Laura V. Duggan

The difficult airway with recommendations for management – Part 1 – Difficult tracheal intubation encountered in an unconscious/induced patient

AbstractBackgroundPreviously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered. MethodsNineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.ConclusionsThe clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.RésuméContexteActif au milieu des années 1990, le Canadian Airway Focus Group (CAFG), un groupe dédié à l’étude des difficultés imprévues dans la prise en charge des voies aériennes, a émis des recommandations sur ce sujet dans une publication datant de 1998. Le CAFG s’est réuni à nouveau pour passer en revue la littérature scientifique récente concernant la prise en charge des voies aériennes. Dans cet article, le CAFG s’est donné pour mission d’émettre des recommandations visant la prise en charge du patient inconscient ou anesthésié qui présente des difficultés d’intubation significatives.MéthodeDix-neuf cliniciens ayant une formation en anesthésie, en médecine d’urgence ou en soins intensifs composent le CAFG actuel. Les participants ont passé en revue des sujets précis en consultant les bases de données Medline, EMBASE et Cochrane. Les résultats de ces revues ont été présentés et discutés dans le cadre de téléconférences et de deux réunions en personne. Lorsqu’indiqué, des recommandations fondées sur des données probantes ou sur un consensus ont été émises. Le niveau de confiance attribué à ces recommandations a aussi été défini.ConclusionLe clinicien doit avoir conscience des lésions qu’il peut infliger lors de tentatives multiples d’intubation trachéale. Il est possible d’éviter de telles lésions en abandonnant rapidement une technique d’intubation infructueuse afin d’opter pour une méthode alternative (ou ‘plan B’) à condition que l’oxygénation par masque facial ou par l’utilisation d’un dispositif supraglottique s’avère possible. Nonobstant la ou les techniques choisies, un maximum de trois tentatives infructueuses mène à la conclusion qu’il s’agit d’un échec d’intubation et devrait inciter le clinicien à adopter une stratégie de retrait. Une situation dans laquelle il est impossible de procéder à l’oxygénation du patient à l’aide d’un masque facial, d’un dispositif supraglottique ou de l’intubation endotrachéale est qualifiée de scénario cannot intubate, cannot ventilate. Il est alors impératif de procéder sans délai à une cricothyrotomie, à moins que l’insertion d’un dispositif supraglottique n’ait été tentée. Celle-ci peut alors être effectuée rapidement et parallèlement à la réalisation de la cricothyrotomie.

The difficult airway with recommendations for management – Part 2 – The anticipated difficult airway

BackgroundAppropriate planning is crucial to avoid morbidity and mortality when difficulty is anticipated with airway management. Many guidelines developed by national societies have focused on management of difficulty encountered in the unconscious patient; however, little guidance appears in the literature on how best to approach the patient with an anticipated difficult airway.MethodsTo review this and other subjects, the Canadian Airway Focus Group (CAFG) was re-formed. With representation from anesthesiology, emergency medicine, and critical care, CAFG members were assigned topics for review. As literature reviews were completed, results were presented and discussed during teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made, and levels of evidence were assigned.Principal findingsPreviously published predictors of difficult direct laryngoscopy are widely known. More recent studies report predictors of difficult face mask ventilation, video laryngoscopy, use of a supraglottic device, and cricothyrotomy. All are important facets of a complete airway evaluation and must be considered when difficulty is anticipated with airway management. Many studies now document the increasing patient morbidity that occurs with multiple attempts at tracheal intubation. Therefore, when difficulty is anticipated, tracheal intubation after induction of general anesthesia should be considered only when success with the chosen device(s) can be predicted in a maximum of three attempts. Concomitant predicted difficulty using oxygenation by face mask or supraglottic device ventilation as a fallback makes an awake approach advisable. Contextual issues, such as patient cooperation, availability of additional skilled help, and the clinician’s experience, must also be considered in deciding the appropriate strategy.ConclusionsWith an appropriate airway evaluation and consideration of relevant contextual issues, a rational decision can be made on whether an awake approach to tracheal intubation will maximize patient safety or if airway management can safely proceed after induction of general anesthesia. With predicted difficulty, close attention should be paid to details of implementing the chosen approach. This should include having a plan in case of the failure of tracheal intubation or patient oxygenation.RésuméContexteUne planification adaptée est essentielle afin d’éviter la morbidité et la mortalité lorsqu’on prévoit des difficultés dans la prise en charge des voies aériennes. De nombreuses recommandations émises par des sociétés nationales mettent l’emphase sur la gestion des difficultés rencontrées chez le patient inconscient. Toutefois, il n’existe dans la littérature que peu de suggestions sur la façon d’approcher le patient chez qui les difficultés sont prévisibles.MéthodeAfin de passer en revue ce sujet et d’autres, le Canadian Airway Focus Group (CAFG), un groupe dédié à l’étude de la prise en charge des voies aériennes, a été reformé. Les membres du CAFG représentent diverses spécialités soit l’anesthésiologie, la médecine d’urgence et les soins intensifs. Chaque participant avait pour mission de passer en revue des sujets précis. Les résultats de ces revues ont été présentés et discutés dans le cadre de téléconférences et de deux réunions en personne. Lorsqu’indiqué, des recommandations fondées sur des données probantes ou sur un consensus ont été émises. Le niveau de confiance attribué à ces recommandations a aussi été défini.Constatations principalesPlusieurs éléments permettant de prédire la laryngoscopie directe difficile sont connus. Des études plus récentes décrivent aussi les éléments permettant d’anticiper des difficultés lors de la ventilation au masque facial, de la vidéolaryngoscopie, de l’utilisation d’un dispositif supraglottique ou de la réalisation d’une cricothyrotomie. Tous ces éléments doivent être pris en compte lors de l’évaluation du patient chez qui des difficultés sont anticipées lors de la prise en charge des voies aériennes. De nombreuses études rapportent une morbidité accrue liée à des tentatives multiples d’intubation trachéale. Planifier de procéder à l’intubation trachéale après l’induction de l’anesthésie générale n’est donc recommandé que pour les patients chez qui la ou les techniques prévues ne nécessiteront pas plus de trois tentatives. Il est recommandé de prioriser d’emblée une approche vigile dans les cas où des difficultés reliées à l’utilisation du masque facial ou d’un dispositif supraglottique sont prévues. L’établissement d’une stratégie de prise en charge doit tenir compte d’éléments contextuels telles la collaboration du patient, la disponibilité d’aide supplémentaire et de personnel qualifié, et l’expérience du clinicien.ConclusionUne évaluation adaptée des voies aériennes ainsi que les éléments contextuels propres à chaque situation sont les bases qui permettent de déterminer de manière rationnelle si l’intubation trachéale vigile est apte à optimiser la sécurité du patient, ou si la prise en charge des voies aériennes peut être réalisée de manière sécuritaire après l’induction de l’anesthésie générale. Lorsqu’on prévoit des difficultés, une attention particulière doit être portée aux détails nécessaires au succès de l’approche envisagée. De plus, il convient d’avoir un plan en cas d’échec de l’intubation trachéale ou si l’oxygénation du patient s’avérait difficile.

Updating our approach to the difficult and failed airway: time to “stop and think”

The Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults provocatively include deliberate instructions to ‘‘stop and think’’ (Figure). In so doing, they remind us that management of the difficult and failed airway is as much cerebral and situational as it is procedural and anatomical. The new guidelines are established on a growing evidence base. Accordingly, from a technical point of view, the authors recommend limiting intubation attempts, performing earlier scalpel cricothyrotomy, and avoiding blind techniques. More pertinent to this review, the authors also promote the evidence base supporting the importance of psychological factors, structured communication, and regular practice. Non-technical skills, such as the ability to step back and think, the ability to give and take instructions, and the aptitude to function within a high-stakes team, are increasingly recognized as part of what elevates experts above novices. These guidelines advance the field in many ways, not the least of which is the implicit message that successful difficult airway management requires the use of our hands, brains, and voices. It is important not to oversimplify the technical aspects of airway management. Similarly, the discussion of nontechnical factors, including analogies to other highreliability industries such as aviation, should not be oversimplified. After all, planes often do not take off during particularly inclement weather, whereas practitioners confronted by patients with a difficult or failed airway frequently have to ‘‘fly into the storm’’. Nevertheless, approximately a half-century of research from psychology, anthropology, sociology, and engineering has interrogated the factors that affect behaviour. Despite being leaders in medicine, the subspecialties of anesthesia and critical care are still in their infancy compared with other high-stakes systems. If we agree with the Institute for Healthcare Improvement that ‘‘every system is designed to achieve the results it gets’’, then new guidelines offer fresh impetus to create systems where practitioners are ‘‘fit for task’’ and ‘‘safety is no accident’’. The instruction to ‘‘stop and think’’ applies on many levels.

Front-of-neck airway meets front-of-neck simulation: improving cricothyroidotomy skills using a novel open-access three-dimensional model and the Airway App

To the Editor, Although anesthesiologists, intensivists, and emergency physicians rarely perform cricothyroidotomy, these specialists must maintain the knowledge, decisionmaking, and procedural skill sets to perform cricothyroidotomy quickly and safely. The 2015 Difficult Airway Society guidelines recommend bougie-assisted scalpel cricothyrotomy coupled with regular simulated practice. Regardless of the technique used, the training must be realistic, addressing both technical and non-technical skills and facilitating reflection and data gathering. We outline a novel approach to cricothyrotomy training that we introduced at a recent airway workshop. We are eager to share it, receive feedback, and further develop this airway education and patient safety initiative. Previously, as in many centres, our airway workshops focused on the acquisition of manual skills using mannequins and isolated pig tracheas. As the Canadian Airway Focus Group emphasizes, however, manual skills are only one aspect required for reliable patient rescue in a ‘‘cannot intubate/cannot oxygenate’’ emergency. Specifically, we wished to address the oft-cited reluctance to cut another human’s neck. Accordingly, we sought to create a tool that would increase manual skills and could be coupled with human factors’ training. Nontechnical steps are just as likely to go wrong as technical endeavors, so mental preparedness and cognitive rehearsal are essential. The use of mannequins is commonly criticized for unrealistic anatomy/haptic feedback and lack of ‘‘stress inoculation’’. Although isolated pig tracheas provide more realistic airway anatomy and the ‘‘feel’’ of tissue, there are no real-life hindrances (e.g., from a patient’s chin or thick neck) to overcome with problemsolving. Both mannequins and pig models may also inadvertently send a message that cricothyrotomy requires an elaborate or expensive setup. Inspired by the lecture given by Dr. Ciaran McKenna, we created a three-dimensional (3D) cricothyroidotomy model based on the original 3D anatomic program from The University of Dundee and BodyParts 3D: The Database Center for Life Science Computer Science departments. To achieve the realism of performing cricothyrotomy on a real person, the authors conceptualized modifications to enable this model to be fitted on the neck of a real person. The original Dundee model was modified to include a slightly larger cricothyroid space to accommodate a 6.0 mm endotracheal tube. The posterior aspect of the model is flat and solid. Therefore, despite using scalpels, L. V. Duggan (&) S. L. Lockhart K. R. Romano University of British Columbia, Vancouver, BC, Canada e-mail: laura.duggan@fraserhealth.ca; lauravduggan@gmail.com

Optimizing Crisis Resource Management to Improve Patient Safety and Team Performance - A handbook for acute care health professionals

This monograph is available electronically, free-of-charge, in both English and French via the Royal College of Physicians and Surgeons of Canada. It is divided into six short chapters that reflect the core components of crisis resource management: attention and awareness, decisionmaking, verbal communication, task management, leadership and followership skills, and teamwork. The editors, Peter Brindley and Pierre Cardinal, should be commended for bringing together a panel of experts from the fields of both medicine and psychology. They also succeeded in concisely integrating language and ideas that are often non-medical and non-intuitive into the acute-care field. No matter what specialty, the recognition and initial management of an acutely ill patient whether in an office, airplane, or hospital setting must be a core competence for all healthcare workers. Managing life-threatening conditions means coordinating multiple tasks and people, often working with incomplete information. Having the right people to do the right things at the right times can be lifesaving. The importance of communication and collaboration are so important they comprise two of the six CanMeds roles defining a medical expert. Honing these skills in the arena of an acute-care crisis is inherently difficult as education is often fragmented and content-based. Learning may not include deliberate reflection of communication or collaboration. When asked, experienced acute-care physicians may or may not know, or have the language, to describe how to perform well or fail to do so. Without metacognition i.e., thinking about how we think practitioners may repeat the same mistakes and patients suffer the consequences. Highlighted in the Attention and Awareness and Decision-Making chapters are the potential biases of healthcare providers and how they can endanger acute care. For example, oversimplifying and premature cognitive closure can result in blind spots as more information becomes available. Yet, without filtering information, one can be overwhelmed by minutia, which could result in incorrect actions or even inaction. The Attention and Awareness chapter includes a brief discussion on ‘‘distraction’’ an increasingly important risk factor in acute-care medicine as many factors, including one’s smartphone, vie for attention during a crisis. Suggestions about how to maintain situational awareness during prolonged resuscitation is also valuable. In the chapter on Verbal Communication, the authors make the compelling point that communication, like a drug, can be either helpful or hazardous, depending on the message and the context. In the Introduction, Dr. Cardinal makes the important point that there is no singular means of crisis management and ends with ‘‘It just depends!’’ To this end, the authors present five paradigms of communication. They also warn against automating such crucial communication. The authors should be commended on their balanced approach of offering suggestions without being prescriptive, although these ideas could have been further illustrated by providing clinical vignettes as examples of varied verbal communication skills in various clinical situations. The authors devote a chapter to Leadership and Followership. The Royal College of Canada CanMeds L. V. Duggan, MD, FRCPC (&) University of British Columbia, Vancouver, BC, Canada e-mail: laura.duggan@fraserhealth.ca; lauravduggan@gmail.com

Deliberately restricted laryngeal view with GlideScope(®) video laryngoscope: ramifications for airway research and teaching.

To the Editor, We congratulate Dr. Gu et al. for their sound, thoughtprovoking article that addresses the issue of optimizing intubation conditions during video laryngoscopy by purposely using a restricted laryngeal view. Teaching direct laryngoscopy generally focuses on obtaining the best possible glottic view, with the ease of intubation generally being directly proportional to this view. Unlike direct laryngoscopy, however, the authors have shown that a deliberately restricted view of the glottis when using GlideScope GVL video laryngoscopy is associated with both improved ease and decreased time to endotracheal intubation in essence, the ease of intubation was inversely proportional to the quality of the glottic view. The authors’ findings may have a significant impact on the interpretation and conclusions of video laryngoscopy research that uses the glottic view [e.g., modified CormackLehane or POGO (percentage of glottic opening) score], as a surrogate end point for ease of intubation. This assumption may simply not be the case. The authors’ findings may also have a significant impact on optimizing teaching of video laryngoscopy skills. Perhaps we should curb our enthusiasm about obtaining the best view of the glottis and, instead, emphasize that this approach is a complete departure from what is currently being taught regarding direct laryngoscopy. It raises the question as whether, given their findings, we should reject the view of the glottis as a surrogate end point for intubation in articles about video laryngoscopy. It is exciting to see video laryngoscopy research maturing beyond simply the direct laryngoscopy vs video laryngoscopy paradigm into how best to optimize endotracheal intubation when we have access to both techniques. Just as video laryngoscopy and direct laryngoscopy are different but complementary techniques, it is not surprising that their optimal research and teaching approaches may differ as well.

Laparoscopic cholecystectomy under spinal anesthesia in a patient with limb-girdle muscular dystrophy

To the Editor, A 61-yr-old gentleman with longstanding muscular dystrophy presented with acute cholecystitis and sepsis. Three months later, with a biliary drainage tube still in place, he presented for semi-elective laparoscopic cholecystectomy. This patient kindly gave consent for publication of this report. The exact type of the patient’s muscular dystrophy was unclear despite extensive workup by his neurologist; however, his presentation was most in keeping with limbgirdle muscular dystrophy Type 2A. His symptoms began at age 14 yr when he developed proximal upper arm weakness and subsequent muscle wasting. By age 50 yr, he began to develop progressive weakness and wasting of his proximal lower limbs. He is now unable to climb out of bed or climb stairs easily. His echocardiogram was unremarkable and, surprisingly, so was the result of his preoperative spirometry test. Nevertheless, his respiratory therapist noted he was quite dyspneic at the end of the spirometry testing. Limb-girdle muscular dystrophy, a class of muscular dystrophy, is a heterogeneous group of neuromuscular diseases characterized by progressive muscle weakness and atrophy of the shoulder and/or hip girdle muscles. Cardiac involvement is rare. Respiratory involvement may be present in long-standing disease. Although laparoscopic cholecystectomy is generally performed with endotracheal intubation and positive pressure ventilation, we were concerned about the ability to wean this patient from the ventilator postoperatively. Laparoscopic cholecystectomy under spinal anesthesia has been described. Sinha et al. published a retrospective review of 3,492 laparoscopic cholecystectomy procedures under spinal anesthesia. Findings included a lower incidence of nausea and vomiting and decreased intravenous analgesic requirements. Abdominal muscle relaxation was not problematic. Shoulder and neck pain occurred in 12.3% of patients. Conversion to general anesthesia was required in 0.5% of cases. Given our concerns about the potential for problematic weaning from ventilation, a discussion took place between anesthesiology and general surgery about how best to proceed. We elected to offer this patient spinal anesthesia for his procedure. Complicating this choice was a significant language barrier. His daughter offered to join us intraoperatively for translation and emotional support. Her presence was invaluable. We performed a subarachnoid block at approximately the L3/4 level with a midline approach using a 25G pencilpoint spinal needle. This was performed in the right lateral position as the patient was unable to sit due to his muscle weakness. A T4-level block was achieved using 0.75% hyperbaric bupivacaine 21 mg (2.8 mL) and fentanyl 20 lg. The patient was placed in a supine, not Trendelenburg, position to achieve this block. Invasive blood pressure monitoring was used, and blood pressure was supported throughout the surgery with a phenylephrine infusion when required. The patient complained of diaphragmatic discomfort and right shoulder pain intermittently, which was managed using a remifentanil infusion of 0.05 0.15 lg kg min, shoulder massage, and reassurance from his daughter. The surgeon also sprayed the patient’s diaphragm with 1% M. C. Chuang, MD L. V. Duggan, MD (&) R. D. van Heest, MD W. MacLeod, MD Department of Anesthesiology and Perioperative Medicine, Royal Columbian Hospital, University of British Columbia, New Westminster, BC, Canada e-mail: laura.duggan@fraserhealth.ca; lauraduggan@yahoo.com

Improving communication, teamwork, and action during a “cannot intubate cannot oxygenate (CICO)” emergency: employing CICO as a cognitive aid mnemonic

Anesthesiology, critical care, and emergency medicine share the common goal of safe airway management. While often performed uneventfully, adverse patient anatomy, physiology, or situational acuity can precipitate an airway emergency. The outcome of an airway emergency may result as much from non-technical skills as from technical expertise. Airway guidelines now highlight the importance of these non-technical skills such as teamwork and effective communication during airway emergencies. One example of an airway emergency requiring timely and structured teamwork is the rare life-threatening ‘‘cannot intubate, cannot oxygenate’’ (CICO) emergency. The CICO emergency requires immediate transition from tracheal intubation attempts to an emergency front-of-neck airway (eFONA) procedure. While often technically successful, eFONA is frequently performed too late to save the patient from hypoxemic brain damage or death. This delay may reflect the lack of a vital non-technical skill—i.e., establishing a shared mental model about what is occurring and initiating the predictable next steps required to remedy the CICO emergency. Lack of such a shared mental model may be related to: i) the failure to recognize a CICO emergency; ii) once recognized, the failure to promptly and unequivocally declare a CICO emergency to the entire team; and/or iii) once a CICO emergency is declared, the failure to rapidly perform eFONA. Cognitive aids, like checklists, appear to be more effective if they direct action rather than simply listing concerns. This article offers a simple mnemonic as a four-part cognitive aid—corresponding to the letters ‘‘CICO’’—that can be easily recalled and summarizes the key sequential steps to identifying and managing the CICO airway emergency.

In reply: Glottic impersonation, perhaps, but direct visualization remains vital to confirm successful intubation

To the Editor, We greatly appreciate the interest from Bowness et al. and welcome their detailed commentary, most of which we agree with. With experience, time, and a scenario void of duress, differentiating the glottic inlet from the esophagus as displayed in our ‘‘glottic impersonation’’ image should not be difficult. We would, however, caution against anything that might lead a reader to conclude that misidentification of the glottic inlet can threaten only inexperienced or infrequent airway managers. Esophageal intubation in cases that were not considered difficult remain an important cause of airway-related medicolegal action. We teach our learners the importance of relational anatomy that allows orientation and cognitive confirmation of where structures should be located based on a positive identification of a known piece of the airway’s anatomical puzzle. The educational value of our glottic impersonation image is to visualize both the esophagus and glottic inlet in a single image for comparison. Given the modified original image (see Figure) that simulates a situation where one might not have the full reference to the glottic inlet, misidentification becomes a more realistic threat. Indeed, we all have a tendency to see what we want to see and often fail to see what we do not expect to see. Bowness et al. also outlined an example of where no end tidal carbon dioxide was seen on capnography due to pronounced bronchospasm after intubation. The 4th National Audit Project study, however, outlined where similar thinking could spell disaster – e.g., the assumption that absent waveform capnography was the result of low cardiac output rather than erroneous esophageal intubation. Dismissing non-confirmatory capnography may be another form of seeing what we want to see. Pilots, sailors, and drivers know that it is dangerous to ignore their instruments unless they have absolute confirmation of the same information. We also simply, but strongly, suggest that airway managers do the same. This is why we politely disagree with the conclusions of Bowness et al. that visualization is a superior method of confirming endotracheal tube position. Furthermore, clinical decisions are rarely binary. This is particularly important when our clues and data points are neither fully sensitive nor specific – and when error could mean death. Visualization is certainly an important component of establishing correct endotracheal intubation, but it cannot always be trusted in isolation. Thus, we stand by our contention that capnography is indispensable. If there remains any question about the endotracheal tube position, flexible bronchoscopy is also extremely valuable. G. Kovacs, MD, MHPE, FRCPC (&) Departments of Emergency Medicine, Anaesthesia, Medical Neuroscience, Dalhousie University, Halifax, NS, Canada e-mail: gkovacs@dal.ca