Oxygen therapy: Nursing pharmacology

Oxygen therapy is the delivery of supplemental oxygen to treat hypoxia, which is when there is not enough oxygen to meet the needs of the body.

Hypoxia can be caused by various lung diseases that interfere with its ability to properly absorb oxygen, such as pneumonia, chronic pulmonary obstructive disease, or COPD for short, and sleep apnea; as well as blood disorders like various types of anemia, where the red blood cells are not able to carry enough oxygen to meet the body’s demands.

Oxygen also acts as a potent pulmonary vasodilator and thus, it can be helpful in clients with heart problems like heart failure, where the heart has trouble pumping enough blood to meet the body’s demands.

Now, various delivery devices can be applied to administer oxygen therapy. The most common choice is the nasal cannula, which typically is used to deliver oxygen at 1 to 6 liters per minute.

This consists of two prongs that are placed into the nostrils, and a band of tubing wraps around the cheeks and behind the ears to keep it in place. A nasal cannula is easy to apply and is less intrusive, so the client can eat, drink, and talk freely.

Bear in mind that nasal cannulas are not ideal for clients who breathe through their mouths, or those who require high oxygen concentrations. In these cases, the preferred choice is usually a face mask that covers the client’s nose and mouth.

There’s a variety of face masks, ranging from simple ones used to deliver oxygen at 6 to 12 liters per minute, to face masks connected with reservoir bags, used to deliver oxygen at 10 to 15 liters per minute.

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.

Finally, some important devices to administer oxygen therapy include oxygen tents and hoods. An oxygen tent is a bendable clear plastic that’s held over the bed to deliver high concentrations of oxygen, and can be used for both adult and pediatric clients.

On the other hand, an oxygen hood is a clear plastic box or dome that contains warmed and humidified oxygen, and is typically used for infants who are able to breathe on their own but need supplemental oxygen.

Alright, although oxygen therapy should never be denied to a client who needs it, it should be used with caution. When a client is given oxygen therapy, as their condition stabilizes, oxygen concentration should be decreased to achieve an oxygen saturation equal or greater than 94%.

That’s because giving supplemental oxygen for a prolonged period can lead to oxygen toxicity, which can result in detrimental effects to the lungs, causing severe coughing, trouble breathing, and can eventually lead to death.

In addition, giving higher oxygen concentrations for an extended period may lead to pulmonary fibrosis. Finally, for clients with COPD, oxygen should not be used in high concentrations at all because they may lose their hypoxic respiratory drive.

Okay, before administering supplemental oxygen to a client, first assess for signs of hypoxia, such as confusion, difficulty speaking, tachycardia, dyspnea, pallor, or cyanosis.

In addition, they may also have an increased rate and depth of respirations, accessory muscle use, and an SpO2 less than 92%.

Then, verify the correct oxygen delivery device is ordered for the prescribed flow rate, confirm if the oxygen is to be humidified, and note the target oxygen saturation.