Figure 4-12.Placement of an oropharyngeal airway.
Figure 4-13.Bag-valve-mask system.
cardiac compressions, the cardiac output is cut
to 25 to 30 percent of the normal capacity and
artificial ventilation does not supply enough ox-
ygen through the circulatory system to maintain
life for a long period.
Various types of bag-valve-mask systems that
come in both adult and pediatric sizes are in use
in the Navy. Essentially, they consist of a self-
filling ventilation bag, an oxygen reservoir, plastic
face masks of various sizes, and tubing for con-
nection to an oxygen supply.
The bag-valve-mask system is difficult to use
if the corpsman has not had a great deal of prac-
tice with it. It must not be used by inexperienced
persons. The system can be hard to clean and
reassemble properly, the bagging hand can tire
easily, and an airtight seal at the face is hard to
maintain, especially if a single rescuer must also
keep the airway open. In addition, the amount
of air delivered to the victim is limited to the
volume that the hand can displace from the bag
(approximately 1 liter per compression).
TECHNIQUE. Hook the bag up to an oxy-
gen supply and adjust the flow from 10 to 15 liters
per minute depending on the desired concentra-
tion (15 liters per minute will deliver an oxygen
concentration of 90 percent). After hyper-
extending the neck to open airway or inserting an
oropharyngeal airway, place the mask over the
face and hold it firmly in position with the index
finger and thumb, while the remaining fingers
keep the jaw tilted upward (fig. 4-14). The other
hand is used to compress the bag once every 5
seconds. Observe the chest and abdomen for ex-
pansion. If none is observed, the face mask seal
may not be airtight, the airway may be blocked,
or some component of the bag-valve-mask system
may be malfunctioning.
A pocket mask designed for mouth-to-mask
ventilation, with an oxygen-inlet flow valve, can
be used to give oxygen enriched artificial ventila-
tion. Although this system cannot achieve oxygen
concentrations as high as the bag-valve-mask
Figure 4-14.Bag-valve-mask system in use.