Arterial blood gases: The value obtained from arterial blood gases or ABGs (SaO2) describes the oxygen saturation of arterial blood. It is obtained by drawing blood from an artery such as the radial artery in the wrist or the femoral artery in the groin. ABGs are measured in millimeters of mercury (mmHg) and can be a clue as to how efficiently your body is exchanging oxygen and carbon dioxide. A problem with any of these factors — for example, high altitude, asthma or heart disease — might result in hypoxemia, particularly under more extreme conditions, such as exercise or illness. When your blood oxygen falls below a certain level, you might experience shortness of.

1. Oxygen Levels In The 70s
2. Healthy Blood Oxygen Level Spo2
3. What Is A Healthy Blood Oxygen Level Chart

Overview

What is hypoxemia?

Hypoxemia occurs when levels of oxygen in the blood are lower than normal. If blood oxygen levels are too low, your body may not work properly.

Blood carries oxygen to the cells throughout your body to keep them healthy. Hypoxemia can cause mild problems such as headaches and shortness of breath. In severe cases, it can interfere with heart and brain function. Hypoxemia that causes low oxygen levels in your body’s tissues is called hypoxia. Sometimes people use the two terms interchangeably, but they are not the same thing.

Symptoms and Causes

What causes hypoxemia?

A variety of conditions and circumstances can interfere with the body’s ability to deliver normal levels of oxygen to the blood. Some of the most common causes of hypoxemia include:

• Heart conditions, including heart defects
• Lung conditions such as asthma, emphysema, and bronchitis
• Locations of high altitudes, where oxygen in the air is lower
• Strong pain medications or other problems that slow breathing
• Sleep apnea (impaired breathing during sleep)
• Inflammation or scarring of the lung tissue (as in pulmonary fibrosis)

What are the symptoms of hypoxemia?

Symptoms of hypoxemia vary depending on the severity of the condition. They include:

• Shortness of breath
• Fast heartbeat
• Coughing
• Confusion
• Bluish color in skin, fingernails, and lips

Diagnosis and Tests

How do doctors diagnose hypoxemia?

To diagnose hypoxemia, your doctor will do a physical examination to listen to your heart and lungs. Abnormalities in these organs can be a sign of low blood oxygen. Your doctor may also check to see if your skin, lips, or fingernails look bluish.

Doctors use tests to check your oxygen levels, including:

• Pulse oximetry: A sensor that slips over your finger measures the amount of oxygen in your blood. Pulse oximetry is painless and noninvasive. Many doctors use it routinely each time you visit.
• Arterial blood gas test: A needle is used to take a blood sample from your artery to measure the levels of oxygen in your blood.
• Other breathing tests: These might involve breathing into tubes that are connected to computers or other machines.

Management and Treatment

How do doctors treat hypoxemia?

Treatment for hypoxemia aims to raise the levels of oxygen in the blood. Doctors can use medications to treat underlying conditions that cause hypoxemia. These medications are often given through an inhaler that enables you to breathe the medicine into your lungs.

In more severe cases, your doctor may prescribe oxygen therapy. People typically receive extra oxygen through a device called a cannula (tube) that is clipped to the outside of the nose, or through a breathing mask. The location and amount of time people receive oxygen therapy is based on individual needs. You may receive oxygen at home, with a portable machine while you travel, or in the hospital.

What are the complications or side effects of hypoxemia?

If your blood does not have enough oxygen, it cannot deliver enough oxygen to the organs and tissues that need it. This situation can be fatal if severe in the short term and can affect the heart or brain if it persists over a long period of time.

Prevention

Oxygen Levels In The 70s

Can hypoxemia be prevented?

There are steps you can take to prevent hypoxemia from returning after treatment. To increase the oxygen levels in your blood, your doctor may recommend:

• Deep breathing exercises
• Mild exercise such as walking or yoga
• Eating a healthy diet
• Drinking plenty of water
• Quitting smoking

Outlook / Prognosis

What is the outlook for people with hypoxemia?

Hypoxemia symptoms can go away with treatment. Depending on the cause, people with hypoxemia may require treatment once or on an ongoing basis. Your doctor will work with you to manage the condition so you can live an active, healthy life.

Living With

When should I call a doctor regarding hypoxemia?

Contact your doctor if you experience symptoms of hypoxemia. Early diagnosis and treatment can help ensure the condition does not get worse and cause dangerous complications.

Oxygen saturation is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 95–100 percent. If the level is below 90 percent, it is considered low and called hypoxemia.^[1] Arterial blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules (O
₂) enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation.

Definition[edit]

In medicine, oxygen saturation, commonly referred to as 'sats', measures the percentage of hemoglobin binding sites in the bloodstream occupied by oxygen.^[2] At low partial pressures of oxygen, most hemoglobin is deoxygenated. At around 90% (the value varies according to the clinical context) oxygen saturation increases according to an oxygen-hemoglobin dissociation curve and approaches 100% at partial oxygen pressures of >11 kPa. A pulse oximeter relies on the light absorption characteristics of saturated hemoglobin to give an indication of oxygen saturation.

Physiology[edit]

The body maintains a stable level of oxygen saturation for the most part by chemical processes of aerobic metabolism associated with breathing. Using the respiratory system, red blood cells, specifically the hemoglobin, gather oxygen in the lungs and distribute it to the rest of the body. The needs of the body's blood oxygen may fluctuate such as during exercise when more oxygen is required ^[3] or when living at higher altitudes. A blood cell is said to be 'saturated' when carrying a normal amount of oxygen.^[4] Both too high and too low levels can have adverse effects on the body.^[5]

Measurement[edit]

An SaO₂ (arterial oxygen saturation, as determined by an arterial blood gas test^[6]) value below 90% indicates hypoxemia (which can also be caused by anemia). Hypoxemia due to low SaO₂ is indicated by cyanosis. Oxygen saturation can be measured in different tissues:^[6]

• Venous oxygen saturation (SvO₂) is the percentage of oxygenated hemoglobin returning to the right side of the heart. It can be measured to see if oxygen delivery meets the tissues' demands. SvO₂ typically varies between 60% and 80%.^[7] A lower value indicates that the body is in lack of oxygen, and ischemic diseases occur. This measurement is often used under treatment with a heart lung machine (extracorporeal circulation), and can give the perfusionist an idea of how much flow the patient needs to stay healthy.
• Tissue oxygen saturation (StO₂) can be measured by near infrared spectroscopy. Although the measurements are still widely discussed, they give an idea of tissue oxygenation in various conditions.
• Peripheral oxygen saturation (SpO₂) is an estimation of the oxygen saturation level usually measured with a pulse oximeter device. It can be calculated with pulse oximetry according to the formula^[6] where HbO₂ is oxygenated hemoglobin (oxyhemoglobin) and Hb is deoxygenated hemoglobin.

Pulse oximetry[edit]

Pulse oximetry is a method used to estimate the percentage of oxygen bound to hemoglobin in the blood.^[8] This approximation to SaO₂ is designated SpO₂ (peripheral oxygen saturation). The pulse oximeter consists of a small device that clips to the body (typically a finger, an earlobe or an infant's foot) and transfers its readings to a reading meter by wire or wirelessly. The device uses light-emitting diodes of different colours in conjunction with a light-sensitive sensor to measure the absorption of red and infrared light in the extremity. The difference in absorption between oxygenated and deoxygenated hemoglobin makes the calculation possible.^[6]

Medical significance[edit]

Healthy individuals at sea level usually exhibit oxygen saturation values between 96% and 99%, and should be above 94%. At 1,600 meters' altitude (about one mile high) oxygen saturation should be above 92%.^[9]

Healthy Blood Oxygen Level Spo2

An SaO₂ (arterial oxygen saturation) value below 90% causes hypoxia (which can also be caused by anemia). Hypoxia due to low SaO₂ is indicated by cyanosis, but oxygen saturation does not directly reflect tissue oxygenation. The affinity of hemoglobin to oxygen may impair or enhance oxygen release at the tissue level. Oxygen is more readily released to the tissues (i.e., hemoglobin has a lower affinity for oxygen) when pH is decreased, body temperature is increased, arterial partial pressure of carbon dioxide (PaCO₂) is increased, and 2,3-DPG levels (a byproduct of glucose metabolism also found in stored blood products) are increased. When the hemoglobin has greater affinity for oxygen, less is available to the tissues. Conditions such as increased pH, decreased temperature, decreased PaCO₂, and decreased 2,3-DPG will increase oxygen binding to the hemoglobin and limit its release to the tissue.^[10]

See also[edit]

References[edit]

1. ^'Hypoxemia (low blood oxygen)'. Mayo Clinic. mayoclinic.com. Retrieved 6 June 2013.
2. ^Kenneth D. McClatchey (2002). Clinical Laboratory Medicine. Philadelphia: Lippincott Williams & Wilkins. p. 370. ISBN9780683307511.
3. ^'Understanding Blood Oxygen Levels at Rest'. fitday.com. fitday.com. Retrieved 6 June 2013.
4. ^Ellison, Bronwyn. 'NORMAL RANGE OF BLOOD OXYGEN LEVEL'. Livestrong.com. Livestrong.com. Retrieved 6 June 2013.
5. ^'Hypoxia and Hypoxemia: Symptoms, Treatment, Causes'. WebMD. Retrieved 2019-03-11.
6. ^ ^abcd'Understanding Pulse Oximetry: SpO2 Concepts'. Philips Medical Systems. Retrieved 19 August 2016.
7. ^https://www.lhsc.on.ca/critical-care-trauma-centre/central-venous/mixed-venous-oxygen-saturation
8. ^Peláez EA, Villegas ER (2007). 'LED power reduction trade-offs for ambulatory pulse oximetry'. Conf Proc IEEE Eng Med Biol Soc. 2007: 2296–9. doi:10.1109/IEMBS.2007.4352784. ISBN978-1-4244-0787-3. PMID18002450. S2CID34626885.
9. ^'Normal oxygen level'. National Jewish Health. MedHelp. February 23, 2009. Retrieved 2014-01-28.
10. ^Schutz (2001). 'Oxygen Saturation Monitoring by Pulse Oximetry'(PDF). American Association of Critical Care Nurses. Archived from the original(PDF) on January 31, 2012. Retrieved September 10, 2011.

External links[edit]

What Is A Healthy Blood Oxygen Level Chart