Module 1: The Bronchoscope - Advanced Knowledge
How does the fiberoptic bronchoscope work?
The insertion cord contains 1 – 2 light bundles and 1 image transmission bundle. These glass bundles run the length of the scope containing thousands of glass fibers, approx 8 – 10 microns in diameter. The image transmission bundle allows light to travel along the length of the fiber, being internally reflected along its length to the eyepiece whilst still retaining a sharp image of the object. Because many of these glass fibers are bundled together, the image is built as a composite of that obtained by each fibre, similar to pixels on a television screen. A typical fiberoptic bundle contains 10,000 glass fibers.
How does the video bronchoscope work?
The light source for a video bronchoscope is generally halogen or incandescent, and is transmitted via fiberoptic bundles. The light source may also be LED. The video bronchoscope does not have an eyepiece. This is replaced by a tiny chip at the distal end of the scope that transmits images electronically. The result is an improved image, since the direct method of image acquisition is superior to coupling a video camera with a conventional fiberoptic eyepiece, which can degrade the image. The chip may be a CCD (charge coupled device) or CMOS (complimentary metal-oxide semiconductor) camera which is placed on the distal end of the scope. The articulating lever still allows control like a standard fiberoptic scope.
Sterilization and care of the bronchoscope
Cleaning and disinfecting the bronchoscope following each use are essential parts of safe bronchoscopy. The working channel must be wire brushed and flushed using a syringe as soon as possible after use, to prevent secretions from drying and hardening. As autoclaving and heating will damage the glass fibers, a variety of cold chemical sterilization processes can be used (Steris, 2% alkaline glutaraldehyde, peracetic acid etc) according to manufacturer's recommendations. Most are time effective allowing rapid turnover of instruments. The bronchoscope should be rinsed with filtered water after sterilization. The external surface of the bronchoscope should be inspected for damage and leak-tested after each procedure. Cleaning brushes should either be single-use or be sterilized after each use. Suction valves should be disposable.
Continue to: Module 2: Ancillary Equipment