Airway Management and Respiratory Support
Assessment and strategy
Mallampati class, mouth opening, thyromental distance, neck mobility, and prior difficulty are screening tools with limited individual predictive power; they are used together. Plan A/B/C/D thinking - laryngoscopy (direct or video), supraglottic rescue, front-of-neck access, and an extubation strategy - mirrors the ASA difficult airway algorithm.
Tube math and confirmation
Adults: women usually 7.0–7.5 mm ID, men 7.5–8.0 mm ID, secured 21–23 cm at the incisors with the cuff just below the cords. Children: uncuffed ID ≈ age/4 + 4, cuffed ≈ age/4 + 3.5, oral depth ≈ age/2 + 12 cm. Confirm placement with continuous waveform capnography plus auscultation; a colorimetric device is an adjunct only.
Supraglottic airways sit above the larynx - keep cuff pressure under about 60 cmH2O and remember they do not protect against aspiration. Mask ventilation is a two-person skill where jaw thrust and an oral airway solve more problems than force.
Rule of thumb: an airway is not secured until you have a sustained capnogram, stable SpO2, and bilateral breath sounds.
Trap: treating 100% saturation on a preoxygenation mask as proof of ventilation. Saturation falls late in children and the obese - watch chest rise and the capnogram instead. A second trap is assuming a stylet or bougie is sterile after a wipe; it is a semicritical device.