In 1895 Professor Roentgen discovered the existence of X-rays during the course of an experiment with cathode rays which had previously been discovered by Crookes, an English observer, in 1849. The X-rays, though invisible to the eye, have the property of penetrating solid substances to a considerable degree and are capable of affecting a photographic plate. The value of such a discovery to surgical and medical diagnosis is at once apparent. By these rays fractures can be accurately portrayed, foreign substances located, and many obscure conditions cleared up.
Preparation of a patient for X-ray examination consists in the removal of metal splints, pins, and adhesive plaster from the area to be examined, as these substances are more or less opaque to the rays and will cast confusing shadows on the photographic plate, thereby impairing its usefulness. If a wound exists in the field, any bismuth or iodoform dressing must be removed, since these substances also are non-permeable.
For diagnostic purposes, it is frequently desirable to radiograph the stomach or intestine. Since these organs are more or less permeable to the rays, it is necessary that some metallic substance, such as bismuth, be ingested shortly before the exposure is made, in order that the outline of the organs may be more clearly defined. Some cereal mixed with bismuth is frequently employed for this purpose. In searching for calculus in the kidneys, ureters, or gall-bladder, it is highly important that the colon should be empty and that a large meal be not taken for some hours prior to exposure. A cathartic is frequently administered the previous day and a cleansing enema given, so as to avoid the possibility of the presence of faecal masses, which will seriously obscure the plate.
The X-rays have been found to have a marked curative effect on some forms of lupus, eczema, and epithelioma. It is sometimes desired to push their use until a reaction occurs, known as an X-ray burn, and it is necessary that a nurse should be able to recognize the symptoms of such reaction, which may be delayed and may not appear for days or even weeks after the exposure has been made. It is characterized by marked reddening of the part exposed, accompanied by some pain and slight swelling. If the "burn" be not severe, the redness disappears in a few days and the part desquamates. In severe cases the condition goes on to vesication and even to severe sloughing and destruction of the tissue accompanied by agonizing pain.
It should be remembered that some persons exhibit a marked idiosyncrasy to the rays and will develop a burn after a few seconds' exposure for radiographic purposes. The main points to be remembered are that the reaction is never apparent at the time and may be considerably delayed, and that any reddening of the part is a danger signal that should not be overlooked so that it may be immediately reported and appropriate treatment instituted.
The use of this substance as a therapeutic agent is still in the experimental stages. Its existence was first demonstrated by the Curies in France in 1898, and was proven to be radio-active, i. e., to have the power of emitting rays without relation to the sun or other external conditions. Experiments are being made as to its effects on the physiological processes of the body. It is known that it causes the blood-vessels to dilate, is possibly bacteriacidal, has some electrical action, and influences quickly growing tissues such as cancerous growth. Its future as a remedial agent in these conditions remains to be determined.