Direct laryngoscopy, which involves picking up the base of the tongue and epiglottis directly with a direct laryngoscope, is not a routine examination of the larynx
because it is an invasive method of laryngeal examination, which is difficult for patients to tolerate under mucosal surface anesthesia and usually requires hospitalization under general anesthesia. Direct laryngoscopy provides a detailed view of the structural abnormalities of the
larynx, identifies the location and extent of the lesion, and biopsies the diseased tissue if necessary. Direct laryngoscopy cannot obtain functional indicators of the larynx. Since the development of fiberoptic laryngoscopy and electronic laryngoscopy, direct laryngoscopy has been used less and less as an examination tool, but it is widely used as a surgical tool in clinical practice.
Direct laryngoscopes can be of various types according to their uses, such as lamellar laryngoscopes (straight and curved laryngoscopes, which are generally used in anesthesiology departments), general direct laryngoscopes, direct laryngoscopes of side-slit, anterior combined laryngoscopes, support laryngoscopes, and suspension laryngoscopes, etc. According to their sizes, there are also infant, pediatric, and pediatric laryngoscopes. According to its size, there are infant, child and adult laryngoscopes. If special equipment is attached, such as microscope,
laser system, endoscopic system, camera and video system, etc., it is more convenient for examination, surgical treatment and teaching [2].
1. Indications
(1) Indirect laryngoscopy and fiberoptic laryngoscopy are unsuccessful, or indirect laryngoscopy and fiberoptic laryngoscopy visual field exposure is unsatisfactory for those who can feasibly use direct laryngoscopy.
(2) Take laryngeal tissue biopsy specimen, or directly wipe the laryngeal secretion for examination.
(3) Treatment of laryngeal lesions such as resection of benign tumors (e.g., polyps of the vocal cords, resection of small benign laryngeal tumors). Surgery such as laryngeal scarring stenosis dilatation, electrocautery, local medication and removal of foreign bodies from the larynx, trachea and upper esophagus.
(4) endotracheal anesthesia or bronchoscopy is not easy to go down the tube can borrow direct laryngoscope assistance.
(5) It is used for endotracheal intubation, for anesthesia intubation and rescue of patients with laryngeal obstruction.
(6) For pediatric bronchoscopy, the vocal folds can be exposed with a lateral fissure direct laryngoscope and then introduced into the bronchoscope [3].
2. Contraindications
Cervical spine pathology, such as dislocation, tuberculosis, and trauma, are not suitable for this procedure. Serious illness, severe debility and late pregnancy are not absolute contraindications, but great caution should be exercised.
3. Inspection methods (except support laryngoscope and suspension laryngoscope)
Direct laryngoscopy under mucosal surface anesthesia, the operator's left hand holds the mirror, put a thick layer of gauze to protect
protection of the upper teeth, with the right hand finger to push open the upper lip, so as not to be pressed by the mirror in the teeth injured, and then the mirror along the back of the tongue into the oral cavity, transfer to the midline deep into the root of the tongue, from the laryngoscope to see the epiglottis, the right hand thumb to see the epiglottis. When the epiglottis is seen, the right thumb and index finger assist in holding the tube from the anterior
back, respectively. Tilt the proximal end of the laryngoscope upward (forward in the seated position) and point the distal end toward the posterior pharyngeal wall, but do not make contact with it. Continue to advance the scope beyond the free edge of the epiglottis, and after visualizing the epiglottic nodes, the left hand lifts the laryngoscope with a parallel upward force
and presses on the epiglottis so that it is completely lifted and the laryngeal cavity can be exposed. At this time, if laryngospasm occurs and the glottic fissure is tightly closed and the glottic fissure cannot be glimpsed, the laryngoscope should be fixed in place and not moved, and after a few moments of waiting for the laryngospasm to come into contact with the laryngopharynx
the image of the larynx can be seen. If the laryngoscope is too deep, touching the mucosa of the laryngeal cavity caused reflex spasm, should withdraw the laryngoscope a little, after the laryngeal spasm is lifted, and then observe, tell the examinee to pronounce the "clothes" sound, to observe the movement of the vocal cords, at this time
the operator can use the right hand to engage in a variety of necessary operations.
If the patient's neck is short and thick, and it is not easy to expose the anterior connection of the vocal cords, the patient's head should be raised, the left hand should be lifted upward
Lift up the laryngoscope with force, the right thumb should be pressed upward from the lower part of the laryngoscope, and the rest of the right hand's fingers should be held on the patient's right side of the upper teeth, and the patient's anaeroid should be held up with force. If this method is unsuccessful, you can ask the assistant to press the thyroid cartilage downward or switch to anterior combined laryngoscopy
. The anterior combined laryngoscope not only allows clear visualization of the anterior vocal folds, but also allows insertion into the glottic fissure to examine the subglottic cavity. When examining young children, in order to prevent laryngeal edema after this procedure, the tip of the laryngoscope may not compress the epiglottis, but only the root of the tongue is lifted forward
, and the epiglottis is then erected to expose the laryngeal cavity.
4. Complications
are usually rare. In young children, especially those with spasmodic qualities, severe, even life-threatening laryngospasm can occur intraoperatively. During the operation, the movement is as gentle as possible to reduce the damage to the pharyngeal and laryngeal mucosa and reduce the chance of hematoma, bleeding or secondary infection.