arteriovenous fistula localization test

The arteriovenous fistula positioning test is an auxiliary test method for checking whether the venous blood vessels are normal. Arterial blood contains more oxygen, less carbon dioxide, and is bright red; venous blood contains less oxygen, more carbon dioxide, and is dark red. When arteriovenous fistula is present, arterial blood enters the vein because the arterial pressure is higher than the vein, causing the venous blood near the fistula to become lighter. Because the blood pressure of the arteries changes with the contraction and relaxation of the heart, when the arteriovenous fistula is thicker, the blood flow into the vein is pulsed. Through this examination, the corresponding symptoms can be judged. Basic Information Specialist Category: Cardiovascular Examination Category: Other Examinations Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: Dark red is negative. Positive: The blood entering the syringe is bright red for the test positive. 1. The color of the blood entering the syringe is bright red, and it is injected into the pulse. The frequency is consistent with the pulse rate of the patient, which proves that there is a large arteriovenous fistula near the puncture site. 2. The color of the blood entering the syringe is bright red, but the speed of entering is basically uniform, and there is no pulse phenomenon, suggesting that there are fine arteriovenous fistulas near the puncture site. 3. The larger the arteriovenous fistula, the closer the blood color entering the syringe is to the arterial blood. Tips: Maintain a normal diet and sleep. Normal value The blood entering the syringe was bright red for the test positive and dark red for the negative. Clinical significance Abnormal result 1. The color of the blood entering the syringe is bright red, and it is injected into the pulse. The frequency is consistent with the pulse rate of the patient, which proves that there is a large arteriovenous fistula near the puncture site. 2. The color of the blood entering the syringe is bright red, but the speed of entering is basically uniform, and there is no pulse phenomenon, suggesting that there are fine arteriovenous fistulas near the puncture site. 3. The larger the arteriovenous fistula, the closer the blood color entering the syringe is to the arterial blood. People who need to be examined: suspicious limbs or superficial arteriovenous fistulas. Positive results may be diseases: pulmonary arteriovenous fistula, renal arteriovenous fistula, acquired arteriovenous fistula Taboo before the test: maintain a normal diet and sleep. Requirements for inspection: 1. If the puncture site is located at the distal end of the arteriovenous fistula, the color of the blood entering the syringe can be close to the venous blood. The change in color depends on the level of blood pressure, the ratio of the fistula to the venous canal, the distance between the puncture site and the fistula. 2. This test can only be initially located, accurate positioning depends on Doppler ultrasound or angiography. Inspection process 1. According to the clinical manifestations, select the site of suspected arteriovenous fistula and routine skin disinfection. 2. Inhale a proper amount of normal saline in the syringe, remove the air and then puncture the vein with a 7-gauge needle. Do not apply pressure to the syringe plunger. 3. Observe the blood color and blood flow pattern entering the syringe. Not suitable for the crowd Inappropriate crowd: the torso, deep arteriovenous fistula. Adverse reactions and risks Nothing.