To evaluate the efficiency of pulmonary gas exchange

To assess the integrity of the ventilatory control system

To determine the acid-base level of the blood (see Understanding acid-base disorders)

To monitor respiratory therapy

Explain that arterial blood gas analysis evaluates how well the lungs are delivering oxygen to the blood and eliminating carbon dioxide.

If the blood sample will be drawn from an arterial catheter, reassure the child that he won’t feel pain.

If the sample will be taken via arterial puncture, keep in mind that this is typically more painful than a venous puncture. Be honest and explain that it will hurt for a few seconds.

Allow the parents to comfort the child during the blood drawing to reassure the child.

Explain that only a small amount of blood will be taken, and that the child’s body will quickly make new blood to replace it.

Inform the child and his parents that he need not restrict food and fluids.

Instruct the child to breathe normally during the test.

Wait at least 20 minutes before drawing arterial blood when starting, changing, or discontinuing oxygen therapy; after initiating or changing mechanical ventilation settings; or after extubation.

Use a heparinized blood gas syringe to draw the sample.

Confirm the child’s identity by checking two patient identifiers.