Various Types of Oxygen Delivery

Oxygen in the human body is measured through a pulse oximeter, a small instrument placed on the finger to measure arterial blood oxygen levels. Normal readings fall between 95 to 100 percent, according to the Mayo Clinic. Anything below 90 is considered low and usually requires supplemental oxygen. This oxygen can be delivered in a number of ways, depending on how much supplemental oxygen is required.

Types

• A nasal cannula, the most common type of oxygen delivery system, consists of a disposable plastic tube with two small prongs that are inserted into the nostrils. Several different types of masks, including simple, partial rebreather, nonrebreather and Venturi, are placed directly over the mouth and nose and allow different levels of oxygen to be delivered. An oxygen tent, a portable clear plastic structure attached to an oxygen source, can be placed around a patient unable to tolerate other delivery systems.

Uses

• A nasal cannula is used when low levels of oxygen up to 40 percent are needed. A simple mask can provide up to 60 percent and allows room air to mix with the delivered oxygen. A partial rebreather can deliver concentrations up to 70 percent and is similar to a simple mask but has a bag attached to collect the first half of exhaled oxygen, which is rebreathed by the patient. A nonrebreather has a one-way valve to prevent rebreathing of exhaled air and is used when high levels of oxygen up to 95 percent are required. Venturi masks deliver oxygen levels up to 55 percent, but the oxygen is delivered at a faster flow rate, allowing more to reach the lungs. A tent can deliver up to 50 percent and is generally used with children.

Benefits

• The nasal cannula is simple to insert and does not hinder eating or talking. It is also fairly easy to use. Simple and partial rebreather masks have the advantage of allowing the patient to breath room air should the oxygen delivery system fail. Nonrebreathers can be used to deliver other gases if required, and Venturi masks allow a precise concentration of oxygen to be provided. Tents do not limit patient movement in a significant way, which reduces the risk of the patient accidentally disengaging from the oxygen delivery system.

Drawbacks

• Each system has drawbacks to consider. A nasal cannula can become dislodged very easily or twisted as the patient moves around, and can dry out the nasal passageways. Masks limit the ability to eat and talk, and the vents can become blocked by bedding or patient movement. Tents are often attached to a humidifier and can cause the bedding to become wet if not frequently checked. They also do not allow for delivery of precise concentrations of oxygen.

Warning

• Regardless of the type of delivery system, safety precautions need to be taken when using oxygen. Oxygen cylinders are highly combustible; never allow smoking near the tank and keep open flame away from it. Ensure that electronics used near the tank are grounded and in good working order to prevent shorts. Do not store tanks near any source of heat, and note the placement of fire extinguishers in case of combustion.