History

In which conditions may the pulse rate in one arm differ from that in the other?

Usually, slowing of the pulse on one side occurs distal to the aneurysmal sac. Therefore, an aneurysm of the transverse or descending aortic arch causes a retardation of the left radial pulse. Also the artery feels smaller and is more easily compressed than usual. An aneurysm of the ascending aorta or common carotid artery may result in similar changes in the right radial pulse.

What are the causes of absent radial pulse?

What are the causes of differences in blood pressure between arms or betweens the arms and legs?

What is Adson’s test?

The clinician palpates the radial pulse and abducts the arm slightly (Fig. 30.1). The clinician asks the patient to hyperextend the neck and turn it to the affected side and inhale deeply. Adson’s test is positive if the patient reports paraesthesias or if the pulse fades away. Diminution or obliteration of the pulse probably is caused by compression of the axillary artery by the anterior scalene muscle. The patient should turn the head to the opposite side (reverse Adson’s test) to test compressive effect of the middle scalene.

Fig. 30.1 Adson’s test. Hold patient’s arm in slight abduction while palpating the radial pulse. Ask the patient to extend the neck and rotate toward the affected side. Adson’s test is positive if the patient reports paresthesias or if the pulse fades away.

What do you know about Takayasu’s arteritis?

It tends to affect young women and most of the cases have been from Japan. Prodromal systemic symptoms include fever, night sweats, anorexia, weight loss, malaise, fatigue, arthralgia and pleuritic pain. It predominantly involves the aorta and is of three types: type I (Shimizu–Sano), which involves primarily the aortic arch and brachiocephalic vessels; type II (Kimoto), which affects the thoracoabdominal aorta and particularly the renal arteries; and type III (Inada), which has features of types I and III. Types I and III may be complicated by aortic regurgitation.

What is the Allen test?

The Allen test is used to determine patency of radial or ulnar artery (Fig. 30.2). To perform an Allen test, both the radial and the ulnar artery should be occluded while the atient elevates the hand and makes fist. The patient extends the fingers and blanching of the hand is seen. When the radial artery alone is released, and colour of hand returns to normal. An abnormal test result occurs when the colour of the hand does not return within 5–10 s. In thrombosis of the ulnar artery, the hand remains blanched when this artery alone is released. Allen’s test can be used before puncturing the radial artery for cannulation as it is important to identify a competent ulnar artery should injury to the radial artery occur.

Fig. 30.2 Allen test for patency of radial and ulnar arteries. Blanching can be seen with both arteries occluded (B); releasing the radial artery alone returns the hand colour to normal (C). If the ulnar artery alone is released, the hand remains blanched if there is thrombosis of the ulnar artery.