Oxygen is essential to life. No cell in the body can survive without adequate oxygen, and this is normally supplied to each cell through the circulating blood. The red blood cells are so designed that they can transport oxygen in a very efficient manner. These cells are filled with a substance called hemoglobin, which becomes saturated with oxygen gas in the lungs and gives it up in the tissues. The red blood cells also absorb the carbon dioxide waste product from the tissues and deliver it to the lungs, where it is released in a gaseous form. The liquid portion of the circulating blood also carries some oxygen, but not in quantities comparable to that transported by the red blood cells. The supply of oxygen to the body cells depends, of course, on an efficient circulation of the blood by the action of the heart.
In health the body has the ability to increase the oxygen supply to the various cells according to the demands. With exercise, where the muscle cells greatly increase their oxygen consumption, the breathing is more rapid to promote a greater turnover of gases in the lungs; the heart beats faster to speed the delivery process; the blood vessels to the muscles may dilate with constriction of vessels in other areas so that the blood is directed to the place of greatest demand; and a greater number of red cells may be called out from the spleen and the bone marrow to work in the process.
This is a complicated operation which goes on every minute in the human body, with rates varying with the tissue’s needs, but there are several conditions which may decrease the efficiency of the process. In diseases of the lungs there may be lessened ability to absorb oxygen and expel carbon dioxide. With anemia, where the number of red cells or the amount of hemoglobin is below normal, the carrying capacity of the blood is decreased. If the circulation of blood is inadequate, as in heart disease or blood vessel disease, the supply of oxygen to the tissues may not be adequate, and occasionally certain toxic conditions block the exchange of gases in the tissues.
In any of these conditions, it is helpful to increase the amount of oxygen the lungs receive. Air is approximately 20 per cent oxygen, and by increasing this percentage the oxygenation processes of the body may work more effectively. Oxygen therapy is of benefit not only in diseases of the lungs, circulation, and blood; it has also been found of value in many conditions in preventing complications, hastening recovery, and making the patient more comfortable. The body actually has less work to do with a greater percentage of oxygen in the inhaled air.
Formerly oxygen therapy was used only in extreme cases, but now, with its greater availability, it is used more liberally and with worthwhile dividends. Occasionally, however, patients feel that the situation has become helpless when oxygen is ordered for them, and their spirits become very low. This is usually not the case. Oxygen is a supportive drug and is used to facilitate the body’s processes. It actually decreases the amount of work the body must do to keep the tissues functioning, and it allows the patient to rest more easily. One should not be alarmed when oxygen is employed. There are no complications from oxygen, and the benefits from it are invaluable.
Oxygen therapy is commonly administered by three techniques:
- the tent,
- the mask,
- the nasal catheter.
The oxygen tent is a large plastic or canvas hood which is placed over the upper half of the patient in bed. The oxygen is piped into the tent from a supply tank nearby. There is also some sort of electrical or ice cooling device to keep the temperature down within the tent. With proper usage, concentrations of oxygen up to 40 per cent may be obtained, and the patient may be kept very comfortable in this air-conditioned canopy. With this method no appliances on the face are required. However, when greater concentrations of oxygen are needed, or when the patient requires frequent nursing care, this means is not practical. In order to obtain adequate oxygen concentrations inside the tent, it must be kept closed, tightly tucked in at the bottom, and have no leaks. This is not feasible when a patient’s condition requires frequent opening of the tent for nursing care.
The oxygen mask may cover the nose and mouth, or just the nose. The principal advantage of the mask for administering oxygen therapy is the efficiency with which high concentrations are obtained. It is easily used and can be left at the bedside for the patient to use intermittently. The mask usually does not interfere with nursing care.
The nasal catheter method of administering oxygen is usually the most practical, except where it is to be used for only a short time or intermittently, in which case the mask may be more applicable. The nasal catheter is a tube which is placed into the nose, supplying a flow of oxygen to the throat. High concentration can be obtained. Patients always like this method best, for it impairs their activity very little. They can talk and visit freely. Nursing care is unhampered.
If your doctor elects to order oxygen therapy for you, do not be alarmed; rather, try to realize the value of it in hastening recovery, preventing complications, and increasing your comfort. Oxygen therapy is used frequently after a patient has had an anesthetic. Your physician will choose the technique most suitable for your case. He will choose it on the basis of its efficaciousness, economy, simplicity, and convenience to patient and nursing care.