In the field, a Hospital Corpsman may have access to a fixed (installed) suction unit or a portable suction device. Both types of suction devices are equipped with flexible tubing, suction tips and catheters, and a non-breakable collection container.

Maintenance of suction devices consists of testing the suction pressure regularly and cleaning the device after each use.

Before using a suction device, always test the apparatus. Once the suction pressure has been tested, attach a suction catheter or tip. Position the patient on his side, and open the patient's mouth. This position permits secretions to flow from the patient's mouth while suction is being delivered. Use caution in patients with suspected neck or spinal injuries. If the patient is fully and securely immobilized on a backboard, the backboard may be tilted to place the patient on his side. If you suspect such injuries but the patient is not immobilized, suction as best you can without turning the patient. Carefully insert the suction tip or catheter at the top of the throat (fig. 4-25). DO NOT push the tip down into the throat or into the larynx. Apply suction, but for no more than a few seconds, since supplemental oxygen or ventilations cease while suctioning, keeping oxygen from the patient. Suction may be repeated after a few breaths.

CRICOTHYROIDOTOMY
A cricothyroidotomy, often called an emergency tracheotomy, consists of incising the cricothyroid membrane, which lies just beneath the skin between the thyroid cartilage and the cricoid cartilage. In most cases, the cricothyroid membrane can be easily located by hyperextending the neck so that the thyroid notch (Adam's apple) becomes prominent anteriorly. Identify the position of the thyroid notch with the index finger. This finger descends in the midline to the prominence of the cricoid cartilage. The depression of the cricothyroid membrane is identified above the superior margin of the cricoid cartilage (fig. 4-26). Make a small lateral incision at the base of the thyroid cartilage to expose the cricothyroid membrane. Excise this membrane (taking care not to go too deeply) and insert a small-bore air line into the trachea.

Figure 4-25.-Proper insertion of suction tip.

Figure 4-26.-Anatomical structures of the neck to identify the cricothyroid membrane.

An alternate method is to use a 12-to 16-gauge intercatheter. Locate the cricothyroid membrane as described above and insert the needle into the trachea. Immediately upon penetration of the cricothyroid membrane, thread the plastic catheter into the trachea and remove the needle. Then connect the catheter to an oxygen line for translaryngeal oxygen jet insufflation.

Do not attempt a cricothyroidotomy except as a last resort when other methods of opening the airway have been unsuccessful.