The evolution of a national, advanced airway management simulation-based course for anaesthesia trainees

BACKGROUND

Needs analyses involving patient complaints and anaesthesiologists' confidence levels in difficult airway management procedures in Denmark have shown a need for training in both technical and non-technical skills.

OBJECTIVE

To provide an example of how to design, implement and evaluate a national simulation-based course in advanced airway management for trainees within a compulsory, national specialist training programme.

DESIGN AND RESULTS

A national working group, established by the Danish Society for Anaesthesiology and Intensive Care Medicine, designed a standardised simulation course in advanced airway management for anaesthesiology trainees based on the six-step approach. Learning objectives are grounded in the curriculum and analyses-of-needs (in terms of knowledge, skills and attitudes, including non-technical skills, which encompass the cognitive skills and social skills, necessary for safe and effective performance). A total of 28 courses for 800 trainees have been conducted. Evaluation has been positive and pre and posttests have indicated a positive effect on learning.

CONCLUSION

The course was successfully designed and implemented within the national training programme for trainees. Important factors for success were involvement of all stakeholders, thorough planning, selection of the most important learning objectives, the use of interactive educational methods and training of the facilitators.

Anterior neck soft tissue measurements on computed tomography to predict difficult laryngoscopy: a retrospective study

Predicting difficult laryngoscopy is an essential component of the airway management. We aimed to evaluate the use of anterior neck soft tissue measurements on computed tomography for predicting difficult laryngoscopy and to present a clear measurement protocol. In this retrospective study, 281 adult patients whose tracheas were intubated using a direct laryngoscope for thyroidectomy were enrolled. On computed tomography, the distances from the midpoint of the thyrohyoid membrane to the closest concave point of the vallecular (membrane-to-vallecula distance; dMV), and to the most distant point of the epiglottis (membrane-to-epiglottis distance; dME) were measured, respectively. The extended distances straight to the skin anterior from the dMV and dME were called the skin-to-vallecula distance (dSV) and skin-to-epiglottis distance (dSE), respectively. Difficult laryngoscopy was defined by a Cormack-Lehane grade of > 2. Difficult laryngoscopy occurred in 40 (14%) cases. Among four indices, the dMV showed the highest prediction ability for difficult laryngoscopy with an area under the receiver operating characteristic curve of 0.884 (95% confidence interval 0.841–0.919, P < 0.001). The optimal dMV cut-off value for predicting difficult laryngoscopy was 2.33 cm (sensitivity 75.0%; specificity 93.8%). The current study provides novel evidence that increased dMV is a potential predictive indicator of difficult laryngoscopy.

Factors and Economic Outcomes Associated with Documented Difficult Intubation in the United States

Purpose

Establishing good mechanical ventilation is a critical component and prerequisite to a wide range of surgical and medical interventions. Yet difficulties in intubating patients, and a variety of associated complications, are well documented. The economic burden resulting from difficult intubation (DI), however, is not well understood. The current study examines the economic burden of documented DI during inpatient surgical admissions and explores factors that are associated with DI.

Patients and Methods

Using data from the Premier Healthcare Database, adult patients with inpatient surgical admissions between January 1, 2016 and December 31, 2018 were selected. International Classification of Diseases, Tenth Edition, Clinical Modification (ICD-10-CM) diagnosis codes were used to classify the patients into matched cohorts of DI and non-DI patients.

Results

Patients in the DI group have mean inpatient costs and intensive care unit (ICU) costs that are substantially higher than patients without difficult intubations ($14,468 and $4,029 higher, respectively). Mean hospital length of stay and ICU length of stay were 3.8 days and 2.0 days longer, respectively (all p<0.0001, except ICU cost p=0.0001) in the DI group. Obesity, other chronic conditions, and larger hospital size were significantly associated with DI.

Conclusion

DI is associated with higher average cost and longer average length of stay.

Post-intubation subglottic stenosis: aetiology at the cellular and molecular level

Subglottic stenosis (SGS) is a narrowing of the airway just below the vocal cords. This narrowing typically consists of fibrotic scar tissue, which may be due to a variety of diseases. This review focuses on post-intubation (PI) SGS. SGS can result in partial or complete narrowing of the airway. This narrowing is caused by fibrosis and can cause serious breathing difficulties. It can occur in both adults and children. The pathogenesis of post-intubation SGS is not well understood; however, it is considered to be the product of an abnormal healing process. This review discusses how intubation can change the local micro-environment, leading to dysregulated tissue repair. We discuss how mucosal inflammation, local hypoxia and biomechanical stress associated with intubation can promote excess tissue deposition that occurs during the pathological process of SGS.

COVID-19 may cause an increased incidence of subglottic stenosis (SGS). In this review, the cellular and molecular aetiology of post-intubation SGS is outlined and we discuss how better knowledge of the underlying biology can inform SGS management.https://bit.ly/2RSliRK

Analysis of endotracheal intubation-related judicial precedents in South Korea

Background

Medical malpractice during endotracheal intubation can result in catastrophic complications. However, there are no reports on these severe complications in South Korea. We aimed to investigate the severe complications associated with endotracheal intubation occurring in South Korea, via medicolegal analysis.

Methods

We retrospectively analyzed the closed judicial precedents regarding complications related to endotracheal intubation lodged between January 1994 and June 2020, using the database of the Supreme Court of Korea. We collected clinical and judicial characteristics from the judgments and analyzed the medical malpractices related to endotracheal intubation.

Results

Of 220 potential cases, 63 were included in the final analysis. The most common event location was the operating room (n = 20, 31.7%). All but 3 cases were associated with significant permanent or more severe injury, including 31 deaths. The most common problems were failed or delayed intubation (n = 56, 88.9%). Supraglottic airway device was used in 5.2% (n = 3) cases of delayed or failed intubation. Fifty-one (81%) cases were ruled in favor of the plaintiff in the claims for damages, with a median payment of Korean Won 133,897,845 (38,000,000, 308,538,274). The most common malpractice recognized by the court was that of not attempting an alternative airway technique (n = 32, 50.8%), followed by violation of the duty of explanation (n = 10, 15.9%).

Conclusions

Our results could increase physicians’ awareness of the major complications related to endotracheal intubation and help ensure patient safety.

Wristbands use to identify adult patients with difficult airway: a scoping review

Background

Difficult airway is a clinical situation in which a trained anesthesiologist experiences trouble with facemask ventilation and/or laryngoscopy and/or intubation. Poor identification of at-risk patients has been identified as one of the causes of difficult airway management.

Objectives

We aimed to review the literature regarding the use of wristbands to identify adult patients with known or predicted difficult airway in hospitals.

Methods

We searched Web of Science (WoS), Scopus, MEDLINE and OVID following the stages described by the PRISMA Extension for Scoping Reviews (PRISMA-ScR). We used a combination of MeSH terms and non-controlled vocabulary regarding the use of difficult airway wristbands in adults. Three researchers independently reviewed the full texts and selected the papers to be included based on the inclusion criteria.

Results

Our search generated 334 articles after removing duplicates. After reviewing full text articles, only seven studies were included. Here we found that most were from the United States, in which the authors report the use of in-patients’ wristbands in adults. According to the authors, the use of wristbands is being implemented as a measure of improved quality and safety of in-patients with difficult airway either known or suspected.

Conclusions

The identification with wristbands of a difficult airway at an appropriate time is an identification strategy can have a low cost but a high impact on morbidity. It is pertinent to develop a methodology such as the use of wristbands, that allows a good classification and identification of patients with difficult airway in hospitals from Latin America.

Adverse Event Reporting in Otolaryngology

OBJECTIVES

Adverse events are common occurrences in hospitals that detract from quality of care. There are few data on errors in otolaryngology (ENT) and even fewer data comparing ENT to other services.

METHODS

We retrospectively reviewed adverse event data collected across a regional hospital network from July 2014 to August 2017. We examined categories of adverse events that occurred most commonly in ENT and compared the number of adverse events reported in ENT to those reported across all other departments. Descriptive analysis and the paired t test were used to analyze the data.

RESULTS

Two hundred ninety-one adverse events were reported in ENT departments during the period studied compared to 58,219 events reported across all other specialties. In ENT, the most commonly reported adverse events occurred in the perioperative setting, followed by issues regarding equipment and medical devices and, lastly, airway management. Across all other departments, the most common categories included medication and fluid errors, falls, and safety and security events. ENT departments had significantly higher proportions of perioperative and airway management errors and significantly lower proportions of events related to diagnosis and treatment (P = .004), falls (P < .001), lab results and specimens (P = .001), medication and fluids (P < .001), and safety and security (P < .001).

CONCLUSION

Perioperative and airway management errors occur with a statistically higher frequency in ENT compared to other in-patient and out-patient departments across hospitals. It is important to analyze adverse event reporting in surgical specialties to ensure the development of appropriate quality initiatives.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:509-512, 2021.

Impact of videolaryngoscopy introduction into prehospital emergency medicine practice: a quality improvement project

INTRODUCTION

Advanced airway management is necessary in the prehospital environment and difficult airways occur more commonly in this setting. Failed intubation is closely associated with the most devastating complications of airway management. In an attempt to improve the safety and success of tracheal intubation, we implemented videolaryngoscopy (VL) as our first-line device for tracheal intubation within a UK prehospital emergency medicine (PHEM) setting.

METHODS

An East of England physician-paramedic PHEM team adopted VL as first line for undertaking all prehospital advanced airway management. The study period was 2016-2020. Statistical process control charts were used to assess whether use of VL altered first-pass intubation success, frequency of intubation-related hypoxia and laryngeal inlet views. A survey was used to collect the team's views of VL introduction.

RESULTS

919 patients underwent advanced airway management during the study period. The introduction of VL did not improve first-pass intubation success, view of laryngeal inlet or intubation-associated hypoxia. VL improved situational awareness and opportunities for training but performed poorly in some environments.

CONCLUSION

Despite the lack of objective improvement in care, subjective improvements meant that overall PHEM clinicians wanted to retain VL within their practice.

Risk factors for difficult Laryngeal Mask Airway LMA-Supreme™ (LMAS) placement in adults: a multicentric prospective observational study in an Italian population

BACKGROUND

Supraglottic airway devices (SADs) are precious tools for airway management in both routine and rescue situations; few studies have analyzed the risk factors for their difficult insertion.

METHODS

The aim of this study was to identify the risk factors for difficult insertion for a specific SAD, the Laryngeal Mask Airway LMA-Supreme™ (LMAS). This was a prospective multicentric observational study on a cohort of Italian adult patients receiving general anesthesia for elective surgery. The possible causes of difficulty in LMAS placement (difficulty in insertion or unsatisfactory ventilation) were identified based on literature and on the opinion of international airway management experts. A dedicated datasheet was prepared to collect patients' data, including anthropometric-parameters and parameters for the prediction of difficult airway management, as well as technical choices for the use of LMAS. Data were analyzed to discover the risk factors for difficult LMAS placement and the association between each risk factor and the proportion of incorrect positioning was evaluated through the relative risk and its confidence interval.

RESULTS

Four hundred thirty-two patients were enrolled; seventy required two or more attempts to insert the LMAS; nine required a change of strategy. At multivariate analysis, the following factors were significantly associated with difficult LMAS placement: Mallampati III-IV with either phonation or not; inter-incisor distance < 3 cm; reduced neck mobility; no administration of neuromuscular blocking agents (NMBAs).

CONCLUSIONS

The alignment of the laryngeal and pharyngeal axes seems to facilitate the procedure, together with NMBA administration; on the contrary, Mallampati grade III-IV are associated with difficult LMAS placement.

Effect of simulation-based team training in airway management: a systematic review

Major complications associated with airway management are rare but often have serious consequences. Complications frequently result from failures in communication and teamwork. We performed a systematic review on the effect of simulation-based team training on patient outcomes, healthcare professionals' clinical performance and preparedness for airway management. We included studies with simulation-based team training in airway management as the educational intervention, using any comparator, outcome and design. Two authors independently selected articles and assessed risk of bias using the Medical Education Research Study Quality Instrument and Newcastle-Ottawa Scale-Education. We screened 1248 titles and evaluated 116 full-text articles. Twenty-two studies were included. The Kirkpatrick model for evaluation of training was used to organise outcomes. Four studies reported patient-centred outcomes (Kirkpatrick level 4), and three studies' outcomes related to healthcare professionals' clinical performance (Kirkpatrick level 3). The results were ambiguous and the studies had significant methodological limitations, making it difficult to draw conclusions on the effect of simulation-based team training. To describe preparedness for airway management, we used outcomes related to participants' attitudes or perceptions and outcomes related to knowledge or skills demonstrated in a test setting (Kirkpatrick level 2). Most studies reporting these outcomes were in favour of simulation-based team training, but were prone to bias. We consider the current evidence to be weak and recommend that future research should be based on randomised study designs and patient-centred outcomes.

Oxygenation laryngoscope vs. nasal standard and nasal high flow oxygenation in a technical simulation of apnoeic oxygenation

Background

Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist’s life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control.

Methods

In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min^− 1 via nasal cannula, high flow 90% oxygen application at 20 l·min^− 1 using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min^− 1. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min.

Results

Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p < 0.001 between all groups).

Conclusions

In this technical simulation, oxygenation via oxygenation laryngoscope was more effective than standard oxygen insufflation via nasal cannula, which was more effective than nasal high flow insufflation of 90% oxygen.

Characteristics, physiology and mortality of intubated patients in an emergency care population in sub-Saharan Africa: a prospective cohort study from Kigali, Rwanda

BACKGROUND

Formalised emergency departments (ED) are in early development in sub-Saharan Africa and there are limited data on emergency airway management in those settings. This study evaluates characteristics and outcomes of ED endotracheal intubation, as well as risk factors for mortality, at a teaching hospital in Rwanda.

METHODS

This was a prospective observational study of consecutive patients requiring endotracheal intubation at the University Teaching Hospital of Kigali ED conducted between 1 January and 31 December 2017. A standardised data collection tool was used to record patient demographics, preintubation clinical presentation, indication for intubation, vital signs. medications and equipment used, and periintubation complications. The primary outcome was in-hospital mortality. Univariate associations were determined for risks of mortality.

RESULTS

Of 198 intubations were analysed, 72.7% were male and the median age was 35 years (IQR 23-51). Airway protection was the most common indication for intubation (73.7%). Rapid sequence intubation was performed in 74.2% of cases; sedative-only facilitated intubation in 20.6% and non-drug assisted in 5.2%. The most common agents used were Ketamine for sedation (85.4%) and vecuronium for paralysis (65.7%). All patients were successfully intubated within three attempts, 85.4% on the first attempt. During intubation, 23.1% of patients experienced hypoxia, 6.7% aspiration and 3.6% cardiac arrest. Median ED length of stay was 2 days. Outcome data were available for 164 patients of whom 67.7% died. Bonferroni-corrected univariate analysis demonstrated that mortality was associated with higher postintubation shock index (p=0.0007) and lower postintubation systolic blood pressure (SBP) (p=0.0006).

CONCLUSION

The first-attempt and overall success rates for intubation in this ED in Rwanda were comparable to those in high-income countries (HIC). Mortality postintubation is associated with lower postintubation SBP and higher postintubation shock index. The high complication and mortality rates suggest the need for better resources and training to address differences in compared with HIC.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 2. Planning and implementing safe management of the patient with an anticipated difficult airway

PURPOSE

Since the last Canadian Airway Focus Group (CAFG) guidelines were published in 2013, the published airway management literature has expanded substantially. The CAFG therefore re-convened to examine this literature and update practice recommendations. This second of two articles addresses airway evaluation, decision-making, and safe implementation of an airway management strategy when difficulty is anticipated.

SOURCE

Canadian Airway Focus Group members, including anesthesia, emergency medicine, and critical care physicians were assigned topics to search. Searches were run in the Medline, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL databases. Results were presented to the group and discussed during video conferences every two weeks from April 2018 to July 2020. These CAFG recommendations are based on the best available published evidence. Where high-quality evidence is lacking, statements are based on group consensus.

FINDINGS AND KEY RECOMMENDATIONS

Prior to airway management, a documented strategy should be formulated for every patient, based on airway evaluation. Bedside examination should seek predictors of difficulty with face-mask ventilation (FMV), tracheal intubation using video- or direct laryngoscopy (VL or DL), supraglottic airway use, as well as emergency front of neck airway access. Patient physiology and contextual issues should also be assessed. Predicted difficulty should prompt careful decision-making on how most safely to proceed with airway management. Awake tracheal intubation may provide an extra margin of safety when impossible VL or DL is predicted, when difficulty is predicted with more than one mode of airway management (e.g., tracheal intubation and FMV), or when predicted difficulty coincides with significant physiologic or contextual issues. If managing the patient after the induction of general anesthesia despite predicted difficulty, team briefing should include triggers for moving from one technique to the next, expert assistance should be sourced, and required equipment should be present. Unanticipated difficulty with airway management can always occur, so the airway manager should have a strategy for difficulty occurring in every patient, and the institution must make difficult airway equipment readily available. Tracheal extubation of the at-risk patient must also be carefully planned, including assessment of the patient's tolerance for withdrawal of airway support and whether re-intubation might be difficult.

First-attempt success rate of video laryngoscopy in small infants (VISI): a multicentre, randomised controlled trial

BACKGROUND

Orotracheal intubation of infants using direct laryngoscopy can be challenging. We aimed to investigate whether video laryngoscopy with a standard blade done by anaesthesia clinicians improves the first-attempt success rate of orotracheal intubation and reduces the risk of complications when compared with direct laryngoscopy. We hypothesised that the first-attempt success rate would be higher with video laryngoscopy than with direct laryngoscopy.

METHODS

In this multicentre, parallel group, randomised controlled trial, we recruited infants without difficult airways abnormalities requiring orotracheal intubation in operating theatres at four quaternary children's hospitals in the USA and one in Australia. We randomly assigned patients (1:1) to video laryngoscopy or direct laryngoscopy using random permuted blocks of size 2, 4, and 6, and stratified by site and clinician role. Guardians were masked to group assignment. The primary outcome was the proportion of infants with a successful first attempt at orotracheal intubation. Analysis (modified intention-to-treat [mITT] and per-protocol) used a generalised estimating equation model to account for clustering of patients treated by the same clinician and institution, and adjusted for gestational age, American Society of Anesthesiologists physical status, weight, clinician role, and institution. The trial is registered at ClinicalTrials.gov, NCT03396432.

FINDINGS

Between June 4, 2018, and Aug 19, 2019, 564 infants were randomly assigned: 282 (50%) to video laryngoscopy and 282 (50%) to direct laryngoscopy. The mean age of infants was 5·5 months (SD 3·3). 274 infants in the video laryngoscopy group and 278 infants in the direct laryngoscopy group were included in the mITT analysis. In the video laryngoscopy group, 254 (93%) infants were successfully intubated on the first attempt compared with 244 (88%) in the direct laryngoscopy group (adjusted absolute risk difference 5·5% [95% CI 0·7 to 10·3]; p=0·024). Severe complications occurred in four (2%) infants in the video laryngoscopy group compared with 15 (5%) in the direct laryngoscopy group (-3·7% [-6·5 to -0·9]; p=0·0087). Fewer oesophageal intubations occurred in the video laryngoscopy group (n=1 [<1%]) compared with in the direct laryngoscopy group (n=7 [3%]; -2·3 [-4·3 to -0·3]; p=0·028).

INTERPRETATION

Among anaesthetised infants, using video laryngoscopy with a standard blade improves the first-attempt success rate and reduces complications.

FUNDING

Anaesthesia Patient Safety Foundation, Society for Airway Management, and Karl Storz Endoscopy.

The Lost Airway

Management of the unanticipated difficult airway is one of the most relevant and challenging crisis management scenarios encountered in clinical anesthesia practice. Several guidelines and approaches have been developed to assist clinicians in navigating this high-acuity scenario. In the most serious cases, the clinician may encounter a failed airway that results from failure to ventilate an anesthetized patient via facemask or supraglottic airway or intubate the patient with an endotracheal tube. This dreaded cannot intubate, cannot oxygenate situation necessitates emergency invasive access. This article reviews the incidence, management, and complications of the failed airway and training issues related to its management.

Difficult and failed intubation in the first 4000 incidents reported on webAIRS

A review of the first 4000 reports to the webAIRS anaesthesia incident reporting database was performed to analyse cases reported as difficult or failed intubation. Patient, task, caregiver and system factors were evaluated. Among the 4000 reports, there were 170 incidents of difficult or failed intubation. Difficult or failed intubation incidents were most common in the 40-59 years age group. More than half of cases were not predicted. A total of 40% involved patients with a body mass index >30 kg/m² and 41% involved emergency cases. A third of the reports described multiple intubation attempts. Of the reports, 18% mentioned equipment problems including endotracheal tube cuff rupture, laryngoscope light failure, dysfunctional capnography and delays with availability of additional equipment to assist with intubation. Immediate outcomes included 40 cases of oxygen desaturation below 85%; of these cases, four required cardiopulmonary resuscitation. The majority of the incidents resulted in no harm or minor harm (45%). However, 12% suffered moderate harm, 3.5% severe harm and there were three deaths (although only one related to the airway incident). Despite advances and significant developments in airway management strategies, difficult and failed intubation still occurs. Although not all incidents are predictable, nor are all preventable, the information provided by this analysis might assist with future planning, preparation and management of difficult intubation.

A comparison of ramping position and sniffing position during endotracheal intubation: a systematic review and meta-analysis

Objectives

Positioning during endotracheal intubation (ETI) is critical to ensure its success. We aimed to determine if the ramping position improved laryngeal exposure and first attempt success at intubation when compared to the sniffing position.

Methods

PubMed, EMBASE, and Cochrane CENTRAL databases were searched systematically from inception until January 2020. Our primary outcomes included laryngeal exposure as measured by Cormack-Lehane Grade 1 or 2 (CLG 1/2), CLG 3 or 4 (CLG 3/4), and first attempt success at intubation. Secondary outcomes were intubation time, use of airway adjuncts, ancillary maneuvers, and complications during ETI.

Results

Seven studies met our inclusion criteria, of which 4 were RCTs and 3 were cohort studies. The meta-analysis was conducted by pooling the effect estimates for all 4 included RCTs (n = 632). There were no differences found between ramping and sniffing positions for odds of CLG 1/2, CLG 3/4, first attempt success at intubation, intubation time, use of ancillary airway maneuvers, and use of airway adjuncts, with evidence of high heterogeneity across studies. However, the ramping position in surgical patients is associated with increased likelihood of CLG 1/2 (OR = 2.05, 95% CI 1.26 to 3.32, p = 0.004) and lower likelihood of CLG 3/4 (OR = 0.49, 95% CI 0.30 to 0.79, p = 0.004), moderate quality of evidence.

Conclusion

Our meta-analysis demonstrated that the ramping position may benefit surgical patients undergoing ETI by improving laryngeal exposure. Large scale well designed multicentre RCTs should be carried out to further elucidate the benefits of the ramping position in the surgical and intensive care unit patients.

A Prospective Audit of Airway Code Activations and Adverse Events in Two Tertiary Hospitals

INTRODUCTION

Airway management outside the operating room can be challenging, with an increased risk of difficult intubation, failed intubation and complications. We aim to examine airway practices, incidence of difficult airway and complications associated with airway code (AC) activation.

METHODS

We conducted a prospective audit of AC activations and adverse events in two tertiary hospitals in Singapore. We included all adult patients outside the operating room who underwent emergency intubation by the AC team after AC activation. Adult patients who underwent emergency intubation without AC activation or before the arrival of the AC team were excluded. Data were collected and documented by the attending anaesthetists in a standardised survey form shortly after their responsibilities were completed.

RESULTS

The audit was conducted over a 20-month period from July 2016 to March 2018, during which a total of 224 airway activations occurred. Intubation was successful in 218 of 224 AC activations, giving a success rate of 97.3%. Overall, 48 patients (21.4%) suffered an adverse event. Thirteen patients (5.8%) had complications when intubation was carried out by the AC team compared with 35 (21.5%) by the non-AC team.

CONCLUSION

Dedicated AC team offers better success rate for emergency tracheal intubation. Non-AC team attempted intubation in the majority of the cases before the arrival of the AC team. Increased intubation attempts are associated with increased incidence of adverse events. Equipment and patient factors also contributed to the adverse events. A multidisciplinary programme including the use of supraglottic devices may be helpful to improve the rate of success and minimise complications.

[A comparison of ramping position and sniffing position during endotracheal intubation: a systematic review and meta-analysis]

OBJECTIVES

Positioning during endotracheal intubation (ETI) is critical to ensure its success. We aimed to determine if the ramping position improved laryngeal exposure and first attempt success at intubation when compared to the sniffing position.

METHODS

PubMed, EMBASE, and Cochrane CENTRAL databases were searched systematically from inception until January 2020. Our primary outcomes included laryngeal exposure as measured by Cormack-Lehane Grade 1 or 2 (CLG 1/2), CLG 3 or 4 (CLG 3/4), and first attempt success at intubation. Secondary outcomes were intubation time, use of airway adjuncts, ancillary maneuvers and complications during ETI.

RESULTS

Seven studies met our inclusion criteria, of which 4 were RCTs and 3 were cohort studies. The meta-analysis was conducted by pooling the effect estimates for all 4 included RCTs (n=632). There were no differences found between ramping and sniffing positions for odds of CLG 1/2, CLG 3/4, first attempt success at intubation, intubation time, use of ancillary airway maneuvers and use of airway adjuncts, with evidence of high heterogeneity across studies. However, the ramping position in surgical patients is associated with increased likelihood of CLG 1/2 (OR=2.05, 95% CI 1.26 to 3.32, p=0.004) and lower likelihood of CLG 3/4 (OR=0.49, 95% CI 0.30 to 0.79, p=0.004), moderate quality of evidence.

CONCLUSION

Our meta-analysis demonstrated that the ramping position may benefit surgical patients undergoing ETI by improving laryngeal exposure. Large-scale well-designed multicentre RCTs should be carried out to further elucidate the benefits of the ramping position in the surgical and intensive care unit patients.

Evaluating the utility of pre-operative airway assessment for intubation management in difficult airway patients

OBJECTIVE

To assess intubation management in difficult airway patients by performing a multidisciplinary pre-operative examination of the airway using a flexible fibre-optic laryngoscope.

METHODS

Patients with a known but stable difficult airway were evaluated prior to surgery in the pre-operative holding suite by both an ENT surgeon and an anaesthesiologist via a fibre-optic laryngeal examination.

RESULTS

Performing a pre-operative fibre-optic examination of the difficult airway led to a change in intubation strategy in 6 out of 12 cases. Intubation 'first-pass' success occurred in 9 out of 12 (75 per cent) of our patients.

CONCLUSION

By performing a multidisciplinary airway examination immediately prior to surgery, a safe plan to intubate on the initial attempt was developed. This resulted in improved first-pass success at intubation compared to historical data.

Anesthetic considerations for tracheobronchial surgery

Tracheobronchial pathology can be related to trauma, infection, tumor, or a combination of these. Per definition, planning for tracheobronchial surgery can be complicated by the overlap of anesthesiological interests in airway management and the primary surgical field. Therefore, following a detailed description of the stenosis, management of tracheobronchial surgery requires an interdisciplinary discussion and individualized planning of the procedure. There are several options for intraoperative ventilation depending on the exact localization of the defect. Hence, different tubes and ventilation techniques from cross-field ventilation, to jet ventilation, or even spontaneous breathing under regional anesthesia, have to be discussed. Moreover, an innovative ventilation mode called flow-controlled ventilation (FVC) has been developed, which allows to apply standard tidal volumes through a narrow-bore endotracheal tube. In addition, the Ventrain has been developed as an emergency device following the same technique of an active expiration based on the Venturi principle and a controlled gas flow. In critical situations, it allows even ventilation through the working channel of a bronchoscope. Overall, tracheobronchial surgery is performed under total intravenous anesthesia and the aim of an early extubation at the end of surgery. Airway management has to be discussed and planned between surgeon and anesthesiologist. All of the steps of the procedure need constant and clear communication.

Usage of airway ultrasound as an assessment and prediction tool of a difficult airway management

Airway assessment is important in emergency airway management. A difficult airway can lead to life-threatening complications. A perfect airway assessment tool does not exist and unanticipated difficulty will remain unforeseen. Current bedside clinical predictors of the difficult airway are unreliable but airway ultrasound can be used as an adjunct to predict difficult laryngoscopy. We report a case of a 60-year-old man presenting to the emergency department with shortness of breath, hoarseness of voice and stridor. Airway ultrasound revealed a large laryngeal mass narrowing the upper airway, extending to bilateral vocal cords with heterogenous echogenicity. In view of impending complete upper airway obstruction, acute respiratory distress and airway ultrasound findings, urgent emergency tracheostomy was chosen as definitive airway over endotracheal intubation or surgical cricothyroidotomy. Point of care ultrasound (POCUS) was used to evaluate this patient with severe upper airway obstruction. A laryngeal mass was detected by ultrasound and this pointed towards the presence of a difficult airway. POCUS was a good non-invasive tool used for airway assessment in this uncooperative and unstable patient. Ultrasound predictors of the difficult airway include the inability to visualize the hyoid bone, short hyomental distance ratio, high pretracheal anterior neck thickness and large tongue size. Besides airway assessment, ultrasound can also help to predict endotracheal tube size, confirm intubation and guide emergency airway procedures such as cricothyroidotomy and tracheostomy. Point of care ultrasound of the upper airway can be used in airway assessment to identify distorted airway anatomy, pathological lesions and guide treatment decisions.

General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multicentre observational study

There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients' (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16-22) and failed intubation in 1 in 312 (95%CI 1 in 169-667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%).

Radiological indicators to predict the application of assistant intubation techniques for patients undergoing cervical surgery

Background

We aimed to distinguish the preoperative radiological indicators to predict the application of assistant techniques during intubation for patients undergoing selective cervical surgery.

Methods

A total of 104 patients were enrolled in this study. According to whether intubation was successfully accomplished by simple Macintosh laryngoscopy, patients were divided into Macintosh laryngoscopy group (n = 78) and Assistant technique group (n = 26). We measured patients’ radiographical data via their preoperative X-ray and MRI images, and compared the differences between two groups. Binary logistic regression model was applied to distinguish the meaningful predictors. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to describe the discrimination ability of indicators. The highest Youden’s index corresponded to an optimal cut-off value.

Results

Ten variables exhibited significant statistical differences between two groups (P <  0.05). Based on logistic regression model, four further showed correlation with the application of assistant techniques, namely, perpendicular distance from hard palate to tip of upper incisor (X2), atlanto-occipital gap (X9), angle between a line passing through posterior-superior point of hard palate and the lowest point of the occipital bone and a line passing through the anterior-inferior point and the posterior-inferior point of the second cervical vertebral body (Angle E), and distance from skin to hyoid bone (MRI 7). Angle E owned the largest AUC (0.929), and its optimal cut-off value was 19.9° (sensitivity = 88.5%, specificity = 91.0%). the optimal cut-off value, sensitivity and specificity of other three variables were X2 (30.1 mm, 76.9, 76.9%), MRI7 (16.3 mm, 69.2, 87.2%), and X9 (7.3 mm, 73.1, 56.4%).

Conclusions

Four radiological variables possessed potential ability to predict the application of assistant intubation techniques. Anaesthesiologists are recommended to apply assistant techniques more positively once encountering the mentioned cut-off values.

Low skill fibreoptic intubation using i-gel™ and air-Q™ in simulated difficult airways: A randomised study in manikin and in patients

Background:

Fibreoptic intubation via a supraglottic device (SAD) is ‘low skill fibreoptic intubation’ (LSFOI). ‘Standard’ second generation SADs (i-gelTM) have a gastric port. ‘Specialised’ second generation SADs (air-QTM) are designed to facilitate LSFOI and have wider ventilation ports. Our hypothesis was that performance of LSFOI differs between i-gelTM and air-QTM in a manikin with a simulated difficult airway.

Methods:

Our primary outcome was fibreoptic intubation success rate. Our secondary outcomes included SAD insertion and LSFOI times. A difficult airway was simulated by applying a hard cervical collar to a manikin. Anaesthetists performed LSFOI serially using both SADs in a random sequence. In the manikin study, 80 anaesthetists were recruited. To test the robustness of the conclusion from our manikin study, we repeated the study in 22 anaesthetised patients. Patients were fitted with the same cervical collar and randomly allocated to either devices. We used McNemar’s statistical test to analyse our primary outcome of successful intubations and paired nominal data. A Wilcoxon signed-ranks test was used to analyse nonparametric paired data and a Mann–Whitney U test was used for unpaired data analysis where appropriate. A p-value of <0.05 was considered statistically significant.

Results:

In the manikin study, the i-gelTM was superior to the air-QTM for successful tracheal intubation (98.8% vs 83.8%, respectively; p=0.002) and LSFOI times (34.0 s vs 36.0 s, respectively; p=0.012). In the patient study, LSFOI success rates were not significantly different between i-gelTM and air-QTM (100% vs 91.6%, respectively; p=0.545) but intubation times were shorter (52.5 s vs 60.0 s, respectively; p=0.036).

Conclusion:

In conclusion, we obtained LSFOI success rates for the i-gelTM or air-QTM of 98.8% and 83.8% respectively in a manikin; and 100% and 91.6% respectively in patients. It is in fact ‘low skill’ as many participants were successful despite no prior experience with LSFOI. The i-gelTM is superior for LSFOI compared with the air-QTM. This is despite being a ‘standard’ second generation SAD as compared to a ‘specialised’ second generation SAD (air-QTM).

Trial Registration:

The manikin and patient studies were conducted after being approved by the SingHealth Centralised Institutional Review Board (CRB reference number 2014/2039 and 2016/2069, respectively). The patient study was registered at ClinicalTrials.gov (ID: NCT02663843).

Sternomental Distance Ratio as a Predictor of Difficult Laryngoscopy: A Prospective, Double-Blind Pilot Study

Background:

No single test has shown to be an accurate predictor of difficult laryngoscopy.

Aims:

This study aims to evaluate the effectiveness of the ratio of the sternomental distance (SMD) in neutral and full neck extension position SMD ratio (SMDR) as a predictor of difficult laryngoscopy and any need of assisted intubation.

Settings and Design:

Prospective, double-blind pilot study.

Materials and Methods:

This study included 221 consecutive adult patients scheduled to undergo elective surgery under general anesthesia. Physical and airway characteristics, SMDR, difficult laryngoscopy (using Cormack/Lehane [C/L] scale), and any kind of assisted intubation were assessed.

Statistical Analysis:

The optimal cutoff point for SMDR was identified using receiver operating characteristic (ROC) analysis. The association between SMDR and the intubation method was evaluated through multiple logistic regression analysis.

Results:

A SMDR below 1.55 led in 33% of the cases to assisted intubation and 33%–53% of C/L III–IV glottic views for McCoy and Macintosh blades, respectively. On the other hand, SMDR above 1.9 led to no C/L IV glottic views for both blades and 4% and 11% C/L III views glottic views for McCoy and Macintosh, respectively. The best sensitivity and specificity cutoff point as defined by the ROC curve was identified for an SMDR value of 1.7 (area[s] under the curve: 0.815; 95% confidence interval: 0.743–0.887). Assisted intubation rates were significantly higher in patients with an SMDR inferior to 1.7 (30.5% compared to 3.5%, P < 0.001).

Conclusions:

SMDR is a simple, objective, and easy to perform test. The present study indicates that SMDR may be helpful in predicting difficult laryngoscopy and assisted intubation.

Securing the Airway in Maxillofacial Trauma Patients: A Systematic Review of Techniques

Study Design

The present study is a systematic review of the literature.

Objective

The goal of this study is to review our experience and the current literature on airway management techniques in maxillofacial trauma.

Methods

Independent searches of the PubMed and MEDLINE databases were performed from January 1, 2019 to February 1, 2019. Articles from the period of 2008 to 2018 were collected. All studies which described both airway management and maxillofacial trauma using the Boolean method and relevant search term combinations, including "maxillofacial," "trauma," and "airway," were considered.

Results

A total of 452 relevant articles in total were identified. Articles meeting inclusion criteria by abstract review included 68 total articles, of which 16 articles were focused on airway management techniques for maxillofacial trauma in the general population and were deemed appropriate for inclusion in the literature review.

Conclusions

Establishing an effective and stable airway in patients with maxillofacial trauma is of paramount concern. In both the acute setting and during delayed reconstruction, special considerations must be taken when securing a reliable airway in this patient population. The present article provides techniques for securing the airway and algorithms for utilization of these techniques, including both during the initial evaluation and the definitive operative management.

The role of ultrasound in front-of-neck access for cricothyroid membrane identification: A systematic review

PURPOSE

Conventional palpation techniques for cricothyroid membrane (CTM) identification are inaccurate and unreliable. Ultrasound plays a multi-faceted role in airway management, however there is limited literature around its use for CTM identification prior to cricothyrotomies. This review sought to compare ultrasound to palpation in the general population, identify its indications in subjects with ill-defined neck anatomy, and determine its role in defining neck anatomy.

METHODS

Two reviewers independently assessed titles, abstracts and full-text English articles through the Ovid Medline and EMBASE databases. Studies related to ultrasound for CTM assessment and/or cricothyrotomy in subjects older than 12 years were included.

RESULTS

Fourteen studies were selected. Compared to palpation, ultrasound has greater accuracy, but longer CTM identification times in those with normal airway anatomy. Interestingly, ultrasound offers comparable times to palpation in patients with difficult airways. Ultrasound also helps define anatomical parameters in the neutral and extended neck positions thereby underscoring the importance of neck positioning during cricothyrotomies and confirming consensus-based incision recommendations set by the Difficult Airway Society.

CONCLUSION

Ultrasound appears to be superior to palpation for CTM localization especially in those with difficult airway anatomy and objectively defines neck anatomy. Its pre-emptive use should be incorporated during difficult airway management.

Intubation in burns patients: a 5-year review of the Manchester regional burns centre experience

Despite criteria to guide intubation from the American Burn Association (ABA), concerns remain regarding over-intubation of burns patients. The purpose of this study was to review appropriateness of intubation at a UK regional burns centre over a 5-year period. A 5-year retrospective review of adult patients admitted to the Manchester Burns Centre who underwent intubation at or prior to admission was performed. Intubations for non-burn indications or burns >40%TBSA were excluded. Patient demographic and burn characteristics data were extracted from medical records. Indications for intubation were compared to ABA and Denver criteria. 47 patients were identified, of which 40 met inclusion criteria for analysis. 72.5% and 95% of these patients met ABA or Denver criteria respectively. 30.8% of patients were extubated within 48 h. 50% patients extubated within 48 h had ≤1 indication for intubation or negative laryngoscopy. Complications related to intubation and ventilation were noted in 37.5% of patients, with ventilation associated pneumonia (VAP) being the most common occurring in 27.5%. 95% of patients fulfilled recognised criteria for intubation. However, 30% were extubated within 48 h, suggesting potentially avoidable intubation. This study suggests current intubation criteria may over-estimate risk of airway compromise and supports results from non-UK studies that a proportion of patients may be suitable for close observation rather than early intubation.

Comparison of Glidescope® Go™, King Vision™, Dahlhausen VL, I‑View™ and Macintosh laryngoscope use during difficult airway management simulation by experienced and inexperienced emergency medical staff: A randomized crossover manikin study

Background

In pre-hospital emergency care, video laryngoscopes (VLs) with disposable blades are preferably used due to hygienic reasons. However, there is limited existing data on the use of VLs with disposable blades by emergency medical staff. Therefore, the aim of this study was to compare the efficacy of four different VLs with disposable blades and the conventional standard Macintosh laryngoscope, when used by anesthetists with extensive previous experience and paramedics with little previous experience in endotracheal intubation (ETI) in a simulated difficult airway.

Methods

Fifty-eight anesthetists and fifty-four paramedics participated in our randomized crossover manikin trial. Each performed ETI with the new Glidescope^® Go^™, the Dahlhausen VL, the King Vision^™, the I-View^™ and the Macintosh laryngoscope. “Time to intubate” was the primary endpoint. Secondary endpoints were “time to vocal cords”, “time to ventilate”, overall success rate, number of intubation attempts and optimization maneuvers, Cormack-Lehane score, severity of dental compression and subjective impressions.

Results

The Glidescope^® Go^™, the Dahlhausen VL and the King Vision^™ provided superior intubation conditions in both groups without affecting the number of intubation attempts or the time required for successful intubation. When used by anesthetists with extensive experience in ETI, the use of VLs did not affect the overall success rate. In the hands of paramedics with little previous experience in ETI, the failure rate with the Macintosh laryngoscope (14.8%) decreased to 3.7% using the Glidescope^® Go^™ and the Dahlhausen VL. Despite the advantages of hyperangulated video laryngoscopes, the I-View^™ performed worst.

Conclusions

VLs with hyperangulated blades facilitated ETI in both groups and decreased the failure rate by an absolute 11.1% when used by paramedics with little previous experience in ETI. Our results therefore suggest that hyperangulated VLs could be beneficial and might be the method of choice in comparable settings, especially for emergency medical staff with less experience in ETI.

Efficacy and safety of videolaryngoscopy versus direct laryngoscopy in paediatric intubation: A meta-analysis of 27 randomized controlled trials

OBJECTIVE

Anatomical and physiological differences in paediatric and adult airways make intubation of paediatric patients a challenge. This study aimed to compare the efficacy and safety of video laryngoscopy (VL) to direct laryngoscopy (DL) on intubation outcomes in paediatric patients.

DESIGN

Systematic review and meta-analysis.

SETTING

Operating room.

PATIENTS

Paediatric patients who needed tracheal intubation.

INTERVENTION

Video laryngoscopy or direct laryngoscopy.

MEASUREMENTS

Electronic searches in PubMed, Embase, and the Cochrane Library were performed to identify relevant randomized controlled trials published through January 2020. Outcomes included time to intubate, intubation failure at first attempt, Cormack-Lehane laryngeal view grade, intubation difficulty scale (IDS), percentage of glottic opening score (POGO), optimal external laryngeal manipulation (OLEM), and complications. Relative risks and weighted mean difference (WMD), with 95% CI, were employed to calculate summary results using a random-effects model.

MAIN RESULTS

Overall, 27 trials including 2461 paediatric patients were analysed. Children with video laryngoscopy intubation required longer time to intubate than direct laryngoscopy intubation (WMD 3.41, 95% CI: 1.29-5.53, P = 0.002), whereas infants receiving video laryngoscopy and direct laryngoscopy intubation experienced similar time to intubate (WMD 1.72, 95% CI: -1.09-4.54, P = 0.230). No significant differences were observed on intubation failure at first attempt between video laryngoscopy and direct laryngoscopy intubations in children and infants, respectively. Video laryngoscopy improved the POGO and intubation trauma but not Cormack-Lehane laryngeal view grade, IDS, external laryngeal manipulation, hoarseness, or oxygen desaturation.

CONCLUSIONS

Compared with direct laryngoscopy intubation, there were no benefits for paediatric patients with video laryngoscopy on time to intubate and failure at first attempt, but there were benefits with regard to POGO and intubation trauma.

Study of early warning for desaturation provided by Oxygen Reserve Index in obese patients

Acute hemoglobin desaturation can reflect rapidly decreasing PaO₂. Pulse oximetry saturation (SpO₂) facilitates hypoxia detection but may not significantly decrease until PaO₂ < 80 mmHg. The Oxygen Reserve Index (ORI) is a unitless index that correlates with moderately hyperoxic PaO₂. This study evaluated whether ORI provides added arterial desaturation warning in obese patients. This IRB approved, prospective, observational study obtained written informed consent from Obese (body mass index (BMI) kg m^-2; 30 < BMI < 40) and Normal BMI (19 < BMI < 25) adult patients scheduled for elective surgery requiring general endotracheal anesthesia. Standard monitors and an ORI sensor were placed. Patient's lungs were pre-oxygenated with 100% FiO₂. After ORI plateaued, general anesthesia was induced, and endotracheal intubation accomplished using a videolaryngoscope. Patients remained apneic until SpO₂reached 94%. ORI and SpO₂ were recorded continuously. Added warning time was defined as the difference between the time to SpO₂ 94% from ORI alarm start or from SpO₂ 97%. Data are reported as median; 95% confidence interval. Complete data were collected in 36 Obese and 36 Normal BMI patients. ORI warning time was always longer than SpO₂ warning time. Added warning time provided by ORI was 46.5 (36.0-59.0) seconds in Obese and 87.0 (77.0-109.0) seconds in Normal BMI patients, and was shorter in Obese than Normal BMI patients difference 54.0 (38.0-74.0) seconds (p < 0.0001). ORI provided what was felt to be clinically significant added warning time of arterial desaturation compared to SpO₂. This added time might allow earlier calls for help, assistance from other providers, or modifications of airway management.Trial registration ClinicalTrials.gov NCT03021551.

Mortality and Morbidity in Office-Based General Anesthesia for Dentistry in Ontario

Our objective was to estimate the prevalence of mortality and serious morbidity for office-based deep sedation and general anesthesia (DS/GA) for dentistry in Ontario from 1996 to 2015. Data were collected retrospectively in 2 phases. Phase I involved the review of incidents, and phase II involved a survey of DS/GA providers. In phase I, cases involving serious injury or death for dentistry under DS/GA, sourced from the Office of the Chief Coroner of Ontario and from the Royal College of Dental Surgeons of Ontario (RCDSO), were reviewed. Phase II involved a survey of all RCDSO-registered providers of DS/GA in which they were asked to estimate the number of DS/GAs administered in 2015 and the number of years in practice since 1996. Clinician data were pooled to establish an overall number of DS/GAs administered in dental offices in Ontario from 1996 to 2015. Prevalence was calculated using phase I (numerator) and phase II (denominator) findings. The estimated prevalence of mortality in the 20-year period from 1996 to 2015 was 3 deaths in 3,742,068 cases, with an adjusted mortality rate of 0.8 deaths per 1 million cases. The estimated prevalence of serious morbidity was 1 injury in 3,742,068 cases, which adjusts to a serious morbidity rate of 0.25 per 1 million cases. The mortality rate found in this study was slightly lower than those published by earlier studies conducted in Ontario. The risk of serious morbidity was found to be low and similar to other studies investigating morbidity in office-based dental anesthesia.

Ultrasound for diagnosing new difficult laryngoscopy indicator: a prospective, self-controlled, assessor blinded, observational study

Background:

Unpredictable difficult laryngoscopy (DL) remains a challenge for anesthesiologists, especially when difficult ventilation occurs during standard laryngoscopy. Accurate airway assessment should always be performed, but the common airway assessment methods only perform superficial screening. Thus, the deep laryngopharyngeal anatomy may not be evaluated. Ultrasound-based airway assessment has been recently proposed as a useful, simple, and non-invasive bedside tool as an adjunct to clinical methods, which may facilitate identification of DL. The present study aimed to determine the correlation between ultrasound-measured indicators and DL.

Methods:

Patients undergoing elective surgery under general anesthesia with tracheal intubation were enrolled. Ultrasonic airway assessments were performed before anesthesia induction. Ultrasound diagnostic indicators included the thickness and width of the base of the tongue, the angle between the epiglottis and glottis, the length of the thyrohyoid membrane, and the thickness of the lateral pharyngeal wall. A score of ≥3 in the Modified Cormack-Lehane Scoring System was used as a standard of DL and was also applied to divide patients into DL and non-DL groups. The area under the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic ability of various diagnostic indicators.

Results:

A total of 499 patients were enrolled into non-DL and DL groups comprising 452 (452/499, 90.6%) and 47 (47/499, 9.4%) patients, respectively. One ultrasonic diagnoses indicator correlated with DL, namely, the angle between the epiglottis and glottis. When the angle between the epiglottis and glottis was 50°, the area under the ROC curve was maximum (0.902), and the best sensitivity (81%) and specificity (89%) were achieved.

Conclusions:

Airway ultrasounds should be considered to identify DL. The ultrasonic angle measured between the epiglottis and glottis is highly associated with DL, which may occur when the angle is less than 50°.

Clinical trial registration:

ChiCTR-DDT-13004102, http://www.chictr.org.cn/showproj.aspx?proj=5465

Ultrasonography for predicting a difficult laryngoscopy. Getting closer

Our objective was to evaluate the usefulness of five ultrasound measurements to predict a difficult laryngoscopy (DL). Prospective observational study. 50 patients underwent scheduled surgery under general anesthesia with orotracheal intubation with classical laryngoscopy at the University Hospital of Jaén (Spain). Sociodemographic variables, classic preintubation screening tests and ultrasound measurements of the neck soft tissue from skin to hyoid (DSH), epiglottis (DSE) and glottis (DSG) were obtained, as well as two measurements derived from the above: DSH + DSE and DSE - DSG. The relationship between a DL and ultrasound measurements was evaluated using t student test. The ROC Curve was used to establish the diagnostic accuracy of ultrasound measurements to discriminate a DL and logistic regression was used to establish a cut-off point. Multivariate analysis was performed to assess the impact of these measures in clinical practice. Patients with DL showed greater thickness of DSE (2.9 ± 0.46 cm vs 2.32 ± 0.54 cm; p = 0.001), DSH + DSE (4.25 ± 0.45 cm vs 3.62 ± 0.77 cm; p = 0.001) and DSE - DSG (1.83 ± 0.54 cm vs 1.24 ± 0.46 cm; p = 0.001) than those with an easy laryngoscopy. DSE and DSE - DSG had the highest diagnostic accuracy for DL with an area under the ROC curve of 0.79 [95%IC 0.66-0.92] and 0.82 [95%IC 0.68-0.96], respectively. It was established that DSE ≥ 3 cm, could predict a DL with a positive predictive value (PPV) of 69.23% [95%CI 40.3-98.2], and DSE - DSG ≥ 1.9 cm would do so with a PPV of 78.57% [95%CI 53.31-100%]. The multivariate analysis endorsed that DSE and DSE - DSG combined with classic tests (the Modified Mallampati score, the thyromental distance and the upper lip bite test) improved the preoperative detection of a DL. The inclusion of DSE and DSE - DSG in a multivariate model with classic parameters may offer the anesthesiologist better information for detecting a DL preoperatively.

Interprofessional simulation training in difficult airway management: a narrative review

The aim of this narrative literature review was to explore the impact of interprofessional simulation-based team training on difficult airway management. The Fourth National Audit Project of The Royal College of Anaesthetists and The Difficult Airway Society identified recurrent deficits in practice that included delayed recognition of critical events, inadequate provision of appropriately trained staff and poor collaboration and communication strategies between teams. Computerised databases were assessed to enable data collection, and a narrative literature review and synthesis of eight quantitative studies were performed. Four core themes were identified: debriefing, measures of assessment and evaluation, non-technical skills and patient safety, and patient outcomes. There are many benefits to be gained from interprofessional simulation training as a method of teaching high-risk and infrequent clinical airway emergencies. The practised response to emergency algorithms is crucial and plays a vital role in the reduction of errors and adverse patient outcomes.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Rescue supraglottic airway devices at caesarean delivery: What are the options to consider?

Tracheal intubation is considered the gold standard means of securing the airway in obstetric general anaesthesia because of the increased risk of aspiration. Obstetric failed intubation is relatively rare. Difficult airway guidelines recommend the use of a supraglottic airway device to maintain the airway and to allow rescue ventilation. Failed intubation is associated with a further increased risk of aspiration, therefore there is an argument for performing supraglottic airway-guided flexible bronchoscopic intubation (SAGFBI). The technique of SAGFBI has a high success rate in the non-obstetric population, it protects the airway and it minimises task fixation on repeated attempts at laryngoscopic tracheal intubation. However, after failed intubation via laryngoscopy, there is a lack of specific recommendations or indications for SAGFBI in current obstetric difficult airway guidelines in relation to achieving tracheal intubation. Our narrative review explores the issues pertaining to airway management in these cases: the use of supraglottic airway devices and the techniques of, and technical issues related to, SAGFBI. We also discuss the factors involved in the decision-making process as to whether to proceed with surgery with the airway maintained only with a supraglottic airway device, or to proceed only after SAGFBI.

Percutaneous vs surgical emergency cricothyroidotomy: An experimental randomized crossover study on an animal-larynx model

BACKGROUND

Airway management is a paramount clinical skill for the anaesthesiologist. The Emergency Cricothyroidotomy (EC) constitutes the final step in difficult airway algorithms securing a patent airway via a front-of-neck access. The main distinction among available techniques is whether the procedure is surgical and scalpel-based or percutaneous and needle-based.

METHODS

In an experimental randomized crossover trial, using an animal larynx model, we compared two EC techniques; the Rapid Four Step Technique and the Melker Emergency Cricothyrotomy Kit®. We assessed time expenditure and success rates among 20 anaesthesiologists and related this to previous training, seniority and clinical experience with EC.

RESULTS

All participants achieved successful airway access with both methods. Average time to successful airway access for scalpel-based EC was 54 (±31) seconds and for percutaneous EC 89 (±38) seconds, with 35 (95% CI: 14-57) seconds time difference, P = .003. Doctors with recent (<12 months) EC training performed better compared to the non-training group (37 vs 61 seconds, P = .03 for scalpel-based EC, and 65 vs 99 seconds, P = .02 for percutaneous EC). We found no differences according to clinical seniority or previous real-life EC experience.

CONCLUSIONS

Our study demonstrated that anaesthesiologists achieved successful airway access on an animal experimental model with both EC methods within a reasonable time frame, but the scalpel-based EC is performed more promptly. Recent EC training affected the time expenditure positively, while seniority and clinical EC experience did not. EC procedures should be regularly trained for.

Perioperative fasting: A review

Preprocedural/preoperative fasting is a key part of preparing a patient for undergoing sedation or anaesthesia to minimise the risk of pulmonary aspiration of gastric contents. As part of caring for elective surgical patients it is important that healthcare staff in the perioperative environment have a good understanding of both the current guidelines and underpinning evidence so that they can effectively manage preoperative patients. This article looks to summarise the latest guidelines regarding perioperative fasting for adult and paediatric patients, the underlying evidence behind these guidelines and finally review current literature which will inform future practice. This article therefore looks to reinforce best practice, to ensure that the safety and comfort of patients in the perioperative period is optimised.