Tracheal placement of a gum elastic bougie using the laryngeal mask airways

Blind intubation through Laryngeal Mask Airway in a cannot intubate-difficult to ventilate patient with massive hematemesis

Massive hematemesis could be challenging situation requiring emergency airway control and urgent surgical treatment. We report a case of difficult airway management with blind intubation through Laryngeal Mask Airway in a 56-year-old patient with massive hematemesis. After failed endoscopic attempts to stop bleeding, worsening of hemodynamics called for emergency intubation and surgery. After failed intubation attempts and face-mask ventilation worsening, a classic LMA was used for rescue ventilation and decision was made to intubate through LMA. The airway exchange was aided by a nasogastric tube (NGT) through LMA, confirmed with capnography and surgery was started successfully and uneventfully. Unexpected difficult airway can be extremely challenging situation, especially in emergency settings with no possibility to delay surgery. In those cases, literature suggests different intubating techniques through LMA. Blind intubation through LMA aided by NGT showed to be a suitable option in resources-limited settings, where advanced supraglottic devices and/or optical devices are not available.

Airway Management in the Pediatric Trauma Patient

The most immediate concern in the management of any pediatric emergency, including trauma, is airway assessment with assisted or controlled ventilation as needed. In the trauma setting, several factors may increase the risks associated with airway management including cardiorespiratory instability, associated maxillofacial injuries, cervical spine injuries, and the risk of acid aspiration. The author reviews the techniques used to manage the airway in the pediatric trauma patient including the evaluation of the cemcal spine and techniques to protect the cenical spine during endotracheal intubation. Airway management techniques including standard oral endotracheal intubation with sedation and neuromuscular blockade, the approach to the recognized difficult airway, and the techniques used in the “cannot intubate/cannot ventilation” scenario are discussed.

An Airway Management Device: The Laryngeal Mask Airway—A Review

The laryngeal mask airway (LMA) is an airway management device that has become an accepted part of anesthetic practice in both pediatric and adults surgical patients. It is inserted without the use of a laryngoscope or muscle relaxants into the hypopharynx forming a low pressure seal around the glottis. The LMA provides a better airway than a face mask with or without an oral airway. Insertion techniques are quickly learned and are described in this review. Since the LMA forms a less secure seal than an endotracheal tube (ETT), several important limitations and contraindications exist. This includes patients at high risk for regurgitation of gastric contents into the lungs causing pulmonary aspiration and patients requiring high ventilatory pressures or prolonged ventilation. These contraindications have limited its introduction and utilization in the intensive care unit (ICU). The LMA is a helpful tool in the management of both the expected and unexpected difficult airway, where it may serve both as an emergency airway and as a conduit to intubation of the trachea with an ETT over a fiberoptic bronchoscope (FOB) or gum elastic bougie. A lifesaving airway has been provided by the LMA where no other means of achieving ventilation were possible in patients, including neonates, trauma victims, woman undergoing cesarean section, and in the setting of cardiac arrest. There are very few reported uses of the LMA in the ICU. We believe that familiarity with the LMA's design, use, and limitations by critical care practitioners will increase its use in emergency airway management and in the ICU. The LMA may prove to be the first of a new generation of airway devices placed into the hypopharynx to provide an alternative to the endotracheal tube and mask airway.

Comparison of oral fiberoptic intubation via a modified guedel airway or a laryngeal mask airway in infants and children

BACKGROUND

Though fiberoptic intubation (FOI) is considered the gold standard for securing a difficult airway in a child, it may be technically difficult in an anesthetized child. The hypothesis for this study was that it would be easier to perform FOI via a laryngeal mask airway (LMA) than a modified oropharyngeal airway with the advantage of maintaining anesthesia and oxygenation during the process.

MATERIALS AND METHODS

30 children aged 6 months to 5 years undergoing elective surgery under general anesthesia were randomized to two groups to have fiberoptic bronchoscope (FOB) guided intubation either via a modified Guedel airway (FOB-ORAL) or a classic LMA (FOB-LMA). In the FOB-LMA group, the LMA was removed when a second smaller endotracheal tube was anchored to the proximal end of the tracheal tube in place.

RESULTS

Oral fiberoptic intubation was successful in all children. The first attempt success rate was 11/15 (73.33%) in the FOB-LMA group and 3/15 (20%) in the FOB-ORAL group (P = 0.012). Subsequent attempts at intubation were successful after 90° anticlockwise rotation of the endotracheal tube over the FOB. The time taken for fiberoptic bronchoscopy was significantly less in FOB-LMA group (59.20 ± 42.85 sec vs 108.66 ± 52.43 sec). The incidence of desaturation was higher in the FOB-ORAL group (6/15 vs 0/15).

CONCLUSION

In children, fiberoptic bronchoscopy and intubation via an LMA has the advantage of being easier, with shorter intubation time and continuous oxygenation and ventilation throughout the procedure. Removal of the LMA following intubation requires particular care.

Use of intubation introducers through a supraglottic airway to facilitate tracheal intubation: a brief review

PURPOSE

This article is a narrative review regarding the usage and effectiveness of introducers or catheters to facilitate tracheal intubation through a supraglottic airway (SGA) as an alternative intubation technique in normal and difficult airway management.

SOURCES

Relevant articles were obtained through Medline (1948-July 2011). The articles were subsequently cross-referenced for additional literature, and only articles published in English were included.

PRINCIPAL FINDINGS

In this review, we consider 32 reports using the LMA Classic™, LMA Unique™, LMA ProSeal™, LMA Supreme™, AuraOnce™, and i-gel™ as SGA conduits for intubation. In 13 articles, the use of an Aintree Intubation Catheter was described as an intubation introducer and resulted in high success rates in both elective and emergent situations. Eight studies used a guidewire exchange catheter technique. Although blind intubation using a guidewire resulted in a high failure rate, these studies found that using a bronchoscope improved successful intubation. Ten studies showed that insertion of a gum elastic bougie with a bronchoscope as an intubation introducer has high success rates compared with blind bougie insertion. One article described the use of a small endotracheal tube as an intermediary for tracheal intubation.

CONCLUSIONS

In failed intubation scenarios, supraglottic airways, such as the LMA Classic™ or LMA ProSeal™ can serve as a conduit for tracheal intubation. A number of techniques using introducers or catheters can facilitate the insertion of an adequately sized endotracheal tube, particularly guided by a bronchoscope. Usage of introducers or catheters through a supraglottic airway may be a useful alternative intubation technique in difficult airway management.

Developments in general airway management

Since the 1970s, improvements in airway management have been significant. New imaging modalities such as CT and MRI can display airway structures with unparalleled detail, which improves preoperative planning and the treatment of patients with pathologic processes involving the respiratory tract or with difficult-to-manage airways. Because of the introduction of flexible fiberscopes, pulmonologists and thoracic surgeons can diagnose diseases of the respiratory tract effectively and treat patients with these diseases safely. The use of flexible fiberscopes has expanded rapidly into other medical specialties, including anesthesia and critical care. Modem anesthesiologists now use flexible fiberscopes daily to intubate patients safely, especially when traditional intubating techniques fail. The cost of fiberscopes has decreased dramatically, and their optical systems have improved. Several centers of excellence have been developed where clinicians can learn basic and advanced techniques of fiberoptic intubation. The LMA has shown that the supraglottic airway approach is not only feasible, but also in many situations superior to tracheal intubation. Although the LMA initially was recommended as an alternative to the facemask, its use has expanded, benefiting many children and adults undergoing a variety of diagnostic and therapeutic procedures. Use of an LMA in combination with a flexible fiberscope has opened up new possibilities for treating patients safely and effectively while providing optimal comfort during a procedure and has been particularly beneficial in thoracic surgery. The most recent iteration of the ASA Difficult Airway Algorithm has revised further a systematic approach to the clinical care of patients with different types of difficult-to-manage airways.

Management of the difficult airway: alternative airway techniques and adjuncts

Rapid-sequence intubation using conventional laryngoscopic technique remains the standard of airway management in emergency medicine and continues to have a success rate of approximately 98%. Preparation and proper intubation technique must be optimized at the initial attempt using direct laryngoscopy. Failure causes multiple repeated attempts, leading to a failed airway. Each repeated attempt increases the likelihood of bleeding, oral, pharyngeal, and laryngeal edema, and malposition, causing decreased visualization of the glottic opening, equipment failure, and hypoxia. Preparation must be an ongoing process. Faulty suction, no oxygen source, choice of the wrong laryngoscopic blade or ETT, poor light source, or misplaced equipment can domino into mechanical failure. Intubation equipment stations must be inventoried constantly, organized, and kept simple in their layout to decrease confusion during selection. Medication for sedation and paralysis should be readily available and not kept distant from the intubation station in a medication-dispensing unit that would require time for acquisition. Proper positioning of the patient remains paramount for alignment of the oral, pharyngeal, and laryngeal axis to provide optimal visualization of the vocal cords. Proper technique during insertion of the laryngoscope blade in the oral cavity for displacement of the tongue must be ensured. Without proper technique, even with proper positioning, the glottic opening cannot be visualized. Laryngeal pressure to maneuver the larynx into position should be exerted initially by the laryngoscopist's right hand and, when in view, maintained by an assistant to free the laryngoscopist's hand for ETT insertion. With preparation and proper technique, the first attempt is the best attempt, and the vicious cycle of multiple attempts and complications will be averted.

Special devices and techniques

Management of the difficult airway remains one of the most challenging tasks for anesthesia care providers. Most airway problems can be solved with relatively simple devices and techniques, but clinical judgment borne of experience is crucial to their application. As with any intubation technique, practice and routine use improve performance and may reduce the likelihood of complications. Each airway device has unique properties that may be advantageous in certain situations, yet limiting in others. Specific airway management techniques are greatly influenced by individual disease and anatomy, and successful management may require combinations of devices and techniques.

Tracheal intubation through the laryngeal mask airway using a gum elastic bougie: the effect of head position

STUDY OBJECTIVE

To determine the effect of head position on success of tracheal intubation through a Laryngeal Mask Airway (LMA) using a gum elastic bougie.

DESIGN

Randomized, controlled study.

SETTING

Anesthesia and operating rooms of the University Hospital, Nottingham, UK.

PATIENTS

20 patients scheduled to undergo routine elective surgery requiring the use of an LMA for anesthesia.

INTERVENTIONS

Blind placement of a gum elastic bougie through an LMA in two head positions.

MEASUREMENTS AND MAIN RESULTS

Final position of the gum elastic bougie after removal of the LMA as determined by fiberoptic laryngoscopy. The gum elastic bougie was correctly sited in the trachea in the classical intubating position in 4/20 (20%) and in the neutral position in 0/20 (0%). There was no difference in the success of this technique between the two head positions.

CONCLUSIONS

This technique cannot be recommended as an alternative to direct laryngoscopy following a failed intubation.

The laryngeal mask airway: a comprehensive review for the Emergency Physician

The Laryngeal Mask Airway (LMA) was developed in the 1980s, but has only recently begun to be used in Emergency Medicine. The LMA affords effective assisted ventilation without requiring endotracheal intubation or visualization of the glottis. In doing so, it is more efficacious than a bag-valve-mask apparatus, although the risk of aspiration of gastric contents persists, particularly if the device is not properly placed. The LMA also has significant potential utility in management of the difficult airway. Most reported clinical experience with the LMA has come from the operating room. This article provides an overview of the extensive potential utility of the LMA in the Emergency Department and prehospital settings as well as a comprehensive review of the pertinent advantages, disadvantages, and complications associated with its use.

The 'dedicated airway': a review of the concept and an update of current practice

The term 'dedicated airway' was first used in connection with nasal fibreoptic intubations using the cuffed nasopharyngeal airway. Since that time, the concept has developed and the term has been extended to include fibreoptic intubation techniques involving both the laryngeal mask airway and cuffed oropharyngeal airway. 'Dedicated airway' can now be defined as: 'An upper airway device dedicated to the maintenance of airway patency while other major airway interventions are anticipated or are in progress. The device should be compatible with spontaneous and controlled ventilation. 'Dedicated airway techniques allow planned fibreoptic intubations in difficult cases and provide an emergency airway option in an unexpected difficult intubation when the alternative may be to wake the patient. As well as promoting safe conditions for training fibreoptic intubation in general, there is the particular advantage of being able to train using these techniques in patients known to be difficult to intubate. The authors' evolved clinical experiences in promoting the concept and the relevant literature are reviewed.

Nasal fibreoptic tracheal intubation in anaesthetised patients breathing via a modified laryngeal mask airway

A modified laryngeal mask airway was used to facilitate nasotracheal intubation with a fibreoptic laryngoscope. A size 4 laryngeal mask airway was modified by creating a defect at the base of the stem and removing the bars to allow passage of the fibreoptic laryngoscope from the nasopharynx to the larynx. The laryngeal mask airway cuff was split and the cut edges were sealed with silicone. This design allowed the cuff to function normally and allowed removal of the split laryngeal mask airway after the tracheal tube had been 'railroaded' into place. Thirty-four patients were studied. The split laryngeal mask airway was easily inserted with satisfactory airway maintenance in 32 patients. Nasal airway endoscopy and laryngoscopy were successfully achieved with the split laryngeal mask airway in place in 31 of 32 patients. Railroading the tracheal tube over the fibreoptic laryngoscope with the split laryngeal mask airway in place was successful in all 31 of these patients. This prototype split laryngeal mask airway allows good airway maintenance while fibreoptic nasotracheal intubation is performed.

Fibreoptic intubation using the cuffed oropharyngeal airway and Aintree intubation catheter

A cuffed oropharyngeal airway has recently been introduced which has larger internal dimensions than a comparable Guedel airway. This allows a ventilation/exchange bougie, the Aintree Intubation Catheter, mounted on a fibreoptic laryngoscope to pass through it. Its 15-mm connector and pharyngeal cuff suggested the possibility of using a Rüsch sealed-port angle piece to allow ventilation through the oropharyngeal airway during fibreoptic laryngoscopy. This study investigated using this equipment to intubate the trachea through the cuffed oropharyngeal airway in paralysed patients, whilst maintaining ventilation manually with a Bain system. In 20 patients, airway control was satisfactory throughout and tracheal intubation was accomplished without complications. The cuffed oropharyngeal airway was easy to manipulate to improve a suboptimal fibreoptic view of the larynx. This may give it an advantage over the laryngeal mask airway when used as a ventilation/intubation conduit.

The unanticipated difficult airway with recommendations for management

PURPOSE

To review the current literature and generate recommendations on the role of newer technology in the management of the unanticipated difficult airway.

METHODS

A literature search using key words and filters of English language and English abstracted publications from 1990-96 contained in the Medline, Current Contents and Biological Abstracts databases was carried out. The literature was reviewed and condensed and a series of evidence-based recommendations were evolved.

CONCLUSIONS

The unanticipated difficult airway occurs with a low but consistent incidence in anaesthesia practice. Difficult direct laryngoscopy occurs in 1.5-8.5% of general anaesthetics and difficult intubation occurs with a similar incidence. Failed intubation occurs in 0.13-0.3% general anaesthetics. Current techniques for predicting difficulty with laryngoscopy and intubation are sensitive, non-specific and have a low positive predictive value. Assessment techniques which utilize multiple characteristics to derive a risk factor tend to be more accurate predictors. Devices such as the laryngeal mask, lighted stylet and rigid fibreoptic laryngoscopes, in the setting of unanticipated difficult airway, are effective in establishing a patient airway, may reduce morbidity and are occasionally lifesaving. Evidence supports their use in this setting as either alternatives to facemask and bag ventilation, when it is inadequate to support oxygenation, or to the direct laryngoscope, when tracheal intubation has failed. Specifically, the laryngeal mask and Combitube have proved to be effective in establishing and maintaining a patent airway in "cannot ventilate" situations. The lighted stylet and Bullard (rigid) fibreoptic scope are effective in many instances where the direct laryngoscope has failed to facilitate tracheal intubation. The data also support integration of these devices into strategies to manage difficult airway as the new standard of care. Training programmes should ensure graduate physicians are trained in the use of these alternatives. Continuing medical education courses should allow physicians in practice the opportunity to train with these alternative devices.

Use of a lighted stylet for intubation via the laryngeal mask airway

PURPOSE

To assess a new technique for intubation via the laryngeal mask airway (LMA) in which a lighted stylet is used to optimise the position of the LMA before intubation.

METHODS

In 114 patients, following LMA insertion, the lighted stylet (Trachlight Wand) with mounted tracheal tube (TT) was advanced 1.5 cm beyond the mask aperture bars and the anterior neck observed for a distinct central point of light at the cricothyroid membrane (CTM). If this was not seen, the LMA was repositioned in the pharynx, depending on the location of the light, by manually advancing, withdrawing or rotating the device, manipulating the head/neck or trying an alternative size. Tracheal intubation was attempted only when transillumination was correct. The TT with lighted stylet was advanced until the supra-sternal notch was transilluminated.

RESULTS

In 89 patients (78%) the CTM was transilluminated without repositioning, in 12 (10%) a single positional adjustment was required, and in 10 (9%) a change of LMA size was required. In three patients (3%) transillumination of the CTM was impossible. In the 97% of patients in whom transillumination was correct, tracheal intubation was successful in all at the first attempt without the need for further repositioning or size change.

CONCLUSION

The lighted stylet is useful in facilitating intubation via the LMA in anaesthetised adult patients when used as a guide to optimal LMA position.

Tracheal intubation through the laryngeal mask using a gum elastic bougie in the presence of cricoid pressure and manual in line stabilisation of the neck

Forty adult patients had a gum elastic bougie passed blindly through a laryngeal mask on two occasions, after standard insertion, and after the application of cricoid pressure with manual in line stabilisation of the neck. After standard insertion the bougie entered the trachea on 11/40 occasions. With manual in line stabilisation of the neck and cricoid pressure applied, the bougie entered the trachea on 9/40 occasions. These results were not statistically significant. Blind passage of a gum elastic bougie through a laryngeal mask does not provide a reliable route into the trachea in either of the circumstances studied.

Use of LMA for awake intubation for caesarean section

PURPOSE

This case report describes the use of a Laryngeal Mask Airway in a morbidly obese parturient with the H.E.L.L.P. syndrome. An urgent Caesarean section was required because of vaginal bleeding and fetal distress.

CLINICAL FEATURES

The patient was a 32 year old G3, T1, P1, L1 who presented with epigastric pain, headache, vomiting, and diarrhoea. She was hypertensive (180/110 mmHg) and thrombocytopaenic (18 x 10(-9). L-1). Examination of the airway revealed a short neck, receded jaw, full dentition, large breasts and she was considered to be a potential intubation problem. The patient required an awake intubation using a technique that minimized hypertension, aspiration risk, airway trauma, and hypoxia. A laryngeal mask was used to facilitate tracheal intubation, and the patient tolerated the procedure with no adverse outcome.

CONCLUSION

The LMA has a place to facilitate potentially difficult awake tracheal intubation with the pregnant patient.

Laryngeal mask airway positioning is related to Mallampati grading in adults

The Mallampati classification is a commonly used means of preoperatively predicting a difficult endotracheal intubation. As the laryngeal portion of the laryngeal mask airway (LMA) must sit over the larynx, we wondered whether the Mallampati classification also predicts difficulty in achieving adequate seating of the LMA. LMA positioning was assessed prospectively in 100 adult patients by fiberoptic bronchoscopy to determine whether there was a relationship between the ease of seating of the LMA and the Mallampati classification. In 72 patients, optimal seating of the LMA was achieved on the first attempt at insertion, and all these patients were classified as Mallampati class 1 or 2. In all 28 cases of difficulty with LMA insertion, the patients were Mallampati class 2 or 3. In two cases the LMA was abandoned, and in these cases both patients were Mallampati class 3, (P = 0.0001 by chi 2 analysis). We conclude that the Mallampati classification indicates difficulty not only in tracheal intubation but also in achieving an adequate airway with the LMA.

A new technique for fibreoptic intubation in children

We describe a technique involving the use of a laryngeal mask airway, fibreoptic bronchoscope and a guide wire to manage the intubation of a child who was known to be a difficult intubation. The technique is simple, atraumatic, permits the use of an adult bronchoscope for infants and children, and allows control of the airway and ventilation throughout the period of intubation.

The laryngeal mask airway: its features, effects and role

The laryngeal mask airway was designed as a new concept in airway management and has been gaining a firm position in anaesthetic practice. Numerous articles and letters about the device have been published in the last decade, but few large controlled trials have been performed. Despite widespread use, the definitive role of the laryngeal mask has yet to be established. In some situations, such as after failed tracheal intubation or in anaesthesia for patients undergoing laparoscopic or oral surgery, its use is controversial. There are a number of unresolved issues, for example the effect of the laryngeal mask on regurgitation and whether or not cricoid pressure prevents placement of the mask. We review the techniques of insertion, details of misplacement, and complications associated with the use of the laryngeal mask. We discuss the features and physiological effects of the device, including the changes in intra-cuff pressure during anaesthesia and effects on blood pressure, heart rate and intra-ocular pressure. We then attempt to clarify the role of the laryngeal mask in airway management during anaesthesia, based on the current knowledge, by discussing the advantages and disadvantages as well as the indications and contraindications of its use. Lastly we describe the use of the laryngeal mask in circumstances other than airway maintenance during anaesthesia: fibreoptic bronchoscopy, tracheal intubation through the mask and its use in cardiopulmonary resuscitation.

The distance between the grille of the laryngeal mask airway and the vocal cords. Is conventional intubation through the laryngeal mask safe?

The distance between the grille of the laryngeal mask airway and the vocal cords was measured with a fibreoptic bronchoscope in 30 male and 30 female patients. The mean distance was 3.6 cm (SD 0.5 cm; range 2.5-4.7 cm) in males and 3.1 cm (SD 0.5 cm; range 2.0-4.2 cm) in females. These results suggest that the cuff of an uncut 6.0 mm tracheal tube would often lie between the vocal cords when the tube is fully inserted through a laryngeal mask airway. To avoid this complication, the tracheal tube must protrude more than 9.5 cm beyond the grille of the laryngeal mask airway. When either neck extension or flexion is required, the laryngeal mask airway should be removed as the margin of safety is small.

Remember the gum-elastic bougie at extubation

Although the use of a gum-elastic bougie to secure an airway is well described, its use during extubation is not well documented. A bougie was passed through the endotracheal tube (ETT) prior to extubation in anticipation of possible reintubation of a patient with a difficult airway. Once the bougie was in place, the ETT was removed over it. Later, when the patient's airway did become compromised, the trachea was rapidly reintubated using the bougie, without the need for direct laryngoscopy, fiberoptic bronchoscopy, or, worse, emergency tracheostomy.

The laryngeal mask airway

The laryngeal mask airway (LMA) is a new concept in airway management. A miniature inflatable mask is positioned in the hypopharynx, forming a low-pressure seal around the laryngeal inlet. The mask is attached via a tube to the breathing circuit. It is inserted after induction of anesthesia without the need for muscle relaxants or laryngoscopy. The LMA can be used to facilitate both spontaneous and controlled ventilation in adults and children. The LMA has been used for a wide variety of surgical procedures but is probably best suited to short procedures, especially if a light general anesthetic is used in combination with a regional technique. It may be particularly useful in outpatient anesthesia, as it avoids the need for intubation or muscle relaxants. It can be used as an alternative to mask anesthesia or when an endotracheal tube would have been inserted to allow surgical access. It has been used successfully in cases of difficult or failed intubation, although its role here needs further appraisal. It does not protect against aspiration of stomach contents and should not be used when aspiration is a risk. Controversy exists regarding its use to facilitate positive-pressure ventilation (PPV) due to concern that gases under pressure may be forced into the stomach and predispose the patient to regurgitation. It may be more difficult to use in children. It is now widely used in the United Kingdom; however, it is not yet available for sale in the U.S. It has already had a major effect on practice in Britain and has the potential to do the same in the United States.