Blood Gas Analysis: What is it? Procedure and Values

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Doctors use blood gas analysis to understand how effectively the gas exchange takes place at the level of the pulmonary alveoli, an exchange on which blood oxygenation depends.
Among the medical conditions for which the use of blood gas analysis is useful, there are: pulmonary and respiratory diseases, renal insufficiency, heart failure, diabetes, nocturnal sleep diseases, some types of infections, strokes to the head affecting respiratory capacity, drug overdose, etc.
Carried out in a medical-hospital center, the blood gas analysis consists in taking a small sample of blood and in the subsequent laboratory analysis of this sample.
Generally, the results of the blood gas analysis are available to those who have undergone it already after 10-15 minutes.

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partial oxygen (PaO2). It is the pressure that oxygen would exert inside the lungs, if it were the only gas present. Its measurement provides information on how effective is the passage into the blood of the oxygen contained in the inhaled air and reached the innermost cavities of the lungs.

The partial pressure of carbon dioxide (PaCO2). It is the pressure that carbon dioxide would exert inside the lungs, if it were the only gas present. Its measurement provides information on how effective is the release of carbon dioxide from the human body.

The blood pH. Measuring the pH of blood or another substance means calculating the quantity of hydrogen ions (or H +) present inside. Under normal conditions, the pH of human blood is included in a range of values ​​that are 7.35 and 7.45.
A blood whose pH deviates from normal values, resulting below 7, is acidic; conversely, a blood whose pH is higher than the normal values ​​is basic (or alkaline).

Blood levels of bicarbonate (HCO3). Bicarbonate is a very important substance in keeping blood pH under control, preventing the latter from becoming too acidic or too basic.

Blood oxygen content and oxygen saturation (SAT). By blood oxygen content, we mean how much oxygen is present in the blood.
Oxygen saturation, on the other hand, is a measure of how many oxygen molecules are bound to hemoglobin.
It is worth reminding readers that oxygen saturation values ​​above 95% are considered normal, while oxygen saturation values ​​of 90% or less begin to become life-threatening.

The excess of bases (BE). It is a parameter that allows to establish if a person suffers from some disturbance of the acid-base balance.
If this value is negative, it means that c "is a lack of bases in the blood and that the patient is in conditions of metabolic acidosis; vice versa, if BE is positive it means that c" is an excess of bases in the blood and that the patient is in conditions of metabolic alkalosis.

The electrolytes. In particular, the blood gas analysis quantifies the levels of sodium, potassium, calcium and chlorine.
The quantification of the aforementioned electrolytes is especially important in dialysis patients: dialysis, in fact, could cause variations in sodium, potassium, calcium and chlorine, which should be identified promptly to avoid unpleasant consequences.
Electrolytes can also be measured by simply taking venous blood; however, their quantification by blood gas analysis is quicker and more immediate.

, in which blood poor in oxygen but rich in carbon dioxide circulates, the pulmonary alveoli have the task of withdrawing oxygen from the air, exchanging it with the carbon dioxide of the blood.

Thanks to the aforementioned gas exchange, whose specific name is hematosis, the blood thus becomes able to oxygenate and keep alive all the cells, tissues and organs of the human body.

The blood gas analysis is used by doctors to understand what is the effectiveness of the gaseous exchange of blood / alveoli in an individual. In other words, blood gas analysis allows to establish the ability of a person to oxygenate the blood and to free the latter from carbon dioxide.