Required Instruments
- Laryngeal mirrors, K6 to K10 [Figure 44].
- Laryngeal mirror handle.
- Mirror warmer or anti-condensation tissues.
- Head lamp.
- Large gauze dressings.
- Lidocaine spray 10%.
Figure 44
Procedure
- For all indirect laryngoscopies, the patient sits on a chair with adequate back support.
- Sit on a height-adjustable stool beside or in front of the patient.
- Your eyes should be at the same height as the patient’s nose.
- If required, prepare the patient for this examination by numbing the pharyngeal arches, tonsillar fossae, the posterior pharyngeal wall and the base of the tongue, using lidocaine spray [Figure 45].
- Do not apply more than 3-4 squirts.
Figure 45
- Choose the laryngeal mirror (K6 or K7) that you will use for the examination.
- Place it in the laryngeal mirror handle and give the mirror an ‘anti-condensation treatment’.
- You can do this by warming it up in an electric mirror heater. The temperature of the heater can be set at exactly 37°C. An alternative option is to rub the mirror with an anti-condensation tissue.
- Check whether the lidocaine spray has taken effect by touching the base of the tongue with a tongue spatula. If this does not elicit a gag reflex, the anaesthetic has taken sufficient effect.
- Ask the patient to open their mouth wide and to stick out their tongue.
- Wrap a long piece of folded gauze dressing [Figure 46] around the patient’s tongue [Figure 47] and hold the tongue with your non-dominant hand [Figure 48].
- Make sure that the lingual frenulum does not become trapped between the patient’s teeth, particularly if teeth are not properly aligned.
- Aim the light from the head lamp on the posterior oropharyngeal wall [Figure 49].
- Insert the mirror into the oropharynx with your dominant hand, whilst keeping it parallel to the palate.
- The mirrored side should point downwards during this manoeuvre [Figure 50].
- The uvula will be positioned at the back of the mirror.
- Take care not to touch the posterior oropharyngeal wall and the base of the tongue during this manoeuvre.
- If there is insufficient space between the base of the tongue and the pharyngeal arches, you can ask the patient to say “hahahahaha” whilst you insert the mirror.
- This will pull the pharyngeal arches up slightly and the floor of the mouth will be moved downwards, creating more space.
Figure 46
Figure 47
Figure 48
Figure 49
Figure 50
- The light should now shine onto the mirror [Figure 51].
- Tilt the mirror in such a way that the larynx, the hypopharynx and the vocal cords are visualised.
- Assess the mucosa for intactness, colour, hyperaemia and any swellings or foreign objects.
- Inspect the position of the vocal cords.
Figure 51
- Ask the patient to say “ee” and see if the vocal cords move symmetrically and close fully on the midline of the larynx.
- Also, in this position, assess the smoothness of the vocal cords, their colour, vessel injection and the presence of any swellings.
- Once you have finished the examination, instruct the patient not to eat or drink for one and a half hours, until the feeling in the tongue and throat has returned (risk of choking).
- The mirror should be cleaned with soap and water.