or the patient being exposed to the unhealthy at-
mosphere. This is carried out by a coupling on
the face of each mask. When they are joined, an
airway is formed, allowing ventilation to proceed.
Sometimes during artificial ventilation, air is
forced into the stomach instead of into the lungs.
The stomach becomes distended (bulges), in-
dicating that the airway is blocked or partially
blocked, or that ventilations are too forceful. This
problem is more commonly seen in children but
can occur with any patient. A slight bulge is of
little worry, but a major distention can cause two
serious problems. First is a reduced lung volume;
the distended stomach forces the diaphragm up.
Second, there is a strong possibility of vomiting.
The best way to avoid gastric distention is to
properly position the head and neck and/or limit
the volume of ventilations delivered.
NOTE: THE AMERICAN HEART ASSO-
CIATION (AHA) STATES THAT NO AT-
TEMPT SHOULD BE MADE TO FORCE AIR
FROM THE STOMACH UNLESS SUCTION
EQUIPMENT IS ON HAND FOR IMMEDI-
If suction equipment is ready and the patient
has a marked distention, you can turn the patient
on his or her side facing away from you. With
the flat of your hand, apply gentle pressure be-
tween the navel and the rib cage. Be prepared to
use suction should vomiting occur.
AS a corpsman, you should become familiar
with various pieces of supportive equipment that
may be available to help you to maintain an open
airway and to restore breathing in emergency
situation. They include artificial airways, the bag-
valve-mask system, the mouth-to-mask system
with the oxygen-inlet valve, and suction.
Use of Oxygen (O2)
In an emergency first aid situation, the corps-
man will probably have a size E, 650-liter cylinder
available. This is fitted with a yoke-style pressure
reducing rcgtilator, with gauges to show tank
pressure and flow
liters per minute)
to the flowmeter
rate (adjustable from 0 to 15
A humidifier can be attached
nipple to help prevent tissue
drying caused by the water vapor free oxygen. An
oxygen line can be connected from the flowmeter
nipple or humidifier to a number of oxygen
delivery devices that will be discussed later.
When available, oxygen should be ad-
ministered, as described below, to cardiac arrest
patients and to self-ventilating patients who are
unable to inhale enough oxygen to prevent hy-
poxia (oxygen deficiency). Hypoxia is char-
acterized by tachycardia, nervousness, irritability,
and finally cyanosis. It develops in a wide range
of situations from poisoning to shock, crushing
chest injuries, cerebrospinal accidents, and heart
Oxygen must never by used near open flames
since it supports burning. The cylinders must be
handled carefully since they are potentially lethal
missiles if punctured or broken.
The oropharyngeal and nasopharyngeal air-
ways are primarily used to keep the tongue from
occluding the airway.
OROPHARYNGEAL AIRWAY. This air-
way can be used only on unconscious victims
because a conscious person will gag on it. They
come in various sizes for different age groups (it
is important to choose the correct size for the vic-
tim), and they are shaped to rest on the contour
of the tongue and extend from the lips to the
One method of insertion is to depress the
tongue with a tongue blade and slide the airway
in. Another method is to insert the airway upside
down into the victims mouth; then rotate it 180
degrees as it slides into the pharynx (fig. 4-12).
NASOPHARYNGEAL AIRWAY. This
airway may be used on conscious victims since it
is better tolerated because it generally does not
stimulate the gag reflex. Since they are made of
flexible material, they are designed to be
lubricated and then gently passed up the nostril
and down into the pharynx. If the airway meets
an obstruction in one nostril, withdraw it and try
to pass it up the other nostril.
The bag-valve-mask system (fig. 4-13) is
designed to help ventilate an unconscious victim
for long periods, while delivering high concentra-
tions of oxygen. This system can be useful in ex-
tended CPR attempts because when using external