A comparison of the intubating laryngeal mask airway and the Bonfils intubation fibrescope in patients with predicted difficult airways*

Prehospital fiberoptic intubation

We present a case of a patient with severe multiple trauma who was treated at the scene by a physician-staffed trauma life support team. Due to a complete tracheal transection, a "cannot ventilate, cannot intubate"-situation occurred. The patient was then intubated using a fiberoptic bronchoscope in the prehospital setting. The current literature concerning fiberoptic intubation in emergencies is discussed.

Comparison of the Levitan FPS Scope and the single-use bougie for simulated difficult intubation in anaesthetised patients

A randomised cross-over study was performed in 34 patients with no evidence of airway difficulties, following induction of general anaesthesia, to compare the efficacy of the Levitan FPS scope (LFPS) and the single-use bougie for tracheal intubation during simulated grade IIIa laryngoscopy. Success rates for intratracheal placement of the device, and the time required for insertion and tracheal intubation were recorded. Both devices were equally successful (31/34 for the LFPS vs 29/34 for the bougie) for insertion into the glottis. The mean insertion time for the LFPS was statistically longer than that for the bougie (4.4-12.5 s) but this difference was not clinically relevant. Intubation times were similar between the two devices. Major problems hindering successful intubation using the LFPS were the presence of a narrow epiglottic-pharyngeal wall space and copious secretions. An inability to maintain the desired shape was the principal cause of failure with the bougie.

Prehospital emergency endotracheal intubation using the Bonfils intubation fiberscope

Among all prehospital emergency intubations, difficulties occur in 7-10%. Furthermore, intubation conditions often worsen when the cervical spine is immobilized in trauma patients. We report on six patients in whom the Bonfils intubation fiberscope, a reusable, rigid fiberoptic device, was used for emergency endotracheal intubation in the field. Three of these patients had an anticipated or unanticipated difficult airway: two trauma patients with immobilized cervical spine and one patient in cardiac arrest in whom direct laryngoscopy failed twice. Endotracheal intubation with the Bonfils intubation fiberscope was successful in all cases in the first attempt. The Bonfils intubation fiberscope therefore demonstrated its value as an additional airway management device in both emergency and prehospital settings.

Awake Fiberoptic Intubation Using an Optical Stylet in an Anticipated Difficult Airway

Numerous rigid indirect fiberoptic and video-based airway tools have been developed as potential alternatives to direct laryngoscopy for intubation. Compared with flexible fiberoptic bronchoscopes, these devices are less expensive and may be easier to use. The role of these rigid instruments in managing the difficult airway in the emergency department is yet to be defined. This article details the use of a rigid fiberoptic stylet to manage an anticipated difficult airway by using topical anesthetic without sedation.

Bonfils semirigid endoscope for guidance during percutaneous tracheostomy

We report on the use of the Bonfils semirigid scope for endoscopic guidance during percutaneous dilational tracheostomy. Forty patients requiring percutaneous dilational tracheostomy on the General or Neurosurgical Intensive Care Unit were enrolled in this study. We used the '45 degree curved distal tip' scope in the first 15 patients, evaluating its ease of use, optical quality of focus and image resolution as well as light intensity on a 10-point scale. We evaluated straight and curved versions of it in another 15 and 10 patients, respectively. We examined the impact on ventilation and cardiovascular parameters. In all patients (n = 40) visualisation of the procedure was satisfactory. There were no clinically significant changes in ventilatory or cardiovascular parameters. The image quality for most patients received a score of 7-10. The Bonfils scope provides a practical alternative to flexible bronchoscopes in this setting.

A comparison of the Seeing Optical Stylet and the gum elastic bougie in simulated difficult tracheal intubation: a manikin study

Management of the difficult airway is one of the major challenges that anaesthetists face. The flexible fibreoptic scope is widely available but its use requires a level of skill, training and continued practice that is not universally found in all anaesthetists, particularly trainees. The Seeing Optical Stylet is a new, semirigid fibreoptic stylet 'scope. We compared the Seeing Optical Stylet with a gum elastic bougie in a simulated Cormack and Lehane Grade 3 laryngoscopy in a manikin. Forty-four anaesthetists were timed while intubating the manikin's trachea with both devices. The mean (SD) time taken with the Seeing Optical Stylet was 20.8 (9.3) s and with the bougie 30 (19.8) s (p = 0.001). Oesophageal intubation occurred six times with the bougie but did not occur with the Seeing Optical Stylet (p = 0.011). We conclude that the Seeing Optical Stylet may be superior to the bougie in difficult tracheal intubation. We feel that the results of this manikin trial are sufficiently encouraging to proceed to a clinical trial in patients.

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.

Airway management in emergency situations

Securing and monitoring the airway are among the key requirements of appropriate therapy in emergency patients. Failures to secure the airways can drastically increase morbidity and mortality of patients within a very short time. Therefore, the entire range of measures needed to secure the airway in an emergency, without intermediate ventilation and oxygenation, is limited to 30-40 seconds. Endotracheal intubation is often called the 'gold standard' for airway management in an emergency, but multiple failed intubation attempts do not result in maintaining oxygenation; instead, they endanger the patient by prolonging hypoxia and causing additional trauma to the upper airways. Thus, knowledge and availability of alternative procedures are also essential in every emergency setting. Given the great variety of techniques available, it is important to establish a well-planned, methodical protocol within the framework of an algorithm. This not only facilitates the preparation of equipment and the training of personnel, it also ensures efficient decision-making under time pressure. Most anaesthesia-related deaths are due to hypoxaemia when difficulty in securing the airway is encountered, especially in obstetrics during induction of anaesthesia for caesarean delivery. The most commonly occurring adverse respiratory events are failure to intubate, failure to recognize oesophageal intubation, and failure to ventilate. Thus, it is essential that every anaesthesiologist working on the labour and delivery ward is comfortable with the algorithm for the management of failed intubation. The algorithm for emergency airway management describing the sequence of various procedures has to be adapted to internal standards and to techniques that are available.

Trends in tracheal intubation: emphasis on the difficult airway

PURPOSE OF REVIEW

This review will summarize the progress made during the last year in improving difficult-airway management.

RECENT FINDINGS

The UK Difficult Airway Society have published extensive guidelines for the management of unanticipated difficult intubation in the unobstructed adult patient. That such an approach is useful has been demonstrated in an independent study which showed that simple guidelines using familiar equipment will solve the majority of intubation difficulties likely to be encountered. However, their limitation lies in the fact that the worst-case scenario (i.e. inability to ventilate or intubate) is so rare that it cannot be studied systematically. It is postulated that a different approach geared to understanding the causes of difficulties with intubation may provide an alternative strategy for providing an evidence base.

SUMMARY

Significant steps have been made in our management of the difficult airway, and the majority of the problems encountered can be solved with recourse to simple published guidelines.

Recent trends in tracheal intubation: emphasis on the difficult airway

PURPOSE OF REVIEW

Difficult airways can lead to critical incidents during anaesthesia, and death. Although many cases can be anticipated, some still go undiscovered before induction, thereby exposing the patient to unexpected risks and the anaesthesiologist to unexpected challenges. In addition to improving prediction of difficult airways, education for skill acquisition and management planning, and a quest for superior management techniques and airway tools are of the utmost importance in preventing airway catastrophes.

RECENT FINDINGS

We review recent advances in predicting difficult airways in special population groups that are known to have a higher incidence of difficult airway. Education, exercising airway skills, management planning with both predicted and unpredicted difficult airways, and the need for adherence to algorithms for management of difficult airway are emphasized as key to successful management. Finally, recent developments in airway management techniques and new airway devices are summarized.

SUMMARY

Improving reproducibility and reliability in predicting a difficult airway may limit the number of unpredicted difficult intubations. A safer approach to management of the difficult airway can be achieved by improving airway management skills and adhering to universally accepted and proven airway algorithms, including developing approaches to management of predicted and unpredicted difficult airways. Improving on existing airway techniques and tools (of which there are many), rather than creating new devices, is a desirable trend that may contribute to safer airway management in the future.

Tracheal intubation using the Bonfils intubation fibrescope after failed direct laryngoscopy*

Failed tracheal intubation due to a difficult airway is an important cause of anaesthetic morbidity and mortality. This study was undertaken to evaluate the effectiveness of the Bonfils intubation fibrescope for tracheal intubation after failed direct laryngoscopy. Twenty-five patients undergoing coronary artery bypass grafting were enrolled in the study after two attempts at conventional laryngoscopy by a board certified anaesthetist had failed. Intubation with the Bonfils fibrescope was successful on the first attempt in 22 patients (88%) and on the first or second attempt in 24 patients (96%); in one patient intubation was impossible. Median (IQR [range]) time to intubation using the Bonfils intubation fibrescope was 47.5 (30-80 [20-200]) s. Tracheal intubation using the Bonfils intubation fibrescope appears to be a simple and effective technique for the management of a difficult intubation.

Alternative management techniques for the difficult airway: optical stylets

PURPOSE OF REVIEW

We present the newest devices being promoted for difficult-airway management. Our focus is on optical stylets which offer a forward view from the stylet end positioned within the tip of the endotracheal tube.

RECENT FINDINGS

Reports suggest that these devices are mastered quickly and offer effective airway management aid. Available in adult and pediatric sizes they are economically priced at approximately US$ 3000.

SUMMARY

Generally favorable experience with use of optical stylets continues to be reported. Our survey of clinicians' opinions reflects our own experience; these devices are unique and are attractive adjuncts to standard- and difficult-airway carts.