Kudos to Yen Chow (@TBayEDGuy) for alerting us to these two useful instructional clips on the HQMedEd page:
Time to get down and bougie?
Intubation in a young child with a severe submandibular abscess using the paediatric Bonfils rigid intubating endoscope under inhalational general anaesthesia. Direct laryngoscopy showed only severe swelling with a Cormack-Lehane grade 3b view. A standard laryngoscope was used with the left hand to create an open path for the Bonfils just right of the midline, avoiding the worst of the submandibular swelling. 3.5mm Bonfils allowed intubation with a 4.5 mm uncuffed ETT. Note that because this is a rigid intubating scope, it is not inserted through the vocal cords, but they are visible through the tube as it is inserted with the Bonfils held steady.
Nice illustration of the various lung volumes and capacities courtesy of www.medicomic.com. Easy aide memoire: a capacity is always the sum of two or more volumes. Note that the absolute volumes reflected here would be for a normal sized adult.
Flexible fibreoptic and video endoscopes are fantastic but expensive pieces of equipment. In order to be maintained in top working condition, they need a little tender loving care. A particular problem occurs when the sheath of the scope becomes damaged or cracked, allowing fluid (especially corrosive cleaning solutions) to enter the inner workings of the scope, causing irreparable damage. The inner workings of the scope are a sealed environment. The patency of the seal – and thus the presence or absence of any damage – can easily be determined by performing a leak test. Although this is usually performed by medical technologists who are looking after the scopes, it can just as be performed quickly by the user while the scope is being prepared, or just before cleaning. Spend 100 seconds watching this brief, unadorned video which will walk you through the process. The demonstration here is using our Storz equipment, but is very similar regardless of the make or model of endoscope.
@fibroanestesia comes up with some interesting ideas. Here they use a combination of the AScope3 (a disposable flexible video endoscope) and the King Vision video laryngoscope to perform a highly controlled intubation in a patient with an intrathoracic goitre. They have obviously pre-assessed this patient and concluded that the risk of failed intubation or positional loss of the intrathoracic airway due to compression is minimal.
What a great idea. Consume, rather than be consumed by your fears 😉 Credit to Rob Bryant and his team.
Here are some real-life examples of Cormack-Lehane classification of laryngoscopic view taken with a video laryngoscope. Although initially described for direct laryngoscopy in obstetric patients, it is a useful descriptive system in many settings, but is frequently misreported and/or misunderstood. We will continue to expand the set as we collect good images.
Original and revised (Yentis & Lee, 1998) CL grading:
Colour-coded to make it a little easier to read:
…and here from the CoPilot VL material, a more anatomically-correct sketch which shows the distinction between 2a and 2b clearly:
See the original article by RS Cormack and J Lehane in Anaesthesia, 1994;(39):1105-1111.
Various modifications to this scheme have been proposed for use with video laryngoscopy (VL), including suggestions by Cook and Fremantle:
The TotalTrack is a new video laryngeal mask that allows intubation through the device without interruption of ventilation. Recruitment of the first independent clinical trial is well underway in Cape Town, with European studies nearing commencement. Here is an example video taken with the device, showing intubation in a patient with severe obstructive sleep apnoea (OSA).
This common problem is worst with small bougies, such as in this paediatric example of a child with severe burns and a difficult airway. The bevel of the ETT allows the tip of the tube to stick out right (laterally) of the bougie and snag on the right arytenoid cartilage. This can be remedied by withdrawing the ETT slightly (to disengage it from the arytenoid), effecting a one-quarter counter-clockwise rotation of the ETT on the bougie (bringing the bevel and tip of the ETT into a superior midline position snug with the bougie), and then advancing again.