Deck 7: The Blood Vessels of the Upper Extremity

Question 1

A young secretary, running from her office, had a glass door swing back in her face. To protect herself, she held out her left hand, which smashed through the glass. On admission to the hospital, she was bleeding profusely from a superficial laceration in front of her left wrist. She had sensory loss over the palmar aspect of the medial one and a half fingers but normal sensation of the back of these fingers over the middle and proximal phalanges. She had difficulty in grasping a piece of paper between her left index and middle fingers. All her long flexor tendons were intact.

-The following statements concerning this patient are correct except which?

A) The radial artery was cut in front of the flexor retinaculum, and this accounted for the profuse bleeding.
B) The loss of skin sensation on the palmar aspect of the medial one and a half fingers was caused by the severance of the ulnar nerve as it crossed in front of the flexor retinaculum.
C) The normal sensation on the back of the medial one and a half fingers over the proximal phalanges was caused by the fact that the posterior cutaneous branch of the ulnar nerve arises about 2.5 in. (6.25 $\mathrm{cm})$ proximal to the flexor retinaculum and was spared.
D) The inability to hold the piece of paper was caused by the paralysis of the second palmar interosseous muscle, which is supplied by the deep branch of the ulnar nerve.
E) There was no sensory loss on the palm of the hand because the palmar cutaneous branch of the ulnar nerve was not cut.

Answer 1

The radial artery was cut in front of the flexor retinaculum, and this accounted for the profuse bleeding.

Question 2

A middle-aged man with a history of chronic duodenal ulcer was seen in the emergency department in a state of severe shock. He was pale, restless, and sweating, and his blood pressure was $80 / 60 \mathrm{~mm} \mathrm{Hg}$ . The resident made a diagnosis of internal hemorrhage, probably due to the erosion of the gastroduodenal artery or one of its branches, and decided to set up a blood transfusion immediately. Based on your knowledge of anatomy, into which superficial vein of the upper limb would you perform the transfusion: in the elbow region or in the forearm? If the veins were too collapsed to be identified, where, in an emergency, could you cut down on a superficial vein in the upper limb?

Answer 2

The cephalic, basilic, and median cubital veins, and their tributaries, are located in front of the cubital fossa and may be used for transfusion (see text Fig. 7-19). In the forearm, the cephalic and basilic veins can be seen as they wind around the lateral and medial borders of the forearm, respectively. The cephalic vein lies in a constant position behind the styloid process of the radius (see text Fig. 7-18), and it is here that it may be exposed through a small skin incision.

Question 3

Palpation of the radial artery at the wrist can provide the experienced medical professional with considerable insight into the state of the patient's circulatory system. The degree of hardness of the arterial wall can be appreciated by the examining finger; the pulse rate and quality of the rhythm can be determined; and the amount of pressure required to occlude the vessel can be used to assess the blood pressure. What are the relations of the radial artery at this site where the pulse is taken?

Answer 3

The radial artery lies in front of the distal third of the shaft of the radius; it is directly in contact with the front of the bone (see text Fig. 7-11. On its lateral side lies the tendon of the brachioradialis, and on its medial side is the tendon of the flexor carpi radialis muscle. The artery is covered anteriorly by skin and fascia.

Question 4

An 8-year-old boy fell off a swing and sustained a supracondylar fracture of his left humerus. Following the reduction of the fracture, a suitable splint was applied and the child was sent home. A few hours later, the child complained of pain in the forearm, which persisted. Four hours later, the parents decided to return to the hospital, since the child's left hand looked dusky white and the pain in the forearm was still present. On examination, there was found to be a complete loss of skin sensation of the hand. After removal of the splint, the pulse of the radial and ulnar arteries could not be felt. Every possible effort was made to restore the circulation of the forearm, without avail. What has happened to this child's circulation in the forearm? What deformity would you expect this child to have 1 year later?

Question 5

Why is the radial artery chosen in preference to the ulnar artery or brachial artery for direct blood pressure monitoring? Why are the upper limb arteries used in preference to the dorsalis pedis artery of the foot? What are the important anatomic relations of the radial artery at the site of cannulation? Why is it necessary to extend the wrist joint when the canula is introduced?

Question 6

During an emergency procedure it is sometimes necessary to monitor central venous pressure via peripheral access. Why is the basilic vein more often used to establish a central venous pressure line than the cephalic vein?

Question 7

A 29-year-old woman was seen in the emergency department complaining of severe pain and discoloration of the fourth and fifth fingers of both hands. She said that she had had similar symptoms before and that they always occurred in very cold weather. Initially, her fingers turned white on exposure to cold and then became deep blue in color. The color change was confined to the distal half of each finger and was accompanied by an aching pain. Placing her hands in hot water was the only treatment that relieved the pain. As the pain disappeared, she said, her fingers became red and swollen. Using your knowledge of anatomy, make the diagnosis.

Question 8

A 23-year-old medical student decided to assist his father in building a garden shed. Unfortunately, much of the wood had to be cut to length by using a hand saw. He noticed on the third day that his right arm felt heavy and that his right hand was swollen. At the emergency department, a diagnosis of right subclavian vein thrombosis was made. Can you explain the possible anatomic reasons why thrombosis occurred in this vein in a healthy individual?