IDENTIFYING NEED FOR OXYGEN THERAPY
Certain medical conditions require that the patient receive oxygen in greater
amounts than is available in the atmosphere.
a. Cardiac conditions, such as heart attack and congestive heart failure, require
oxygen therapy. Congestive heart failure (CHF) is a condition in which the heart fails to
maintain an adequate output, resulting in a diminished blood flow to the tissues and
congestion in the pulmonary and/or systemic circulation.
b. Pulmonary edema (an excessive collection of fluid in the pulmonary tissues
and air spaces), shock, hemorrhage, or any airway obstruction requires the use of
oxygen. An acute respiratory failure and/or pulmonary insufficiency (impaired gas
exchange between the circulating blood and the surrounding air) also requires the
administration of oxygen. All trauma patients should receive oxygen, if possible. In the
combat environment, this may not be available until much later in the care of the patient
than is commonly recommended.
The two major devices for oxygen delivery are the non-rebreathing face mask
and the nasal prongs (cannula). The amount of oxygen delivered is dependent upon
the flow rate (given in liters per minute) and the patient's respiration rate.
a. Nasal Prongs. The nasal prongs (nasal cannula) are most frequently used to
administer a low concentration of oxygen. It is a short, disposable, plastic tube with two
plastic prongs that fit into the patient's nostrils. It is held in place with an elastic
headband (figure 3-1). The nasal cannula is relatively comfortable and enables the
patient to eat, talk, and move without difficulty; however, the prongs can be easily
dislodged by restless or disoriented patients. To be effective, the patient's nasal
passages must be clear.
Figure 3-1. Nasal cannula.