Laryngoscopes

There are two principal designs of laryngoscope for use in children: the straight-blade and the curved-blade laryngoscope. In general the straight-blade laryngoscope is designed to lift the epiglottis under the tip of the blade, whereas the curved-blade laryngoscope is designed to rest in the vallecula. The straightblade device can also be placed short of the epiglottis in the vallecula. The advantage of taking the epiglottis is that it cannot then obscure the view of the vocal cords (vocal folds). The advantage of stopping short of the epiglottis is that it causes less stimulation, and is less likely to cause laryngospasm. The blade length should be varied according to age. It should be noted that it is possible to intubate successfully with a blade that is too long, but not with one that is too short. In general, straight blades are preferred up to the age of 1 year, and many prefer to use them up to the age of 5 years.

It is important to have a spare laryngoscope available, together with spare bulbs and batteries, to overcome equipment failure. In fibreoptic designs, the bulbs are set in the top of the blade handle rather than in the blade itself. This has advantages in terms of bulb protection and the ability to clean the blade after use.

The essential parts of these laryngoscopes are shown in Figures 5.1 and 5.2. The blade is designed to displace the tongue to the left in order to optimise the view of the larynx. Failure to control the tongue adequately in the haste to see the vocal cords may leave a portion of the tongue overhanging the blade. It may still be possible to see the larynx at first, but as soon as the tracheal tube is placed in the mouth, the view is obscured.

Figure 5.1. (a) Mackintosh Figure 5.2. (a) Straight-blade curved-blade laryngoscope; (b) laryngoscope; (b) blade cross-section blade cross-section

Figure 5.1. (a) Mackintosh Figure 5.2. (a) Straight-blade curved-blade laryngoscope; (b) laryngoscope; (b) blade cross-section blade cross-section

0 0

Post a comment