Erol Cavus

Ischemic or volatile anesthetic preconditioning is defined as tissue protection from impending ischemic cell damage by repetitive short periods of tissue exposure to ischemia or volatile anesthetics. Objective of this study was to elucidate, if ischemic preconditioning and pharmacological preconditioning with sevoflurane have effects on muscle tissue oxygen saturation in patients undergoing surgical revascularization of the lower limb.

Recently, indirect videolaryngoscopes have become increasingly important devices in difficult airway management. The aim of the present study was to investigate laryngoscopic view and intubation success using the new C-MAC® D-Blade in comparison to the established GlideScope® videolaryngoscope and conventional direct laryngoscopy in a randomized controlled trial. Ninety-six adult patients with expected difficult airways undergoing elective ear, nose and throat surgery (ENT) requiring general anesthesia were investigated. Repeated laryngoscopy was performed using a conventional direct Macintosh laryngoscope (DL), C-MAC D-Blade (DB) and GlideScope (GS) in a randomized sequence before patients were intubated with the last device used. Both videolaryngoscopes showed significantly better C/L (Cormack-Lehane) classes than DL. Insufficient laryngoscopic view, defined as C/L ≥ III, was experienced in 18 patients (19.2%) with DL, in two patients with GS (2.1%) and in none with DB (0%). Time to best achievable laryngoscopic view did not differ between devices. Intubation time was significantly longer with both videolaryngoscopes (Median [Range] DB: 18 [8-33] s, and GS: 19 [9-34] s) than with DL (11 [5-26] s). However, intubation success was 100% for both DB and GS, whereas four patients could not be intubated using conventional direct laryngoscopy. Compared to direct Macintosh laryngoscopy, both C-MAC® D-Blade and GlideScope® comparably resulted in an improved view of the glottic opening with successful tracheal intubation in all patients.

Die endotracheale Intubation stellt innerklinisch den sogenannten ”Goldstandard“ zur Sicherung der Atemwege dar. Lassen sich Probleme bei der Intubation durch konventionelle Maßnahmen nicht bewältigen, oder ist eine schwierige Intubation a priori zu erwarten, ist der Einsatz videoassistierter Verfahren zu bevorzugen. Diese ermöglichen eine indirekte Sicht auf die laryngealen Strukturen, das erfasste Bild wird per fiberoptischer oder Kamera-Chip-Technik auf einen Monitor geleitet. Bei erwartet schwieriger Intubation stellt die endoskopisch geführte Wachintubation mit einer flexiblen Fiberoptik immer noch die Methode der Wahl dar. Unter der Maßgabe, dass eine sichere Oxygenierung über Maskenbeatmung oder Einsatz einer supraglottischen Beatmungshilfe zu gewährleisten ist, können alternativ auch ein Intubationsendoskop oder ein Videolaryngoskop eingesetzt werden. Bei Beherrschung des Algorithmus für den unerwartet schwierigen Atemweg können letztgenannte Hilfsmittel auch als Notfallalternative zum Einsatz kommen. 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.

Background In this preliminary prospective observational study at four physician-led air rescue centres, the efficacy of the C-MAC (Karl Storz, Tuttlingen, Germany), a new portable videolaryngoscope, was evaluated during prehospital emergency endotracheal intubations. Methods 80 consecutive patients requiring prehospital emergency intubation, treated by a physician introduced in the use of the C-MAC were enrolled in this study. Results Indication for prehospital intubation was trauma in 45 cases (including maxillo-facial trauma in 10 cases), cardiopulmonary resuscitation in 14 cases, and unconsciousness of neurological aetiology and cardiogenic dyspnoea in 21 cases. Forty-nine patients were intubated with a C-MAC blade size 3, and 31 with a C-MAC blade size 4. Median time to successful intubation was 20 (min−max: 5−300) seconds; 63 patients were intubated on the first attempt, 13 on the second and four after more than two attempts. A Cormack-Lehane class 1 view of the glottis was seen in 46 patients, class 2a view in 21, class 2b in eight, class 3 in three and class 4 in two. Six patients could not be intubated with the videolaryngoscopic view, but were successfully intubated at the same attempt using the C-MAC with the direct laryngoscopic view. Conclusion The C-MAC videolaryngoscope was suitable for prehospital emergency endotracheal intubations with complicated airway conditions, such as maxillo-facial trauma. The option to perform direct laryngoscopy and videolaryngoscopy with the same device appears to be exceptionally important in the prehospital setting.

The C-MAC® (Karl Storz, Tuttlingen, Germany) has recently been introduced as a new device for videolaryngoscopy guided intubation. The purpose of the present study was to compare for the first time the C-MAC with conventional direct laryngoscopy in 150 patients during routine induction of anaesthesia.

In the present preliminary study we evaluated the C-MAC® D-Blade (Karl Storz, Tuttlingen, Germany), a new videolaryngoscopic C-MAC blade for difficult intubation, during both routine and difficult intubations. First, both the conventional direct laryngoscopy and the D-Blade were used in 15 consecutive patients with normal airways during routine induction of anesthesia. Second, the D-Blade was used as a rescue device in 20 of 300 (6.7%) consecutive patients, when conventional direct laryngoscopy failed. In the 15 patients during routine induction of anesthesia, with direct laryngoscopy, a Cormack-Lehane (C/L) grade 1 and grade 2a view was seen in 7 and 8 patients, respectively. It was possible to insert the D-Blade and to get a video view of the glottis on the first attempt in all patients; with the D-Blade, all 15 patients had a C/L 1 view. The time to successful intubation with the D-Blade was 15 (8-26) seconds (median (range)). In the 20 patients, in whom unexpected difficulty with direct laryngoscopy was observed, C/L grades 3 and 4 were present in 15 and 5 patients, respectively. With the use of the D-Blade, indirect C/L video view improved to C/L class 1 in 15 patients, and to 2a in 5 patients, respectively. The time from touching the laryngoscope to optimal laryngoscopic view was 11 (5-45) seconds and for successful intubation 17 (3-80) seconds. In all 35 patients, with the D-Blade no direct view of the glottis was possible and subsequently a semiflexible tube guide was required.