If the body is already dressed and the hands or feet need to be re-injected, the radial or posterior tibial likely will be most convenient as their use will not necessitate the removal or cutting of the clothing.
Oftimes there is but a single window to admit light and the operator should be so skilled as to be able to raise the arteries either on the right or left side without having to turn the cooling board.
In emaciated subjects the linear and anatomical guides are always plain but in fleshy subjects this is not always the case. Look over the subject and see which artery will be the most convenient to raise. Usually in fleshy subjects the femoral is hard to raise as there is a great amount of fat in Scarpa's triangle making the artery lie very deep, but in these subjects the guide for the brachial is quite plain, a distinct groove being seen between the biceps and triceps muscles.
In a short necked subject it is never advisable or convenient to raise the carotid as there is not much room to work and the incision is very liable to show. Another artery will be found much more advantageous in these subjects.
In accident cases the seat of injury will determine the artery to be raised, using the one through which you can give the body the greatest supply of fluid to all parts. Often it will be necessary to raise several arteries to complete the injection.
There is no necessity for undue exposure in either sex, however it is hardly ever advisable to inject the femoral in the female, as some mischief-maker might without any real cause influence others in the community against your methods.
When selecting the brachial and femoral arteries always raise them at a place below the point where collateral circulation is given off or in other words raise them in the middle third. By so doing the fluid will reach, by means of collateral circulation, the tissues of the arm and leg below the point of injection.
As far as the injection of fluid is concerned, one artery is just as good as another. All arteries are parts of the same channel branches of the aorta. No valves exist in any part of their course.
How to Raise an Artery.
—With the scalpel make an incision an inch long in the average size arm, cutting through the skin and then through the fat. Reverse the blade and at each end of the wound cut forward and upward to make it clean. Take the grooved director and with the small end puncture the deep fascia, then reverse ends of the director and force the blunt end up the wound, underneath this deep fascia, one-fourth to one-half an inch longer than the wound. Now take the scalpel with the edge of the blade upward and split the fascia as far up as the needle extends and cut the tissue (fascia and fat) up to the skin, being careful not to cut the skin. Reverse the needle and cut the lower end of the wound the same way. This will give you an incision one inch long on top and one and one-half or two inches at the bottom of the wound, and none of the vessels will be injured.