Management of haematoma after thyroid surgery: systematic review and multidisciplinary consensus guidelines from the Difficult Airway Society,the British Association of Endocrine and Thyroid Surgeons and the British Association of Otorhinolaryngology,Head and Neck Surgery

Haematoma after thyroid surgery can lead to airway obstruction and death. We therefore developed guidelines to improve the safety of peri-operative care of patients undergoing thyroid surgery. We conducted a systematic review to inform recommendations, with expert consensus used in the absence of high-quality evidence, and a Delphi study was used to ratify recommendations. We highlight the importance of multidisciplinary team management and make recommendations in key areas including: monitoring; recognition; post-thyroid surgery emergency box; management of suspected haematoma following thyroid surgery; cognitive aids; post-haematoma evacuation care; day-case thyroid surgery; training; consent and pre-operative communication; postoperative communication; and institutional policies. The guidelines support a multidisciplinary approach to the management of suspected haematoma following thyroid surgery through oxygenation and evaluation; haematoma evacuation; and tracheal intubation. They have been produced with materials to support implementation. While these guidelines are specific to thyroid surgery, the principles may apply to other forms of neck surgery. These guidelines and recommendations provided are the first in this area and it is hoped they will support multidisciplinary team working, improving care and outcomes for patients having thyroid surgery.     

清醒气管插管气道局部麻醉技术的研究进展

对于术前评估为困难气道的患者应当采用清醒镇静表面麻醉下实施气管插管。实施清醒气管插管的关键技术是完善的气道局部麻醉。清醒气管插管是麻醉科医师必须掌握的技能之一。本文通过回顾近十年的文献,旨为麻醉科医师提供清醒气管插管气道局部麻醉技术相关理论参考。     

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.     

Airway management and oxygenation in obese patients

Purpose

The purpose of this Continuing Professional Development module is to describe anatomic and physiologic challenges in obese patients, review their effects on oxygenation and airway management, and propose strategies for perioperative management.

Principal findings

The combination of excess adipose tissue deposition, increased oxygen consumption, reduced lung volumes, and increased airway resistance in obese patients increases the risk of a difficult airway and rapid oxygen desaturation in the perioperative period. Preoxygenation can be optimized by a head-up or reverse Trendelenburg position, continuous positive airway pressure, and pressure support ventilation. Difficulties in bag and mask ventilation may occur. Laryngeal exposure during direct laryngoscopy is best achieved with the patient in the “ramped” position. Tracheal tube introducers or intubating stylets can assist tracheal intubation when suboptimal laryngeal views are obtained, and video laryngoscopy may help improve the glottic view and success of tracheal intubation. New generation double-lumen supraglottic airway devices provide higher leak pressures and may be safer in obese patients, and they can also provide a conduit for bronchoscopic intubation. In patients with anticipated difficult airways, preparations should be made for awake tracheal intubation. Intraoperatively, ventilatory strategies, such as recruitment maneuvers with positive end-expiratory pressure, may reduce atelectasis and improve oxygenation. Tracheal extubation in the head-up position and continuous positive airway pressure reduce postoperative hypoxemia. Following a difficult tracheal intubation, extubation over an airway exchange catheter should be considered.

Conclusions

Rapid oxygen desaturation may occur in obese patients. Potential difficulties in airway management should be assessed and anticipated, and oxygenation, ventilation, and airway management strategies should be optimized perioperatively.     

Major complications of airway management: a prospective multicentre observational study

We conducted an observational study of serious airway complications, using similar methods to the fourth UK National Audit Project (NAP4) over a period of 1 year across four hospitals in one region in the UK. We also conducted an activity survey over a week, using NAP4 methods to yield an estimate for relevant denominators to help interpret the primary data. There were 17 serious airway complications, defined as: failed airway management leading to cancellation of surgery (eight); airway management in recovery (five); unplanned intensive care admission (three); and unplanned emergency front of neck access (one). There were no reports of death or brain damage. This was an estimate of 0.028% (1 in 3600) complications using the denominator of 61,000 general anaesthetics per year in the region. Complications in patients with ‘predicted easy’ airways were rare (approximately 1 in 14,200), but 45 times more common in those with ‘predicted difficult’ airways (approximately 1 in 315). Airway management in both groups was similar (induction of anaesthesia followed by supraglottic airway or tracheal tube). Use of awake/sedation intubation, videolaryngoscopy and high-flow nasal oxygenation were uncommon even in the predicted difficult airway patients (in 2.7%, 32.4% and 9.5% of patients, respectively). We conclude that the incidence of serious airway complications is at least as high as it was during NAP4. Despite airway prediction being used, this is not informing subsequent management.     

Usability of AirWay Scope for awake tracheal intubation in a burn patient with difficult airway

The AirWay Scope (AWS; PENTAX Corporation, Tokyo, Japan) is a newly developed rigid video laryngoscope with a built-in LCD monitor that provides accurate verification of tube passage through the vocal cords during tracheal intubation procedures. The blade is shaped to fit the oropharyngeal anatomy, which enables operators to achieve an optimal view for tracheal intubation without requiring alignment of the oral, pharyngeal, and laryngeal axes. We used an AWS for awake intubation in a 34-year-old male burn patient with a difficult airway under conscious sedation obtained with infusion of dexmedetomidine (DEX). Following topical anesthesia of the upper airway and preoxygenation, sedation was induced with 6 microg kg(-1) hr(-1) of DEX for 13 minutes and maintained at 0.5 microg kg(-1) hr(-1). Thereafter, insertion of the AWS gave a Cormack grade 1 glottic view, and endotracheal anesthesia was provided by use of a modified spray tube through the AWS blade without patient anxiety or discomfort. The trachea was intubated using the AWS without respiratory depression or other complications while the patient was sedated (Ramsay sedation scale class 4). We consider the AWS to be useful for awake tracheal intubation in patients with a difficult airway.     

Intubation au vidéolaryngoscope sous-sédation

We report a video laryngoscopic tracheal intubation under sedation in a patient with a hip fracture. Preoperative assessment revealed signs of difficult airway management linked to a cervical spine immobilization. Here we describe an alternative method to awake fiber optic flexible intubation.     

Awake tracheal intubation using the Airtraq® laryngoscope: a case series

The Airtraq^® laryngoscope (AL) is a new single use indirect laryngoscope designed to facilitate tracheal intubation in anaesthetised patients either with normal or difficult airway anatomy. It is designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. We report four cases of successful awake tracheal intubation using the AL. The first case is a patient with severe ankylosing spondylitis and the other three cases with anticipated difficult airway. An awake intubation under sedation and topical airway anaesthesia was chosen. We consider that the AL can be used effectively to accomplish an awake intubation in patients with a suspected or known difficult airway and may be a useful alternative where other methods for awake intubation have failed or are not available.     

Monitoring during difficult airway management

Monitoring is crucial to assure safety during difficult airway management. Several reports have indicated that the most of the adverse outcomes associated with difficult airway management could have been avoided with the use of necessary monitors, such as a pulse oximeter and a capnometer. Nevertheless, airway complications continue to be major problems during anesthesia, in particular, in patients with difficult airways. In this brief review, I stress the role of monitoring in detecting inadvertent esophageal intubation, during sedation for awake tracheal intubation, during general anesthesia, and during emergence from anesthesia, in patients with difficult airways.     

Awake tracheal intubation through the intubating laryngeal mask airway in a patient with halo traction

PURPOSE: To report a case of awake tracheal intubation through the intubating laryngeal mask airway (ILMA) in a patient with halo traction. Clinical features: A 16-yr-old, 40 kg, boy with atlanto-occipital instability and halo traction was scheduled for surgery under general anesthesia. The head of the patient was fixed in a position of flexion and extension was impossible. Cranial magnetic resonance imaging revealed that pharyngeal and laryngeal axes were aligned, but that the oral axis was in an extreme divergent plane. The tongue and oropharynx were anesthetized with 10% lidocaine spray and bilateral superior laryngeal nerve blockade was performed. Under sedation, awake orotracheal intubation via ILMA was successful. Fibreoptic bronchoscopy has been recommended for awake tracheal intubation in such patients. Other techniques, such as use of the Bullard laryngoscope have been described also but awake tracheal intubation through the ILMA in patients with a halo device in situ has seldom been reported in the medical literature. CONCLUSION: Airway management of patients with cervical spine instability includes adequate preoperative evaluation of the airway and choosing the appropriate intubation technique. We suggest that the ILMA may be an adequate alternative for awake tracheal intubation in patients with an unstable cervical spine and cervical immobilization with a halo device.     

Atomised lidocaine for airway topical anaesthesia in the morbidly obese: 1% compared with 2%*

Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in morbidly obese patients was evaluated using two doses of local anaesthetic. In this randomised, blinded prospective study, 40 ml of atomised 1% (n = 11) or 2% (n = 10) lidocaine was administered with high oxygen flow as carrier. Outcomes included time for intubation, patient tolerance to airway manipulation, haemodynamic parameters, the bronchoscopist’s overall satisfaction, and serial serum lidocaine concentrations. Patients receiving lidocaine 1% had a longer mean (SD) time from the start of topicalisation to tracheal tube cuff inflation than those receiving lidocaine 2% (8.6 (0.9) min vs 6.9 (0.5) min, respectively; p < 0.05). Patients in the 1% cohort demonstrated increased responses to airway manipulation (p < 0.0001), reflecting lower bronchoscopist’s satisfaction scores (p < 0.03). Haemodynamic responses to topicalisation and airway manipulation were similar in both groups. Peak plasma concentration was lower in the 1% group (mean (SD) 1.4 (0.3) and 3.8 (0.5) μg.ml^?1, respectively; p < 0.001). Airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in the morbidly obese is efficacious, rapid and safe. Compared with lidocaine 1%, the 2% dose provides superior intubating conditions.     

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.     

A feasibility study of awake videolaryngoscope‐assisted intubation in patients with periglottic tumour using the channelled King Vision® videolaryngoscope

Airway management in patients with periglottic tumour is a high‐risk procedure with potentially serious consequences. There is no consensus on how best to secure the airway in this group of patients. We conducted a feasibility study of awake tracheal intubation using a King Vision^® videolaryngoscope with a channelled blade in a cohort of 25 patients, with a periglottic tumour requiring diagnostic or radical surgery. We used 10% and 4% lidocaine to topicalise the airway and midazolam and remifentanil for sedation. We recorded the success rate, number of attempts, time to obtain glottic view, time to intubation and complications. Twenty‐three of the 25 patients (92%, 95%CI 75–98%) were intubated with the awake videolaryngoscope‐assisted technique, with 17/23 (74%, 95%CI 54–87%) intubations achieved at the first attempt. Five patients required two and one patient, three attempts at intubation. Two patients (8%, 95%CI 2–25%) could not tolerate the procedure due to inadequate topical anaesthesia. Median (IQR [range]) times to obtain glottic view and to intubate were 19 (17–22 [10–30]) s and 49 (42–71 [33–107]) s, respectively. Traces of blood in the airway were observed in 4/25 (16%, 95%CI 6–35%) patients. Although airway management in this group of patients was expected to be difficult, successful awake intubation with the King Vision videolaryngoscope was achieved in the majority of patients within less than a minute. This study highlights a number of potential advantages of awake videolaryngoscope‐assisted intubation over other awake methods of securing the airway in patients with upper airway obstruction due to periglottic mass.     

Use of the intubating laryngeal mask airway to facilitate awake orotracheal intubation in patients with cervical spine disorders.

Airway management in patients with unstable cervical spines remains a challenge for anesthesia providers. Because neurologic evaluations may be required following tracheal intubation and positioning for the surgical procedure, an awake intubation technique is desirable in this patient population. In this report, we describe the use of an intubating laryngeal mask airway (ILMA) to facilitate awake tracheal intubation in two patients with cervical spine disorders. After topical local analgesia, the ILMA was inserted easily, and a tracheal tube was passed through the glottic opening without complications. Thus, the ILMA may be an acceptable alternative to the fiberoptic bronchoscope for awake tracheal intubation.     

The use of extracorporeal membrane oxygenation in the anticipated difficult airway: a case report and systematic review

While extracorporeal membrane oxygenation (ECMO) is an effective method of oxygenation for patients with respiratory failure, further refinement of its incorporation into airway guidelines is needed. We present a case of severe glottic stenosis from advanced thyroid carcinoma in which gas exchange was facilitated by veno-arterial ECMO prior to achieving a definitive airway. We also conducted a systematic review of the MEDLINE, EMBASE, CINAHL, and Web of Science databases, using the keywords “airway/ tracheal obstruction”, “anesthesia”, “extracorporeal”, and “cardiopulmonary bypass” to identify reports where ECMO was initiated as the a priori method of oxygenation during difficult airway management.Thirty-six papers were retrieved discussing the use of ECMO or cardiopulmonary bypass (CPB) for the management of critical airway obstruction. Forty-five patients underwent pre-induction of anesthesia institution of CPB or ECMO for airway obstruction. The patients presenting with critical airway obstruction had a range of airway pathologies with tracheal tumours (31%), tracheal stenosis (20%), and head and neck cancers (20%) being the most common. All cases reported a favourable patient outcome with all patients surviving to hospital discharge without significant complications.While most practitioners are familiar with the fundamental airway techniques of bag-mask ventilation, supraglottic airway use, tracheal intubation, and front-of-neck airway access for oxygenation, these techniques have limitations in managing patients with pre-existing severe airway obstruction. The use of ECMO should be considered in patients with severe (or near-complete) airway obstruction secondary to anterior neck or tracheal disease. This approach can provide essential tissue oxygenation while attempts to secure a definitive airway are carried out in a controlled environment.     

Airway topicalisation in morbidly obese patients using atomised lidocaine: 2% compared with 4%

We evaluated the technique of airway anaesthesia using atomised lidocaine for awake oral fibreoptic intubation in morbidly obese patients using two doses of local anaesthetic. Morbidly obese patients were allocated to receive either 2% or 4% lidocaine (40 ml) for oral airway anaesthesia using an atomiser with high oxygen flow. Patients were carefully sedated using midazolam and fentanyl. Outcomes included patient tolerance to airway manipulation, haemodynamic parameters, and serial plasma lidocaine concentrations. In all, 27 patients were enrolled in the study (2% cohort n = 14, 4% cohort n = 13). Patient characteristics and time for topicalisation and airway management were similar. Haemodynamic parameters did not change significantly. Tolerance to insertion of the Ovassapian airway, bronchoscopy, and tracheal tube positioning was excellent (12 vs 12 patients, 12 vs 12 patients, and 8 vs 12 patients had no response, respectively, 2% vs 4%). Differences did not reach statistical significance. Peak plasma lidocaine concentration was significantly lower in the 2% group (2.8 (0.8) microg.ml(-1) compared with 6.5 (1.0) microg.ml(-1), p < 0.05). Airway anaesthesia using atomised lidocaine for awake fibreoptic intubation in the morbidly obese is efficacious, rapid, and safe. Compared with 4% lidocaine, the 2% dose provides acceptable intubating conditions in most cases and produces lower plasma lidocaine levels.     

Obstetric Anaesthetists' Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics

The Obstetric Anaesthetists' Association and Difficult Airway Society have developed the first national obstetric guidelines for the safe management of difficult and failed tracheal intubation during general anaesthesia. They comprise four algorithms and two tables. A master algorithm provides an overview. Algorithm 1 gives a framework on how to optimise a safe general anaesthetic technique in the obstetric patient, and emphasises: planning and multidisciplinary communication; how to prevent the rapid oxygen desaturation seen in pregnant women by advocating nasal oxygenation and mask ventilation immediately after induction; limiting intubation attempts to two; and consideration of early release of cricoid pressure if difficulties are encountered. Algorithm 2 summarises the management after declaring failed tracheal intubation with clear decision points, and encourages early insertion of a (preferably second‐generation) supraglottic airway device if appropriate. Algorithm 3 covers the management of the ‘can't intubate, can't oxygenate’ situation and emergency front‐of‐neck airway access, including the necessity for timely perimortem caesarean section if maternal oxygenation cannot be achieved. Table 1 gives a structure for assessing the individual factors relevant in the decision to awaken or proceed should intubation fail, which include: urgency related to maternal or fetal factors; seniority of the anaesthetist; obesity of the patient; surgical complexity; aspiration risk; potential difficulty with provision of alternative anaesthesia; and post‐induction airway device and airway patency. This decision should be considered by the team in advance of performing a general anaesthetic to make a provisional plan should failed intubation occur. The table is also intended to be used as a teaching tool to facilitate discussion and learning regarding the complex nature of decision‐making when faced with a failed intubation. Table 2 gives practical considerations of how to awaken or proceed with surgery. The background paper covers recommendations on drugs, new equipment, teaching and training.     

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

Background

Previously 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.

Methods

Nineteen 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.

Conclusions

The 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.