Alternative techniques for tracheal intubation

Conventional direct laryngoscopy with the curved Macintosh blade is a fundamental skill for all anaesthetists and has been the cornerstone of airway management for many years. This technique relies on the operator aligning the oro-pharyngo-laryngeal structures and inserting an endotracheal tube into the trachea under direct vision. There is a recognized failure rate with this technique and thus alternative techniques for tracheal intubation should be available for use in difficult situations. Awake fibreoptic intubation (AFOI) remains the ‘gold standard’ method for securing the airway in an anticipated difficult intubation. Advances in optical technology over recent years have lead to the development of several rigid indirect devices, which improve glottic visualization by enabling the operator to ‘see around the corner’. With improved views at laryngoscopy these videolaryngoscopes are emerging as important tools in airway management and useful teaching and training aids.     

Alternative techniques for tracheal intubation

Conventional direct laryngoscopy with the curved Macintosh blade is a fundamental skill for all anaesthetists and has been the cornerstone of airway management for many years. This technique relies upon the operator aligning the oro-pharyngo-laryngeal structures and inserting a tracheal tube into the trachea under direct vision. However, there is a recognized failure rate with this technique, thus alternative techniques for tracheal intubation are available and should be considered. Awake fibreoptic intubation remains the ‘gold standard’ method for securing the airway in an anticipated difficult airway. Advances in optical technology over recent years have led to the development of several rigid indirect devices, which improve glottic visualization by enabling the operator to ‘see around the corner’. With improved views at laryngoscopy these devices have emerged as important tools in airway management and are useful teaching and training aids.     

Direct laryngoscopy and endotracheal intubation in the prone position following traumatic thoracic spine injury

Perioperative airway management in trauma victims presenting with penetrating thoracic spine injury poses a major challenge to the anesthesiologist. To avoid further neurological impairment it is essential to ensure maximal cervical and thoracic spine stability at the time of airway manipulation (e.g., direct laryngoscopy and endotracheal intubation). Airway management in the prone position additionally increases the incidence of cervical/thoracic spine injury, difficult ventilation, and difficult airway instrumentation. Although awake fiberoptic intubation of the trachea is considered the gold standard for airway instrumentation in patients with posterior thoracic/cervical trauma, this technique requires the patient's cooperation, special equipment, and extensive training, all of which might be difficult to accomplish in emergency situations. We herein present the first reported case of an adult trauma patient who underwent direct laryngoscopy and endotracheal intubation under general anesthesia in the prone position. Although the prone position is not the standard position for airway instrumentation with direct laryngoscopy and endotracheal intubation under general anesthesia, our experience indicates that this technique is possible (and relatively easy to perform) and might be considered in an emergency situation.     

Fiberoptic techniques

Fiberoptic intubation of the spontaneously breathing patient is the gold standard and technique of choice for the elective management of a difficult airway. In the hands of the properly trained and experienced user, it is also an excellent 'plan B' alternative when direct laryngoscopy unexpectedly fails. Fiberscope-assisted intubation through an endoscopy face mask, laryngeal mask airway or intubating laryngeal mask airway secures ventilation and oxygenation, and permits endotracheal intubation in airway emergency situations. Portable fiberscopes can be used in remote settings, increasing patient safety. This review discusses current fiberoptic intubation techniques and their applications in the management of both the anticipated and unanticipated difficult airway.     

The difficult airway in obstetric anesthesia: Techniques for airway management and the role of regional anesthesia

A case is presented illustrating the use of a continuous spinal anesthetic in a parturient with a difficult airway who required urgent cesarean delivery. Options for endotracheal intubation of a parturient with a difficult airway are reviewed. The role of regional anesthesia in this setting is discussed. The most appropriate methods for intubation of the obstetric patient are direct laryngoscopy, the lighted stylet, and fiberoptic endoscopy. Available data suggest that regional anesthesia, specifically continuous spinal anesthesia, may be a safe and effective option for management of a parturient with a difficult airway. Further investigation of this technique is merited.     

Canadian pediatric anesthesiologists prefer inhalational anesthesia to manage difficult airways: A survey

PURPOSE: To survey Canadian pediatric anesthesiologists to assess practice patterns in managing pediatric patients with difficult airways. METHODS: Canadian pediatric anesthesiologists were invited to complete a web survey. Respondents selected their preferred anesthetic and airway management techniques in six clinical scenarios. The clinical scenarios involved airway management for cases where the difficulty was in visualizing the airway, sharing the airway and accessing a compromised airway. RESULTS: General inhalational anesthesia with spontaneous respiration was the preferred technique for managing difficult intubation especially in infants (90%) and younger children (97%), however, iv anesthesia was chosen for the management of the shared airway in the older child (51%) where there was little concern regarding difficulty of intubation. Most respondents would initially attempt direct laryngoscopy for the two scenarios of anticipated difficult airway (73% and 98%). The laryngeal mask airway is commonly used to guide fibreoptic endoscopy. The potential for complete airway obstruction would encourage respondents to employ a rigid bronchoscope as an alternate technique (17% and 44%). CONCLUSION: Inhalational anesthesia remains the preferred technique for management of the difficult pediatric airway amongst Canadian pediatric anesthesiologists. Intravenous techniques are relatively more commonly chosen in cases where there is a shared airway but little concern regarding difficulty of intubation. In cases of anticipated difficult intubation, direct laryngoscopy remains the technique of choice and fibreoptic laryngoscopy makes a good alternate technique. The use of the laryngeal mask airway was preferred to facilitate fibreoptic intubation.     

Flexible fibre-optic intubation

Flexible fibre-optic intubation has been practised for 40 years. It is an enormously useful skill, but it is not always the most appropriate tactic to deploy. The great advantage of flexible endoscopy is that the passage of an endoscope is acceptable to conscious patients, so that a tracheal tube can be placed easily when face-mask ventilation or direct laryngoscopy is likely to be difficult. The best position for the endoscopist is by the patient’s side (whether the patient is conscious or not) and the patient should be semi-sitting when possible. Disorientation because of premature entry is the most frequent source of difficulty in the authors’ experience. ‘Railroading’ the tracheal tube can also cause difficulty. In the authors’ experience flexible reinforced tubes are the easiest to use, and it is vital to refrain from pushing the tube – it must be advanced gently while being constantly rotated. Lidocaine in generous doses (< 9 mg/kg) is used for topical anaesthesia, but can cause airway obstruction as a result of glottic irritation. It must be applied cautiously. There are several successful methods of sedation available, with remifentanil infusion probably being the most popular in the UK at present.     

视频喉镜在气道管理中应用的进展

视频喉镜是能够提供上呼吸道间接视野的新型气管插管设备。在困难气道管理处理方面．与直接喉镜相比．视频喉镜能够改善声门显露的Cormack—Lehane分级,并能在较短时间内达到相同或更高的气管插管成功率。尽管视频喉镜可获得非常好的声门显露．但是应用视频喉镜时插入和推进气管导管有时可发生失败。到目前为止,尚无确切证据表明在正常或困难气道患者视频喉镜应取代直接喉镜。     

Management choices for the difficult airway by anesthesiologists in Canada

PURPOSE: This study assessed difficult airway management, training and equipment availability among Canadian anesthesiologists. METHODS: A postal survey of active members of the Canadian Anesthesiologists' Society was conducted in 2000. Respondents chose an induction condition and intubation technique for each of ten difficult airway scenarios. Availability of airway devices in their workplaces was assessed. Chi square analyses were used to compare groups. A P value of < 0.05 was considered statistically significant. RESULTS: Eight hundred and thirty-three of 1702 (49%) surveys were returned. Staff comprised 88%, and residents 12%. Fifty-five percent had attended a difficult airway workshop within five years and 30% received mannequin airway training during residency. Direct laryngoscopy (48%) or fibreoptic bronchoscopy (34%) were the preferred techniques for intubation. For laryngeal, subglottic and unstable cervical spine scenarios, awake intubation with fibreoptic bronchoscope was most widely chosen. Asleep intubation with direct laryngoscopy was most commonly selected for trauma scenarios. Availability of difficult airway equipment varied between regions and types of hospital. Cricothyroidotomy equipment and difficult airway carts were not universally available. CONCLUSIONS: Our survey assessed current preferences, training and equipment availability for the difficult airway amongst Canadian anesthesiologists. Direct laryngoscopy and fibreoptic bronchoscopy were the preferred technique for intubation despite widespread availability of newer airway equipment. Lack of certain essential airway equipment and difficult airway training should be addressed.     

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.     

Tracheal intubation using suspension laryngoscopy in an infant with Goldenhar's syndrome.

We present a case of a ten-month-old boy with Goldenhar's syndrome and significant retrognathia in whom a tracheostomy was performed to relieve upper airway obstruction. Tracheal intubation was facilitated by direct suspension laryngoscopy using a slotted rigid laryngoscope. We propose this technique as an alternative method for tracheal intubation in infants and young children with a difficult airway. The management of the difficult airway in children with Goldenhar's syndrome is discussed.     

Infraglottic airway devices and techniques

Infraglottic airway management techniques, such as intubation of the trachea with a cuff-sealed endotracheal tube, offer significant advantages for the anaesthetized patient, especially for patients in critical condition.There are numerous ways of intubation of the trachea; the most common and popular is direct laryngoscopy. The variety of laryngoscope blades offers choices to solve difficult intubations, but all different techniques and devices need experience in routine clinical use.In case of failure, unsuccessful attempts to intubate the trachea should be limited to three, in order to use different—e.g. supraglottic or fibreoptic—techniques.Nasotracheal intubation causes an inherent risk of severe epistaxis, which may severely compromise airway management options and endangers the patient's life. Prior to passing the tube through the nose, direct laryngoscopy should be performed to estimate the Cormack–Lehane score.Rigid intubation fibrescopes—as flexible ones—do improve the view of the larynx and permit tracheal intubation with less head and cervical spine movement than direct laryngoscopy. Success with these devices requires considerable experience and clinical practice.The use of retrograde intubation has reduced during recent years, mainly due to the availability of flexible and rigid intubation fibrescopes.The EasyTube—a relatively new device—combines the advantages of both an endotracheal tube with a supraglottic airway device.The Combitube is a well-established emergency airway used widely for solving unanticipated and anticipated difficult airways. International guidelines recommend the use of Combitube following the number of studies and reports associated with its use.     

Indirekte Laryngoskopie

Endotracheal intubation remains the gold standard for securing the airway in emergency medicine. However, difficult endotracheal intubation and complications are common during emergency intubation. In contrast to conventional direct laryngoscopy, the new generation of devices does not require direct visualization of the vocal cords for endotracheal tube placement. These devices allow a better glottic view and successful endotracheal placement of the tube, especially if direct laryngoscopy is difficult. Recent studies showed that utilization of these devices can be easily learned. The technique of indirect laryngoscopy is currently used for securing the airway in daily anesthesia routine as well as for managing the difficult airway in the operating room. This article gives an overview of available devices for indirect endotracheal intubation as well as the current literature.     

A multicentre randomised controlled trial of the McGrath™ Mac videolaryngoscope versus conventional laryngoscopy

Before completion of this study, there was insufficient evidence demonstrating the superiority of videolaryngoscopy compared with direct laryngoscopy for elective tracheal intubation. We hypothesised that using videolaryngoscopy for routine tracheal intubation would result in higher first-pass tracheal intubation success compared with direct laryngoscopy. In this multicentre randomised trial, 2092 adult patients without predicted difficult airway requiring tracheal intubation for elective surgery were allocated randomly to either videolaryngoscopy with a Macintosh blade (McGrath™) or direct laryngoscopy. First-pass tracheal intubation success was higher with the McGrath (987/1053, 94%), compared with direct laryngoscopy (848/1039, 82%); absolute risk reduction (95%CI) was 12.1% (10.9–13.6%). This resulted in a relative risk (95%CI) of unsuccessful tracheal intubation at first attempt of 0.34 (0.26–0.45; p < 0.001) for McGrath compared with direct laryngoscopy. Cormack and Lehane grade ≥ 3 was observed more frequently with direct laryngoscopy (84/1039, 8%) compared with McGrath (8/1053, 0.7%; p < 0.001) No significant difference in tracheal intubation-associated adverse events was observed between groups. This study demonstrates that using McGrath videolaryngoscopy compared with direct laryngoscopy improves first-pass tracheal intubation success in patients having elective surgery. Practitioners may consider using this device as first choice for tracheal intubation.     

Oral to nasal tube exchange under fibroscopic view: a new technique for nasal intubation in a predicted difficult airway

For a predicted difficult airway, oral intubation techniques are well established in pediatric anesthesia, but nasotracheal intubation remains a problem. There are many reports concerning this, but the risk of bleeding, added to the lack of cooperation make this procedure difficult and hazardous. We describe a modification of the nasal intubation technique in two stages. First an oral intubation and then exchanging the oral for a nasal tube, in the case of a 13-year-old boy affected by an advanced stage of cherubism. Oral intubation using a laryngeal mask technique has already been reported, but problems appear during the exchange procedure and even more when direct laryngoscopy is impossible. Fiberscopic control of the exchange, and the introduction of a Cook Exchange Catheter into the trachea through the oral tube before withdrawal, permits oxygenation of the patient and acts as a guide for oral tube reintroduction if required.     

Lightwand guided intubation in paediatric patients with a known difficult airway: a report of four cases

The anaesthetic management of children with craniofacial abnormalities often presents unique challenges because soft tissue and bony abnormities can affect the airway and influence airway management. We report four paediatric patients with predicted difficult airways due to craniofacial abnormalities. They all had a laryngeal view of Cormack–Lehane grade IV and were impossible to intubate using direct laryngoscopy. Fibreoptic intubation was also repeatedly attempted but was not successful. All the tracheal intubations were completed using a lightwand on the first attempt in less than 30 s. We consider that lightwand guided intubation technique may be a useful alternative approach to fibreoptic intubation technique in managing the difficult paediatric airway.     

Supraglottic airway devices in difficult airway management: a retrospective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database

Indications for using supraglottic airway devices have widened over time and they now hold a prominent role in guidelines for difficult airway management. We aimed to describe the use of supraglottic airway devices in difficult airway management. We included adult patients undergoing general anaesthesia registered in the Danish Anaesthesia Database from 2008 to 2012 whose airway management had been recorded as difficult, defined as: ≥ 3 tracheal intubation attempts; failed tracheal intubation; or difficult facemask ventilation. In the Danish Anaesthesia Database, a separate difficult airway management module requires the technique used in each successive airway management attempt to be recorded. The primary aim of the study was to describe the use of supraglottic airway devices in cases of difficult airway management. Secondary aims were to examine success rates of supraglottic airway devices in difficult airway management cases, and specifically in the cases of ‘cannot intubate, cannot facemask ventilate’. Difficult airway management occurred in 4898 (0.74% (95%CI 0.72–0.76%)) of 658,104 records of general anaesthesia. Supraglottic airway devices were used or use was attempted in 607 cases of difficult airway management (12.4% (95%CI 11.5–13.3%)), and were successful in 395 (65.1% (95%CI 61.2–68.8%)) cases. In ‘cannot intubate, cannot facemask ventilate’ situations, supraglottic airway devices were used in 86 (18.9% (95%CI 15.6–22.8%)) of 455 records and were successful in 54 (62.8% (95%CI 52.2–72.3%)) cases. We found that supraglottic airway devices are not widely used in the management of the difficult airway despite their prominent role in difficult airway management guidelines.     

Management of the anticipated difficult airway—a systematic approach: Continuing Professional Development

Purpose

The purpose of this Continuing Professional Development module (CPD) is to update clinicians regarding a systematic approach for anticipated difficult airway management.

Principal findings

The focus of the approach should be directed towards providing adequate oxygenation and ventilation and not necessarily intubating the trachea. The purpose of preoperative airway assessment is not only to detect possible difficult direct laryngoscopy, but also to evaluate the probability of effective ventilation using supraglottic airway devices, such as the oropharyngeal airway or the laryngeal mask airway. Predicting the degree of difficulty with direct laryngoscopy or ventilation with a supraglottic device remains an imperfect science, and the experience of the anesthesiologist plays an important role in the clinical decision-making process. When a difficult airway is anticipated, the need for tracheal intubation should be carefully assessed. If tracheal intubation is deemed non-essential, the role of a supraglottic device should be considered. If adequate management with a supraglottic device is unlikely, then intubation is indicated with the patient awake. In certain cases, a sevoflurane induction may be chosen to test the efficacy of a supraglottic device while simultaneously maintaining spontaneous ventilation. If tracheal intubation is required, a supraglottic device may be used as a bridge during induction of anesthesia and may even be used to insert the tracheal tube. The choice of either the supraglottic device or another aid to intubation depends essentially on the anesthesiologist’s experience.

Conclusion

Airway management should be approached systematically, always keeping in mind the importance of uninterrupted oxygenation and ventilation, especially when difficulties are anticipated. Supraglottic devices can play an important role in the management of the difficult airway, whether used for the duration of surgery or inserted as an aid to intubation.     

Videolaryngoskopie olé!

A number of video laryngoscopy systems have been introduced into anesthetic practice in recent years. Due to the technical concepts of these systems exposure of the laryngeal structures is usually better than with direct laryngoscopy, both in normal airways as well as in those that are difficult to manage. With the increasing use of video laryngoscopy it seems as if direct laryngoscopy and flexible fibrescopic intubation are at risk of becoming redundant. This article describes current developments and discusses why expertise in direct laryngoscopy and flexible fibrescopic intubation should be maintained, particularly by experts in airway management.     

A two-person technique for fiberscope-aided tracheal extubation/reintubation in intensive care unit (ICU) patients

The technique of fiberoptic-aided intubation for management of a difficult airway is often limited in the presence of blood or secretions and conditions in which the passage of a fiberoptic bronchoscope ("fiberscope") beneath the epiglottis and into the glottic opening may prove difficult. Direct laryngoscopy can be utilized in combination with the fiberscope as a two-person technique to overcome these challenges. We report the usefulness of a two-person technique using the flexible fiberscope in combination with direct laryngoscopy for extubation/reintubation in two intensive care unit patients with known difficult airways.