Direct Laryngoscope Blades — Mac, Miller, McCoy

Tip placed in the vallecula (the space between the tongue base and the epiglottis).

Pressure on the hyoepiglottic ligament indirectly lifts the epiglottis out of the line of sight, exposing the vocal cords.

Adult workhorse — most direct laryngoscopies use a Mac 3 or Mac 4. Wide flange leaves room on the right side for ETT passage past the blade.

Sizes 3 for most adults, 4 for large adults, occasional 2 for small adults or larger children.

Disadvantages: a large or floppy epiglottis may not lift reliably (Cormack 3 view), and a very anterior larynx demands more lifting force than the curved geometry transmits efficiently.

Designed to be advanced PAST the epiglottis and used to lift the epiglottis directly from below — bypassing the unreliable indirect lift of the Mac.

Less ETT delivery room than Mac — operators sometimes pull the blade slightly toward midline to make room.

Pulling the lever flexes the blade tip ~70°, mechanically lifting the epiglottis when a standard Mac view is inadequate.

Useful as a rescue without changing blades or repositioning the patient.

C-spine-immobilized patients benefit because the tip flex achieves what neck extension cannot.

Modern video laryngoscopes have largely displaced McCoy in many practices, but it remains on difficult-airway carts as a low-cost, no-power-required tool.

III = epiglottis only (bougie strongly recommended, or switch to video laryngoscope).

IV = no epiglottis seen (do not persist; call for help, awake technique, video laryngoscope, fiberoptic).

Grade III/IV laryngoscopy is associated with difficulty in the literature and warrants documentation for future encounters.

Each repeat attempt under the same conditions decreases success and worsens edema — change ONE variable per attempt (operator, blade, position, technique) and limit to 3 total attempts before escalating.

Improves view in ~50% of difficult laryngoscopies.

CRITICAL distinction from cricoid pressure (Sellick): cricoid pressure is on cricoid (not thyroid), pressed straight down (not B-U-R), and is for aspiration prevention only — it can WORSEN the laryngoscopic view in 30% of cases.

Single pillow under occiput in lean adults; remove for children <8 (large occiput already positions them).

Ramped position (HELP — Head Elevated Laryngoscopy Position) for obese: stack blankets or use commercial ramp until tragus is at the level of the sternum, with shoulders elevated.

Pre-oxygenation effectiveness also improves with head-up positioning.

Recheck position after sterile drapes go on — head can drop and shift the alignment.

Confirm with capnography + bilateral breath sounds + chest rise — visual passage through cords is NOT confirmation alone.

Obese: ramped position with head elevated 25°.

Lift in line of handle axis (45° upward, NOT pry).

Look directly through laryngoscope's view, not at TV monitor (with direct laryngoscopy).