Understanding COPD Hypoxia
Chronic obstructive pulmonary disease (COPD) is a group of lung conditions that includes chronic bronchitis and emphysema. Restricted airflow characterizes all these conditions, and COPD causes difficulty when breathing.
The inability to get enough oxygen into the lungs raises the risk of developing hypoxia. Hypoxia is a condition where not enough oxygen makes it to the cells and tissues in the body.
Hypoxia can lead to many serious, sometimes life-threatening complications. But if you know what to look for, you can manage the condition before it leads to dangerous complications.
Hypoxia vs. hypoxemia
You may have heard of both hypoxia and hypoxemia. The two conditions sound similar but are different.
Hypoxemia is a term to describe when oxygen levels are low in the blood. Hypoxia is a term to describe low levels of oxygen in the tissue.
Your doctor can measure your blood and body’s oxygen levels in a couple of different ways. The less invasive method is using a pulse oximeter, in which a device is placed on the skin to measure levels.
Pulse oximeter level of less than 90 percent is considered abnormal and corresponds to an arterial blood oxygen level of 60mmHg, which would indicate hypoxemia. Tissue hypoxia is generally identified by other means like organ function, lactate levels, and central venous oxygenation.
Types of hypoxia
Hypoxia may be minor or severe while also varying in the length of time your body is affected. Sometimes, it comes and goes rather quickly, while other times, it can last for months.
There are four types of hypoxia:
- Hypoxemic hypoxia. This is when oxygen is unable to pass through alveoli to oxygenate the blood.
- Circulatory hypoxia. Here, the heart is unable to pump enough blood, which impairs oxygen delivery.
- Anemia hypoxia. This is when low hemoglobin in the blood reduces oxygen delivery.
- Histotoxic hypoxia. Cells are unable to accept and use oxygen.
Symptoms of hypoxia
Oxygen plays an integral part in your body’s cells and tissues. But the only way for your body to get oxygen is through your lungs. COPDTrusted Source is common and treatable, but the limited airflow can cause significant damage that may be irreversible.
COPD results in inflammation and swelling of your airways. It also destroys the lung tissue called alveoli. As a result, COPD causes a restricted oxygen flow in your body.
Symptoms of the specific type of COPD, called emphysema, often include:
- respiratory distress
- muscle wasting
- labored breathing
- persistent cough
- prolonged exhale
- pursed-lip breathing
- barrel chest
- bluish color to skin, lips, and gums
- enlarged fingers, also known as clubbing
These symptoms are less common in other types of hypoxia and COPD, like bronchitis.
When to call a doctor
When you find it hard to catch your breath or notice changes in your body, it can be alarming — even when it lasts for months. The most important thing is to listen to your gut and know when you need help.
You should seek emergency care if you experience:
- a hard time talking or catching your breath
- your lips or fingernails turning gray or blue
- people commenting that you are not mentally alert or acting yourself
- your heart beating very fast
- worsening symptoms despite treatments
Causes of hypoxia
Hypoventilation occurs when there is a decrease in oxygen in the lungs. This impairment can come from some of the following factors:
- airway obstruction
- excessive carbon dioxide
- obesity hypoventilation syndrome
- high altitude
Ventilation-perfusion (V/Q) mismatch
Ventilation is the airflow distributed via your lungs, and perfusion is how much oxygen your organs and tissues receive.
When you have high perfusion but low ventilation, it can cause hypoxia. You see this impaired exchange with conditions like chronic bronchitis and pulmonary edema.
On the other hand, when your ventilation is high but perfusion is low, it also leads to hypoxia. You find that type of V/Q mismatch with a pulmonary embolism and emphysema.
Right to Left Shunt
Your blood starts to circulate from the right side of the heart to the left side. But before it reaches the left, it’s usually oxygenated by the lungs first. Sometimes, it moves without being oxygenated first.
This can happen because of a structural defect in the heart, like a ventricular septal defect. Although, certain medical conditions can also cause this, like pneumonia and acute respiratory distress syndrome.
Impaired oxygen diffusion
When the oxygen doesn’t effectively travel from the alveoli to your blood vessels, this leads to hypoxia. Causes include pulmonary fibrosis and interstitial lung disease.
Complications from COPD hypoxia
COPD hypoxia makes breathing difficult, affecting more than just the lungs.
When you can’t breathe in enough oxygen, the condition deprives your body of this vital component. Oxygen is necessary for your body to carry out essential functions.
For example, when your brain experiences a lack of oxygen, it can lead to a hypoxic brain injury which is very severe and can lead to cardiac arrest.
Here are other complications of hypoxia:
- Acute exacerbation of COPD. You experience a period where your symptoms are much worse during this time.
- Acute or chronic respiratory failure. This is another more severe worsening of your symptoms that leads to a need for oxygen supplementation.
- Pulmonary hypertension. This is high blood pressure in the blood vessels of your lungs.
- Cor pulmonale. A dysfunction in the right ventricular of the heart.
- Bacterial infections. When you cannot move air well or you cough up phlegm in your lungs, it can lead to an overgrowth of bacteria and impair your immunity leading to infection.
Reversing hypoxia involves increasing your oxygen intake. A standard method for providing extra oxygen is oxygen therapy. Oxygen therapy is also called supplemental or prescribed oxygen. It consists of using a mechanical device that supplies oxygen to your lungs. The most commonly used device is a nasal cannula.
Supplemental oxygen can reduce shortness of breath, increase oxygen in your blood, and ease the amount of work your heart and lungs have to do. It can also decrease hypercapnia. Before prescribing oxygen, your doctor will run tests to measure your blood oxygen levels.
With chronic and severe conditions, you may need positive pressure ventilation provided with a CPAP or BiPAP machine to open your airways.
Oxygen therapy uses compressed oxygen stored in a portable tank.
The tank delivers oxygen to your body through nasal tubes, a face mask, or a tube inserted in your windpipe. A meter on the tank keeps track of the amount of oxygen you breathe in.
Oxygen therapy is also available in concentrator form. An oxygen concentrator takes air from the environment, filters out other gases, and stores oxygen for use. Unlike compressed oxygen, you don’t have to use prefilled oxygen containers.
Concentrators are helpful for people who need oxygen therapy all the time. But concentrators need electricity to work, so they may not be as versatile as compressed oxygen.
One common form of oxygen therapy is called bilevel positive airway pressure (BiPap).
Your regular medications for COPD will help prevent and control your hypoxia symptoms. But you may need additional drugs to control hypoxia when exacerbated. These medications may include:
- Bronchodilators. An inhaled medication used to widen airways to increase airflow and exchange.
- Steroids. These may be inhaled or taken by mouth to reduce inflammation.
- Antibiotics. These are for people who experience common exacerbation. One example is Azithromycin.
You’ll also want to ensure you regularly obtain your flu and pneumonia vaccines to prevent further complications.
Pulmonary hygiene techniques are ways to treat your hypoxia symptoms without medication or oxygen. The techniques include:
- cough and deep breathe
- chest physiotherapy
- flutter valve use
- incentive spirometry
If COPD causes hypoxia, it may seriously impact your activities of daily living. Firstly, quitting smoking and avoiding lung irritants is a great way to improve your symptoms. Lung irritants come from secondhand smoke, excessive dust, and fumes.
Sometimes, you may experience challenges with eating since hypoxia causes fatigue and shortness of breath. As a result, you may lose too much weight. You’ll want to discuss an eating plan with your doctor to ensure you get the nutrition your body needs.
Although there’s no cure for COPD, you can manage your symptoms and slow the progression of the disease. As a result, people can live a long and happy life with COPD. It all comes down to your cooperation with the treatment plan and avoidance of things that can cause a worsening of the disease.