Use of the Ambu® aScope™ in 10 patients with predicted difficult intubation

Fibreoptic intubation is the gold standard for patients with predicted difficult intubation. The Ambu^® aScope? is a single‐use device for fibreoptic tracheal intubation. We assessed its performance in 10 patients with predicted difficult tracheal intubation. The procedure was easy and successful in nine patients. However, the limited time of use did not permit intubation in one patient who required three attempts with different size tracheal tubes. The limited image resolution that can be expected of a single‐use fibreoptic system and the absence of a suction channel are other potential limitations. On the other hand, being single‐use this device has the advantage of avoiding the risk of infectious disease transmission and is always ready to use.     

新型气管插管器具发展的新特点

背景自上世纪40年代Macintosh和Miller喉镜片问世以来，各种新的气管插管器具被商业性推广。目的综述与目前临床实践相关的新型气管插管器具。内容重点阐述新型气管插管器具与传统直接喉镜性能的比较、新型气管插管器具的并发症、新型气管插管器具在清醒气管插管方法中的应用以及新型气管插管器具气管插管失败的预测等。趋向在预知的和未预知的困难气管插管或者气管插管失败的情况下，应用新型气管插管器具可获得极高的气管插管成功率。然而更重要的是，操作者应用各种新型气管插管器具的经验和技能是保证其在不同临床情况下成功应用的关键。     

A comparison of tracheal intubation using the Airtraq or the Macintosh laryngoscope in routine airway management: A randomised, controlled clinical trial

The Airtraq laryngoscope is a novel single use tracheal intubation device. We compared the Airtraq with the Macintosh laryngoscope in patients deemed at low risk for difficult intubation in a randomised, controlled clinical trial. Sixty consenting patients presenting for surgery requiring tracheal intubation were randomly allocated to undergo intubation using a Macintosh (n = 30) or Airtraq (n = 30) laryngoscope. All patients were intubated by one of four anaesthetists experienced in the use of both laryngoscopes. No significant differences in demographic or airway variables were observed between the groups. All but one patient, in the Macintosh group, was successfully intubated on the first attempt. There was no difference between groups in the duration of intubation attempts. In comparison to the Macintosh laryngoscope, the Airtraq resulted in modest improvements in the intubation difficulty score, and in ease of use. Tracheal intubation with the Airtraq resulted in less alterations in heart rate. These findings demonstrate the utility of the Airtraq laryngoscope for tracheal intubation in low risk patients.     

Use of the Airtraq laryngoscope in a model of difficult intubation by prehospital providers not previously trained in laryngoscopy

This study evaluated the ability of prehospital providers who had no previous training in intubation, to use an Airtraq laryngoscope to intubate a manikin model of a Cormack and Lehane grade III/IV view. Volunteers attending the Australian College of Ambulance Professionals conference, Adelaide, in November 2006 received approximately 5 min of Airtraq training. First-time intubation success rate was 26/33 (79%) (95% CI 61-91%); oesophageal intubation rate was 0/33 (0%) (95% CI 0-11%); median time to intubation was 17 s (IQR 10-25 s (range 5-30 s)); and median subject-rated difficulty of use score was 21 out of a maximum of 100 (IQR 7.5-35.5 (range 1-65)). Pre-hospital providers without previous laryngoscopy training achieved high first-time intubation success rates when managing a model of a grade III/IV difficult intubation with an Airtraq laryngoscope. Users evaluated it as easy to use and achieved intubation within an acceptable breath-to-breath interval.     

Evidence for benefit vs novelty in new intubation equipment

A myriad of new intubation equipment has been introduced commercially since the appearance of Macintosh/Miller blades in the 1940s. We review the role of devices that are relevant to current clinical practice based on their presence in the scientific literature. The comparative performance of new vs traditional direct laryngoscopes, their complications, their use in awake intubation techniques and the prediction of unsuccessful intubation with new devices are reviewed. Manikin studies are of limited value in this area. We conclude that in both predicted and unpredicted difficult or failed intubation, carefully selected new intubation equipment has a high success rate for tracheal intubation. Ideally, such devices should be available in all settings where tracheal intubation is performed. Most importantly, experience and competence with any of the new devices are critical for their successful use in any clinical setting.     

An evaluation of the gum elastic bougie

This study was designed to evaluate the routine use of a gum elastic bougie for tracheal intubation. The median time to intubation with the gum elastic bougie while simulating an 'epiglottis only' view was only 10 s longer than the time taken during conventional intubation with an optimum view. Three of the patients required a gum elastic bougie-assisted intubation after attempts at conventional visual intubation had failed. There was no significant difference in the incidence of postoperative sore throat and hoarseness between the two groups. We recommend that anaesthetists should use the gum elastic bougie whenever a good view of the glottis is not immediately obtained.     

Le glottiscope AWS-Pentax™, alternative à la fibroscopie dans deux cas d’intubation difficile prévue du brûlé grave

Intubating patients with facial burn is difficult to most anesthesiologists. Awake flexible fiberoptic intubation is the gold standard for management of anticipated difficult tracheal intubation. However, serious facial burn and dysmorphic syndrome can make fiberoptic intubation more difficult or impossible. We report the use of awake oral intubation using the Pentax-Airway Scope (AWS) in two major burn patients with facial injury, in whom awake fiberoptic intubation was impossible. As shown in morbidly obese patient and in patients with unstable necks, AWS could be useful to facilitate tracheal intubation in awake, facial burn patients presenting with a potentially difficult airway. Awake AWS intubation seems as a potential alternative to awake fiberoptic intubation.     

Use of premedication for intubation in tertiary neonatal units in the United Kingdom

Background:  Endotracheal intubation and laryngoscopy are frequently performed procedures in neonatal intensive care. These procedures represent profoundly painful stimuli and have been associated with laryngospasm, bronchospasm, hemodynamic changes, raised intracranial pressure and an increased risk of intracranial hemorrhage. These adverse changes can cause significant neonatal morbidity but may be attenuated by the use of suitable premedication.
Aims:  To evaluate current practices for premedication use prior to elective intubation in UK tertiary neonatal units.
Methods:  Telephone questionnaire survey of all 50 tertiary neonatal units in the UK.
Results:  Ninety percent of units report the routine use of sedation prior to intubation and 82% of units routinely use a muscle relaxant. Morphine was the most commonly used sedative and suxamethonium was the most commonly used muscle relaxant. Approximately half of the units also used atropine during intubation. Seventy seven percent of units had a written policy for premedication. Ten percent of the units did not routinely use any sedatives or muscle relaxants for elective intubation.
Conclusions:  In comparison with data from a 1998 survey, our study demonstrated an increase in the number of units that have adopted a written policy for premedication use, and in the number routinely using premedication drugs for elective intubation. There remains little consensus as to which drugs should be used and in what dose.     

Intubating laryngeal mask airway

The Intubating Laryngeal Mask Airway (ILMA) was introduced into clinical practice in 1997 following numerous clinical trials involving 1110 patients. The success rate of blind intubation via the device after two attempts is 88% in "routine" cases. Successful intubation in a variety of difficult airway scenarios, including awake intubation, has been described, with the overall success rate in the 377 patients reported being approximately 98%. The use of the ILMA by the novice operator has also been investigated with conflicting reports as to its suitability for emergency intubation in this setting. Blind versus visualized intubation techniques have also been investigated. These techniques may provide some benefits in improved safety and success rates, although the evidence is not definitive. The use of a visualizing technique is recommended, especially whilst experience with intubation via the ILMA is being gained. The risk of oesophageal intubation is reported as 5% and one death has been described secondary to the complications of oesophageal perforation during blind intubation. Morbidity described with the use of the ILMA includes sore throat, hoarse voice and epiglottic oedema. Haemodynamic changes associated with intubation via the ILMA are of minimal clinical consequence. The ILMA is a valuable adjunct to the airway management armamentarium, especially in cases of difficult airway management. Success with the device is more likely if the head of the patient is maintained in the neutral position, when the operator has practised at least 20 previous insertions and when the accompanying lubricated armoured tube is used.     

Evaluation of the Airtraq and Macintosh laryngoscopes in patients at increased risk for difficult tracheal intubation

The Airtraq, a novel single use indirect laryngoscope, has demonstrated promise in the normal and simulated difficult airway. We compared the ease of intubation using the Airtraq with the Macintosh laryngoscope, in patients at increased risk for difficult tracheal intubation, in a randomised, controlled clinical trial. Forty consenting patients presenting for surgery requiring tracheal intubation, who were deemed to possess at least three characteristics indicating an increased risk for difficulty in tracheal intubation, were randomly assigned to undergo tracheal intubation using a Macintosh (n = 20) or Airtraq (n = 20) laryngoscope. All patients were intubated by one of three anaesthetists experienced in the use of both laryngoscopes. Four patients were not successfully intubated with the Macintosh laryngoscope, but were intubated successfully with the Airtraq. The Airtraq reduced the duration of intubation attempts (mean (SD); 13.4 (6.3) vs 47.7 (8.5) s), the need for additional manoeuvres, and the intubation difficulty score (0.4 (0.8) vs 7.7 (3.0)). Tracheal intubation with the Airtraq also reduced the degree of haemodynamic stimulation and minor trauma compared to the Macintosh laryngoscope.     

Airwaymanagement: video-assisted airway management

Endotracheal intubation remains the "goldstandard" in airway management. If with use of conventional techniques intubation of the patient fails, or if an anticipated difficult airway is present, video-assisted techniques may help to increase intubation success. Video-assisted techniques give the possibility to indirectly visualise the laryngeal structures with fibreoptical or camerachip-technique, and to display the videopicture on an external or integrated monitor. For the anticipated difficult airway, awake flexible fibreoptical intubation still is the first choice. However, if Oxygenation and Ventilation can be established with bag-mask ventilation or supraglottic airways, the use of an endoscopic optical stylet or a videolaryngoscope may be alternatives. If the algorithm for the unanticipated difficult airway can be safely administered, the latter techniques may also be used as emergency intubation devices.     

Risk factors for peri‐anaesthetic dental injury

In this retrospective case–control study, we evaluated peri‐operative dental injury risk factors following tracheal intubation. Ninety‐four of 290,415 patients experienced dental injury following tracheal intubation over a 10‐y period. A control group was matched for surgery type and intubating anaesthetist. The incidence of dental injury was 0.03%. Univariate analysis revealed that previous and current difficult intubation, male gender, hepatitis, neurological disease, anticonvulsant use, pre‐existing poor dentition and the use of airway devices (other than a laryngoscope) were associated with dental injury. Multivariate analysis revealed that predictors of dental injury were: history of hepatitis, odds ratio (95% CI) 10.1 (1.02–100.3); poor dentition, 8.8 (3.9–20.0); alternative airway device use, 3.1 (1.2–8.0); and intubation difficulty, 3.7 (1.0–13.3). As well as confirming previously reported risk factors for dental injury during tracheal intubation, this study also suggests hepatitis and the use of alternative airway devices as additional risk factors.     

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.     

Intubation through intubating laryngeal mask with and without a lightwand: a randomized comparison.

The combined use of a lightwand and the intubating laryngeal mask airway (ILMA) was compared with the use of the ILMA alone to determine whether the combination was a more efficient method of endotracheal intubation. One hundred healthy patients were randomly assigned to two groups. After induction of anaesthesia, Group A patients were intubated blindly through the ILMA while in Group B, intubation was guided by a lightwand. A sequence of standard manoeuvres was followed it attempts at intubation failed. The number of manoeuvres used, the time taken for successful intubation and complications associated with intubation were recorded. Intubations were successful in all patients, but the mean endotracheal intubation time was longer in Group A than in Group B (38.3 +/- 10.4 s versus 26.4 +/- 9.1 s, P < 0.001). The number of patients who needed one or more manoeuvres was significantly higher in Group A than in Group B (76% versus 42%, P = 0.001). We conclude that the lightwand is a useful adjunct in endotracheal intubation through an ILMA.     

A randomised, crossover study of the Dorges, McCoy and Macintosh laryngoscope blades in a simulated difficult intubation scenario

The use of alternative adult laryngoscope blades in an unexpected difficult intubation was evaluated with a human patient simulator manikin. Twenty anaesthetists of varying experience attempted to intubate the trachea of a high fidelity simulator in both its normal and difficult intubation settings using Macintosh, Dorges and McCoy laryngoscopes in a randomised order. The time taken to intubate, Cormack and Lehane scores, percentage of glottic opening visible, failure rate, number of attempts and subjective ease of use were recorded. The Dorges and McCoy blades did not perform any better than the standard Macintosh blade in either the easy or difficult tracheal intubation settings. Guidelines recommending the use of an alternative blade in an unexpected difficult intubation scenario have limited supporting evidence. This study does not support this recommendation.     

GlideScope-assisted fiberoptic bronchoscope intubation in a patient with severe rheumatoid arthritis

Here, we report that, under the assistance of both the GlideScope and a fiberoptic bronchoscope, tracheal intubation was accomplished successfully in a 50-year-old woman with severe rheumatoid arthritis who underwent tongue lump resection under general anesthesia. Either the GlideScope or the fiberoptic bronchoscope alone failed to secure the airway; the use of both in combination facilitated airway intubation. This case report indicate that, even with careful preoperative assessment, patients who suffer from rheumatoid arthritis may have severe airway difficulty with intubation, and the combined use of the GlideScope and a fiberoptic bronchoscope can be a novel alternative for tracheal intubation in patients with severe airway difficulty.     

Fibre-optic intubation,including local anaesthesia for awake intubation

Airway problems are a major concern to anaesthetists; however, the introduction of fibre-optic intubation and awake fibre-optic intubation have revolutionized the anaesthetic management of the difficult airway. To perform fibre-optic intubation it is essential to have a basic understanding of the equipment, how to use it and how to prepare and maintain the airway for intubation under local or general anaesthetic. Effective endoscopy requires a good view, skilful manipulation of the instrument and a thorough understanding of airway anatomy. Careful handling of the endoscope and effective cleaning are essential for patient safety and to preserve the life of the equipment. Steps must be taken to ensure effective decontamination and to prevent recontamination before use.     

Nasotracheal intubation in a child with treacher collins syndrome using the bullard intubating laryngoscope

Tracheal intubation may be difficult or impossible in children with Treacher Collins syndrome. Nasotracheal intubation may be required for appropriate repair of cleft palate in these patients. This report describes the use of the Bullard intubatiog laryngoscope to facilitate nasotracheal intubation in a child with severe mandibulofacial dysplasia.     

Nasotracheal intubation for head and neck surgery

Nasotracheal intubation offers the head and neck surgeon more scope for surgical manoeuvre in operations of the mouth, pharynx, larynx and also the neck. Concern over the complications of using this route of intubation and lack of training may be limiting its use. A thorough knowledge of the anatomy, benefits of using nasal vasoconstrictors and attention to technique are prerequisites to maintaining the skill. This article reviews each of these topics and aims to encourage the appropriate use of nasotracheal intubation in current practice.     

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.