Use-Dependent Curvature Changes in the GlideRite® Reusable Intubation Stylet

Area of Science:

• Medical Devices
• Anesthesiology
• Surgical Technology

Background:

• The Glidescope® is a widely used video laryngoscope.
• It is commonly paired with the reusable GlideRite® stylet, designed with a specific curvature.
• The long-term shape retention of these 'nonmalleable' stylets after repeated use and sterilization is not well understood.

Purpose of the Study:

• To investigate whether GlideRite® stylets maintain their original shape and curvature through repeated clinical use and sterilization.
• To assess the impact of repeated insertion and removal on stylet shape.

Main Methods:

• High-resolution digital photography of 55 GlideRite® stylets (5 new, 50 from operating room stock) against a grid background.
• Analysis of stylet curvature using Adobe Photoshop®.
• A new stylet underwent 100 insertion/removal cycles from an endotracheal tube, with photography every 20 cycles to track shape changes.

Main Results:

• New GlideRite® stylets exhibited a consistent handle-to-tip angle (23.44° ± 1.04°).
• Stylets from clinical use showed significant variations in curvature, with some straighter (18.39° ± 2.59°) and others more curved (27.65° ± 2.73°) than new ones.
• Repeated insertion/removal cycles caused a new stylet to gradually straighten from 22° to 19.2°.

Conclusions:

• Used GlideRite® reusable stylets do not reliably maintain their original shape or curvature compared to new ones.
• Repeated clinical use likely causes stylet straightening, similar to laboratory findings.
• Practitioners may manually bend stylets, potentially altering the intended curvature and impacting intubation effectiveness.