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Video Laryngoscopy — Glidescope, C-MAC, McGrath

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Airway I · 9 min read

Better view, harder tube delivery. The skill is matching blade geometry to stylet shape so the tube reaches what you see.

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Choose between hyperangulated and Mac-shape video blades.
Use video laryngoscopy as a first-line and rescue tool.
Pair the right stylet with the right blade.
Recognize the limits of VL (blood, secretions, equipment failure).

Why VL exists — and where it changes practice

Video laryngoscopy provides indirect view via a camera at the blade tipdisplays larynx on screeneliminates the need for a direct line of sight from operator's eye to glottis.

Benefits

improved view in anterior airways
less cervical spine motion
easier teaching (instructor sees what trainee sees)
better view in obese/Mallampati 3-4 patients

Multiple meta-analyses + the AAGBI + DAS now suggest VL as first-line for predicted difficult airway and consider it for routine use when available.

The 2022 ASA difficult airway algorithm explicitly includes VL as a Plan A option, not just a rescue.

Device categories

Hyperangulated blades (Glidescope GVL, McGrath X-blade, Storz D-Blade, Pentax) — steep ~70-90° curve provides best view of anterior larynx but REQUIRES a matched rigid pre-formed stylet.

Mac-shape video blades (C-MAC, McGrath Mac, Glidescope Spectrum Mac) — same blade geometry as a Macintosh, so backward-compatible with direct laryngoscopy AND camera view simultaneously.

Good for teaching, transitioning operators, and patients where you want both options.

Channeled blades (Pentax AWS, Airtraq) — integrated tube guide channel makes delivery easier but the device has to be precisely positioned for the channel to align with the cords.

Glidescope (hyperangulated) technique step-by-step

Insert midline along the tongue, no need to sweep — the blade tip travels straight along midline to vallecula.

Advance until the epiglottis is visible on screen.

Lift to expose cords — aim for ~70% glottic view, not 100%.

Excessive lift pushes the larynx anterior and makes tube delivery harder.

Pre-shape the ETT around the manufacturer's rigid stylet matching the blade curve.

Insert the tube from the RIGHT corner of the mouth, not under the blade — and watch the tube tip on the screen, not the patient.

Advance tube to the cords; if it hangs up, rotate counter-clockwise 90°.

Once tip past cords, withdraw stylet 2-3 cm before advancing tube fully (rigid stylet can't navigate the tracheal curve).

C-MAC vs Glidescope — when to pick which

C-MAC (Mac-shape) advantages: backward compatibility (you can intubate via direct vision if the screen goes dark or fails), familiar geometry, easier transition for operators trained on direct laryngoscopy.

C-MAC + bougie is a very popular and high-success combination.

Glidescope (hyperangulated) advantages: superior view in anterior anatomy, smaller blade footprint useful in limited mouth opening, dedicated stylet matched to blade.

Tube delivery harder than C-MAC.

The skill differential at the institution often matters more than blade brand — pick the one you and your team are practiced with.

For the predicted-difficult airway, many practitioners default to hyperangulated for the view advantage and pair it with a bougie.

Stylet pairing — the actual cognitive load of VL

KeyHyperangulated blades REQUIRE a rigid stylet pre-shaped to match the ~70° blade angle.

A standard malleable stylet won't navigate the curve and the tube will get hung up on anterior tracheal wall.

Manufacturer-matched stylets exist (Glidescope GVL stylet, McGrath stylet, Storz hyperangulated).

Alternative: bougie railroad approach — pass bougie under cord visualization, then railroad the ETT over the bougie.

This combines VL's view advantage with the bougie's tube-delivery advantage and is now a widely-taught best-practice.

Some operators use Parker Flex-Tip ETT to reduce hang-up at the cords.

Cervical spine injury + manual in-line stabilization

KeyVL produces significantly less cervical motion than direct laryngoscopy (the camera obviates the need to extend the neck for visual alignment).

Preferred technique for known or suspected cervical spine injury under manual in-line stabilization (MILS — assistant holds head + neck neutral).

MILS itself worsens DL view (Cormack III-IV in ~50%) but does not impede VL view.

C-collar can be left ON during VL intubation; for DL, the anterior portion must be opened.

Awake VL + difficult-airway role

For anticipated difficult intubation: awake fiberoptic intubation has been gold standard, but awake video laryngoscopy is increasingly used as an alternative — especially when the patient cannot tolerate a flexible scope, or when secretions/blood limit fiberoptic visualization.

Setup

glycopyrrolate antisialogogue
nebulized + atomized 4% lidocaine
± transtracheal lidocaine
dexmedetomidine sedation

Patient cooperative + breathing spontaneously.

View cords on screen pass tube.

Awake VL has been studied in head-and-neck cancer, obesity, and ankylosing spondylitis with good success.

Delivery-failure troubleshooting

KeyMost common VL frustration: 'see but can't deliver.' Cords are right there on the screen but the ETT keeps catching anteriorly or on the right arytenoid.

Fixes in order: (1) withdraw stylet slightly once tube tip is past the cords — rigid stylet can't make the bend.

Rotate ETT 90° counter-clockwise — repositions bevel.

Insert bougie through the cords first, then railroad ETT over bougie (most reliable rescue).

Switch to a Mac-shape blade — the geometry change often solves the delivery problem.

Downsize ETT (7.5 → 7.0).

Re-do the laryngoscopy aiming for a SMALLER view (70% glottis, not 100%) — over-lifting pushes the larynx too anterior.

Limitations + when DL still wins

KeyVL limitations: blood/vomit/secretions on the lens make it useless — must suction aggressively.

Camera failures or screen dropouts mid-attempt require an immediate fallback (have a DL handle on the cart).

Cost and equipment-cleaning load is higher.

In a true cannot-intubate-cannot-oxygenate emergency, time spent setting up VL when a Mac blade is already in hand can be wasted.

Best practice

have BOTH available
default to VL for known/anticipated difficulty
default to whichever you're fastest with for routine

⚠ Common pitfalls

Looking at the screen without first achieving a direct view — Mac-shape blades reward both.
Hyperangulated stylet too straight — tube delivery fails despite good glottic view.
Heavy secretions obscuring the camera lens — suction + reposition; don't keep trying blindly.
Skipping the bougie when the view is poor — bougie + VL is a powerful combination.

💎 Clinical pearls

Hyperangulated (Glidescope, McGrath X) for anterior airway; Mac-shape (CMAC, McGrath Mac) for routine + rescue.
First-pass success ↑ with VL — ASA DAA 2022 mandates VL availability everywhere anesthesia is given.
If the view is great but the tube won't pass: change the stylet angle, withdraw + redirect, then bougie rescue.
Carry a backup VL battery — equipment failure rate is real; manifest itself at the worst moment.

Recap

Hyperangulated (Glidescope, McGrath X) for anterior airway; Mac-shape (CMAC, McGrath Mac) for routine + rescue.
First-pass success ↑ with VL — ASA DAA 2022 mandates VL availability everywhere anesthesia is given.
If the view is great but the tube won't pass: change the stylet angle, withdraw + redirect, then bougie rescue.
Carry a backup VL battery — equipment failure rate is real; manifest itself at the worst moment.

Mark each section done to complete the module.