Respiratory: Oxygen therapy

Oxygen therapy is the delivery of extra oxygen to those with conditions that cause hypoxia, which is when there is not enough oxygen to meet the needs of the body.

This includes clients with various diseases that interfere with the lungs’ ability to properly absorb oxygen from the inhaled air like pneumonia, chronic bronchitis, emphysema, and sleep apnea as well as blood problems like anemia where the blood doesn't carry enough oxygen and heart problems like heart failure where the heart has trouble pumping blood around the body.

Now, oxygen is considered a medication so, as a nursing assistant, you will provide care for clients receiving oxygen therapy.

However, it’s a nurse’s or respiratory therapist’s task to start and maintain the oxygen therapy, and a healthcare provider will be the one to order when and how to administer supplemental oxygen.

Okay, now, an oxygen setup consists of an oxygen source and a delivery device. There are several sources for oxygen therapy, including a wall outlet, an oxygen tank, a liquid oxygen system, and an oxygen concentrator.

With a wall outlet, oxygen is delivered into each client’s room from a central supply. Next, an oxygen tank is filled with oxygen under pressure and is typically portable, so it can be carried along as the client moves.

However, this should be moved very carefully; if the tank tips over and the valve breaks open, pressurized oxygen can burst out forcefully and result in severe trauma.

Oxygen tanks also have a gauge that shows how much oxygen is left. There are also liquid oxygen systems that consist of a portable component which can be worn over the shoulder.

The portable component needs to be filled by a large reservoir that is kept at home. Finally, oxygen concentrators pull in air from the atmosphere and selectively remove nitrogen to deliver 100% oxygen.

These devices need a power supply and are very easy to use because they have an on-off switch.

They are usually preferred at home or in healthcare facilities for clients who only need oxygen therapy every now and then rather than on a regular basis.

All oxygen sources are attached to a flow meter that indicates the flow rate, or the liters of oxygen administered per minute. This usually falls somewhere between 1 and 15 liters per minute.

Now, oxygen delivery, especially at high flow rates, can have a drying effect on mucous membranes which may cause discomfort to the client.

To prevent that from happening, the oxygen also passes through a humidifier bottle before reaching the delivery device. This bottle contains distilled water which turns into water vapor.

Water vapor is then picked up by the oxygen, creating bubbles. And if bubbling occurs, vapor is being produced and humidified oxygen is being delivered to the client

Now, various delivery devices can be applied to administer supplemental oxygen. The most common choice is the nasal cannula.

This consists of two prongs that are placed into the nostrils and a band of tubing which wraps around the cheeks and behind the ears to keep it in place.

A nasal cannula is simple to apply and is less intrusive, so it lets the client eat, drink, and talk freely. However, high flow rates can cause the nasal passages to dry out and sometimes bleed.

If the bands are too tight, they might also irritate the skin around the nose, cheekbones, and ears and potentially lead to open sores.

Bear in mind that nasal cannulas are typically not preferred for clients who breathe through their mouths or those in serious conditions who require high oxygen concentrations.

In these cases, face masks which cover the client’s nose and mouth are usually used. There’s a variety of face masks, ranging from simple ones to face masks connected with reservoir bags.

These include partial-rebreather masks which consist of a simple face mask and a bag storing exhaled air and pure oxygen.

Every time the client inhales, they breathe in oxygen and exhale air from the bag as well as an amount of room air.

With non-rebreather masks, only oxygen from the bag is breathed in, while exhaled air escapes through holes on the sides of the mask.

Venturi masks are another variety and can be used when a precise amount of oxygen needs to be administered.

Compared to nasal cannula, face masks are more complicated, they might be more uncomfortable for the client, and they make it harder to eat, drink, and talk.

In some cases, when the client is comatose or has received sedative drugs, accessory devices can be used along with the nasal cannula or face mask in order to secure an open airway, by keeping the tongue off the back of the throat.

These are flexible tubes that go through the nose and up to the throat, known as nasopharyngeal airways, or into the mouth and back to the throat, called oropharyngeal airways.