“Blood gas” is a biological test performed by taking arterial or venous blood samples, depending on the measurements required. In most cases, arterial blood is taken from the inside of the wrist, where the pulse can be felt. This sampling is particularly painful because of the innervation of the arterial walls, which is why it may be advisable to insert an arterial catheter to allow continuous access to arterial blood without multiple punctures. Blood gases are frequently taken in cases of respiratory failure, but also in cases of shock. Blood oxygen and carbon dioxide are monitored, as is blood acidity (pH).
