Complete airway obstruction during awake fibreoptic intubation

Clinical Approach to Massive Hemoptysis: Perioperative Focus on Causes and Management

Massive hemoptysis is a time critical airway emergency in the perioperative setting, with an associated mortality exceeding 50%. Causes of hemoptysis in the perioperative setting include procedural complication, coagulopathy, malignancy, chronic lung disease, infection, left-sided cardiac disease, pulmonary vascular disease and autoimmune disease. A rapid and coordinated multidisciplinary response is required to secure the airway, isolate the lung, ensure adequate oxygenation and ventilation, identify the underlying cause and initiate specific systemic, bronchoscopic, endovascular, or surgical treatment. This review examines the etiology, pathophysiology, as well as approach to management and interventions in perioperative massive hemoptysis.

Incidence, causes, and management of failed awake fibreoptic intubation-A retrospective study of 833 procedures

Awake fibreoptic intubation has been considered a gold standard in the management of the difficult airway. However, failure may cause critical situations. The aim of this study was to investigate the incidence and causes of failed awake fibreoptic intubation at a tertiary care hospital. The study was conducted at St. Olav University Hospital in Trondheim, Norway. Problems occurring during anaesthesia are routinely recorded in the electronic anaesthesia information system (Picis Clinical Solutions Inc.), including difficult intubations. We applied text search on all anaesthesia records between 2011 and 2021 and identified 833 awake fibreoptic intubations. The anaesthesia records were examined to identify failed awake fibreoptic intubations, the cause of failure and how the airway ultimately was secured. Among 233,938 patients who received anaesthesia, 90,397 received tracheal intubation and 833 received awake fibreoptic intubation. Twenty-nine of the procedures failed. In nine patients the failure caused loss of airway control with desaturation and hypoventilation. The major causes of failure were dislodged tube after induction of general anaesthesia (n = 8), patient distress (n = 5), tube not able to pass (n = 5), and airway bleeding (n = 3). The situations were primarily solved using direct laryngoscopy, with or without bougie, or with video laryngoscopy. Tracheostomy was performed in four patients. Awake fibreoptic intubation failed in 3.5% of patients, most often due to dislocation, problems passing the tracheal tube, or patient discomfort. The failure rate was higher than in previous studies.

Airway devices for awake tracheal intubation in adults: a systematic review and network meta-analysis

BACKGROUND

Awake tracheal intubation is commonly performed with flexible bronchoscopes, but the emerging role of alternative airway devices, such as videolaryngoscopes, direct laryngoscopes, and optical stylets, has been recognised.

METHODS

CENTRAL, CINAHL, EMBASE, MEDLINE, and Web of Science were searched for RCTs that compared flexible bronchoscopes, direct laryngoscopes, optical stylets and channelled or unchannelled videolaryngoscopes in adult patients having awake tracheal intubation were included. The co-primary outcomes were first-pass success rate and time to tracheal intubation. Continuous outcomes were extracted as mean and standard deviation, and dichotomous outcomes were converted to overall numbers of incidence. Frequentist network meta-analysis was conducted, and network plots and network league tables were produced.

RESULTS

Twelve RCTs were included, none of which evaluated direct laryngoscopes. The first-pass success rate was not different between flexible bronchoscopes, optical stylets, and channelled and unchannelled videolaryngoscopes, with the quality of evidence rated as moderate in view of imprecision. Optical stylets, followed by unchannelled videolaryngoscopes and then felxible bronchoscopes resulted in the shortest time to tracheal intubation, with the quality of evidence rated as high. No differences were shown between the airway devices with respect to the incidence of oesophageal intubation, change of airway technique, oxygen desaturation, airway bleeding, or the rate of hoarseness and sore throat.

CONCLUSIONS

Flexible bronchoscopes, optical stylets, and channelled and unchannelled videolaryngoscopes were clinically comparable airway devices in the setting of awake trachela intubation and the time to tracheal intubation was shortest with optical stylets and longest with flexible bronchoscopes.

Practice and outcomes of airway management in patients with cervical orthoses

BACKGROUND/PURPOSE

Increasing evidence indicates an association of video laryngoscopy with the success rate of airway management in patients with neck immobilization. Nevertheless, clinical practice protocols for tracheal intubation in patients immobilized using various types of cervical orthoses and the outcomes remain unclear.

METHODS

We retrospectively assessed the tracheal intubation techniques selected for patients immobilized using cervical orthoses from 2015 to 2018. The endpoints were the intubation outcomes of the different techniques and the factors associated with the selection of the technique.

RESULTS

We included 218 patients, 118 of whom wore halo vest braces (halo vest group) and 100 wore cervical collars (collar group). GlideScope video laryngoscopy (GVL) and fiberoptic bronchoscopy (FOB) were the initial intubation methods in 98 and 120 patients, respectively. GVL had a higher first-attempt success rate than did FOB in the collar group (p = 0.002) but not in the halo vest group (p = 0.522). GVL was associated with a lower risk of episodes of SaO₂< 90% (adjusted relative risk [aRR], 0.11; 95% CI, 0.02-0.67; p = 0.016) and shorter intubation time (aRR, -3.52; 95% CI, -4.79∼-2.25; p < 0.001) in the collar group. However, in the halo vest group, more frequent requirement of a rescue technique (p = 0.002) and necessity of patient awakening (p = 0.001) was noted when GVL was used. Use of the halo vest brace and noting of severe cord compression were independent predictors of the initial selection of FOB.

CONCLUSION

Caution should be exercised when using GVL for tracheal intubation in patients immobilized using halo vest braces.

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.

Preemptive veno-venous ECMO support in a patient with anticipated difficult airway: A case report

This report presents a case of endotracheal metastasis in which elective veno-venous extracorporeal membrane oxygenation (VV ECMO) was used to undergo tracheal laser-surgery prior to establishment of a definitive airway. Specifically, we describe the respiratory and airway management in an adult patient from the preclinical phase throughout elective preoperative ECMO implantation to postoperative ECMO weaning and decannulation in the Intensive Care Unit. This case report lends further supports to the idea that the extracorporeal membrane oxygenation could be electively used to provide safe environment for surgery in situations where the standard maneuvers of sustaining adequate gas exchange are anticipated to fail.

Recommendations for the evaluation and management of the anticipated and non-anticipated difficult airway of the Societat Catalana d'Anestesiologia, Reanimació i Terapèutica del Dolor, based on the adaptation of clinical practice guidelines and expert consensus

The Airway Division of the Catalan Society of Anaesthesiology, Intensive Care and Pain Management (SCARTD) presents its latest guidelines for the evaluation and management of the difficult airway. This update includes the technical advances and changes observed in clinical practice since publication of the first edition of the guidelines in 2008. The recommendations were defined by a consensus of experts from the 19 participating hospitals, and were adapted from 5 recently published international guidelines following an in-depth analysis and systematic comparison of their recommendations. The final document was sent to the members of SCARTD for evaluation, and was reviewed by 11 independent experts. The recommendations, therefore, are supported by the latest scientific evidence and endorsed by professionals in the field. This edition develops the definition of the difficult airway, including all airway management techniques, and places emphasis on evaluating and classifying the airway into 3 categories according to the anticipated degree of difficulty and additional safety considerations in order to plan the management strategy. Pre-management planning, in terms of preparing patients and resources and optimising communication and interaction between all professionals involved, plays a pivotal role in all the scenarios addressed. The guidelines reflect the increased presence of video laryngoscopes and second-generation devices in our setting, and promotes their routine use in intubation and their prompt use in cases of unanticipated difficult airway. They also address the increased use of ultrasound imaging as an aid to evaluation and decision-making. New scenarios have also been included, such as the risk of bronchoaspiration and difficult extubation Finally, the document outlines the training and continuing professional development programmes required to guarantee effective and safe implementation of the guidelines.

Fibreoptic intubation in airway management: a review article

Since the first use of the flexible fibreoptic bronchoscope, a plethora of new airway equipment has become available. It is essential for clinicians to understand the role and limitations of the available equipment to make appropriate choices. The recent 4th National Audit Project conducted in the United Kingdom found that poor judgement with inappropriate choice of equipment was a contributory factor in airway morbidity and mortality. Given the many modern airway adjuncts that are available, we aimed to define the role of flexible fibreoptic intubation in decision-making and management of anticipated and unanticipated difficult airways. We also reviewed the recent literature regarding the role of flexible fibreoptic intubation in specific patient groups who may present with difficult intubation, and concluded that the flexible fibrescope maintains its important role in difficult airway management.

Use of a trans-tracheal rapid insufflation of oxygen device in a "cannot intubate, cannot oxygenate" scenario in a parturient -a case report

Background

The trans-tracheal rapid insufflation of oxygen (TRIO) device is less commonly used and is an alternative to trans-tracheal jet ventilation for maintaining oxygenation in a "cannot intubate, cannot oxygenate" (CICO) scenario.

Case

We report the successful use of this device to maintain oxygenation after jet ventilator failure in a parturient who presented with the CICO scenario during the procedure for excision of laryngeal papilloma.

Conclusions

A stepwise approach to the airway plan and preparation for an event of failure is essential for good materno-fetal outcomes. The TRIO device may result in inadequate ventilation that can lead to hypercarbia and respiratory acidosis. Hence, it should only be used as a temporizing measure before a definitive airway can be secured.

Use of Helium/Oxygen Mixture in Noninvasive Ventilation During Urgent Tracheotomy for Upper Airway Compression: A Case Report

Ventilation or oxygenation can be difficult or even impossible in cases of upper airway obstruction. In this case report, we used a helium/oxygen mixture administered via noninvasive positive-pressure ventilation to perform an urgent tracheotomy under local anesthesia on a patient presenting upper airway compression. It improved his comfort and his stridor, facilitating supine positioning. This case describes another potential indication of the helium/oxygen mixture in noninvasive ventilation.

Topicalisation of airway for awake fibre-optic intubation: Walking on thin ice

Topicalisation of the airway by various techniques has routinely been recommended for awake fibre-optic bronchoscopy in cases of difficult airway. However, topicalisation by itself can cause airway obstruction by decreasing the tone of the laryngeal muscles and causing a dynamic air inflow obstruction. Two cases of difficult airway are illustrated where anaesthetising upper airway with nebulisation with 4% lignocaine (Xylocaine™) or 2% lignocaine (Xylocaine™) jelly resulted in stridor and upper airway obstruction. This is the first reported case of airway obstruction after lignocaine (Xylocaine™) jelly. We would like to highlight that topicalisation of airway, once thought as a relatively safe technique, can cause airway collapse if not detected and anticipated at the earliest. Pre-operative spirometry and airway ultrasonography can be useful in detecting the patients at risk of developing airway obstruction. Using a nasopharyngeal airway during topicalisation can serve as a valuable device in preventing total airway obstruction in susceptible patients.

Guidelines for the management of tracheal intubation in critically ill adults

These guidelines describe a comprehensive strategy to optimize oxygenation, airway management, and tracheal intubation in critically ill patients, in all hospital locations. They are a direct response to the 4^th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, which highlighted deficient management of these extremely vulnerable patients leading to major complications and avoidable deaths. They are founded on robust evidence where available, supplemented by expert consensus opinion where it is not. These guidelines recognize that improved outcomes of emergency airway management require closer attention to human factors, rather than simply introduction of new devices or improved technical proficiency. They stress the role of the airway team, a shared mental model, planning, and communication throughout airway management. The primacy of oxygenation including pre- and peroxygenation is emphasized. A modified rapid sequence approach is recommended. Optimal management is presented in an algorithm that combines Plans B and C, incorporating elements of the Vortex approach. To avoid delays and task fixation, the importance of limiting procedural attempts, promptly recognizing failure, and transitioning to the next algorithm step are emphasized. The guidelines recommend early use of a videolaryngoscope, with a screen visible to all, and second generation supraglottic airways for airway rescue. Recommendations for emergency front of neck airway are for a scalpel-bougie-tube technique while acknowledging the value of other techniques performed by trained experts. As most critical care airway catastrophes occur after intubation, from dislodged or blocked tubes, essential methods to avoid these complications are also emphasized.

Can videolaryngoscopy be a first option in a patient with laryngeal amyloidosis?

Amyloidosis is a term that involves a group of diseases characterised by deposition of extracellular monoclonal light-chain fibrillar immunoglobulin aggregates in the body, including many organs, with the larynx among them. A case is presented of a 78 year-old man who was referred to our institution for strangulated umbilical hernia treatment. He suffered from progressive hoarseness and dysphagia for 5months. He had a history of primary laryngeal amyloidosis. Awake intubation was performed successful with the King Vision^® video-laryngoscopy. Sedation was achieved using a remifentanil infusion and midazolam. Haemorrhagic lesions are caused by deposition of amyloid in and around vessels, resulting in increased vascular fragility. Therefore, anaesthetists should take care in intubating the tracheas of these patients.

Use of the TotalTrack VLM for emergent endotracheal intubation in predicted difficult airway with obstruction by expanding space-occupying lesions and reduced interincisor opening

Acute cervical pathology may lead to serious airway compromise resulting from anatomical distortion secondary to obstruction or deviation of the upper airway, scenarios where any airway device can be fallible. Passage of a fiberoptic bronchoscopy to expose the glottis may be very difficult and tracheostomy may be impractical or risky in advanced cases. We present the use of the TotalTrack VLM to secure the airway for emergent surgery in 2 uncooperative patients with difficult airway due to Ludwig's angina and neck hematoma, respectively, both accompanied by trismus.

Airway management in patients with deep neck infections: A retrospective analysis

Securing the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method.We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologist's perspective.When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected.When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients' symptoms is needed.

Anaesthetic management of acute airway obstruction

The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom's 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists' difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan.

Optimizing oxygenation and intubation conditions during awake fibre-optic intubation using a high-flow nasal oxygen-delivery system

BACKGROUND

Awake fibre-optic intubation is a widely practised technique for anticipated difficult airway management. Despite the administration of supplemental oxygen during the procedure, patients are still at risk of hypoxia because of the effects of sedation, local anaesthesia, procedural complications, and the presence of co-morbidities. Traditionally used oxygen-delivery devices are low flow, and most do not have a sufficient reservoir or allow adequate fresh gas flow to meet the patient's peak inspiratory flow rate, nor provide an adequate fractional inspired oxygen concentration to prevent desaturation should complications arise.

METHODS

A prospective observational study was conducted using a high-flow humidified transnasal oxygen-delivery system during awake fibre-optic intubation in 50 patients with anticipated difficult airways.

RESULTS

There were no episodes of desaturation or hypercapnia using the high-flow system, and in all patients the oxygen saturation improved above baseline values, despite one instance of apnoea resulting from over-sedation. All patients reported a comfortable experience using the device.

CONCLUSIONS

The high-flow nasal oxygen-delivery system improves oxygenation saturation, decreases the risk of desaturation during the procedure, and potentially, optimizes conditions for awake fibre-optic intubation. The soft nasal cannulae uniquely allow continuous oxygenation and simultaneous passage of the fibrescope and tracheal tube. The safety of the procedure may be increased, because any obstruction, hypoventilation, or periods of apnoea that may arise may be tolerated for longer, allowing more time to achieve ventilation in an optimally oxygenated patient.

The incidence, success rate, and complications of awake tracheal intubation in 1,554 patients over 12 years: an historical cohort study

PURPOSE

Awake tracheal intubation is one recommended option to address select situations in the management of a patient with an anticipated difficult airway. A scarcity of data exists on how often awake intubation is performed or whether its use is changing over time, particularly with the increasingly widespread availability of video laryngoscopy. This retrospective database review was undertaken to determine the incidence, success, and complications of awake intubation and the incidence of other tracheal intubation techniques in the operating room over a 12-yr period (2002-2013) at our institution.

METHODS

The Anesthesia Information Management System in use at a Canadian tertiary care centre was searched for all awake intubations that occurred during the years 2002-2013. Records were also searched to identify airway methods other than direct laryngoscopy that may have been used after the induction of general anesthesia. Changes in both the incidence of awake intubation and in the use of video laryngoscopy over the 12 years were analyzed using linear regression modelling.

RESULTS

Of 146,252 cases performed under general anesthesia with endotracheal intubation, 1,554 intubations (1.06%) were performed awake. There was no significant change in the rate of awake intubation over the studied years (slope -1.4(-4) incidence·year(-1); 95% confidence interval [CI]: -3.0(-4) to 3.0(-5); P = 0.102). The relatively steady rate of awake intubation occurred despite a significant increase in the use of video laryngoscopy over the same time (slope 0.080 incidence·year(-1); 95% CI: 0.076 to 0.083; P < 0.001), particularly from 2009 onwards. Attempted awake intubation failed in 31 (2%) of the cases. Self-reported complications occurred in 15.7% of successful procedures. In addition, in a convenience sample of three years (2011-2013), the rate at which each of 49 attending staff performed awake intubation varied widely from 0-3.4 awake intubations per 100 cases of general anesthesia with endotracheal intubation.

CONCLUSIONS

At our tertiary care centre, we did not find a significant change in the use of awake tracheal intubation over the studied years 2002-2013 despite increasing availability and use of video laryngoscopy. It appears that awake tracheal intubation retains an important and consistent role in the management of the difficult airway.

Cervical spine overflexion in a halo orthosis contributes to complete upper airway obstruction during awake bronchoscopic intubation: a case report

PURPOSE

We present a case of upper airway obstruction in a patient with an unstable cervical spine fracture in a halo orthosis. We also describe the mechanism by which the obstruction occurred and identify features that predispose patients in a halo orthosis to upper airway obstruction.

CASE

An 81-yr-old female presenting to hospital with an unstable cervical spine fracture was scheduled for spinal fusion. She was fitted with a halo traction device in a flexed position, and an awake tracheal intubation was planned. The patient's airway was topicalized and 1 mg of midazolam was administered. Her oxygen saturation dropped, and mask ventilation was difficult and insufficient. She then became unresponsive and pulseless. Emergency release of the halo orthosis device was carried out and her neck was held in a neutral position. Mask ventilation was successfully performed and oxygenation improved. The patient's trachea was intubated via video laryngoscopy, and she was resuscitated and taken to the intensive care unit. The degree of cervical spine flexion resulting from the halo fixation was examined in subsequent radiographs, as defined by the occiput to C2 (O-C2) angle, and the oropharyngeal cross-sectional area was measured. Spine flexion from halo fixation in concert with the topical treatment and sedation predisposed the patient to acute airway obstruction.

CONCLUSION

In this case, external cervical spine fixation in flexion resulted in a change to the O-C2 angle, which reduced the oropharyngeal area and predisposed to upper airway obstruction. This highlights the need for anesthesiologists to evaluate the degree of cervical spine flexion in patients with halo devices and to have the surgical team present during airway management in the event of acute airway obstruction.

The difficult airway with recommendations for management--part 2--the anticipated difficult airway

BACKGROUND

Appropriate 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.

METHODS

To 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 FINDINGS

Previously 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.

CONCLUSIONS

With 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.

Conscious sedation for awake fibreoptic intubation: a review of the literature

PURPOSE

Awake fibreoptic intubation (AFOI) is the gold standard of management of the predicted difficult airway. Sedation is frequently used to make the process more tolerable to patients. It is not always easy to strike a balance between patient comfort and good intubating conditions on the one hand and maintaining ventilation and a patent airway on the other. In the last 30 years, many drugs and drug combinations have been described, but there is very little in the literature to help guide the practitioner to choose between them. The objective of this article is to discuss the evidence supporting the use of the agents described with regard to their efficacy, recommended doses and techniques, and limitations to their use for AFOI.

SOURCE

Publication databases were searched for articles published from 1996 to 2012 relating to sedation for AFOI.

PRINCIPLE FINDINGS

Benzodiazepines, propofol, opioids, alpha2-adrenoceptor agonists, and ketamine are the main classes of drugs that have been described to facilitate AFOI. Drugs that are most suitable have a combination of both anxiolytic and analgesic properties. The ideal choice of drug may vary depending on the patient and the indication for AFOI.

CONCLUSION

There is good evidence to support the use of two drugs in particular, remifentanil and dexmedetomidine. Each has certain unique characteristics that make them an attractive choice for an AFOI.

Laryngeal radiation fibrosis: a case of failed awake flexible fibreoptic intubation

Awake fibreoptic intubation is accepted as the gold standard for intubation of patients with an anticipated difficult airway. Radiation fibrosis may cause difficulties during the intubation procedure. We present an unusual severe case of radiation induced changes to the larynx, with limited clinical symptoms, that caused failure of the fibreoptic intubation technique. A review of the known literature on radiation fibrosis and airway management is presented.

[Severe airway distress following cervical spine operation: retrospective breakdown of the chain of errors]

A 71-year-old female patient received a prothesis due to a cervical disc prolapsed and bleeding into the collar soft tissues occurred postoperatively. Following a computed tomography examination severe peracute respiratory decompensation occurred while administering topical anesthesia to the pharynx in order to perform fiber optic intubation. Endotracheal intubation using conventional laryngoscopy was unsuccessful and the patient required immediate cricothyroidotomy. As an on-site cricothyrotomy set to establish a secure airway was not available the decision was taken to perform surgical cricothyroidotomy. As a conclusion to this life-threatening event in the case of symptoms, such as dyspnea, dysphonia and dysphagia after operations of the cervical spine the airway has to be secured early and according to the local algorithm.

Awake intubation using the LMA-CTrach in patients with difficult airways

We studied 21 patients with known difficult airways who underwent awake tracheal intubation using the LMA CTrach. Patients were given midazolam, atropine, a continuous infusion of remifentanil and topical lidocaine applied to the oropharyx. We limited the number of insertion attempts to three and the time to adjust the view to 5 min. In case of failure, we performed awake fibreoptic tracheal intubation. We found insertion of the device was successful and well tolerated in all patients. Vocal cords could be seen immediately in nine patients and following corrective manoeuvres in 10 patients. Tracheal intubation was successful in 20 patients: 19 cases under direct vision and in one blindly. In one patient with undiagnosed lingual tonsil hyperplasia, tracheal intubation was impossible using the device. No patient had an unpleasant recall of the procedure. We conclude that the LMA CTrach is easy to use, well tolerated and suitable for awake orotracheal intubation in patients with known difficult airways.

The difficult airway in adult critical care

INTRODUCTION

The difficult airway is a common problem in adult critical care patients. However, the challenge is not just the establishment of a safe airway, but also maintaining that safety over days, weeks, or longer.

AIMS

This review considers the management of the difficult airway in the adult critical care environment. Central themes are the recognition of the potentially difficult airway and the necessary preparation for (and management of) difficult intubation and extubation. Problems associated with tracheostomy tubes and tube displacement are also discussed.

RESULTS

All patients in critical care should initially be viewed as having a potentially difficult airway. They also have less physiological reserve than patients undergoing airway interventions in association with elective surgery. Making the critical care environment as conducive to difficult airway management as the operating room requires planning and teamwork. Extubation of the difficult airway should always be viewed as a potentially difficult reintubation. Tube displacement or obstruction should be strongly suspected in situations of new-onset difficult ventilation.

CONCLUSIONS

Critical care physicians are presented with a significant number of difficult airway problems both during the insertion and removal of the airway. Critical care physicians need to be familiar with the difficult airway algorithms and have skill with relevant airway adjuncts.

Pressure support ventilation during fibreoptic intubation under propofol anaesthesia †

GOAL OF THE STUDY

To assess the benefit of pressure support ventilation during fibreoptic intubation performed under propofol anaesthesia in patients having an anticipated difficult intubation.

PROCEDURES

Thirty-two patients with ENT cancer, and having at least two criteria for anticipated difficult intubation were prospectively included. All patients received topical lidocaine 2% and propofol by plasma target control infusion (initial target concentration 3 microg ml(-1), then adjusted to maintain loss of consciousness without apnoea). They were randomly assigned between two groups: spontaneous breathing (SB) or pressure support ventilation (with a support level set at 10 cm H(2)O) both using Fi(o(2))=1. Conditions for fibreoptic intubation, respiratory parameters (pulse oxymetry, ventilatory frequency, tidal volume and PetCO2 after intubation) and haemodynamic parameters were recorded.

RESULTS

Patient characteristic data and intubation conditions were similar between both groups. All patients had a successful fibreoptic intubation and none needed a rescue procedure because of desaturation. In spite of a longer duration of intubation, PE'CO2 after intubation was lower and tidal volume during intubation was higher with pressure support ventilation than in SB patients [38.1 (4.2) vs 42.3 (4.7) mm Hg and 371 (139) vs 165 (98) ml, respectively]. Desaturation episodes were observed in two SB patients conversely to no episode during pressure support ventilation, probably because of the higher minute ventilation.

CONCLUSION

Pressure support represents a useful method to improve ventilation during fibreoptic intubation under propofol anaesthesia in patients with an anticipated difficult intubation.

Insertion of the double lumen tube in the difficult airway*

Isolation of a lung and one-lung ventilation are commonly used during thoracic surgery. Insertion of double lumen tubes requires considerable skill and may be especially challenging in the difficult airway. We describe a method of inserting double lumen tubes in two patients with known difficult airways. This technique involves awake nasotracheal intubation followed by insertion of an oral double lumen tube under general anaesthesia.

Awake fibrecapnic intubation: a novel technique for intubation in head and neck cancer patients with a difficult airway

Awake fibreoptic intubation is the gold standard for difficult airway management but failures are reported in the literature in up to 13% of cases. In case of failure, a tracheotomy is often indicated. We describe a novel technique for intubation in head and neck cancer patients with a difficult airway that we call awake fibrecapnic intubation. The aim of this study was to investigate the feasibility of this technique. We studied prospectively 15 consecutive intubations in head and neck cancer patients before diagnostic or therapeutic surgical procedures. After topical anaesthesia, a fibrescope was introduced into the pharynx. Spontaneous respiration was maintained in all patients. Through the suction channel of the fibrescope a special suction catheter was advanced into the airway for carbon dioxide measurements. When four capnograms were obtained, the fibrescope was railroaded over the catheter and after identification of tracheal rings, a tracheal tube was placed. Tracheal intubation was successful in all patients without bleeding or complications, with a median (range) time to intubation of 3 (2-15) min. Identification of the vocal cords and glottis was difficult in four patients due to extensive anatomical abnormalities or poor visibility; even in these patients, a capnogram was obtained within 4 s.

Dynamic Airflow Limitation after Topical Anaesthesia of the Upper Airway

This prospective before-and-after observational study investigated the effect of upper airway anaesthesia on dynamic airflow. Six consenting ASA 1 adults, all authors of this study, underwent a series of Spirometric measurements before and after topical anaesthesia of the upper airway using lignocaine. Peak inspiratory flow rate, forced inspiratory flow between 25% and 75% of the maximum inhaled volume, forced expiratory volume at 1 second, and forced vital capacity in the supine and sitting positions were measured. The measured inspiratory parameters were significantly reduced after lignocaine topical anaesthesia of the upper airway. Expiratory flow parameters were not affected. We conclude that topical anaesthesia of the upper airway leads to dynamic inspiratory airflow limitation.

Evaluation of the airway and preparation for difficulty

Preoperative airway evaluation is essential to consider which is the best method of maintaining and protecting the airway during surgery and whether problems with airway management are likely. In general surgical patients, the prevalence of difficult intubation is low and tests have poor predictive power. This means that the patient may be evaluated as normal but prove to be difficult. The absence of reliable prediction in general surgical patients means that airway strategy holds the key to successful management. Where there are obvious abnormalities in the history, examination or imaging the preoperative evaluation will allow choice of the most appropriate airway strategy which may include preparation of the patient, assembling of alternative airway equipment, advice and help from a more senior or skilled anaesthetist or aid from a surgical colleague or assistant.

Use of a ProSeal™ laryngeal mask airway and a Ravussin cricothyroidotomy needle in the management of laryngeal and subglottic stenosis causing upper airway obstruction

We report the successful use of a ProSeal laryngeal mask airway (PLMA) as a dedicated airway to allow fibre-optic inspection and passage through a tightly stenosed glottic and subglottic lesion, before fibre-optic-guided transtracheal placement of a Ravussin needle and jet ventilation. The described technique avoided both tracheostomy and the potential of 'seeding' the tumour by passage of the needle through the mass. The PLMA may be a useful 'dedicated airway' and has several advantages over the classic LMA(double dagger) and intubating LMA when used for this purpose. These include improved airway seal and reduced risk of aspiration. Four other cases of use of the PLMA as a dedicated airway during management of difficult airways are discussed. double daggerLMA is the property of Intavent Ltd.