2-18
2-18. OXYGEN THERAPY
a. Oxygen is a colorless, tasteless, odorless gas that is slightly heavier than air. Oxygen may be delivered by various administrative devices. The method of delivery selected depends upon the condition of the patient, the concentration of oxygen required, and the preference of the physician. The following equipment will be necessary:
(1) Oxygen source (O2 tank o piped-in wall outlet)
(2) A cylinder regulator (O2 tank) or a flow meter (wall O2)\
(3) Humidifier.
(4) Sterile or distilled water.
(5) Administration device.
b. Administration devices include:
(1) A nasal cannula is a rubber or plastic tube with short curved prongs that extend into the nostrils about 1/4 to 1/2 inch. The cannula is held in place with an elastic band that fits around the patient's head. It is used to administer low to medium concentrations of oxygen. A flow rate of 2-6 liters/minute should provide an oxygen concentration of 25-35 percent. Start the oxygen flow prior to inserting the prongs into the patient's nostrils.
(2) A venturi mask is a facemask designed to deliver precisely controlled oxygen concentrations by providing oxygen mixed with room air. A fixed flow of oxygen is mixed with a flow of air to produce a constant oxygen concentration regardless of rate of breathing. Masks are designed to provide 24 percent, 28 percent, 31 percent, 35 percent, 40 percent, and 50 percent oxygen concentrations. The mask should be assembled according to the manufacturer's instructions for the oxygen concentration prescribed by the physician. Start the oxygen flow at the specified flow rate and adjust the mask over the patient's nose and mouth.
(3) A simple facemask is designed to provide low to medium oxygen concentration using liter flow rates of 2-8 liters/minute. Simple masks come in many sizes and configurations. Follow the manufacturer's instructions for use of the mask. Always begin the oxygen flow prior to placing the mask over the patient's nose and mouth.
(4) Re-breathing masks are designed for inhalation of moderately high concentrations of oxygen from a reservoir bag. A partial re-breathing mask has perforations on both sides of the mask that serves as exhalation ports. Inspired oxygen concentrations of 50-60 percent can be achieved. The non-re-breathing mask differs from the partial re-breathing mask in that it has a one-way valve between the mask and the reservoir bag that ensures that the patient receives only 100 percent oxygen from the reservoir bag. The mask has two flapper valves over the exhalation ports that allow the patient to exhale, but prevent inhalation of room air that would dilute the oxygen concentration.
(5) A T-tube is a device that connects directly to an endotracheal or tracheostomy tube to deliver humidified oxygen. Connecting tubing runs from the T-tube to the humidification device, which is connected to the oxygen source.
c. Safety precautions associated with the use of oxygen include:
(1) Post "Oxygen" and "No Smoking" signs wherever oxygen is stored or in use. Oxygen supports combustion, so things that burn slowly in normal air will burn violently or explosively in the presence of increased oxygen.
(2) Inform the patient and visitors of requirement for no smoking and no open flames. Enforce this rule.
(3) Ensure that oil or grease isn’t used around the oxygen fittings, as petroleum-based products will burn.
(4) Ensure that all electrical equipment is properly grounded and in good condition.
(5) Avoid the use of static-generating materials such as nylon and wool. This applies to uniforms, pajamas, and bedding.
(6) If an oxygen tank is used, secure it away from doors and high traffic areas to reduce the possibility of the cylinder being knocked over and the valve being damaged.
(7) When transporting an oxygen cylinder, strap it to the carrier. An unsecured cylinder may drop or fall, causing injury to patients or staff, and damaging equipment, walls, and flooring. If the valve should break, the sudden release of the high pressure could cause the cylinder to become a high velocity missile. A full oxygen cylinder has enough force to penetrate a concrete wall.
