Flexible fiberscopes have a limited role in emergency airway management. Many emergency airways require a rapid sequence intubation technique with intubation performed using rigid instruments that permit quick tracheal tube placement (laryngoscopes, video laryngoscopes, etc.).
Short, flexible rhinolaryngoscopes (~ 30 centimeters) are commonly used for diagnostic evaluation of the upper airway while intubating fiberscopes (~60 centimeter length) are used for awake intubation through the nose or mouth. Mid-length scopes (~36 centimeters) are also available, and may be the best single device for emergency settings, capable of both diagnostic rhinolaryngoscopy and intubation (with a tube-fiurst approach to intubation).
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The short rhinolaryngoscopes (Olympus ENF-P4: 26 cm length, 3.6 mm outer diameter) have no working channel and are therefore much easier to clean. The mid-range scope (Olympus T3: 36.5 cm working length, 4.8 mm OD, 2.2 mm working channel) is more resistant to breakage than the long intubating bronchoscope (Olympus LF-2: 60 cm L, 3.8 mm OD, 1.5 mm working channel), but slightly larger in outer diameter. The larger working channel of the ENF-T3 is useful for managing blood or secretions and spraying anesthetic, and the shorter length makes it much easier to handle. It may be more uncomfortable for nasoendoscopy, however, because of its larger diameter.
Cases of tuberculosis, hepatitis, Pseudomonas, and other diseases have been transmitted between patients through improperly cleaned endoscopic instruments. Fiberscopes that have a working channel must be wire brished and flushed during the sterilization process. Like all fiberoptic instruments, autoclaving and heating will damage the glass fibers and must not be used. A variety of cold sterilization processes can be used for certain instruments (Steris, glutaraldehyde, Cidex, etc., depending upon manufacturer’s recommendations), but these are often unavailable in emergency settings and some require special ventilation systems.
A better means of handling the logistical problems of cleaning endoscopes in emergency settings is to use an endoscopic sheath developed by Vision Sciences, Inc. (Natick, MA). These sterile disposable sheaths are custom built for a variety of scopes and some models even come with a working channel. The tip of the sheath must be fully slid onto the scope so that the special optical element at the end of the sheath is flat against the tip of the scope. After using the sheath, it can be slid off and disposed of without the need to re-sterilize the scope. These sheaths should never be forcefully removed.
If there is difficulty removing the sheath, make sure to slide off the distal tip first. Alternatively, a drop of an alcohol solution (from an alcohol pad) can be inserted into the sheath, allowing the sheath to slide off easily.