b. Contraindications. Don't use the endotracheal tube if there is upper airway
obstruction due to foreign bodies. Use the endotracheal tube with caution if there is
swelling in the larynx or if the patient has mandibular (horseshoe-shaped bone forming
the lower jaw) or cervical (neck) fractures. Attempts at intubation may make these
2-10. INTUBATING WITH AN ET
a. Equipment. Endotracheal tubes are nontoxic, nonallergenic, and flexible.
These tubes are able to maintain a curved shape and do not conduct electricity. There
are two types of tubes: rubber tubes and plastic tubes. Rubber tubes include the
Murphy, a blunt level type of endotracheal tube with an inflatable cuff. The Cole, a
pediatric tube, is also made of rubber. Plastic tubes, can be either opaque or
transparent; the Protex is an example of such a tube. The Protex tube is made of
transparent vinyl plastic; the tube tends to bend although it is somewhat rigid.
(a) Measure the external diameter of the tube in millimeters.
(b) The internal diameter is measured in millimeters. The internal
diameter size is basically standard but may vary to about 0.5mm.
(c) To determine the length of the oral tube, measure the distance from
the corner of the casualty's mouth to midsternum (mid breast bone).
(d) The casualty's nare size will determine the nasal tube's diameter.
To determine the length of the nasal tube, measure the distance from the earlobe to the
corner of the mouth and add the distance from the corner of the mouth to the
midsternum. The radius of the curvature is greater for oral tubes. The bevel for the
nasal tube has a sharper angle than for the oral tubes. There is also a difference in the
(2) Inflatable cuffs. These are used to attain an airtight seal to prevent
aspiration. The cuffs should be inflated so the balloon indents with thumb pressure.
Such indentation usually occurs when the balloon has been inflated with five to ten
milliliters of air.
Stylet. The stylet allows the proper tube curvature to be maintained.
(4) Magill forceps. These are used to guide the nasal endotracheal tube
into the larynx from the pharynx.