Refractory Hypoxemia: Causes, Symptoms, Diagnosis, and Treatments

refractory hypoxemia definition

Hypoxemia refers to an abnormal reduction of oxygen in arterial blood.

It is a condition in which the content or partial pressure of oxygen in the blood diminishes to remarkably low levels.

As a result, several areas and tissues of the body get deprived of the oxygen they need to function correctly and remain healthy. This lacking supply of oxygen at tissue level gets called hypoxia.”

More often than not, oxygen administration and mechanical ventilation prove to be efficient ways to remedy the reduced level of oxygen in the blood in cases of Hypoxemia.

However, those patients who suffer from Refractory Hypoxemia display the inability to maintain a stable level of oxygen in arterial blood, even when treated with oxygen administration.

This a deadly condition with a high mortality rate and the fact the patient does not respond to usual procedures makes it the more difficult for doctors to deal with this health issue.

Given conventional treatments are ineffective, medical experts need to pinpoint the reason why the partial pressure of oxygen in arterial blood is diminishing.

Refractory Hypoxemia Causes

Hypoxemia is usually a result of a wide variety of respiratory disorders such as Chronic obstructive pulmonary disease (COPD), pulmonary embolism, congenital heart defects, among many others.

Some drugs and medications such as narcotics and anesthetics can induce this condition. That may happen because these substances depress breathing.

When it comes to Refractory Hypoxemia, several medical experts theorize that a couple of respiratory diseases might be the cause of this condition.

Some think an intrapulmonary shunt can cause this deadly disease.

But most researchers are sure the Acute Respiratory Distress Syndrome (ARDS) is related to the development of Refractory Hypoxemia.

A few cases of this condition may occur because the air spaces inside the lungs get filled with fluid. That could happen because of internal bleeding, bacterial infection, or heart failure.


Most the signs of this condition are practically the same as with cases of Hypoxemia.

That means the symptoms of Refractory Hypoxemia would be ones listed below:

  • Cyanosis, due to an inadequate supply of oxygen to tissues.
  • A rapid heart rate (possible Tachycardia). It occurs because the usual flow of blood does not provide the body with enough oxygen, in Hypoxemia cases, so the heart gets forced to work harder.
  • Increased breathlessness, due to the lack of oxygen in arterial blood affecting the lungs.
  • Lethargy, confusion, and lack of coordination.
  • Headaches and dizziness.

Some people who suffer from Hypoxemia are prone to losing consciousness too.

The only difference with regular Hypoxemia is the fact the patients do not improve even when healthcare providers give them extra oxygen.

In the case of lungs getting filled with fluid, doctors would likely hear characteristic crackling noises through the stethoscope.


The first way to identify the condition is measuring the level or the partial pressure of oxygen in arterial blood. Doctors can perform this analysis through a blood test.

Medical experts can also pinpoint the level of oxygen in the blood by using a pulse oximeter, a little clinical device that measures the oxygen saturation of blood.

Doctors use the results of the pulse oximeter as estimations of the content of oxygen the blood.

However, the main sign indicating the presence of Refractory Hypoxemia is the patient not responding to conventional treatments such as oxygen administration or mechanical ventilation.

Refractory Hypoxemia Treatments

Since the application of most standard therapies is not very useful to deal with Refractory Hypoxemia, doctors may have to resort to other methods.

One of such treatments could be prone positioning: doctors have patients lie on their fronts while using special ventilation techniques.

Another way to help patients who suffer from this condition is the use of inhaled vasodilators (substances that relax the muscles of the vessels that supply blood).

Another medical procedure consists of pumping the blood away from the body through an artificial lung to increase oxygen levels, cleaning and purifying the blood before returning it to the body.

One seemingly effective way to treat those who suffer from Refractory Hypoxemia is Neuromuscular Blockade (NMB).

NMB agents can induce a reversible muscle paralysis that would likely improve oxygenation. But it comes with the risk of weakening the muscles of the lung.

Finally, Rescue therapies are quite challenging for medical experts; they require a delicate balance of risks and benefits along with an in-depth knowledge of therapeutic limitations.

Keep in mind, most possible treatments for Refractory Hypoxemia can only alleviate the symptoms, but they can’t cure this disease.