Laryngoscope fiber laryngoscope

Fiberoptic laryngoscope is the most widely used fiberscope in otolaryngology. Fiber laryngoscope is made of the flexibility of transparent glass fiber, the strong brightness of fiber bundle and the ability to guide light in any direction, and the light source is halogen cold light source. Fiberoptic laryngoscope inspection system consists of reflector, cold light source and accessories. Because it can be inserted through the anterior nostril to examine the nasopharynx, oropharynx, larynx and larynx, it is also called fiber nasopharynx laryngoscope. There are different types and specifications of fiber laryngoscopes. The effective length of commonly used fibrolaryngoscope is more than 300mm, and the distal end can be bent upward by 90 ~130, downward by 60 ~ 90, and the viewing angle is 50. At present, the fiber laryngoscope commonly used in clinic has an outer diameter of 3.2mm~6mm ~ 6 mm, which can be used for examination of children and adults. At the same time, the fibrolaryngoscope has a lumen, and tweezers can be placed for biopsy and surgery. At the same time, the lumen can be used for negative pressure suction and local administration through the lumen and throat. Fibrolaryngoscope can be connected with camera system and computer system, and recorded images and videos can be processed by computer.

1. instruction

Basically the same as direct laryngoscopy. Because the fiberoptic laryngoscope is flexible and bright, it can be inserted through the nasal cavity for examination, especially for indirect laryngoscope and direct laryngoscope examination caused by over-sensitivity of the pharynx, clenched teeth, difficulty in opening the mouth, stiff neck, short neck, too high tongue, too short tongue band and epiglottis covering the throat entrance. Because the fibrolaryngoscope can be close to the examination site through the display and enlarged, it can find hidden lesions and early micro-lesions, perform local lesion biopsy and operate on smaller vocal nodules and polyps. Equipped with a video recording system, the development process of the lesion can be observed dynamically.

2. Contraindications

Fiberoptic laryngoscope has no definite absolute contraindication, but it can be regarded as a relative contraindication for patients with acute upper respiratory inflammation accompanied by dyspnea, severe cardiopulmonary disease, tetracaine allergy and unexplained severe laryngeal obstruction.

3. Inspection method

Before the examination, it is usually necessary to anesthetize the nasal cavity and throat mucosa. 1% tetracaine spray is commonly used in anesthesia. Ephedrine spray should also be carried out in the nasal cavity to shrink the nasal cavity after nasal examination. The total dose of tetracaine for adult mucosal anesthesia should not exceed 60 mg.

Fibrolaryngoscope can pass nasal or oral examination. The nasal cavity and nasopharynx can be observed at the same time through nasal examination, and the range is easy to fix. When the fiber laryngoscope is inserted along the posterior pharyngeal wall, the pharyngeal reflex is light, and it is not interfered by the tongue, so the operation is convenient. However, if you encounter nasal septum deviation, lower turbinate hypertrophy, nasal polyps or new organisms, and have recurrent nosebleeds or runny noses recently, you can have an oral examination. Usually, the left hand holds the operating part of the scope, and the right hand holds the distal end of the scope, and enters the nasopharynx along the nasal floor or middle nasal passage. Adjust the curvature of the speculum to bend downward, observe the root of tongue, epiglottis (lingual surface and laryngeal surface), epiglottis valley, pyriform fossa, arytenoid cartilage mucosa and arytenoid cartilage area, ventricular band, vocal cord, anterior commissure and subglottic mucosa, and pay attention to the color and shape of laryngeal mucosa. If it is necessary to observe the larynx and pharynx, instruct the patient to close his mouth and lips and inflate. When the esophageal entrance is open, the piriform fossa and posterior ring area can be observed.

4. Advantages

(1) The endoscope is thin and elastic, and the patient does not need special posture, so the pain and trauma are small. It can be used for the examination of patients with neck deformity, difficulty in opening mouth, weakness and critical illness.

(2) The operation is simple and convenient, which is more conducive to examining various laryngeal lesions in the state of natural pronunciation.

(3) The end of the endoscope tube is close to the anatomical site, which is especially suitable for patients with short neck, thick tongue, narrow pharyngeal cavity and epiglottis in infants.

5. Deficiencies

The small mirror surface and long lens barrel of the objective lens produce fisheye effect, and the image is easily distorted and the color fidelity is low [4].