Arteriovenous fistula localization test

Arteriovenous fistula positioning test is an auxiliary examination method to check whether the veins are normal. Arterial blood contains more oxygen and less carbon dioxide and is bright red; venous blood contains less oxygen and more carbon dioxide and is dark red. When arteriovenous fistulas are present, arterial blood enters the veins because arterial pressure is higher than the veins, making the color of venous blood near the fistula lighter. Because the arterial blood pressure changes with the contraction and relaxation of the heart, when the arteriovenous fistula is relatively large, the blood flow into the vein is pulsed. Through this examination, the corresponding symptoms can be judged.