An assessment of introducers used for airway management.

Different introducers are available to assist with tracheal intubation. Subtle differences in the design of introducers can have a marked effect on safety and performance. The Difficult Airway Society's Airway Device Evaluation Project Team proposal states that devices should only be purchased for which there is at least a case-control study on patients assessing airway devices. However, resources are not currently available to carry out a case-control study on all introducers available on the market. This study comprised a laboratory and manikin-based investigation to identify introducers that could be suitable for clinical investigation. We included six different introducers in laboratory-based assessments (design characteristics) and manikin-based assessments involving the participation of 30 anaesthetists. Each anaesthetist attempted placement in the manikin's trachea with each of the six introducers in a random order. Outcomes included first-time insertion success rate; insertion success rate; number of attempts; time to placement; and distance placed. Each anaesthetist also completed a questionnaire. First-time insertion success rate depended significantly on the introducer used (p = 0.0016) and varied from 47% (Armstrong and P3) to 77% (Intersurgical and Frova). Median time to placement (including oesophageal placement) varied from 10 s (Eschmann and Frova) to 20 s (P3) (p = 0.0025). Median time to successful placement in the trachea varied from 9 s (Frova) to 22 s (Armstrong) (p = 0.037). We found that the Armstrong and P3 devices were not as acceptable as other introducers and, without significant improvements to their design and characteristics, the use of these devices in studies on patients is questionable. The study protocol is suitable for differentiating between different introducers and could be used as a basis for assessing other types of devices.

An assessment of the tolerability of the Cook staged extubation wire in patients with known or suspected difficult airways extubated in intensive care.

The Cook staged extubation set (Cook Medical) has been developed to facilitate management of the difficult airway. A guidewire inserted before tracheal extubation provides access to the subglottic airway should re-intubation be required. This prospective cohort study examines patients' tolerance of the guidewire and its impact on clinical status around tracheal extubation in the intensive care unit. Vital signs, incidence of symptoms and patient tolerance of the wire were recorded. Twenty-three patients were enrolled and 17 (73%) tolerated the wire for 4 h. Nasendoscopy was performed in 11 of these patients and revealed one wire was in the oesophagus. The most common symptom was a mild intermittent cough in 13 patients. There was no impact of the guidewire on nursing care in 16 patients, tolerable impact in five and severe impact necessitating removal of the wire in one patient.

Use of Mechanical Insufflation-Exsufflation Devices for Airway Clearance in Subjects With Neuromuscular Disease.

The aim of this systematic review is to examine the benefit/risk ratio of the use of mechanical insufflation-exsufflation (MI-E) devices for airway clearance in patients with neuromuscular diseases. A search was conducted for relevant studies in MEDLINE, the Cochrane Library, and the Health Technology Assessment Database using the main key words: cough, airway clearance, in-exsufflation. The search limits were studies published in English and French between 1970 and 2014 (literature watch until December 2015). The methodological quality of the studies was assessed using (1) the Cochrane Collaboration's risk of bias tool for randomized controlled trials and (2) the Institute of Health Economics' 20-item checklist for comparative and observational studies. Data were extracted into an evidence table according to (1) study design, (2) population characteristics (including age and type of diseases) and intervention (MI-E associated or not with other interventions), (3) outcome measures, and (4) key findings. Twelve studies met the inclusion criteria (4 randomized controlled trials, 3 comparative studies, and 5 observational studies). The quality of the selected studies was poor. None of the studies reported survival outcome. All studies evaluated change of pulmonary function parameters, such as peak expiratory flow. This review underlines the lack of robust data on mechanical medical devices used for airway clearance. The current scientific evidence does not support the use of MI-E for cough augmentation in patients with neuromuscular diseases, but health-care professionals are faced with the reality of medical practice and the absence of alternatives. Most European and American guidelines recommend the use of MI-E despite low-level evidence. However, even if performing comparative trials in a specific population is difficult, the medical device industry should provide reliable data to assist health-care professionals, providers, and payers in the decision-making process. This is the only way to ensure the best treatment for patients.

Comparison of Metal and Plastic Disposable Laryngoscope Blade with Reusable Macintosh Blade in Difficult and Inhalation Injury Airway Scenario: A Manikin Study.

BACKGROUND: Single-use plastic blades (SUPB) and single-use metal blades (SUMB) for direct laryngoscopy and tracheal intubation have not yet been compared with reusable metal blades (RUMB) in difficult airway scenarios. OBJECTIVE: The purpose of our manikin study was to compare the effectiveness of these different laryngoscope blades in a difficult airway scenario, as well as in a difficult airway scenario with simulated severe inhalation injury. METHODS: Thirty anesthetists performed tracheal intubation (TI) with each of the three laryngoscope blades in the two scenario manikins. RESULTS: In the inhalation injury scenario, SUPB were associated with prolonged intubation times when compared with the metal blades. In the inhalation injury scenario, both metal laryngoscope blades provided a quicker, easier, and safer TI. In the difficult airway scenario, intubation times were significantly prolonged in the SUPB group in comparison to the RUMB group, but there were no significant differences between the SUPB and the SUMB. In this scenario, the RUMB demonstrated the shortest intubation times and seems to be the most effective device. CONCLUSIONS: Generally, results are in line with previous studies showing significant disadvantages of SUPB in both manikin scenarios. Therefore, metal blades might be beneficial, especially in the airway management of patients with inhalation injury.

Design and implementation of the AIRWAYS-2 trial: A multi-centre cluster randomised controlled trial of the clinical and cost effectiveness of the i-gel supraglottic airway device versus tracheal intubation in the initial airway management of out of hospital cardiac arrest.

Health outcomes after out of hospital cardiac arrest (OHCA) are extremely poor, with only 7-9% of patients in the United Kingdom (UK) surviving to hospital discharge. Currently emergency medical services (EMS) use either tracheal intubation or newer supraglottic airway devices (SGAs) to provide advanced airway management during OHCA. Equipoise between the two techniques has led to calls for a well-designed randomised controlled trial. The primary objective of the AIRWAYS-2 trial is to assess whether the clinical effectiveness of the i-gel, a second-generation SGA, is superior to tracheal intubation in the initial airway management of OHCA patients in the UK. Paramedics recruited to the AIRWAYS-2 trial are randomised to use either tracheal intubation or i-gel as their first advanced airway intervention. Adults who have had a non-traumatic OHCA and are attended by an AIRWAYS-2 paramedic are retrospectively assessed against eligibility criteria for inclusion. The primary outcome is the modified Rankin Scale score at hospital discharge. Secondary objectives are to: (i) estimate differences between groups in outcome measures relating to airway management, hospital stay and recovery at 3 and 6 months; (ii) estimate the cost effectiveness of the i-gel compared to tracheal intubation. Because OHCA patient needs immediate treatment there are several unusual features and challenges to the design and implementation of this trial; these include level of randomisation, the automatic enrolment model, enrolment of patients that lack capacity and minimisation of bias. Patient enrolment began in June 2015. The trial will enrol 9070 patients over two years. The results are expected to influence future resuscitation guidelines. Trial Registration ISRCTN: 08256118.

Redesigning an airway cart using lean methodology.

STUDY OBJECTIVE: Use lean methodology to create a more efficient difficult airway management equipment transport and setup. DESIGN: The 5S steps of sort, set in order, sweep, standardize, and sustain were used to create a redesigned airway cart. The 5S steps provided the framework to separate the needed from unneeded equipment, logical equipment placement on the cart, and a plan to maintain improvements. Simulations were utilized to compare the revised airway cart to the previous airway equipment storage. SETTING: Hospital operating rooms and equipment storage rooms. PATIENTS: Simulated difficult airway scenarios without patient involvement. INTERVENTION: Difficult airway equipment 5S process. MEASUREMENTS: Total pieces and cost of airway equipment before and after intervention. Walking distance and time to retrieve equipment, setup equipment, and setup defect rate during a simulation. MAIN RESULTS: Previously, airway equipment was stored in 4 locations which was reduced a single difficult airway cart. The total pieces of equipment stored was reduced 89% and the cost of disposable equipment inventory was reduced 81%. Simulations looking at the acquisition and setup of equipment during a difficult airway scenario revealed a 39% reduction in equipment set up time, a 77% reduction in non-valued-added set up time, and a 74% reduction in walking distance. There was no difference in set up defect rates. CONCLUSION: Application of this lean method resulted in a revised single cart with equipment pared down to only what is needed, arranged according to frequency and order of use in a difficult airway. In a simulated difficult airway, there was a reduction in non-value-added time and walking distance to retrieve the equipment.

Estimating the number of difficult airway carts needed in an operating suite: Resource planning without compromising patient safety.

STUDY OBJECTIVE: To determine the number of difficult airway (DA) carts required based on the number of anesthetising locations and patients risk of DA. DESIGN: Binomial distributions. SETTING AND PATIENTS: Various hypothetical settings and patient cohorts. INTERVENTIONS AND MEASUREMENTS: Binomial distributions were used to calculate the number of distinct combinations of DAs by number of anesthetising locations assuming an average risk of 10%. The 'at least' number of DAs was calculated using cumulative probabilities of having exactly two plus more than 2 DAs up to the total number of simultaneously started anesthetising locations or until the cumulative probability exceeds the 50% threshold, therefore being more likely than not. MAIN RESULTS: The probability of encountering concurrent DAs increases as the number of simultaneously started anesthetising locations increases. For at least 2 concurrent DAs, the probability first exceeds 50% at 17 locations. The corresponding thresholds for at least 3 and 4 concurrent DAs, are 27 and 37 locations respectively. The probability of at least 2 concurrent DAs will exceed 50% when approximately 17 anesthetising sites are started simultaneously and a 10% worst case risk is assumed. CONCLUSIONS: With continuing resource constraints, proper planning of human and capital resources for DAs needs to be addressed without compromising patient safety. It is recommended that every block of 15-20 sites be equipped with a DA cart, that anaesthesia groups develop and rehearse DA algorithms with available equipment, and that preoperative anaesthesia clinics be used to identify DA therefore providing logistical leverage.

Virtual endoscopy--a new assessment tool in difficult airway management.

Preemptive mapping of the airway is a useful adjunct to conventional clinical assessments when airway management planning for patients with complex head and neck pathology. Nasendoscopy is frequently used for this purpose but is also invasive and poorly tolerated in a subset of patients and, even in expert hands, may not allow complete visualization of the glottis and subglottic structures. We present a novel tool for difficult airway management planning in the form of virtual endoscopy by applying free online OsiriX software to head and neck computed tomographic scans to generate a "fly-through" airway reconstruction. To highlight how well virtual endoscopy correlates to conventional fibreoscopy, we compare both of these assessment tools in 3 patients with glottic, subglottic, and multilevel airway pathologies. Virtual endoscopy represents a unique, noninvasive, safe, and accurate airway assessment and educational resource, which warrants further exploration.

Bench Comparative Assessment of Mechanically Assisted Cough Devices.

BACKGROUND: Mechanically assisted cough devices are used in patients with impaired cough to avoid secretion accumulation. We compared 5 mechanically assisted cough devices by bench testing using a breathing simulator and assessed their user-friendliness. METHODS: We measured inspiratory and expiratory airway pressures and peak expiratory flow, the strongest indicator of cough efficacy. We performed 2 bench tests: 1) to ascertain the differences between preset and actual settings in 3 different machines of each mechanically assisted cough device and 2) to assess the effects of varying respiratory impedance and air leaks on performance of the devices. We also evaluated the user-friendliness of the devices by measuring the time required and errors in accomplishing 4 tasks by 10 physicians unfamiliar with mechanically assisted cough devices compared with product specialists from the distributing companies. Physicians also scored the ease of use. RESULTS: Four mechanically assisted cough devices during insufflation and all 5 during exsufflation showed differences between preset and actual airway pressures. All but one device showed uneven actual pressure values between models of the same type. Peak expiratory flow was significantly influenced by the mechanical properties in 2 devices and by air leaks in 4 devices. The median time to accomplish all tasks by the product specialist (10 [interquartile range of 2-29] s) was overall significantly shorter compared with all physicians (from 19 [14-65] to 36 [19-116] s). The number of procedural errors, but not the perceived ease of use, differed significantly between the devices. CONCLUSIONS: The performance of different mechanically assisted cough devices was erratic and included variance between models from the same manufacturer; it was affected by respiratory system impedance and air leaks. Time and rate of errors for performing procedures were elevated. These findings indicate that the devices are not interchangeable and that the settings should be targeted for each patient with the specific machine being used. Improvements in reliability, performance, and user-friendliness are advisable.

Are new supraglottic airway devices, tracheal tubes and airway viewing devices cost-effective?

Over the past two decades, a plethora of new airway devices has become available to the pediatric anesthetist. While all have the laudable intention of improving patient care and some have proven clinical benefits, these devices are often costly and at times claims of an advantage over current equipment and techniques are marginal. Supraglottic airway devices are used in the majority of pediatric anesthetics delivered in the U.K., and airway-viewing devices provide an alternative for routine intubation as well as an option in the management of the difficult airway. Yet hidden beneath the convenience of the former and the technology of the latter, the impact on basic airway skills with a facemask and the lack of opportunities to fine-tune the core skill of intubation represent an unrecognised and unquantifiable cost. A judgement on this value must be factored into the absolute purchase cost and any potential benefits to the quality of patient care, thus blurring any judgement on cost-effectiveness that we might have. An overall value on cost-effectiveness though not in strict monetary terms can then be ascribed. In this review, we evaluate the role of these devices in the care of the pediatric patient and attempt to balance the advantages they offer against the cost they incur, both financial and environmental, and in any quality improvement they might offer in clinical care.

[Airway devices in the intensive care unit]. / Welcher Beatmungszugang für welchen Patienten auf der Intensivstation?

This review presents the potential indications for different airway devices in the intensive care unit (ICU). Since the interface during noninvasive ventilation is located outside the body, sedation is not regularly needed. Therefore, selection of a fitting mask is essential to avoid mask intolerance which is one of the biggest problems during noninvasive ventilation. Full-face masks are the interfaces mostly used for noninvasive ventilation to treat acute respiratory failure; here, mouth breathing is possible which is often necessary during acute respiratory failure. Good alternatives are total face masks and the helmet, whereas nasal masks and mouthpieces are not regularly used on the ICU. Extraglottic airway devices and coniotomy are used for the management of difficult airway situations on the ICU. Endotracheal intubation remains the gold standard procedure for airway management. However, this procedure is associated with a number of complications. Tracheostomy is the airway access of choice when long-term mechanical ventilation is necessary.

The microbiological and sustainability effects of washing anaesthesia breathing circuits less frequently.

In the presence of single-use airway filters, we quantified anaesthetic circuit aerobic microbial contamination rates when changed every 24 h, 48 h and 7 days. Microbiological samples were taken from the interior of 305 anaesthetic breathing circuits over a 15-month period (3197 operations). There was no significant difference in the proportion of contaminated circuits when changed every 24 h (57/105 (54%, 95% CI 45-64%)) compared with 48 h (43/100 (43%, 95% CI 33-53%, p = 0.12)) and up to 7 days (46/100 (46%, 95% CI 36-56%, p = 0.26)). Median bacterial counts were not increased at 48 h or 7 days provided circuits were routinely emptied of condensate. Annual savings for one hospital (six operating theatres) were $AU 5219 (£3079, €3654, $US 4846) and a 57% decrease in anaesthesia circuit steriliser loads associated with a yearly saving of 2760 kWh of electricity and 48 000 l of water. Our findings suggest that extended circuit use from 24 h up to 7 days does not significantly increase bacterial contamination, and is associated with labour, energy, water and financial savings.

Performance assessment in airway management training for nonanesthesiology trainees: an analysis of 4,282 airway procedures performed at a level-1 trauma center.

BACKGROUND: Although the use of an anesthesiology "airway" rotation to train the nonanesthesiologist is commonly employed, little data exist on the utility, clinical exposure, and outcomes of these programs. METHODS: A prospectively collected observational dataset of airway procedures completed by trainees in a 4-week, anesthesiology-based, airway rotation at an academic, level-1 trauma center from July 2010 to September 2012 was reviewed. Prospectively defined data points were collected through an online data tool and included patient demographics, location, date, best laryngoscopic view, and attempt details. At the authors' institution, an attending trauma anesthesiologist is present for all intubation attempts. The primary outcome was first-attempt success. RESULTS: A total of 4,282 self-reported, airway procedures were identified. The median number of procedures performed was 50.4 ± 13.2 (range, 20 to 93; 25th quartile = 41; 75th quartile = 57). Multivariate logistic regression analysis modeling of first-attempt success rate identified two independent predictors of success: rotation week (odds ratio, 1.42; 95% CI, 1.32 to 1.61; P < 0.0001) and number of previous intubation attempts before rotation (odds ratio, 1.23; 95% CI, 1.03 to 1.46; P = 0.02. In addition, the percentage of cases with a self-reported laryngoscopic grade 1 view increased significantly from 61 to 74% (P = 0.015) from week 1 to week 4 of the rotation. CONCLUSIONS: An anesthesiology-based program for airway training of nonanesthesiologists demonstrates improved self-reported, perceived first-attempt success over the course of training with improved ability to visualize glottic structures.

Access to difficult airway equipment and training for rural GP-anaesthetists in Australia: results of a 2012 survey.

INTRODUCTION: In rural Australia, general practitioners (GPs) form the frontline for provision of medical services. Besides responsibilities for primary care via private practice, rural doctors often provide emergency and inpatient services for rural hospitals. The aim of this study was to determine access to difficult airway equipment and training among the GP-anaesthetist cadre in rural Australia. DESIGN: an online survey regarding availability of difficult airway equipment, access to ongoing training and inviting comments on rural anaesthesia in general. SETTING: a questionnaire was distributed to rural doctors in January 2012 via membership databases of the Rural Doctors Association of Australia and state-based Rural Doctor Workforce Agencies. PARTICIPANTS: 293 participants identified as a GP-anaesthetist working in rural Australia (65% response rate). Of these 83% were male, 17% female with the percentage of respondents from each state concordant with the distributions indicated by the 2010 Rural Health Workforce National Minimum Dataset. MAIN OUTCOME MEASURE: closed-ended questions were quantified and open-ended questions analysed to determine issues relevant to GP-anaesthetists. RESULTS: Only 53% of GP-anaesthetists reported access to a difficult airway trolley or box in their facility. Lack of availability of certain airway equipment was reported among GP-anaesthetists, with very few having access to advanced intubation aids such as videolaryngoscopes or fibreoptic devices (flexible fibrescopes and/or malleable fibreoptic stylets). Open-ended questions suggested that GP-anaesthetists desired such aids to manage difficult airways. Only 79% had access to surgical airway or paediatric airway equipment. Of the respondents, 58% reported involvement in prehospital medicine but only 12% had received training in this challenging environment. A formal arrangement for prehospital responses existed for only 7% of respondents. CONCLUSION: Despite the existence of well-publicised algorithms for difficult airway management and the need for specific equipment to manage the difficult airway, Australian GP-anaesthetists report difficulty accessing essential equipment for these infrequent but life-threatening events. This is surprising in the light of recommendations from the Australian and New Zealand College of Anaesthetists. The consequences of difficulty in airway management can be catastrophic. Equipment needs must be balanced against important considerations including ease of use, initial and ongoing training, and cost. Suggestions for affordable equipment and ongoing training for rural GP-anaesthetists are made. The involvement of GP-anaesthetists in prehospital responses occurs in the absence of formal arrangements and with a dearth of training. There is scope to improve rural prehospital responses in Australia, utilising the advanced skills of GP-anaesthetists in resuscitation and airway management.

Multiple airways. Rapid assessment is key for managing numerous patients.

Encountering a situation that necessitates the assessment and management of patients requiring airway management can present a significant challenge. It will require a different thought process and set of decision-making skills that vary from the routine practice of airway management during a single patient encounter. Rapid triaging of the need for airway management is important. Creating a categorization of those patients who simply need supplemental oxygen from those who require assistance with the mechanical opening of the airway, a need for positive-pressure ventilation and those who require protection from aspiration can be a useful starting place for the creation of a treatment plan. Treatment decisions will depend on the amount of equipment and personnel resources that are available. Non-traditional decision procedures and positioning may need to be implemented, such as placing patients in a lateral recumbent position to use gravity to assist in keeping the airway patent. In the setting of multiple patient encounters requiring airway management, it's important to consider the length of time each procedure will take and the amount of equipment that will be required. A rapid securing of the airway by a supraglottic device in suitable patients may be favored over traditional approaches of ETI secondary to the relative complexity of the procedure.

New method for quantitative assessment of airway calibre using a stereovision fibreoptic bronchoscope.

BACKGROUND: We have developed a new bronchoscopy system with two independent lenses at the tip of the device. This enables measurement of object size using the principle of triangulation. This study was performed to assess the accuracy of this system. METHODS: The accuracy of the bronchoscopy system was confirmed by measuring the diameters of four plastic tubes and 36 airway calibres in 12 surgical patients under general anaesthesia. The measured diameters of the tubes and airway tracts were compared with the manufactured diameters of tubes and those measured by high-resolution computed tomography (HRCT)-based virtual bronchoscopy, respectively. RESULTS: Using the new bronchoscope system, tube diameters, 9, 12, 15, and 19 mm, were measured as 9.9 (0.7), 12.8 (1.4), 16.3 (1.6), and 20.1 (2.0) mm, respectively. Airway calibres obtained by a stereovision bronchoscopy and HRCT-based virtual bronchoscopy were 8.66 (4.31) and 9.38 (5.09) mm, respectively. There is a significant correlation between airway calibres with the two measurement methods (r=0.975, P<0.01). CONCLUSIONS: We have confirmed that this new bronchoscopy system could provide relatively accurate quantitative data. This new system may be useful in the clinic to measure airway dimension and lesion sizes such as tumours.

The Difficult Airway Society 'ADEPT' guidance on selecting airway devices: the basis of a strategy for equipment evaluation.

Faced with the concern that an increasing number of airway management devices were being introduced into clinical practice with little or no prior evidence of their clinical efficacy or safety, the Difficult Airway Society formed a working party (Airway Device Evaluation Project Team) to establish a process by which the airway management community within the profession could itself lead a process of formal device/equipment evaluation. Although there are several national and international regulations governing which products can come on to the market and be legitimately sold, there has hitherto been no formal professional guidance relating to how products should be selected (i.e. purchased). The Airway Device Evaluation Project Team's first task was to formulate such advice, emphasising evidence-based principles. Team discussions led to a definition of the minimum level of evidence needed to make a pragmatic decision about the purchase or selection of an airway device. The Team concluded that this definition should form the basis of a professional standard, guiding those with responsibility for selecting airway devices. We describe how widespread adoption of this professional standard can act as a driver to create an infrastructure in which the required evidence can be obtained. Essential elements are that: (i) the Difficult Airway Society facilitates a coherent national network of research-active units; and (ii) individual anaesthetists in hospital trusts play a more active role in local purchasing decisions, applying the relevant evidence and communicating their purchasing decisions to the Difficult Airway Society.