Ichiro Takenaka

The sniffing position provides greater occipito-atlanto-axial angulation than simple head extension: a radiological study.

PurposeWhile the anatomic sniffing position has traditionally been considered the standard head and neck position for laryngoscopy, recent evidence suggests that the sniffing position provides no significant advantage over simple head extension. To establish if the sniffing position provides an anatomic advantage, we compared the occipito-atlanto-axial extension angle, a key determinant for obtaining a good laryngeal view during laryngoscopy, in simple head extension and sniffing positions.MethodsThirty volunteers with normal cervical spines were studied. Radiological examinations of the lateral cervical spine were taken and compared in each of the following three positions for each subject: neutral position (flat on the table with no pillow and without head extension or flexion); simple head extension (head maximally extended without a pillow); and the sniffing position (head extension with cervical flexion obtained by 7 cm occipital elevation).ResultsMean angles of the occipito-atlanto-axial extension in simple head extension and the sniffing position were 20.4°±5.1°and 24.2°± 5.6°, respectively (P < 0.01).ConclusionThe anatomic sniffing position provides greater occipito-atlanto-axial extension compared to simple head extension. These findings should be taken into consideration when optimizing patient positioning for laryngoscopy.RésuméObjectifLa position anatomique de reniflement est traditionnellement considérée comme la position standard de la tête et du cou pour la laryngoscopie; toutefois, des études récentes suggèrent que cette position ne présente aucun avantage significatif par rapport à la simple extension de la tête. Nous avons comparé l’angle d’extension occipito-atlaïdo-axial dans les positions de simple extension de la tête et de reniflement afin de déterminer si la position de reniflement présentait un avantage anatomique, l’angle étant un élément-clé dans l’obtention d’une bonne vision laryngée pendant la laryngoscopie.MéthodeL’étude portait sur trente volontaires avec colonnes cervicales normales. Chaque sujet a subi des examens radiologiques de la colonne cervicale latérale dans les trois positions suivantes: position neutre (à plat sur la table sans oreiller et sans extension ou flexion de la tête); extension simple de la tête (tête en extension maximale sans oreiller); et position de reniflement (extension de la tête avec flexion cervicale obtenue par une élévation occipitale de 7 cm). Les résultats ont ensuite été comparés.RésultatsLes angles moyens d’extension occipito-atlaïdo-axiale dans l’extension simple de la tête et la position de reniflement étaient de 20,4° ± 5,1° et 24,2° ± 5,6° respectivement (P < 0,01).ConclusionLa position anatomique de reniflement présente une plus grande extension occipito-atlaïdo-axiale que la simple extension de la tête. Ces résultats devraient être pris en compte pour obtenir un meilleur positionnement du patient lors de la laryngoscopie.

Kounis syndrome during general anaesthesia and administration of adrenaline

During the course of anaphylaxis, occurrence of myocardial ischaemia has been known, which have recently been named as Kounis syndrome [1]. Regarding treatment for this syndrome, early intravenous administration of adrenaline is the key points for managing anaphylaxis [2–4] but adrenaline can aggravate myocardial ischaemia. Moreover, whether adrenaline is effective or not is controversial [5,6]. We report a case of Kounis syndrome during general anaesthesia in which administration of adrenaline was effective in both anaphylactic shock and myocardial ischaemia, and discuss perioperative problems about diagnosis and therapy. A 61-yr-old man was scheduled for varicose vein stripping. He had in good health, had no past history suggestive of allergy, and took no medications. The operation began uneventfully under spinal anaesthesia. Ten minutes after the start of surgery, the patient became confusional, severely hypotensive and tachycardic. Ephedrine, phenylephrine and noradrenaline were administered in addition to rapid infusion of normal saline but the patient remained hypotensive and tachycardic. Fifteen minutes after occurrence of hypotension, the ECG revealed ST segment elevation in a MCL5 lead. We suspected that hypotension was caused by left ventricular dysfunction as a result of myocardial ischaemia, and started nitroglycerin and noradrenaline continuously. But the patients condition remained unchanged. A few minutes later, the anaesthetist noticed a mildly or moderately erythematous rash at the patients face for the first time and

Malposition of the epiglottis associated with fiberoptic intubation.

A case in which the epiglottis was tucked into the laryngeal inlet by advancement of an endotracheal tube (ETT) during fiberoptic intubation, is presented. In this case, pulling the fibroscope, which was advanced under the displaced epiglottis, was effective for restoration.

Oral styletted intubation under video control in a patient with a large mobile glottic tumour and a difficult airway

PurposeWith fibreoptic intubation, advancement of the endotracheal tube (ETT) through the glottis is blind. Thus, in patients with a laryngeal tumour, there is a potential for damage to the tumour. Previously, we proposed the use of a fibreoptic bronchoscope (FOB)-video camera system to permit visualization of tube passage. We used this technique successfully in a patient with a known difficult airway and a large glottic tumour.Clinical featuresA 61 -yr-old man with a known history of difficult laryngoscopic intubation underwent laryngeal microsurgery for recurrence of a glottic tumour. As preoperative indirect laryngoscopy revealed a large, mobile, and pedunculated glottic lesion obstructing the glottic opening, we planned a conventional awake fibreoptic intubation. Endoscopy showed that the tumour partially obstructed the glottis and the space between the tumour and the glottic opening was very narrow. To avoid damage to the tumour, we changed to an alternative fibreoptic intubation technique. The FOB attached to a video camera was passed nasally and a jaw thrust manoeuver was applied, providing an excellent view of the larynx. An anesthesiologist inserted the ETT with a curved stylet orally, and carefully advanced the tube tip into the space between the tumour and the glottic opening under video control. Absence of damage to the tumour and passage of the tube between the cords were confirmed visually.ConclusionThis alternative intubation technique, providing a view of the tube passage into the glottis, was a reasonable method to avoid potential damage to the glottic tumour by blind tube passage during conventional fibreoptic intubation.RésuméObjectifPendant l’intubation fibroscopique, la poussée du tube endotrachéal (TET) au travers de la glotte se fait à l’aveugle. En présence d’une tumeur laryngée, il y a donc une possibilité d’altérer la tumeur. Auparavant, nous avons proposé d’utiliser un firoscope bronchique (FOB) guidé par une caméra vidéo, ce qui permet de visualiser le passage du tube. Cette technique a été utilisée avec succès chez un patient connu pour problèmes d’intubation et qui présentait une tumeur glottique.Eléments cliniquesUn homme de 61 ans connu pour des problèmes d’intubation a subi une intervention au larynx en microchirurgie pour une tumeur récidivante. Comme la laryngoscopie indirecte préopératoire révélait une importante lésion pédiculée et mobile obstruant l’ouverture glottique, nous avons planifié une intubation fibroscopique vigile traditionnelle. L’endoscopie a montré que la tumeur obstruait partiellement la glotte et que l’espace entre la tumeur et l’ouverture glottique était très étroite. Nous avons donc opté pour une intubation fibroscopique modifiée afin de ne pas toucher à la tumeur. Le FOB, relié à une caméra vidéo, a été passé par voie nasale et une manœuvre de projection de la mandibule a été appliquée pour favoriser une meilleure visualisation du larynx. Un anesthésiologiste a inséré un TET avec un stylet courbé par voie orale et, sous contrôle vidéo, a poussé prudemment la pointe du tube dans l’espace entre la tumeur et l’ouverture glottique. Le système de caméra vidéo a permis de confrmer l’absence de dommage à la tumeur et le passage du tube entre les cordes vocales.ConclusionLa technique d’intubation décrite, qui fournit une visualisation du passage du tube dans la glotte, s’est révélée satisfaisante pour éviter de toucher la tumeur glottique par le passage du tube à l’aveugle pendant l’intubation fibroscopique traditionnelle.

Optimizing endotracheal tube size and length for tracheal intubation through single-use supraglottic airway devices

To the Editor, Supraglottic airway devices have an established role in facilitating tracheal intubation in the setting of difficult airway management. When the laryngeal mask airway (LMA) Classic (LMA North America Inc., San Diego, CA, USA) is used as an airway conduit for tracheal intubation, there are several limitations regarding the compatibility of endotracheal tubes (ETT), because the ETTs must be passed through the relatively narrow and long airway tube of the LMA. Recently, single-use supraglottic airway devices that have configurations similar to that of the LMA Classic have been introduced. These single-use devices include the LMA Unique (LMA North America Inc., San Diego, CA, USA), the Soft Seal Laryngeal Mask (Smiths Medical Ltd., Hythe, Kent, UK), the AuraStraight (Ambu Inc., Glen Burnie, MD, USA), and the AuraOnce (Ambu Inc., Glen Burnie, MD, USA). The effectiveness of these devices to facilitate tracheal intubation has been investigated. Compared with the LMA Classic, these airways differ slightly in their structure. For instance, each of these new single-use supraglottic airways has a unique internal diameter and length, hence, options regarding both the size and length of ETTs that can be used for tracheal intubation may differ from that of the LMA Classic. These differences may be especially important when using these devices in emergent settings. We undertook a comparison of the diameters and lengths of ETTs that can be used for tracheal intubation through each of these supraglottic airways. This comparison revealed that the minimum length of ETT that could be considered suitable to advance through the supraglottic airway was deemed to be the sum of the length of the airway tube of the supraglottic airway, the distance between the mask aperture and the vocal cords (ranging from 2.0 to 4.7 cm), and the distance between the upper border of the ETT cuff and the ETT tip, i.e., B 5.5 cm in a 6 or 6.5 mm ETT and B 6.5 cm in a 7 mm ETT (Table 1). Thus, when the ETTs are passed through the supraglottic airway to the maximum extent possible, 6 mm and 7 mm internal diameter ETTs are required to project about 10 cm (4.7 ? 5.5 cm) and 11 cm (4.7 ? 6.5 cm), respectively, beyond the mask aperture. The airway tube of the LMA Unique is equal in both internal diameter and length to that of the LMA Classic, which needs a longer ETT (Tables 1 and 2). While the length of the Soft Seal Laryngeal Mask is similar to that of the LMA Classic, the former tube is thicker (Table 2). Thus, when using the Soft Seal Laryngeal Mask for tracheal intubation, a longer ETT is needed (Table 1); however, in comparison with the LMA Classic, a large bore ETT can be used (Table 2). In contrast, the airway tube of the AuraStraight has the same internal diameter as that of the LMA Classic, but the tube length is shorter (Table 2). Thus, when using the AuraStraight, normal length ETTs can be used in most cases for tracheal intubation.

Combination of Airway Scope and bougie for a full-stomach patient with difficult intubation caused by unanticipated anatomical factors and cricoid pressure

The Airway Scope, one of the newest video-laryngoscopes, provides an excellent view of the larynx on a built-in monitor screen. Difficulty in introducing an endotracheal tube into the laryngeal aperture may occur, even though the aperture is visible. The bougie may solve this difficulty because its angulated tip can be controlled in a desired direction. The successful use of the bougie along with the Airway Scope in a full-stomach patient with a difficult airway is presented.