospital teams across the country as part of their governance structure. Essex & Herts Air Ambulance has recently updated this practice by reviewing the entire process of performing PHEA. Through experiential learning in a high-volume service, audit, and a contemporary literature review, a new standard operating procedure has been developed to combat common problems, such as hypotension, associated with the more traditional methods of performing PHEA. The aim of this article was to summarize the literature behind this new standard operating procedure, systematically breaking down the core components of performing a PHEA and the rationale behind them. The key components identified in the review are indications for PHEA, airway assessment, peri-intubation oxygenation, preparation for PHEA, drug dosing, special circumstances, and failed intubation. One significant change is the drug dosage regimen; 1 μg/kg fentanyl, 2 mg/kg ketamine, and 2 mg/kg rocuronium is recommended as the main drug dosing regimen for both medical and trauma patients. Other changes include preoxygenation with a nasal cannula in addition to the nonrebreather mask, optimizing patients in the preparation phase by considering inopressors or fluid bolus and ensuring a "sterile cockpit" to control the surrounding environment to ensure the first intubation attempt is the best attempt.

Describing the Challenges of Prehospital Rapid Sequence Intubation by Macintosh Blade Video Laryngoscopy Recordings

Study Objective:

Structured review of video laryngoscopy recordings from physician team prehospital rapid sequence intubations (RSIs) may provide new insights into why prehospital intubations are difficult. The aim was to use laryngoscope video recordings to give information on timings, observed features of the airway, laryngoscopy technique, and laryngoscope performance. This was to both describe prehospital airways and to investigate which factors were associated with increased time taken to intubate.

Methods:

Sydney Helicopter Emergency Medical Service (HEMS; the aeromedical wing of New South Wales Ambulance, Australia) has a database recording all intubations. The database comprises free-text case detail, airway dataset, scanned case sheet, and uploaded laryngoscope video. The teams of critical care paramedic and doctor use protocol-led intubations with a C-MAC Macintosh size four laryngoscope and intubation adjunct. First-pass intubation rate is approximately 97%. Available video recordings and their database entries were retrospectively analyzed for pre-specified qualitative and quantitative factors.

Results:

Prehospital RSI video recordings were available for 385 cases from January 2018 through July 2020. Timings revealed a median of 58 seconds of apnea from laryngoscope entering mouth to ventilations. Median time to intubate (laryngoscope passing lips until tracheal tube inserted) was 35 seconds, interquartile range 28-46 seconds. Suction was required prior to intubation in 29% of prehospital RSIs. Fogging of the camera lens at time of laryngoscopy occurred in 28%. Logistic regression revealed longer time to intubate was associated with airway soiling, Cormack-Lehane Grade 2 or 3, multiple bougie passes, or change of bougie.

Conclusion:

Video recordings averaging 35 seconds for first-pass success prehospital RSI with an adjunct give bed-side “definitions of difficulty” of 30 seconds for no glottic view, 45 seconds for no bougie placement, and 60 seconds for no endotracheal tube placement. Awareness of apnea duration can help guide decision making for oxygenation. All emergency intubators need to be cognizant of the need for suctioning. Improving the management of bloodied airways and bougie usage may reduce laryngoscopy duration and be a focus for training. Video screen fogging and missed recordings from some patients may be something manufacturers can address in the future.

Impact of Operator Medical Specialty on Endotracheal Intubation Rates in Prehospital Emergency Medicine—A Retrospective Cohort Study

Prehospital endotracheal intubation (ETI) can be challenging, and the risk of complications is higher than in the operating room. The goal of this study was to compare prehospital ETI rates between anaesthesiologists and non-anaesthesiologists. This retrospective cohort study compared prehospital interventions performed by either physicians from the anaesthesiology department (ADP) or physicians from another department (NADP, for non-anaesthesiology department physicians). The primary outcome was the prehospital ETI rate. Overall, 42,190 interventions were included in the analysis, of whom 68.5% were performed by NADP. Intubation was attempted on 2797 (6.6%) patients, without any difference between NADPs and ADPs (6.5 versus 6.7%, p = 0.555). However, ADPs were more likely to proceed to an intubation when patients were not in cardiac arrest (3.4 versus 3.0%, p = 0.026), whereas no difference was found regarding cardiac arrest patients (65.2 versus 67.7%, p = 0.243) (p for homogeneity = 0.005). In a prehospital physician-staffed emergency medical service, overall ETI rates did not depend on the frontline operator’s medical specialty background. ADPs were, however, more likely to proceed with ETI than NADPs when patients were not in cardiac arrest. Further studies should help to understand the reasons for this difference.

Airway management in a Helicopter Emergency Medical Service (HEMS): a retrospective observational study of 365 out-of-hospital intubations

Background

Airway management is a key skill in any helicopter emergency medical service (HEMS). Intubation is successful less often than in the hospital, and alternative forms of airway management are more often needed.

Methods

Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patient charts were analysed for all calls to the scene (n = 9,035) taking place between June 2016 and May 2017 (12 months). The primary outcome parameter was intubation success rate. Secondary parameters included the number of alternative techniques that eventually secured the airway, and comparison of patients with and without difficulties in airway management.

Results

A total of 365 patients receiving invasive ventilatory support were identified. Difficulties in airway management occurred in 26 patients (7.1%). Severe traumatic brain injury was the most common indication for out-of-hospital Intubation (n = 130, 36%). Airway management was performed by 129 different Rega physicians and 47 different Rega paramedics. Paramedics were involved in out-of-hospital airway manoeuvres significantly more often than physicians: median 7 (IQR 4 to 9) versus 2 (IQR 1 to 4), p < 0.001.

Conclusion

Despite high overall success rates for endotracheal intubation in the physician-staffed service, individual physicians get only limited real-life experience with advanced airway management in the field. This highlights the importance of solid basic competence in a discipline such as anaesthesiology.

Pediatric tracheal trauma

Tracheal trauma is an uncommon but potentially serious cause of airway injury in children. Presentation may be acute in cases of blunt or penetrating trauma, or delayed in cases of chronic irritation or indwelling endotracheal tubes. Symptoms include dyspnea, progressive respiratory distress, neck and chest swelling and ecchymosis, and dysphonia. Workup is pursued as allowed by the patient's clinical status and may include plain radiography, computed tomography, and endoscopy. Accuracy and efficiency of diagnosis is paramount for those at risk of rapid decompensation. Treatment may include observation, elective and strategic intubation, or primary surgical repair.

Intubation Setting, Aspiration, and Ventilator-Associated Conditions

BACKGROUND

Patients experience endotracheal intubation in various settings with wide-ranging risks for postintubation complications such as aspiration and ventilator-associated conditions.

OBJECTIVES

To evaluate associations between intubation setting, presence of aspiration biomarkers, and clinical outcomes.

METHODS

This study is a subanalysis of data from the NO-ASPIRATE single-blinded randomized clinical trial. Data were prospectively collected for 513 adult patients intubated within 24 hours of enrollment. Patients with documented aspiration events at intubation were excluded. In the NO-ASPIRATE trial, intervention patients received enhanced oropharyngeal suctioning every 4 hours and control patients received sham suctioning. Tracheal specimens for α-amylase and pepsin tests were collected upon enrollment. Primary outcomes were ventilator hours, lengths of stay, and rates of ventilator-associated conditions.

RESULTS

Of the baseline tracheal specimens, 76.4% were positive for α-amylase and 33.1% were positive for pepsin. Proportions of positive tracheal α-amylase and pepsin tests did not differ significantly between intubation locations (study hospital, transfer from other hospital, or field intubation). No differences were found for ventilator hours or lengths of stay. Patients intubated at another hospital and transferred had significantly higher ventilator-associated condition rates than did those intubated at the study hospital (P = .02). Ventilator-associated condition rates did not differ significantly between patients intubated in the field and patients in other groups.

CONCLUSIONS

Higher ventilator-associated condition rates associated with interhospital transfer may be related to movement from bed, vehicle loading and unloading, and transport vehicle vibrations. Airway assessment and care may also be suboptimal in the transport environment.

Impact of Suction-Assisted Laryngoscopy and Airway Decontamination Technique on Intubation Quality Metrics in a Helicopter Emergency Medical Service: An Educational Intervention

OBJECTIVE

Suction-assisted laryngoscopy and airway decontamination (SALAD) was created to assist with the decontamination of a massively soiled airway. This study aims to investigate the usefulness of SALAD training to prehospital emergency providers to improve their ability to intubate a massively contaminated airway.

METHODS

This was a prospective study conducted as a before and after teaching intervention. Participants were made up of prehospital providers who were present at regularly scheduled training sessions and were asked to intubate a high-fidelity mannequin simulating large-volume emesis before and after SALAD instruction. They were subsequently tested on 3-month skill retention. Twenty subjects participated in all stages of the study and were included in the analysis.

RESULTS

The median time to successful intubation for all study participants before instruction was 60.5 seconds (interquartile range [IQR] = 44.0-84.0); post-training was 43.0 seconds (IQR = 38.0-57.5); and at the 3-month follow-up, it was 29.5 seconds (IQR = 24.5-39.0). The greatest improvement was seen on subgroup analysis of the slowest 50th percentile where the median time before instruction was 84.0 seconds (IQR = 68.0-96.0); post-instruction was 41.5 seconds (IQR = 36.0-65.0); and at the 3-month follow-up, it was 29.5 seconds (IQR = 25.0-39.0).

CONCLUSION

The implementation of the SALAD technique through a structured educational intervention improved time to intubation and the total number of attempts.

Comparing the McGrath Mac Video Laryngoscope and Direct Laryngoscopy for Prehospital Emergency Intubation in Air Rescue Patients: A Multicenter, Randomized, Controlled Trial

OBJECTIVES

Tracheal intubation in prehospital emergency care is challenging. The McGrath Mac Video Laryngoscope (Medtronic, Minneapolis, MN) has been proven to be a reliable alternative for in-hospital airway management. This trial compared the McGrath Mac Video Laryngoscope and direct laryngoscopy for the prehospital setting.

DESIGN

Multicenter, prospective, randomized, controlled equivalence trial.

SETTING

Oesterreichischer Automobil- und Touring Club (OEAMTC) Helicopter Emergency Medical Service in Austria, 18-month study period.

PATIENTS

Five-hundred fourteen adult emergency patients (≥ 18 yr old).

INTERVENTIONS

Helicopter Emergency Medical Service physicians followed the institutional algorithm, comprising a maximum of two tracheal intubation attempts with each device, followed by supraglottic, then surgical airway access in case of tracheal intubation failure. No restrictions were given for tracheal intubation indication.

MEASUREMENTS MAIN RESULTS

The Primary outcome was the rate of successful tracheal intubation; equivalence range was ± 6.5% of success rates. Secondary outcomes were the number of attempts to successful tracheal intubation, time to glottis passage and first end-tidal CO2 measurement, degree of glottis visualization, and number of problems. The success rate for the two devices was equivalent: direct laryngoscopy 98.5% (254/258), McGrath Mac Video Laryngoscope 98.1% (251/256) (difference, 0.4%; 99% CI, -2.58 to 3.39). There was no statistically significant difference with regard to tracheal intubation times, number of attempts or difficulty. The view to the glottis was significantly better, but the number of technical problems was increased with the McGrath Mac Video Laryngoscope. After a failed first tracheal intubation attempt, immediate switching of the device was significantly more successful than after the second attempt (90.5% vs 57.1%; p = 0.0003), regardless of the method.

CONCLUSIONS

Both devices are equivalently well suited for use in prehospital emergency tracheal intubation of adult patients. Switching the device following a failed first tracheal intubation attempt was more successful than a second attempt with the same device.

Comparison of video and conventional laryngoscopes for simulated difficult emergency tracheal intubations in the presence of liquids in the airway

The presence of vomit, blood, or other foreign liquid materials in the upper airway is a major obstacle in difficult tracheal intubations (TIs) especially in prehospital care. However, the usefulness of video laryngoscopes (VLs) in these situations has not been investigated. The objective of this study was to compare the Airway Scope (AWS) and the Macintosh laryngoscope (ML) for their performance in TIs performed by emergency medical technicians (EMTs) using mannequin models with liquids in the airway. Rice gruel and mock blood were used to fill the upper airways of mannequins to create mock vomit and hematemesis models, respectively. TIs were performed by certified EMTs after visualizing the glottis using an AWS with an 18-Fr suction catheter and a ML with an 18-Fr suction catheter. TIs with AWS and ML were performed in random order in a comparative crossover trial. The TI success rate was evaluated based on the following: (a) the time taken from laryngoscope insertion into the oral cavity to glottis visualization, tracheal tube passage through the glottis, until the initiation of ventilation and (b) the subjective level of difficulty, which was assessed using a visual analog scale (VAS). TIs in vomiting and hematemesis scenarios were performed by 25 and 26 EMTs, respectively. The TI success rates for these scenarios were 100% with both AWS and ML. The median time required until successful ventilation was significantly shorter with AWS than with ML in both the vomiting (42 vs. 58 s) and hematemesis models (33 vs. 39 s), respectively. In the hematemesis scenarios, difficulty assessed using a VAS was lower with AWS than with ML (13 vs. 38 in median), respectively. Compared to the ML, the AWS was capable of faster and easier TIs, in a simulated model of liquid foreign material in the upper airway.

Comparison of three video laryngoscopes and direct laryngoscopy for emergency endotracheal intubation: a retrospective cohort study

OBJECTIVE

Video laryngoscopes are used for managing difficult airways. This study compared three video laryngoscopes' (Pentax-Airway Scope [Pentax], King Vision[King] and McGrath MAC [McGrath]) performances with the Macintosh direct laryngoscope (Macintosh) as emergency tracheal intubations (TIs) reference.

DESIGN

Retrospective cohort study.

SETTING

The emergency department (ED) and the intensive care unit (ICU) of two Japanese tertiary-level hospitals.

PARTICIPANTS

All consecutive video-recorded emergency TI cases in EDs and ICUs between December 2013 and June 2015.

PRIMARY OUTCOME MEASURES

The primary study endpoint was first-pass intubation success. A subgroup analysis examined the first-pass intubation success of expert versus non-expert operators. A logistic regression analysis was performed to identify the predictors of first-pass intubation success.

RESULTS

A total of 287 emergency TIs were included. The first-pass intubation success rates were 78%, 58%, 78% and 58% for the Pentax, King, McGrath and Macintosh instruments, respectively (p=0.004, Fisher's exact test). The non-expert operators' success rates were significantly higher (p=0.00004, Fisher's exact test) for the Pentax (87%) and McGrath (78%) instruments than that for the King (50%) and Macintosh (46%) instruments, unlike that of the experts (67%, 67%, 78% and 78% for Pentax, McGrath, King and Macintosh, respectively; p=0.556, Fisher's exact test). After TI indication, difficult airway characteristics, and expert versus non-expert operator parameters adjustments, the Pentax (OR=3.422, 95% CI 1.551 to 7.550; p=0.002) and McGrath (OR= 3.758, CI 1.640 to 8.612; p=0.002) instruments showed significantly higher first-pass intubation success odds when compared with the Macintosh laryngoscope (reference, OR=1). The King instrument, however, (OR=1.056; 95% CI 0.487 to 2.289, p=0.889) failed to show any significant superiority.

CONCLUSION

The Pentax and McGrath laryngoscopes showed significantly higher emergency TI first-pass intubation success rates than the King laryngoscope when compared with the Macintosh laryngoscope, especially for non-expert operators.

TRIAL REGISTRATION NUMBER

UMIN000027925; Results.

Best practice advice on pre-hospital emergency anaesthesia & advanced airway management

BACKGROUND

Effective and timely airway management is a priority for sick and injured patients. The benefit and conduct of pre-hospital emergency anaesthesia (PHEA) and advanced airway management remains controversial but there are a proportion of critically ill and injured patients who require urgent advanced airway management prior to hospital arrival. This document provides current best practice advice for the provision of PHEA and advanced airway management.

METHOD

This best practice advice was developed from EHAC Medical Working Group enforced by pre-hospital critical care experts. The group used a nominal group technique to establish the current best practice for the provision of PHEA and advanced airway management. The group met on three separate occasions to discuss and develop the guideline. All members of the working party were able to access and edit the guideline online.

RESULTS

This EHAC best practice advice covers all areas of PHEA and advanced airway management and provides up to date evidence of current best practice.

CONCLUSION

PHEA and advanced airway management are complex interventions that should be delivered by appropriately trained personnel using a well-rehearsed approach and standardised equipment. Where advanced airway interventions cannot be delivered, careful attention should be given to applying basic airway interventions and ensuring their effectiveness at all times.

A Protocol for Helicopter In-Cabin Intubation

OBJECTIVE

The gold standard for prehospital intubation is to avoid intubating in confined spaces. For our helicopter service, this is not always realistic. Operating in a rural region with a subarctic, cold climate, our crews are frequently forced to intubate inside ambulances or in our helicopter. This article describes a protocol for in-cabin intubation and compares it with standard open space conditions.

METHODS

Fourteen prehospital physicians were randomized to solve a simplified clinical scenario during which they were to intubate a mannequin either inside the helicopter, in accordance with our in-cabin protocol, or outside on an ambulance stretcher. Participants scored intubating conditions using a visual analog scale (VAS) and the Cormack-Lehane classification. The number of intubation attempts was recorded. Three timing end points were also measured.

RESULTS

All intubations were successful on the first attempt. All participants reported an optimal glottic view of Cormack-Lehane 1 in both scenario conditions. Participants perceived in-cabin intubation to be less difficult than intubating outdoors. (VAS 1 vs. VAS 2, P = .02). We found no difference in the duration of intubation. Scene time was 53.5 seconds (P = .04) shorter in the in-cabin group. In-cabin intubation delayed the establishment of a secure airway by 63 seconds (P = .01).

CONCLUSION

Our study suggests that protocolized in-cabin intubation can be performed in a timely manner under conditions that are equal to or better than when intubating outside on a stretcher with 360-degree patient access. Although delaying the establishment of a secure airway, in-cabin intubation may reduce scene times.

Standardised data reporting from pre-hospital advanced airway management - a nominal group technique update of the Utstein-style airway template

Background

Pre-hospital advanced airway management with oxygenation and ventilation may be vital for managing critically ill or injured patients. To improve pre-hospital critical care and develop evidence-based guidelines, research on standardised high-quality data is important. We aimed to identify which airway data were most important to report today and to revise and update a previously reported Utstein-style airway management dataset.

Methods

We recruited sixteen international experts in pre-hospital airway management from Australia, United States of America, and Europe. We used a five-step modified nominal group technique to revise the dataset, and clinical study results from the original template were used to guide the process.

Results

The experts agreed on a key dataset of thirty-two operational variables with six additional system variables, organised in time, patient, airway management and system sections. Of the original variables, one remained unchanged, while nineteen were modified in name, category, definition or value. Sixteen new variables were added. The updated dataset covers risk factors for difficult intubation, checklist and standard operating procedure use, pre-oxygenation strategies, the use of drugs in airway management, airway currency training, developments in airway devices, airway management strategies, and patient safety issues not previously described.

Conclusions

Using a modified nominal group technique with international airway management experts, we have updated the Utstein-style dataset to report standardised data from pre-hospital advanced airway management. The dataset enables future airway management research to produce comparable high-quality data across emergency medical systems. We believe this approach will promote research and improve treatment strategies and outcomes for patients receiving pre-hospital advanced airway management.

Trial registration

The Regional Committee for Medical and Health Research Ethics in Western Norway exempted this study from ethical review (Reference: REK-Vest/2017/260).

Electronic supplementary material

The online version of this article (10.1186/s13049-018-0509-y) contains supplementary material, which is available to authorized users.

Airway physical examination tests for detection of difficult airway management in apparently normal adult patients

BACKGROUND

The unanticipated difficult airway is a potentially life-threatening event during anaesthesia or acute conditions. An unsuccessfully managed upper airway is associated with serious morbidity and mortality. Several bedside screening tests are used in clinical practice to identify those at high risk of difficult airway. Their accuracy and benefit however, remains unclear.

OBJECTIVES

The objective of this review was to characterize and compare the diagnostic accuracy of the Mallampati classification and other commonly used airway examination tests for assessing the physical status of the airway in adult patients with no apparent anatomical airway abnormalities. We performed this individually for each of the four descriptors of the difficult airway: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

SEARCH METHODS

We searched major electronic databases including CENTRAL, MEDLINE, Embase, ISI Web of Science, CINAHL, as well as regional, subject specific, and dissertation and theses databases from inception to 16 December 2016, without language restrictions. In addition, we searched the Science Citation Index and checked the references of all the relevant studies. We also handsearched selected journals, conference proceedings, and relevant guidelines. We updated this search in March 2018, but we have not yet incorporated these results.

SELECTION CRITERIA

We considered full-text diagnostic test accuracy studies of any individual index test, or a combination of tests, against a reference standard. Participants were adults without obvious airway abnormalities, who were having laryngoscopy performed with a standard laryngoscope and the trachea intubated with a standard tracheal tube. Index tests included the Mallampati test, modified Mallampati test, Wilson risk score, thyromental distance, sternomental distance, mouth opening test, upper lip bite test, or any combination of these. The target condition was difficult airway, with one of the following reference standards: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

DATA COLLECTION AND ANALYSIS

We performed screening and selection of the studies, data extraction and assessment of methodological quality (using QUADAS-2) independently and in duplicate. We designed a Microsoft Access database for data collection and used Review Manager 5 and R for data analysis. For each index test and each reference standard, we assessed sensitivity and specificity. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where possible, we performed meta-analyses to calculate pooled estimates and compare test accuracy indirectly using bivariate models. We investigated heterogeneity and performed sensitivity analyses.

MAIN RESULTS

We included 133 (127 cohort type and 6 case-control) studies involving 844,206 participants. We evaluated a total of seven different prespecified index tests in the 133 studies, as well as 69 non-prespecified, and 32 combinations. For the prespecified index tests, we found six studies for the Mallampati test, 105 for the modified Mallampati test, six for the Wilson risk score, 52 for thyromental distance, 18 for sternomental distance, 34 for the mouth opening test, and 30 for the upper lip bite test. Difficult face mask ventilation was the reference standard in seven studies, difficult laryngoscopy in 92 studies, difficult tracheal intubation in 50 studies, and failed intubation in two studies. Across all studies, we judged the risk of bias to be variable for the different domains; we mostly observed low risk of bias for patient selection, flow and timing, and unclear risk of bias for reference standard and index test. Applicability concerns were generally low for all domains. For difficult laryngoscopy, the summary sensitivity ranged from 0.22 (95% confidence interval (CI) 0.13 to 0.33; mouth opening test) to 0.67 (95% CI 0.45 to 0.83; upper lip bite test) and the summary specificity ranged from 0.80 (95% CI 0.74 to 0.85; modified Mallampati test) to 0.95 (95% CI 0.88 to 0.98; Wilson risk score). The upper lip bite test for diagnosing difficult laryngoscopy provided the highest sensitivity compared to the other tests (P < 0.001). For difficult tracheal intubation, summary sensitivity ranged from 0.24 (95% CI 0.12 to 0.43; thyromental distance) to 0.51 (95% CI 0.40 to 0.61; modified Mallampati test) and the summary specificity ranged from 0.87 (95% CI 0.82 to 0.91; modified Mallampati test) to 0.93 (0.87 to 0.96; mouth opening test). The modified Mallampati test had the highest sensitivity for diagnosing difficult tracheal intubation compared to the other tests (P < 0.001). For difficult face mask ventilation, we could only estimate summary sensitivity (0.17, 95% CI 0.06 to 0.39) and specificity (0.90, 95% CI 0.81 to 0.95) for the modified Mallampati test.

AUTHORS' CONCLUSIONS

Bedside airway examination tests, for assessing the physical status of the airway in adults with no apparent anatomical airway abnormalities, are designed as screening tests. Screening tests are expected to have high sensitivities. We found that all investigated index tests had relatively low sensitivities with high variability. In contrast, specificities were consistently and markedly higher than sensitivities across all tests. The standard bedside airway examination tests should be interpreted with caution, as they do not appear to be good screening tests. Among the tests we examined, the upper lip bite test showed the most favourable diagnostic test accuracy properties. Given the paucity of available data, future research is needed to develop tests with high sensitivities to make them useful, and to consider their use for screening difficult face mask ventilation and failed intubation. The 27 studies in 'Studies awaiting classification' may alter the conclusions of the review, once we have assessed them.

Success rates of pre-hospital difficult airway management: a quality control study evaluating an in-hospital training program

BACKGROUND

Competence in emergency airway management is key in order to improve patient safety and outcome. The scope of compulsory training for emergency physicians or paramedics is quite limited, especially in Austria. The purpose of this study was to review the difficult airway management performance of an emergency medical service (EMS) in a region that has implemented a more thorough training program than current regulations require, comprising 3 months of initial training and supervised emergency practice and 3 days/month of on-going in-hospital training as previously reported.

METHODS

This is a subgroup analysis of pre-hospital airway interventions performed by non-anesthesiologist EMS physicians between 2006 and 2016. The dataset is part of a retrospective quality control study performed in the ground EMS system of Wiener Neustadt, Austria. Difficult airway missions recorded in the electronic database were matched with the hospital information system and analyzed.

RESULTS

Nine hundred thirty-three of 23060 ground EMS patients (4%) required an airway intervention. In 48 cases, transient bag-mask-valve ventilation was sufficient, and 5 patients needed repositioning of a pre-existing tracheostomy cannula. Eight hundred thirty-six of 877 patients (95.3%) were successfully intubated within two attempts; in 3 patients, a supraglottic airway device was employed first line. Management of 41 patients with failed tracheal intubation comprised laryngeal tubes (n = 21), intubating laryngeal mask (n = 11), ongoing bag-mask-valve ventilation (n = 8), and crico-thyrotomy (n = 1). There was no cannot intubate/cannot ventilate situation. Blood gas analysis at admission revealed hypoxemia in 2 and/or hypercapnia in 11 cases.

CONCLUSION

During the 11-year study period, difficult airways were encountered in 5% but sufficiently managed in all patients. Thus, the training regime presented might be a feasible and beneficial model for training of non-anesthesiologist emergency physicians as well as paramedics.

C-MAC videolaryngoscope compared with direct laryngoscopy for rapid sequence intubation in an emergency department: A randomised clinical trial

BACKGROUND

Airway management in the emergency room can be challenging when patients suffer from life-threatening conditions. Mental stress, ignorance of the patient's medical history, potential cervical injury or immobilisation and the presence of vomit and/or blood may also contribute to a difficult airway. Videolaryngoscopes have been introduced into clinical practice to visualise the airway and ultimately increase the success rate of airway management.

OBJECTIVE

The aim of this study was to test the hypothesis that the C-MAC videolaryngoscope improves first-attempt intubation success rate compared with direct laryngoscopy in patients undergoing emergency rapid sequence intubation in the emergency room setting.

DESIGN

A randomised clinical trial.

SETTING

Emergency Department of the University Hospital, Zurich, Switzerland.

PATIENTS

With approval of the local ethics committee, we prospectively enrolled 150 patients between 18 and 99 years of age requiring emergency rapid sequence intubation in the emergency room of the University Hospital Zurich. Patients were randomised (1 : 1) to undergo tracheal intubation using the C-MAC videolaryngoscope or by direct laryngoscopy.

INTERVENTIONS

Owing to ethical considerations, patients who had sustained maxillo-facial trauma, immobilised cervical spine, known difficult airway or ongoing cardiopulmonary resuscitation were excluded from our study. All intubations were performed by one of three very experienced anaesthesia consultants.

MAIN OUTCOME MEASURES

First-attempt success rate served as our primary outcome parameter. Secondary outcome parameters were time to intubation; total number of intubation attempts; Cormack and Lehane score; inadvertent oesophageal intubation; ease of intubation; complications including violations of the teeth, injury/bleeding of the larynx/pharynx and aspiration/regurgitation of gastric contents; necessity of using further alternative airway devices for successful intubation; maximum decrease of oxygen saturation and technical problems with the device.

RESULTS

A total of 150 patients were enrolled, but three patients had to be excluded from the analysis, resulting in 74 patients in the C-MAC videolaryngoscopy group and 73 patients in the direct laryngoscopy group. Tracheal intubation was achieved successfully at the first attempt in 73 of 74 patients in the C-MAC group and all patients in the direct laryngoscopy group (P = 1.0). Time to intubation was similar (32 ± 11 vs. 31 ± 9 s, P = 0.51) in both groups. Visualisation of the vocal cords, represented as the Cormack and Lehane score, was significantly better using the C-MAC videolaryngoscope (P < 0.001).

CONCLUSION

Our study demonstrates that visualisation of the vocal cords was improved by using the C-MAC videolaryngoscope compared with direct laryngoscopy. Better visualisation did not improve first-attempt success rate, which in turn was probably based on the high level of experience of the participating anaesthesia consultants.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02297113.

Use of the GlideScope Ranger Video Laryngoscope for Emergency Intubation in the Prehospital Setting: A Randomized Control Trial

OBJECTIVES

We sought to assess whether the GlideScope Ranger video laryngoscope may be a reliable alternative to direct laryngoscopy in the prehospital setting.

DESIGN

Multicenter, prospective, randomized, control trial with patient recruitment over 18 months.

SETTING

Four study centers operating physician-staffed rescue helicopters or ground units in Austria and Norway.

PATIENTS

Adult emergency patients requiring endotracheal intubation.

INTERVENTIONS

Airway management strictly following a prehospital algorithm. First and second intubation attempt employing GlideScope or direct laryngoscopy as randomized; third attempt crossover. After three failed intubation attempts, immediate use of an extraglottic airway device.

MEASUREMENTS AND MAIN RESULTS

A total of 326 patients were enrolled. Success rate with the GlideScope (n = 168) versus direct laryngoscopy (n = 158) group was 61.9% (104/168) versus 96.2% (152/158), respectively (p < 0.001). The main reasons for failed GlideScope intubation were failure to advance the tube into the larynx or trachea (26/168 vs 0/158; p < 0.001) and/or impaired sight due to blood or fluids (21/168 vs 3/158; p < 0.001). When GlideScope intubation failed, direct laryngoscopy was successful in 61 of 64 patients (95.3%), whereas GlideScope enabled intubation in four of six cases (66.7%) where direct laryngoscopy failed (p = 0.055). In addition, GlideScope was prone to impaired visualization of the monitor because of ambient light (29/168; 17.3%). There was no correlation between success rates and body mass index, age, indication for airway management, or experience of the physicians, respectively.

CONCLUSIONS

Video laryngoscopy is an established tool in difficult airway management, but our results shed light on the specific problems in the emergency medical service setting. Prehospital use of the GlideScope was associated with some major problems, thus resulting in a lower intubation success rate when compared with direct laryngoscopy.

[Out-of-hospital airway management in trauma patients : Experiences with the C-MAC® video laryngoscope]

BACKGROUND

Securing the airway is the top priority in trauma resuscitation. The most important factor for successful endotracheal intubation (ETI) is good visualization of the vocal cords. The aim of this study was to summarize the practical experiences with the C-MAC® video laryngoscope as initial device in out-of-hospital airway management of trauma patients.

METHODS

The C-MAC® video laryngoscope uses standard Macintosh shaped laryngoscope blades. At the Helicopter Emergency Medical Service (HEMS) Christoph 22 it is used as the initial device for every out-of-hospital ETI. All prehospital data on ETI involving trauma patients were documented for a period of 17 months.

RESULTS

A total of 116 out-of-hospital ETIs were enrolled in this study (overall success rate 100 %). In 88.8 % the first attempt was successful, whereas in 10.3 % a second and in 0.9 % a third ETI attempt was necessary. No patient required alternative airway devices or surgical airway interventions. The results of a subgroup with an immobilized cervical spine (n = 17) did not show any increased difficulties.

CONCLUSION

The use of the C-MAC® video laryngoscope by experienced anesthesiologists in an out-of-hospital setting seems to be a safe method even in patients with an immobilized cervical spine. Adverse laryngoscopy results (C/L III and IV) were reduced compared to other studies.

Derivation and Validation of The Prehospital Difficult Airway IdentificationTool (PreDAIT): A Predictive Model for Difficult Intubation

Introduction

Endotracheal intubation (ETI) in the prehospital setting poses unique challenges where multiple ETI attempts are associated with adverse patient outcomes. Early identification of difficult ETI cases will allow providers to tailor airway-management efforts to minimize complications associated with ETI. We sought to derive and validate a prehospital difficult airway identification tool based on predictors of difficult ETI in other settings.

Methods

We prospectively collected patient and airway data on all airway attempts from 16 Advanced Life Support (ALS) ground emergency medical services (EMS) agencies from January 2011 to October 2014. Cases that required more than two ETI attempts and cases where an alternative airway strategy (e.g. supraglottic airway) was employed after one unsuccessful ETI attempt were categorized as “difficult.” We used a random allocation sequence to split the data into derivation and validation subsets. Using backward elimination, factors with a p<0.1 were included in the multivariable regression for the derivation cohort and then tested in the validation cohort. We used this model to determine the area under the curve (AUC), and the sensitivity and specificity for each cut point in both the derivation and validation cohorts.

Results

We collected data on 1,102 cases with 568 in the derivation set (155 difficult cases; 27%) and 534 in the validation set (135 difficult cases; 25%). Of the collected variables, five factors were predictive of difficult ETI in the derivation model (adjusted odds ratio, 95% confidence interval [CI]): Glasgow coma score [GCS] >3 (2.15, 1.19–3.88), limited neck movement (2.24, 1.28–3.93), trismus/jaw clenched (2.24, 1.09–4.6), inability to palpate the landmarks of the neck (5.92, 2.77–12.66), and fluid in the airway such as blood or emesis (2.25, 1.51–3.36). This was the most parsimonious model and exhibited good fit (Hosmer-Lemeshow test p = 0.167) with an AUC of 0.68 (95% CI [0.64–0.73]). When applied to the validation set, the model had an AUC of 0.63 (0.58–0.68) with high specificity for identifying difficult ETI if ≥2 factors were present (87.7% (95% CI [84.1–90.8])).

Conclusion

We have developed a simple tool using five factors that may aid prehospital providers in the identification of difficult ETI.

Republication: All India Difficult Airway Association 2016 Guidelines for Tracheal Intubation in the Intensive Care Unit

Tracheal intubation (TI) is a routine procedure in the Intensive Care Unit (ICU) and is often lifesaving. In contrast to the controlled conditions in the operating room, critically ill patients with respiratory failure and shock are physiologically unstable. These factors, along with under evaluation of the airway and suboptimal response to preoxygenation, are responsible for a high incidence of life-threatening complications such as severe hypoxemia and cardiovascular collapse during TI in the ICU. The All India Difficult Airway Association (AIDAA) proposes a stepwise plan for safe management of the airway in critically ill patients. These guidelines have been developed based on available evidence; Wherever, robust evidence was lacking, recommendations were arrived at by consensus opinion of airway experts, incorporating the responses to a questionnaire sent to members of the (AIDAA) and Indian Society of Anaesthesiologists. Noninvasive positive pressure ventilation for preoxygenation provides adequate oxygen stores during TI for patients with respiratory pathology. Nasal insufflation of oxygen at 15 L/min can increase the duration of apnea before hypoxemia sets in. High flow nasal cannula oxygenation at 60-70 L/min may also increase safety during intubation of critically ill patients. Stable hemodynamics and gas exchange must be maintained during rapid sequence induction. It is necessary to implement an intubation protocol during routine airway management in the ICU. Adherence to a plan for difficult airway management incorporating the use of intubation aids and airway rescue devices and strategies is useful.

The success of pre-hospital tracheal intubation by different pre-hospital providers: a systematic literature review and meta-analysis

BACKGROUND

Pre-hospital basic airway interventions can be ineffective at providing adequate oxygenation and ventilation in some severely ill or injured patients, and advanced airway interventions are then required. Controversy exists regarding the level of provider required to perform successful pre-hospital intubation. A previous meta-analysis reported pre-hospital intubation success rates of 0.849 for non-physicians versus 0.991 for physicians. The evidence base on the topic has expanded significantly in the last 10 years. This study systematically reviewed recent literature and presents comprehensive data on intubation success rates.

METHODS

A systematic search of MEDLINE and EMBASE was performed using PRISMA methodology to identify articles on pre-hospital tracheal intubation published between 2006 and 2016. Overall success rates were estimated using random effects meta-analysis. The relationship between intubation success rate and provider type was assessed in weighted linear regression analysis.

RESULTS

Of the 1838 identified studies, 38 met the study inclusion criteria. Intubation was performed by non-physicians in half of the studies and by physicians in the other half. The crude median (range) reported overall success rate was 0.969 (0.616-1.000). In random effects meta-analysis, the estimated overall intubation success rate was 0.953 (0.938-0.965). The crude median (range) reported intubation success rates for non-physicians were 0.917 (0.616-1.000) and, for physicians, were 0.988 (0.781-1.000) (p = 0.003).

DISCUSSION

The reported overall success rate of pre-hospital intubation has improved, yet there is still a significant difference between non-physician and physician providers. The finding that less-experienced personnel perform less well is not unexpected, but since there is considerable evidence that poorly performed intubation carries a significant risk of morbidity and mortality careful consideration should be given to the training and experience required to deliver this intervention safely.

Difficult Intubation Factors in Prehospital Rapid Sequence Intubation by an Australian Helicopter Emergency Medical Service

OBJECTIVE

Prehospital rapid sequence intubation (RSI) of critically ill trauma patients is a high-risk procedure that may be associated with an increased rate of severe complications such as failed intubation, failure of oxygenation, hypoxia, hypotension, or need for surgical airway. The objective of this study was to describe the factors associated with difficult intubation in prehospital RSI as defined by more than a single look at laryngoscopy to achieve tracheal intubation.

METHODS

This is an observational study using prospectively collected data.

RESULTS

Four hundred forty-three RSIs were performed. Paramedics were the initial laryngoscopist in 290 (65.5%). First-look laryngoscopy resulted in successful tracheal intubation (TI) in 372 (84.0%) (95% confidence interval, 80.3%-87.1%). Intubation was achieved on second look at laryngoscopy in 58 (13.1%). "First-pass" TI was achieved in 394 (88.9%). Overall, successful TI was achieved in 438 (98.9%) (95% confidence interval, 97.4%-99.5%). Complications occurred in 116 (26.2%), with desaturation the commonest in 77 (17.4%).

CONCLUSION

Factors associated with more than 1 look at laryngoscopy before TI included paramedic laryngoscopist and the presence of at least 1 of the following indicators: blood/vomitus in the airway, limited mouth opening, and limited neck movement. Trauma to face/neck, obese body habitus, C-spine precautions, cricoid pressure, midline stabilization, and intubation on the ground did not influence the level of difficulty encountered.

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.

The All India Difficult Airway Association 2016 guidelines for tracheal intubation in the Intensive Care Unit

Tracheal intubation (TI) is a routine procedure in the Intensive Care Unit (ICU) and is often life-saving. In contrast to the controlled conditions in the operating room, critically ill patients with respiratory failure and shock are physiologically unstable. These factors, along with a suboptimal evaluation of the airway and limited oxygen reserves despite adequate pre-oxygenation, are responsible for a high incidence of life-threatening complications such as severe hypoxaemia and cardiovascular collapse during TI in the ICU. The All India Difficult Airway Association (AIDAA) proposes a stepwise plan for safe management of the airway in critically ill patients. These guidelines have been developed based on available evidence; wherever robust evidence was lacking, recommendations were arrived at by consensus opinion of airway experts, incorporating the responses to a questionnaire sent to members of the AIDAA and the Indian Society of Anaesthesiologists. Non-invasive positive pressure ventilation during pre-oxygenation improves oxygen stores in patients with respiratory pathology. Nasal insufflation of oxygen at 15 L/min can increase the duration of apnoea before the occurrence of hypoxaemia. High-flow nasal cannula oxygenation at 60-70 L/min may also increase safety during TI in critically ill patients. Stable haemodynamics and gas exchange must be maintained during rapid sequence induction. It is necessary to implement an intubation protocol during routine airway management in the ICU. Adherence to a plan for difficult airway management incorporating the use of intubation aids and airway rescue devices and strategies is useful.

Video laryngoscopy in pre-hospital critical care - a quality improvement study

Background

Pre-hospital endotracheal intubation is challenging and repeated endotracheal intubation is associated with increased morbidity and mortality.

We investigated whether the introduction of the McGrath MAC video laryngoscope as the primary device for pre-hospital endotracheal intubation could improve first-pass success rate in our anaesthesiologist-staffed pre-hospital critical care services. We also investigated the incidence of failed pre-hospital endotracheal intubation, the use of airway adjuncts and back-up devices and problems encountered using the McGrath MAC video laryngoscope.

Methods

Prospective quality improvement study collecting data from all adult pre-hospital endotracheal intubation performed by four anaesthesiologist-staffed pre-hospital critical care teams between December 15^th 2013 and December 15^th 2014.

Results

We registered data from 273 consecutive patients. When using the McGrath MAC video laryngoscope the overall pre-hospital endotracheal intubation first-pass success rate was 80.8 %. Following rapid sequence intubation (RSI) it was 88.9 %. This was not significantly different from previously reported first-pass success rates in our system (p = 0.27 and p = 0.41). During the last nine months of the study period the overall first-pass success rate was 80.1 (p = 0.47) but the post-RSI first-pass success rate improved to 94.4 % (0.048).

The overall pre-hospital endotracheal intubation success rate with the McGrath MAC video laryngoscope was 98.9 % (p = 0.17). Gastric content, blood or secretion in the airway resulted in reduced vision when using the McGrath MAC video laryngoscope.

Conclusion

In this study of video laryngoscope implementation in a Scandinavian anaesthesiologist-staffed pre-hospital critical care service, overall pre-hospital endotracheal first pass success rate did not change. The post-RSI first-pass success rate was significantly higher during the last nine months of our 12-month study compared with our results from before introducing McGrath MAC video laryngoscope. The implementation of the Standard Operating Procedure and check list for pre-hospital anaesthesia during the study period may have influenced the first-pass success rate and constitutes a potential confounder.

The potential limitations of the McGrath MAC video laryngoscope when there are gastric content, blood and secretions in the airways need to be further investigated before the McGrath MAC video laryngoscope can be recommended as the primary device in all pre-hospital endotracheal intubations.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-016-0276-6) contains supplementary material, which is available to authorized users.

Comparison of the GlideRite to the conventional malleable stylet for endotracheal intubation by the Macintosh laryngoscope: a simulation study using manikins

Objective

To compare the effectiveness of the GlideRite stylet with the conventional malleable stylet (CMS) in endotracheal intubation (ETI) by the Macintosh laryngoscope.

Methods

This study is a randomized, crossover, simulation study. Participants performed ETI using both the GlideRite stylet and the CMS in a normal airway model and a tongue edema model (simulated difficult airway resulting in lower percentage of glottic opening [POGO]).

Results

In both the normal and tongue edema models, all 36 participants successfully performed ETI with the two stylets on the first attempt. In the normal airway model, there was no difference in time required for ETI (T_ETI) or in ease of handling between the two stylets. In the tongue edema model, the T_ETI using the CMS increased as the POGO score decreased (POGO score was negatively correlated with T_ETI for the CMS, Spearman’s rho=-0.518, P=0.001); this difference was not seen with the GlideRite (rho=-0.208, P=0.224). The T_ETI was shorter with the GlideRite than with the CMS, however, this difference was not statistically significant (15.1 vs. 18.8 seconds, P=0.385). Ease of handling was superior with the GlideRite compared with the CMS (P=0.006).

Conclusion

Performance of the GlideRite and the CMS were not different in the normal airway model. However, in the simulated difficult airway model with a low POGO score, the GlideRite performed better than the CMS for direct laryngoscopic intubation.

Ease and difficulty of pre-hospital airway management in 425 paediatric patients treated by a helicopter emergency medical service: a retrospective analysis

Background

Pre-hospital paediatric airway management is complex. A variety of pitfalls need prompt response to establish and maintain adequate ventilation and oxygenation. Anatomical disparity render laryngoscopy different compared to the adult. The correct choice of endotracheal tube size and depth of insertion is not trivial and often challenged due to the initially unknown age of child.

Methods

Data from 425 paediatric patients (<17 years of age) with any airway manipulation treated by a Swiss Air-Ambulance crew between June 2010 and December 2013 were retrospectively analysed. Endpoints were: 1) Endotracheal intubation success rate and incidence of difficult airway management in primary missions. 2) Correlation of endotracheal tube size and depth of insertion with patient’s age in all (primary and secondary) missions.

Results

In primary missions, the first laryngoscopy-guided endotracheal intubation attempt was successful in 95.3% of cases, with an overall success rate of 98.6%. Difficult airway management was reported in 10 (4.7%) patients. Endotracheal tube size was frequently chosen inadequately large (overall 50 of 343 patients: 14.6%), especially and statistically significant in the age group below 1 year (19 of 33 patients; p < 0.001). Tubes were frequently and distinctively more deeply inserted (38.9%) than recommended by current formulae.

Conclusion

Difficult airway management, including cannot intubate and cannot ventilate situations during pre-hospital paediatric emergency treatment was rare. In contrast, the success rate of endotracheal intubation at the first attempt was very high. High numbers of inadequate endotracheal tube size and deep placement according to patient age require further analysis. Practical algorithms need to be found to prevent potentially harmful treatment.

Airway management in laryngotracheal injuries from blunt neck trauma in children

Pediatric laryngotracheal injuries from blunt neck trauma are extremely rare, but can be potentially catastrophic. Early diagnosis and skillful airway management is critical in avoiding significant morbidity and mortality associated with these cases. We present a case of a patient who suffered a complete tracheal transection and cervical spine fracture following a clothesline injury to the anterior neck. A review of the mechanisms of injury, clinical presentation, initial airway management, and anesthetic considerations in laryngotracheal injuries from blunt neck trauma in children are presented.

Defining the learning curve for endotracheal intubation using direct laryngoscopy: A systematic review

More than two failed intubation attempts and failed endotracheal intubations (ETIs) are associated with severe complications and death. The aim of this review was to determine the number of ETIs a health care provider in training needs to perform to achieve proficiency within two attempts. A systematic search of the literature was conducted covering the time frame of January 1990 through July 2014. We identified 13 studies with a total of 1462 students who had attempted to intubate 19,108 patients. This review shows that in mostly elective circumstances, at least 50 ETIs with no more than two intubation attempts need to be performed to reach a success rate of at least 90%. However, the evidence is heterogeneous, and the incidence of difficult airways in non-elective settings is up to 20 times higher compared to elective settings. Taking this factor into account, training should include a variety of exposures and should probably exceed 50 ETIs to successfully serve the most vulnerable patients.

[The supraglottic airway in the prehospital setting]

The supraglottic airway (SGA) is increasingly considered as a more effective alternative for emergency ventilation compared to bag mask ventilation and is propagated as an "easily" manageable method, compared to endotracheal intubation especially under the often adverse out-of-hospital conditions. Since the skill can easily be acquired during mannequin training, more and more rescue services train their personnel in the use of SGA devices and allow or even recommend their application also by nonphysicians. This recommendation, however, is not unequivocally supported by properly designed and conducted trials. Moreover, the solely available observational studies show contradictory results. Neither superiority nor inferiority of SGAs has been shown. They may, however, be accepted as an addendum to other prehospital ventilation approaches. The SGA airway comprises various problems and inherited risks similar to other ventilation techniques. Randomized studies investigating different techniques for prehospital emergency ventilation are lacking, as are controlled studies comparing SGA devices.

Difficult intubation and outcome after out-of-hospital cardiac arrest: a registry-based analysis

Background

Airway management during resuscitation attempts is pivotal for treating hypoxia, and endotracheal intubation is the standard procedure. This German Resuscitation Registry analysis investigates the influence of airway management on primary outcomes after out-of-hospital cardiac arrest, in a physician-based emergency system.

Methods

A total of 8512 patients recorded in the German Resuscitation Registry (2007–2011) were analyzed. The Return of Spontaneous Circulation After Cardiac Arrest (RACA) score was used to compare observed return of spontaneous circulation (ROSC) rates with the ROSC predicted by the score and to analyze factors influencing the primary outcome. Patients were classified into three groups: difficult intubation, impossible intubation, and a control group with normal airways.

Results

The observed ROSC matched the predicted ROSC in the group with difficult airways. The impossible intubation group had lower ROSC rates (31.3 % vs. 40.5 %; P < 0.05). Impossible intubation was more frequent in men (OR 2.28; 95 % CI, 1.43–3.63; P = 0.001), young patients (OR 2.18; 95 % CI, 1.26–3.76; P = 0.005) and those with trauma (OR 2.22; 95 % CI, 1.01–4.85; P = 0.046). Fewer impossible intubations were reported when the emergency physicians were anesthesiologists (OR 0.65; 95 % CI, 0.44–0.96; P = 0.028). If a supraglottic airway device was not used in the impossible intubation group, the observed ROSC (18.0 %; 95 % CI, 7.4–28.6 %) was poorer than predicted (38.2 %) (P < 0.05).

Conclusions

Outcomes after resuscitation attempts are poorer when endotracheal intubation is not possible. Predictive factors for impossible intubation are male gender, younger age, and trauma. Supraglottic airway devices should be used at an early stage whenever these negative factors are present.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-015-0124-0) contains supplementary material, which is available to authorized users.

Maxillofacial Injury-Not Always a Difficult Airway

The optimal method for securing the airway in injured patients is controversial. Maxillofacial injury has been shown to be a marker for difficult airway management; however, a delay in intubation may result in deterioration of intubating conditions due to further airway bleeding and swelling. Decisions on the timing and method of airway management depend on multiple factors, including patient characteristics, the skill set of the clinicians, and logistical considerations. This report describes the case of a multi-agency response to a motor-vehicle collision in a rural area in Ireland. One young male patient had sustained significant maxillofacial injuries, multiple limb injuries, and had a decreased level of consciousness. Further airway compromise occurred following extrication. Difficult intubation was predicted; however, abnormal jaw mobility from bilateral mandibular fractures enabled easy laryngoscopy and intubation. Although preparation must be made for difficult airway management in the setting of maxillofacial injury, appropriately trained and experienced practitioners should not be deterred from performing early intubation when indicated.

Incidence of difficult airway situations during prehospital airway management by emergency physicians--a retrospective analysis of 692 consecutive patients

INTRODUCTION

In the prehospital setting, advanced airway management is challenging as it is frequently affected by facial trauma, pharyngeal obstruction or limited access to the patient and/or the patient's airway. Therefore, incidence of prehospital difficult airway management is likely to be higher compared to the in-hospital setting and success rates of advanced airway management range between 80 and 99%.

METHODS

3961 patients treated by an emergency physician in Zurich, Switzerland were included in this retrospective analysis in order to determine the incidence of a difficult airway along with potential circumstantial risk factors like gender, necessity of CPR, NACA score, GCS, use and type of muscle relaxant and use of hypnotic drugs.

RESULTS

692 patients underwent advanced prehospital airway management. Seven patients were excluded due to incomplete or incongruent documentation, resulting in 685 patients included in the statistical analysis. Difficult intubation was recorded in 22 patients, representing an incidence of a difficult airway of 3.2%. Of these 22 patients, 15 patients were intubated successfully, whereas seven patients (1%) had to be ventilated with a bag valve mask during the whole procedure.

CONCLUSION

In this physician-led service one out of five prehospital patients requires airway management. Incidence of advanced prehospital difficult airway management is 3.2% and eventual success rate is 99%, if performed by trained emergency physicians. A total of 1% of all prehospital intubation attempts failed and alternative airway device was necessary.