B. M. A. Pieters

Comparison of seven videolaryngoscopes with the Macintosh laryngoscope in manikins by experienced and novice personnel.

Videolaryngoscopy is often reserved for ‘anticipated’ difficult airways, but thereby can result in a higher overall rate of complications. We observed 65 anaesthetists, 67 residents in anaesthesia, 56 paramedics and 65 medical students, intubating the trachea of a standardised manikin model with a normal airway using seven devices: Macintosh classic laryngoscope, Airtraq®, Storz C‐MAC®, Coopdech VLP‐100®, Storz C‐MAC D‐Blade®, GlideScope Cobalt®, McGrath Series5® and Pentax AWS®) in random order. Time to and proportion of successful intubation, complications and user satisfaction were compared. All groups were fastest using devices with a Macintosh‐type blade. All groups needed significantly more attempts using the Airtraq and Pentax AWS (all p < 0.05). Devices with a Macintosh‐type blade (classic laryngoscope and C‐MAC) scored highest in user satisfaction. Our results underline the importance of variability in device performance across individuals and staff groups, which have important implications for which devices hospital providers should rationally purchase.

Videolaryngoscopy vs. direct laryngoscopy use by experienced anaesthetists in patients with known difficult airways: a systematic review and meta-analysis

Experienced anaesthetists can be confronted with difficult or failed tracheal intubations. We performed a systematic review and meta‐analysis to ascertain if the literature indicated if videolaryngoscopy conferred an advantage when used by experienced anaesthetists managing patients with a known difficult airway. We searched PubMed, MEDLINE, Embase and the Cochrane central register of controlled trials up to 1 January 2017. Outcome parameters extracted from studies were: first‐attempt success of tracheal intubation; time to successful intubation; number of intubation attempts; Cormack and Lehane grade; use of airway adjuncts (e.g. stylet, gum elastic bougie); and complications (e.g. mucosal and dental trauma). Nine studies, including 1329 patients, fulfilled the inclusion criteria. First‐attempt success was greater for all videolaryngoscopes (OR 0.34 (95%CI 0.18–0.66); p = 0.001). Use of videolaryngoscopy was associated with a significantly better view of the glottis (Cormack and Lehane grades 1 and 2 vs. 3–4, OR 0.04 (95%CI 0.01–0.15); p < 0.00001). Mucosal trauma occurred less with the use of videolaryngoscopy (OR 0.16 (95%CI 0.04–0.75); p = 0.02). Videolaryngoscopy has added value for the experienced anaesthetist, improving first‐time success, the view of the glottis and reducing mucosal trauma.

Combined technique using videolaryngoscopy and Bonfils for a difficult airway intubation

tically significant differences in heart rate, arterial pressure, anaesthetic vapour concentration, haematocrit, phenylephrine dosing, or the partial pressure of carbon dioxide in arterial blood between the measurement points. The results of the study demonstrate that cerebral oxygenation varies directly with FIO2 in anaesthetized patients with severe carotid artery stenosis. The observed increase in rSO2 was similar to that reported in anaesthetized ventilated patients without vascular disease and in anaesthetized patients after the placement of a carotid cross-clamp. Contrary to previous reports, we did not observe a relationship in the degree of carotid artery stenosis and rSO2 between hemispheres. Recent evidence suggests that bolus-dose phenylephrine is associated with a measureable decrease in rSO2 of 7–8 min duration. 6 Here there was no difference in phenylephrine dosing between the groups. The effect of phenylephrine by infusion has yet to be investigated. Although the clinical significance of an 8% increase in rSO2 remains to be determined, the results provide a rationale to increase FIO2 in ventilated patients with severe carotid artery disease and illustrate that measurement of cerebral oxygenation by NIRS may be helpful for such patients undergoing non-vascular surgical procedures. Increasing FIO2 may be especially helpful during periods of increased neurological risk such as hypotension and anaemia or if surgical positioning is likely to impede cerebral blood flow. The adverse consequences of ventilating patients with 100% O2 for relatively short periods are likely to be limited.

Videolaryngoscopy offers advantages over classic laryngoscopy in a patient with seriously limited lip opening

To the Editor: Inability to intubate the trachea is a leading cause of anesthesia-related injury [1]. Videolaryngoscopy offers advantages over direct laryngoscopy and is less traumatic [2, 3], as the miniature videocamera on the tip of the blade enables the intubator to provide an indirect view of the upper airway. We report a patient with limited lip opening in whom videolaryngoscopy proved to be helpful to provide a patent airway. A 73-year-old woman (160 cm; 75 kg; American Society of Anesthesiologists [ASA] physical status II), scheduled for lip reconstruction following lower lip cancer, underwent extensive lower lip resection with upper lip rotation (AbbeEstlander flap) to fill the lower lip defect [4]. Both lips were sewn together for 6 weeks, leaving an oral opening of 2.6 cm (intercommissural width). At the time of lip reconstruction (dividing the pedicle and releasing the lips), the patient showed asymmetric and limited mouth opening (interincisor distance 1.2 cm, oral width 2.6 cm; thyromental distance 6.8 cm; Mallampati grade IV), normal neck movement, and an adequate oral space. Precautions were taken to deal with a difficult airway: i.e., the provision of a difficult airway trolley, and personnel skilled in performing a surgical airway. After preoxygenation, anesthesia was induced with i.v. propofol 200 mg. Face mask ventilation was successful with capnographic tracing, and 100 mg succinylcholine was administered. The narrow mouth orifice prohibited any direct vision of the oral cavity during direct classic laryngoscopy (Cormack–Lehane grade IV), resulting in excessive tension on both lips. Channeled indirect videolaryngoscopes (Pentax-AWS , Tokyo, Japan; Airtraq , Prodol-Meditec, Vizcaya, Spain) were considered, but they were found to be too bulky to fit into the patient’s mouth, and failed to work, indicating that the wider blades of channeled videolaryngoscopes are a weak point. The insertion of a V-MAC videolaryngoscope (Karl Storz , Tutlingen, Germany), which consists of a less wide Macintosh-blade size three, into the mouth (Fig. 1) showed a Cormack–Lehane grade I on the monitor, and oral endotracheal intubation was successful at the first attempt, without the need to use a stylet. Normally a Macintosh-blade laryngoscope is introduced into the right side of the mouth, deflecting the tongue to the left, and the length of the blade is passed over the contour of the tongue. Subsequently the tongue is lifted upwards and forwards, so that enough room is created next to the blade to both visualize the glottic entrance and to insert the endotracheal tube in situ. In this patient no such maneuvers were an option. This case highlights the advantage of indirect videolaryngoscopy (Macintosh intubation blades incorporating optics in the tip for video-imaging) in patients with very limited mouth openings. The intubator does not need to see the vocal cords directly, as videolaryngoscopy offers both better laryngoscopic views and more successful intubations than classic laryngoscopy [2, 3, 5]. Management of difficult laryngoscopy in the patient with seriously reduced opening of the lips offers a unique and ongoing challenge for the anesthetist. With the present A. van Zundert (&) B. Pieters Department of Anesthesiology, Intensive Care and Pain Therapy, Catharina Hospital-Brabant Medical School, Michelangelolaan 2, NL-5623EJ, Eindhoven, The Netherlands e-mail: zundert@iae.nl

Measurement of forces during direct laryngoscopy and videolaryngoscopy

is undergoing clinical assessment in the UK, and would welcome development of a checklist specifically for this equipment, which is ideal for use in austere environments; the Association is proud of its long history of working to improve safety in anaesthesia around the world, principally through the work of its International Relations Committee (see http://www.aagbi.org/ international/international-relationscommittee). We cannot agree with his suggestion that the oxygen flush is not meant to increase oxygen concentration in the inspired gas: as long ago as 1968, BS4272 [2] specifically described this feature as the emergency oxygen supply, but we agree that this is not a feature of drawover apparatus. Notwithstanding the limitations Dr Fenton has pointed out, we hope he would agree that the guideline covers all of the equipment necessary for safe anaesthesia, not just the workstation, and that much of this is applicable internationally. We hope others using the guideline may avoid the hazards encountered by anaesthetists in the UK and referenced by the many device alerts.

Videolaryngoscopes differ substantially in illumination of the oral cavity: A manikin study

Background and Aims: Insufficient illumination of the oral cavity during endotracheal intubation may result in suboptimal conditions. Consequently, suboptimal illumination and laryngoscopy may lead to potential unwanted trauma to soft tissues of the pharyngeal mucosa. We investigated illumination of the oral cavity by different videolaryngoscopes (VLS) in a manikin model. Methods: We measured light intensity from the mouth opening of a Laerdal intubation trainer comparing different direct and indirect VLS at three occasions, resembling optimal to less-than-optimal intubation conditions; at the photographer′s dark room, in an operating theatre and outdoors in bright sunlight. Results: Substantial differences in luminance were detected between VLS. The use of LED light significantly improved light production. All VLS produced substantial higher luminance values in a well-luminated environment compared to the dark photographer′s room. The experiments outside-in bright sunlight-were interfered with by direct sunlight penetration through the synthetic material of the manikin, making correct measurement of luminance in the oropharynx invalid. Conclusion: Illumination of the oral cavity differs widely among direct and indirect VLS. The clinician should be aware of the possibility of suboptimal illumination of the oral cavity and the potential risk this poses for the patient.

Macintosh Blade Videolaryngoscopy Combined With Rigid Bonfils Intubation Endoscope Offers a Suitable Alternative for Patients With Difficult Airways

BACKGROUND: In the armamentarium of an anesthesiologist, videolaryngoscopy is a valuable addition to secure the airway. However, when the videolaryngoscope (VLS) offers no solution, few options remain. Earlier, we presented an intubation technique combining Macintosh blade VLS and Bonfils intubation endoscope (BIE) for a patient with a history of very difficult intubation. In the present study, we evaluated this technique to establish whether it is a valuable alternative. METHODS: In this single-blinded nonrandomized study, 38 patients with a history of difficult intubation or 1 or more predictors of difficult intubation, scoring a Cormack & Lehane (C&L) grade III or IV using Macintosh blade VLS, were included. Patients were intubated combining the VLS with the BIE. The C&L grade was scored 3 times during (1) direct laryngoscopy; (2) indirect videolaryngoscopy; and (3) using the combined technique (VLS + BIE). Afterward, 2 blinded anesthesiologists assessed the C&L grade using the pictures taken during the procedure. RESULTS: Data of 38 patients were analyzed. An improvement of the C&L grade with the combined technique occurred in 33 of 38 patients (86.8%; 95% confidence interval, 71.9%–95.6%). Reviewer 1 reported an improvement of the C&L grade with the combined technique in 37 of 38 patients. Reviewer 2 reported improvement in 33 and deterioration in 2 of the patients. No complications occurred. CONCLUSIONS: The combined use of a VLS with Macintosh blade and BIE gives the anesthesiologist a valuable alternative intubation option in patients with extremely difficult airways.