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 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.     

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.     

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.     

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

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

Use of a tracheoscopic ventilation tube for endotracheal intubation in the difficult airway

Difficult endotracheal intubation is a clinical challenge for anesthesiologists and other practitioners of airway management. The use of a tracheoscopic ventilation tube, a novel airway device, for endotracheal intubation during general anesthesia in two patients with difficult airways after unsuccessful direct laryngoscopy is presented.     

Difficult intubation managed using standard laryngeal mask airway, flexible fibreoptic bronchoscope and wire guided enteral feeding tube

This case report describes an alternative method of achieving trans-oral intubation in a patient with a difficult airway who was apnoeic secondary to the therapeutic administration of a non-depolarizing neuromuscular blocking drug given to aid laryngoscopy. After attempts to intubate were unsuccessful by means of direct laryngoscopy utilizing various aids including bougies, a standard laryngeal mask airway was used to ventilate the patient and subsequently, with a swivel Y-connector attached in order to maintain PEEP, to aid the passage of a bronchoscope. The flexible guide-wire from an enteral feeding tube was then passed through the suction port of the bronchoscope into the trachea, after which the laryngeal mask airway and bronchoscope were withdrawn. By passing the enteral feeding tube over the guide-wire and then using this as a guide, a cuffed endotracheal tube was inserted into the trachea. The technique described permitted the continuous application of positive airway pressure, which dramatically improved the bronchoscopic view during the crucial step of placing the guide-wire into the trachea. Passing the feeding tube over the guide-wire aided the subsequent passage of the endotracheal tube, by acting as a stiffer and larger diameter guide through the glottis.     

Use of the Laryngeal Tube™ in two unexpected difficult airway situations: lingual tonsillar hyperplasia and morbid obesity

PURPOSE: The 2003 ASA Practice Guidelines for Management of the Difficult Airway suggest the early use of the Laryngeal Mask Airway and Combitube as rescue airway devices in the cannot ventilate-cannot intubate situation, switching the focus from laryngoscopy and intubation to ventilation and oxygenation. The Practice Guidelines are not intended as standards but as recommendations. Multiple new alternative airway devices were described in the last ten years. The Laryngeal Tube (LT) is a new Food and Drug Administration approved supraglottic airway device. The device is in use in Europe since 1999 and in the United States since 2002. CLINICAL FEATURES: We report two cases in which the LT was used to solve two unexpected difficult airway situations. The first case ("cannot intubate-inadequate mask ventilation") involved an undiagnosed lingual tonsillar hyperplasia and the LT provided the means to ventilate and administer the anesthetic. In the second case ("cannot ventilate-cannot intubate") we report the successful use of the LT to rescue the airway in a morbidly obese patient. In both cases an endotracheal tube was ultimately inserted using an awake fibreoptic technique with the patient in the sitting position. CONCLUSIONS: In these clinical situations of unexpected difficult airway with significant periglottic obstruction the LT provided adequate ventilation after the first insertion. The LT may complement the laryngeal mask airway in difficult airway management. Further research is needed to define the role of the LT in the management of difficult airways.     

Use of the video laryngoscopy for Combitube exchange in a difficult airway

Following failed intubation attempts via conventional direct laryngoscopy, an Esophageal Tracheal Combitube was successfully placed in the esophagus of a 51-year-old man with a subdural hematoma and uncleared cervical spine. The decision was made to change the Combitube for an endotracheal tube (ETT). After deflation of the large oropharyngeal cuff of the Combitube, video laryngoscopy was performed with the Direct Coupled Interface (DCI) video intubation system, and the Combitube was exchanged for an ETT with the assistance of a gum elastic bougie.     

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.     

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。     

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.     

Management des schwierigen Atemwegs

Several national airway task forces have recently updated their recommendations for the management of the difficult airway in adults. Routinely responding to airway difficulties with an algorithm-based strategy is consistently supported. The focus is increasingly not on tools and devices but more on good planning, preparation and communication. In the case of anticipated airway difficulties the airway should be secured when the patient is awake with maintenance of spontaneous ventilation. Unaltered a flexible bronchoscopic intubation technique is advised as a standard of care in such patients. The importance of maintenance of oxygenation is emphasized. Face mask ventilation and the use of supraglottic devices are recommended if unexpected airway difficulties occur. Face mask ventilation may be facilitated and optimised by early administration of neuromuscular blocking agents. If required, in not fastened patients threatened by acute hypoxia, carefully applied and pressure-controlled ventilation may ensure sufficient oxygenation until the airway is secured. Apnoeic oxygen techniques are recommended in high-risk patients and to relieve the time pressure of falling oxygen saturation during decision-making processes. The early use of video laryngoscopy is advised for endotracheal intubation in the case of failed direct laryngoscopy or if intubation is expected to be difficult. For the coverage of cannot intubate-cannot oxygenate scenarios, second generation supraglottic devices and invasive airway access are advocated. The discussion regarding the optimal technique for emergency invasive airway access is still in progress. In the case of uncontrollable respiratory deterioration and progressive hypoxia, the algorithm must be consistently executed and without delay due to ineffective activities (straightforward strategy). Although there is no evidence to support the selection of a particular approach, the importance and the need for a defined airway concept/algorithm in any anesthesia department is fostered. Simplicity and clarity are essential for recall under stressful and time-sensitive conditions. The algorithm should be adapted to local conditions and preferences and devices should be limited to a definite number. The acquisition and maintenance of expertise by education and training is demanded.     

Bronchoscopy via a Redesigned Combitube(TM) in the Esophageal Position: A Clinical Evaluation

Background: The esophageal-tracheal Combitube (Kendall-Sheridan Catheter Corp., Argyle, NY) is an effective device for providing adequate gas exchange. However, tracheal suctioning is impossible with the Combitube placed in the esophageal position. To eliminate this disadvantage, the Combitube was redesigned by creating an enlarged hole in the pharyngeal lumen that allows fiberoptic access, tracheal suctioning, and tube exchange over a guide wire.

Methods: The two anterior, proximal perforations of regular Combitubes were replaced by a larger, ellipsoid-shaped hole. After the study was approved by the institutional review board, 20 patients with normal airways (Mallampati I or II) were studied. During general anesthesia, patients were esophageally intubated with the Combitube. A flexible bronchoscope was inserted and guided via the modified hole and glottic opening down the trachea. For the replacement procedure, a J tip guide wire was introduced through the bronchoscope. The bronchoscope and the Combitube were removed and a standard endotracheal tube was advanced over a guide catheter.

Results: Bronchoscopic evaluation of the trachea and guided replacement of the Combitube by an endotracheal tube was successful in all 20 study patients. The average time needed to perform airway exchange was 90 +/- 20 s (mean +/- SD). Arterial oxygen saturation and end-tidal carbon dioxide levels remained normal in all patients. No case of laryngeal trauma was observed during intubation or the airway exchange procedure.     

Case report: Nasotracheal intubation — look before leaping to assess the laryngeal view

PURPOSE: To describe an airway management plan, including oral to nasal endotracheal tube exchange, when nasal intubation is required in the unanticipated difficult airway. CLINICAL FEATURES: A nasal intubation was required for a patient undergoing oropharyngeal surgery. Following loss of consciousness and paralysis, a Cormack-Lehane class 3 view was obtained, and pressure over the thyroid cartilage failed to reveal the vocal cords. An Eschmann bougie was inserted into the oropharynx and blindly entered the trachea. An orotracheal tube was advanced into the trachea over the bougie, and the patient was ventilated with 100% O2 following the bougie's removal. An endotracheal tube was then guided through the right nostril into the hypopharynx. An Eschmann bougie was inserted into the nasal tube, and advanced towards the glottic opening under laryngoscopic view. Digital pressure applied to the oral tube at the base of the tongue brought the vocal cords into view. The oral endotracheal cuff was deflated, and the bougie (inserted into the nasal tube) was advanced into the trachea alongside the orotracheal tube. The orotracheal tube was withdrawn, and the nasal tube was advanced into the trachea over the bougie. The patient's O2 saturation and end-tidal CO2 concentration remained at 99-100% and 30-33 mmHg, respectively, during these maneuvers, which required only a few minutes to perform. CONCLUSION: When nasotracheal intubation is required, a plan of airway management is required to safely secure the airway. We emphasize the importance of direct laryngoscopy prior to insertion of an endotracheal tube through the nose, and describe a strategy for oral to nasal tracheal tube exchange.     

Use of a new videolaryngoscope (GlideScope®) in the management of a difficult airway

PURPOSE: To describe the clinical use of a new videolaryngoscope in a patient who had repeatedly been difficult or impossible to intubate by conventional direct laryngoscopy. This device provided excellent glottic visualization and permitted easy endotracheal intubation. CLINICAL FEATURES: A 74-yr-old male presenting for repeat elective surgery had a history of failed intubations by direct laryngoscopy and pulmonary aspiration with a laryngeal mask airway. He refused awake flexible fibreoptic intubation. After the induction of general anesthesia, laryngoscopy was performed using a GlideScope. This provided complete glottic exposure and easy endotracheal intubation. CONCLUSION: This new videolaryngoscope provided excellent laryngeal exposure in a patient whom multiple experienced anesthesiologists had repeatedly found to be difficult or impossible to intubate using direct laryngoscopy. The clinical role of this device awaits confirmation in a large series of difficult airways.     

Video-laryngoscopes in the adult airway management: a topical review of the literature

The aim of the present paper is to review the literature regarding video-laryngoscopes (Storz V-Mac and C-Mac, Glidescope, McGrath, Pentax-Airway Scope, Airtraq and Bullard) and discuss their clinical role in airway management. Video-laryngoscopes are new intubation devices, which provide an indirect view of the upper airway. In difficult airway management, they improve Cormack-Lehane grade and achieve the same or a higher intubation success rate in less time, compared with direct laryngoscopes. Despite the very good visualization of the glottis, the insertion and advancement of the endotracheal tube with video-laryngoscopes may occasionally fail. Each particular device's features may offer advantages or disadvantages, depending on the situation the anaesthesiologist has to deal with. So far, there is inconclusive evidence indicating that video-laryngoscopy should replace direct laryngoscopy in patients with normal or difficult airways.     

Video-intuboscopic monitoring of tracheal intubation in pediatric patients

PURPOSE: To evaluate the efficacy of video-intuboscopic monitoring during orotracheal intubation in a pediatric anesthesia teaching unit. METHODS: In 100 pediatric patients direct laryngoscopy performed by residents or nurse anesthetists was monitored on a video display using a flexible, ultralight video-endoscopic system (O.D. 2.8 mm/length 1.8 m) within the endotracheal tube (ETT). Best direct laryngoscopic view was assessed by the intubator. The instructor observed the intubation procedure on the video display and noted number of intubation attempts, best laryngoscopic monitor view, tube passage through the larynx and final tube position. If required he gave instructions or corrections. After removal of the laryngoscope, tracheal tube position was adjusted using the monitor view. Difficulties attributed to the fibreoptic endoscope during intubation and removal from the ETT were recorded. RESULTS: The trachea was successfully intubated at the first attempt in all patients. The supervisor detected one esophageal and 12 endobronchial intubations that were immediately corrected before starting ventilation. Final visualized endotracheal tube adjustment above the carina was possible in all patients except in one with copious tracheal secretions. Compared with direct laryngoscopy the video display provided an improved view of the vocal cords during intubation. In six patients direct laryngoscopy was difficult but the tracheas were intubated using the monitor view. No difficulties with the equipment were encountered except that the black coated endoscope compromised recognition of the black ETT depth-markings in small tubes. CONCLUSIONS: Video-intuboscopic monitoring is a useful monitor of tracheal intubation. "The improved view of the cords may provide assistance during difficult laryngoscopy.     

Brief report: Tracheal intubation using the Bonfils intubation fibrescope or direct laryngoscopy for patients with a simulated difficult airway

BACKGROUND: The Bonfils intubation fibrescope (BIF), a rigid, straight and reusable fibreoptic device, is being used increasingly to facilitate endotracheal intubation after direct laryngoscopy has failed. We tested the hypothesis that, with the BIF compared to direct laryngoscopy, the rate of failed endotracheal intubation could be reduced in patients with a difficult airway, simulated by means of a rigid cervical immobilization collar. METHODS: Seventy-six adults undergoing elective gynecological surgery under general anesthesia were randomly assigned to have endotracheal intubation, facilitated with either a standard size 3 Macintosh laryngoscope blade, or the BIF. A rigid cervical immobilization collar was used to simulate a difficult airway, by reducing mouth opening and limiting neck extension. If endotracheal intubation could not be achieved within two attempts, the cervical collar was removed, and direct laryngoscopy was performed thereafter, using a Macintosh blade in all subjects. The success rate of endotracheal tube placement was the primary outcome variable. RESULTS: Patient characteristics were similar in the two groups. After neck immobilization, the inter-incisor distance was reduced to 2.6 +/- 0.7 cm (Macintosh) and 2.6 +/- 0.8 cm (BIF). Tube placement was successful in 15/38 (39.5%) patients with a Macintosh blade, and in 31/38 patients with the BIF (81.6%; P = 0.0003). Time required for tube placement was 53 +/- 22 sec (Macintosh) and 64 +/- 24 sec (BIF; P = 0.15). CONCLUSION: The Bonfils intubation fibrescope is a more effective intubating device for patients with immobilized cervical spine and significantly limited inter-incisor distance, when compared to direct laryngoscopy.     

Laryngeal tube II : alternative airway for children?

Difficult airway situations both expected and unexpected, present major challenges to every anesthesiologist, especially in pediatric anesthesia. However, the integration of extraglottic airway devices, such as the laryngeal mask, into the algorithm of difficult airways has improved the handling of difficult airway situations. A device for establishing a supraglottic airway, the laryngeal tube (LT), was introduced in 1999. The LT is an extraglottic airway designed to secure a patent airway during either spontaneous breathing or controlled ventilation. The design of the device has been revised several times and a further development is the LTS?II/LTS-D, which provides an additional channel for the insertion of a gastric drain tube. This article reports on the successful use of the LTS?II in 12 children aged from 2 days to 6 years when endotracheal intubation, alternative mask or laryngeal mask ventilation failed. Use of the LTS?II was associated with a high level of success, securing the airway when other techniques had failed. The potential advantage of the LTS?II over the standard LT is an additional suction port, which allows gastric tube placement and can be used as an indirect indicator of correct placement. With a modified insertion technique using an Esmarch manoeuvre, placement was simple and fast to perform. In emergency situations when direct laryngoscopy fails or is too time-consuming the LTS?II tube is recommended as an alternative device to secure the airway. As with all extraglottic airway devices, familiarity and clinical experience with the respective device and the corresponding insertion technique are essential for safe and successful use, especially in emergency situations.