Stylet 

A stylet is a malleable metal or plastic introducer inserted into an endotracheal tube (ETT) to provide shape, rigidity, and direction during intubation.

  • It is NOT a guide for tracheal placement (unlike a bougie)
  • It is used to optimize ETT trajectory, especially in difficult airways

Purpose in Critical Care

Core Functions

  1. Shapes the ETT
    • Allows preforming (e.g., “hockey-stick” shape)
  1. Improves intubation success
    • Especially with anterior larynx or limited view
  1. Facilitates rapid intubation
    • Essential in emergency/RSI settings
  1. Useful in video laryngoscopy
    • Required for hyperangulated blades

Types of Stylets

1. Malleable Stylet (Most Common)

  • Aluminum core + plastic sheath
  • Can be shaped as needed
  • Disposable or reusable

2. Rigid Stylet

  • Fixed curvature
  • Less commonly used in ICU
  • Higher trauma risk

3. Optical Stylet

  • Built-in fiberoptic visualization
  • Used in difficult airway settings

4. Pre-shaped Stylets

  • Designed for specific devices (e.g., GlideScope)

Ideal Shape (“Hockey Stick” Configuration)

Standard Recommendation:

  • Distal 5–7 cm angled at 30–35°
  • Proximal shaft remains straight

Why?

  • Aligns with oropharyngeal → laryngeal axis
  • Improves success in:
    • Anterior larynx
    • Cormack-Lehane grade II–III

Video Laryngoscopy:

  • Often requires more acute angulation (≈60°)

Technique of Use 

Preparation

  • Insert stylet into ETT
  • Ensure:
    • Tip of stylet does NOT protrude beyond ETT
  • Always lubricate ETT + stylet

Intubation Steps

  1. Perform laryngoscopy
  2. Advance ETT (with stylet) toward glottis
  3. Once vocal cords crossed:
    • STOP advancing stylet
  1. Withdraw stylet partially or completely
  2. Advance ETT into trachea
  3. Inflate cuff

Complications 

1. Airway Trauma

  • Mucosal injury
  • Vocal cord damage
  • Tracheal perforation

2. Esophageal Perforation (rare but serious)

3. “Hang-up” on Anterior Trachea

  • Due to excessive angulation

4. Shearing Injury

  • If stylet protrudes beyond ETT

5. Infection risk (reusable stylets)

 Stylet vs Bougie 

Feature

Stylet

Bougie

Function

Shapes ETT

Guides ETT into trachea

Visualization

Direct/Video

Often blind

Use

Routine + difficult airway

Difficult airway (esp. poor view)

Confirmation

No tactile feedback

“Clicks” + hold-up sign

First-pass success

Improves

Very high in difficult airway

Indications in ICU

  • Routine intubation (RSI)
  • Video laryngoscopy (almost mandatory)
  • Anticipated difficult airway
  • Limited mouth opening
  • Obese patients
  • Cervical spine immobilization
  • Stylet improves first-pass success in video laryngoscopy
  • Not a substitute for bougie in difficult airway
  • Most common complication → mucosal injury
    • In Cormack-Lehane grade III–IV, a bougie is superior
  • Over-angulation → major cause of failed intubation despite good view