Arterial Blood Gas: Uses, Risk Factors And How it is Performed?

The arterial blood gas (ABG) test examines the arterial blood's pH, oxyhemoglobin saturation (SaO2), carbon dioxide tension (PaO2), oxygen tension (PaO2), and bicarbonate content (HCO3).

Methemoglobin, carboxyhemoglobin, and hemoglobin levels are sometimes measured by blood gas analyzers as well. Such knowledge is essential for treating individuals with acute illnesses, respiratory conditions, or metabolic disorders.

What Is The Use Of the ABG Test?

With the use of an ABG test, you can:

• Examine your acid-base balance.
• Find out whether you have any severe breathing or lung diseases.
• Detection of kidney conditions.
• Check the effectiveness of your current medication for any diseases. that may alter your acid-base balance, such as respiratory problems, kidney disease, or other conditions.

What Diseases Can Be Ruled Out Using ABG Test?

For the purpose of identifying illnesses that result in respiratory failure, ABGs are particularly helpful. Including: 

• Lung Failure
• Acute respiratory distress syndrome (ARDS)
• Sepsis 
• Diabetic ketoacidosis (DKA)
• Cystic fibrosis
• Pneumonia 
• Emphysema 
• Hypovolemic shock
• Acute heart failure 
• Cardiac arrest
• Kidney Failure
• Septic Shock
• Trauma 
• Chronic vomiting
• Uncontrolled diabetes
• Asthma  
• Chronic Obstructive Pulmonary Disease (COPD) 
• Hemorrhage
• Drug Overdose
• Metabolic Disease 
• Chemical Poisoning 

Are There Any Risks Associated With ABG Test?

A blood oxygen level test has relatively little risk. At the location where the needle was inserted, you might have some bleeding, bruising, or soreness. The needle may very infrequently cause damage to an artery or nerve. Following the test, you might be instructed to refrain from lifting anything heavy for 24 hours.

How Is The ABG Test Performed?

Most blood tests collect a sample from a vein whereas for the ABG  a blood sample will be drawn from an artery by a medical professional. Because blood from an artery has more oxygen than blood from a vein, this occurs.

The sample is often obtained from an artery on the inside of your wrist, though it is also possible to have it taken from an artery in your arm or groin. A newborn's heel or the umbilical cord may be used as the source of the sample.

The doctor will check your blood circulation before taking a blood sample from your wrist. In order to temporarily stop the blood flow to your hand, the provider will grip your wrist and apply pressure to the arteries. Then the medical professional will release pressure on your wrist to measure how quickly blood flow returns to your hand. The doctor will take a blood sample if your blood flow is normal.

It is typically more unpleasant to draw blood from an artery than from a vein for the majority of blood tests. As a result, the doctor may first numb your skin using medication. To draw some blood out of the artery, the medical professional will introduce a needle and syringe into it.

A bandage will be applied to the puncture site by the provider after the syringe is filled. To halt the bleeding, the area will be under pressure for at least five minutes.

What Are The Outcomes Of ABG Testing?

The outcomes of ABG tests include numerous interconnected physiological systems. Additionally, a variety of medical problems have the potential to produce unexpected outcomes. For these reasons, it's helpful to have your doctor explain the implications of your test results for your health.

Many measurements are listed in your ABG test results, including:

• Oxygen Saturation, or O2Sat. This measures how much oxygen your red blood cells transport.
• O2 Partial Pressure (PaO2). This measures the pressure of dissolved oxygen in your blood. It demonstrates how efficiently oxygen is transported from your lungs to your blood.
• Carbon dioxide's partial pressure (PaCO2). It measures the level of carbon dioxide in the blood. It also demonstrates how quickly carbon dioxide can leave your body.
• The balance between acids and bases (pH). Your blood's acidity is determined by this. Acidosis refers to an excess of acid. Alkalosis is the result of an excess of base (alkaline). These conditions are signs of underlying issues that throw off the body's acid-base balance.

Typically, an ABG test by itself cannot make a final diagnosis. Therefore, if your results are abnormal, your doctor will probably order more tests to help him or her diagnose you. 

Generally speaking, abnormal results could point to a metabolic condition, renal or lung issue, or both. The way your body uses food as fuel might be impacted by metabolic diseases. Additionally, some medications may disrupt your acid-base balance, causing aberrant ABG test findings.

What Are The Normal Values Of ABG Testing?

When you receive the results of your blood test, there will be information stating what the laboratory's normal ranges are for each value. If you have any questions about your results, consult your healthcare provider.

Normal values at sea level often include:

• pH: 7.35-7.45.
• The oxygen partial pressure (PaO2) range is between 75 and 100 mmHg.
• 35 to 45 mmHg is the range for the partial pressure of carbon dioxide (PaCO2).
• Bicarbonate (HCO3) is present in amounts ranging from 22 to 26 milliequivalents per liter.
• The oxygen saturation ranges from 95% to 100% (also known as SaO2 or O2Sat).
• At altitudes of 3,000 feet (900 meters), the normal oxygen level is lower.

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