Authors: D P Lyle
These are the general questions a physician asks of any patient in an emergency situation. If the victim is not conscious, much of this information can be obtained from relatives, friends, another M.D. who knows the patient, or medical records. MedicAlert bracelets are also helpful.
After this basic data is obtained, more pointed questions are
asked to fill in the areas of concern. For a patient with a head injury, the following questions are essential:
Do you have a headache? Is it localized or general?
Do you have blurred or abnormal vision?
Are you experiencing dizziness or poor balance?
Have you been nauseous or vomiting?
Do you have any soreness or stiffness in the neck?
Do you feel any weakness? Is it generalized or only in one side, arm, or leg?
Are your eyes sensitive to light?
Do any of these symptoms worsen with a change in position or movement?
Then, of course, a complete physical and neurologic exam is performed. Based on the answers and the findings on the exam, lab work, X rays, and other tests would be obtained as indicated.
How Do Hospitals Ration the Blood Supply in Major Natural Disasters?
Q: I have an odd question for you. Let's say the big one hit Los Angeles tomorrow, devastating the city. I imagine the blood supply would be depleted rather quickly. How aggressive would doctors be about getting blood donors? Would doctors at temporary M.A.S.H.-like medical facilities solicit healthy people off the street to give blood? Would they be able to screen this blood quickly for AIDS?
A: Every hospital has an emergency or disaster plan that deals with catastrophes such as an earthquake. That said, whenever a
major event such as you describe occurs, these plans may be overtaxed and become quickly inadequate.
M.A.S.H.-like field hospitals would crop up out of necessity, and the blood supply would be rapidly consumed. The Red Cross and other organizations would transport blood, and volunteer donors would be called in. The Red Cross keeps a list of clean donors that they regularly call on when needed; blood would be obtained from them. Yes, people off the street might be used. So far, so good. Labs would be set up to supplement those of the local hospitals to type and match the blood and screen it for AIDS and hepatitis.
Screening for hepatitis and AIDS cannot be done quickly. Several hours and up to a day or two would be required. As the injured rolled in, it would be necessary for these considerations to take a backseat. After all, would you rather bleed to death or risk the very small possibility of contracting hepatitis or AIDS?
At some point all this would not be enough, and unmatched (type specific) and untested blood would have to be used to save some lives. Type-specific blood is the same type that the patient has, but it does not have full cross-matching of all possible incompatibilities. It takes only a few minutes and very little equipment to determine if blood is O-negative, for example, but it is more involved to actually test the donor blood against that of the recipient for true compatibility. This increases the possibility of a reaction, but this situation exemplifies the old adage: "Any port in a storm."
What Is Artificial Blood?
Q: While on a safari in Africa, one of my characters is attacked and severely injured by a crocodile. His leg is mauled, and he nearly bleeds to death before he is evacuated to a hospital. I've read recently about artificial blood and may want to incorporate it in my story. What is artificial blood? Is it available? Are there any problems?
A: Artificial blood has been the subject of research for three decades. The concerns regarding AIDS and hepatitis, the erratic availability and difficulty in storing and transporting real blood, and the need for blood in remote areas such as war zones has driven this research.
First a word about what artificial blood is and isn't. It is a product that supplies molecules capable of carrying oxygen from the lungs to the tissues and bringing carbon dioxide back to the lungs to be expelled. The normal IV fluids given to patients in shock or those suffering from blood loss are basically water with some electrolytes (sodium, potassium, and so forth) and sugar, and they have no ability to carry oxygen, which is the immediate concern in shock situations. Artificial blood is designed to fill this need.
However, artificial blood is not real blood. It does not contain vitamins, nutrients, hormones, antibodies, platelets (small blood cells involved in clotting), or any of the proteins involved in the clotting of blood. If given injudiciously or in large amounts, it will dilute these needed clotting factors and lead to a worsening of the bleeding, which would be counterproductive. Artificial blood is used as a bridge to stabilize the victim long enough to get him to a proper medical facility, where definitive treatment can be rendered and real blood given.
Early attempts at developing artificial blood revolved around extracting the hemoglobin molecule and modifying it so that it could be given without giving the entire red blood cell (RBC), which must be stored and refrigerated. Hemoglobin is the molecule within the RBCs that binds, carries, and releases oxygen and carbon dioxide. Unfortunately, the hemoglobin molecule when removed from the RBCs is very toxic and causes an increase in mortality. A report in the November 17, 1999, issue of the
Journal of the American Medical Association
showed that such a product, called HemaAssist (Baxter Healthcare), when used in trauma patients led to a mortality rate of 46 percent as compared to a rate of only 17
percent in those who received the typical IV fluids. It was back to the drawing board.
Several other products are under development and being tested at this time. One of the most promising is called Hemopure, which is produced by the Biopure Corporation in Cambridge, Massachusetts. It was recently approved for use in South Africa but as yet is not available in the United States. Hemopure is based on hemoglobin extracted from the RBCs of cow blood. Unlike whole blood, it doesn't need to be refrigerated and has a shelf life of two years (42 days is usual for properly refrigerated blood). Its administration is simple: Start an IV and drip it in.
In your story it would be perfectly reasonable for the medical personnel on your safari to have available Hemopure or any similar product your imagination might create. This is fiction, after all. As long as artificial blood has some factual basis, which it does, you can make up your own brand name.
Your crocodile victim would be removed from the croc's mouth; his wounds would be treated with local compression and tourniquets to control the bleeding; he would be given intravenous fluids (probably D5LR—5 percent dextrose in lactated Ringer's solution) and a couple of bottles of Hemopure (or Product XYZ); and transported to a hospital facility. There, he would receive real blood and undergo surgery to repair his injuries. The artificial blood would be the bridge that allows him to survive.
What Is Blood Doping, and How Does It Work?
Q: I'm writing a story in which a young track star uses the process of blood doping to gain an unfair advantage in an upcoming meet. How is blood doping done? Are there any complications?
A: Athletic performance and endurance are dependent on the ability of the body to supply oxygen and nutrients to working muscles and remove toxic by-products from them. This requires a conditioned cardiovascular system, an adequate supply of glycogen and other energy sources from the liver and muscles, and blood rich in hemoglobin, the molecule in red blood cells (RBCs) that carries the oxygen from the lungs to the muscles. The more hemoglobin in the blood, the better it transports oxygen.
The natural way to increase the RBCs and hemoglobin is to live or train at an altitude where the thinner air stimulates the bone marrow to produce more RBCs. People in Denver, Colorado, tend to have a greater concentration of RBCs and hemoglobin in their blood than those who live at sea level. An athlete who moves to the mountains to train would see results after a few weeks.
Blood doping is a method of doing this artificially. It is basically the removal of blood, separating and storing the RBCs, and giving the plasma back. After three or four weeks the body has replaced the removed RBCs. Then, at a later date, the stored RBCs are given. This immediately increases the concentration of RBCs (and hemoglobin) in the blood, which improves oxygen delivery capacity and thus athletic performance. Marathoners, cyclists, and other endurance athletes can use this procedure to gain an unfair advantage.
Complications are rare if the process is handled appropriately. Transfusion reactions do not occur since the person is receiving his own blood. However, if the blood is mishandled, problems can arise. If the blood is inadequately stored or if its sterility is violated, bacteria can grow in the stored blood and cause septicemia (infection in the bloodstream) when infused. This can lead to severe illness and death. If the blood is frozen or agitated, both of which can damage or shatter the RBCs, kidney damage can result when the blood is given.
Some athletes shortcut this process by taking a transfusion of someone else's blood. There is no removal of their own blood and no three-week wait to rebuild their own blood count. But this raises the problem of a transfusion reaction, which can happen even if the blood is adequately cross-matched. It was alleged that during the 1984 Olympics, some members of the U.S. cycling team blood-doped a week or so before their competition. They apparently didn't have time to do it properly and used type-specific blood donated by relatives and friends. This blood of the same type (for example, O-negative), which has not been matched for compatibility against the recipient's own blood, greatly increases the chance of a reaction, not to mention the transmission of hepatitis or AIDS.
Physicians use type-specific blood in only the direst of medical emergencies, situations where there just isn't time for a complete cross-match because the patient is bleeding to death. You do what's necessary in these circumstances and then deal with the consequences. A bicycle race hardly qualifies.
Another substance used for this type of performance enhancement is recombinant erythropoietin. Erythropoietin occurs naturally in the human body and stimulates the production of RBCs. It is manufactured by recombinant DNA techniques and, when injected, artificially increases the RBC count. Medically it is used in patients with chronic kidney failure where anemia is common and difficult to treat.
One problem that can arise in blood doping, regardless of the method, is a thickening of the blood. The more RBCs the blood contains, the more viscous it is. In fact, there are several medical conditions, such as polycythemia vera, where the concentration of RBCs becomes so great that the patient must be bled. We call this a phlebotomy. Yes, Renaissance medicine still lives. If the blood becomes too thick, it can literally sludge in the capillaries and cause strokes, heart attacks, kidney damage, and loss of digits. It can happen to an athlete whose exercise leads to dehydration if his blood is artificially thickened.
An athlete can botch the process and have a transfusion reaction, damage his kidneys, or become infected, or he can successfully complete the blood doping only to suffer a fatal heart attack during the competition. Or he can get away with it and win the race.
What Is the Basic Procedure for Blood Donation?
Q: It has been a few years since I donated blood. What is the basic medical procedure for drawing your blood? What questions do they ask beforehand?
A: Review the answer to the question regarding the basic medical questions a physician asks in emergent situations. These are important in the donor situation since certain current and past medical problems and the taking of some medications preclude the donation of blood. Other questions are designed to determine the presence or possible presence of any transmittable diseases such as hepatitis or AIDS.
The procedure is basic. A large-bore needle (14 or 16 gauge) is introduced into a vein in the soft depression on the inside of the elbow (called the antecubital fossa). The blood is then drawn into a bottle or plastic bag. The needle is removed and a bandage placed. The major concern for the donor is dizziness or fainting. Some people develop what is called the Vasovagal Syndrome. This is what happens when someone sees blood and faints. It is caused by a massive outpouring of stimuli from the brain, which excites the vagus nerve. This nerve exits the stem of the brain and wanders (like a "vagrant," thus the name) through the body, enervating the heart, lungs, blood vessels, and most of the gastrointestinal tract. It is involved with the regulation of blood pressure, heart rate, and a multitude of other bodily functions. When it is stimulated, the blood vessels dilate (open up), and the heart rate and blood pressure may drop dramatically, leading to dizziness and loss of consciousness.
Also, the removal of a pint of blood in a short period of time decreases the blood volume—the old "quart low" phenomenon. This can also lead to dizziness when the person stands. That is why orange juice or some other fluid is given and the donor is watched for a half hour or so. This gives the body time to rebalance the blood volume.
Over the next few weeks the body revs up the bone marrow to replace the donated blood, and life goes on. Donations should not be made any more often than every six weeks or so to prevent the development of iron deficiency and anemia in the donor.