gastric inflation. The addition of a port for the administration of supplemental oxygen increases the inspired oxygen concentration. A variety of pocket masks are available. Some of these masks are disposed of after the first use while others may be used many times. Most are small and compact enough to fit in a pocket and may be carried with the paramedic. The pocket mask allows an oxygen flow rate of 10 liters per minute. This rate combined with mouth-to-mouth breathing of the rescuer yields an inspired oxygen rate of about 50 percent. This is a significantly higher oxygen concentration level than delivered through the mouth-to-mouth or mouth-to-nose method. Inexpensive protection devices made from a piece of plastic film with a valvular orifice to cover the mouth and nose will provide protection and reduce aesthetic worries of direct contact with patients vomitus, saliva, sputum or blood. The main disadvantage is that the film device requires repositioning for each sequence of breaths. In the community the bystander is likely to be a relative, friend or colleague of the victim and resuscitative efforts should not be deterred by the unavailability of a protective device, as the risk is very small. Bag-Valve Ventilation The self-inflating bag can be connected to either a facemask, a tracheal tube, a laryngeal mask, or a Combitube. The bag consists of an oblong, self-inflating silicone or rubber bag; two one-way valves, and a transparent facemask. They are available in sizes for babies, children and adults. The bag-valve device allows room air or oxygen to be delivered to the patient. When used on its own the bag-valve-mask will allow ventilation of the patient with ambient air (21% oxygen). This can be increased to around 50% by attaching an oxygen supply at 5-6 Lmin-1 directly to the bag next to the air inlet valve. Normally, however, a reservoir bag should be attached, which with oxygen flows of 8-10 Lmin-1, wi...
