Artificial Respiration

Artificial Respiration, forcing of air into and out of the lungs of one person by another person or by mechanical means. It is usually employed during suspension of natural respiration caused by disease, such as poliomyelitis or cardiac failure; by electric shock; by an overdose of depressive drugs such as morphine, barbiturates, or alcohol; or by suffocation resulting from drowning, breathing noxious gases, or blockage of the respiratory tract. If the brain is deprived of oxygen for five minutes, it may be permanently damaged; slightly longer periods without oxygen usually result in death. The exception is drowning in very cold water, in which the body's oxygen demand is greatly reduced; people have been revived after being submerged for one-half hour in cold water.

In the mouth-to-mouth method the unconscious person is laid faceup with the head tilted as far back as possible to prevent the tongue from blocking the air passages. The victim's nose is then pinched shut, and with the reviver's mouth tightly covering the victim's, the reviver gives four quick, deep breaths. If breathing does not resume, the reviver proceeds to give one breath each five seconds, allowing the air to come out of the victim's lungs between breaths. This is continued until the victim resumes breathing or until trained help arrives. If the unconscious person is a baby or small child, both the mouth and nose are covered with the reviver's mouth, and small puffs of air are breathed out to the victim at the rate of one every three seconds.

To restore breathing to a person who is choking, a rescuer gives four quick blows between the victim's shoulder blades with the heel of the hand. If this does not dislodge the obstruction, the rescuer uses the stomach thrust, popularly called the Heimlich maneuver after its developer, the American physician Henry Jay Heimlich. The rescuer places the side of the fist against the victim's stomach, below the ribs and above the navel. Then, using the other hand, the rescuer thrusts the fist up into the victim's stomach forcefully four times. With children, a rescuer first turns the child head-down and slaps the child's back. In applying the Heimlich maneuver to children, the rescuer uses only the first hand, and not the second.

A type of respiratory first aid that requires special training is called cardiopulmonary resuscitation (CPR). In this procedure, which is used for a person who has had a heart attack, the reviver alternately breathes for the victim and performs external massage on the person's chest to keep blood moving through the body. This technique is more easily done by two trained people, one performing each maneuver. This technique is more easily done by two trained people, one performing each maneuver. If the procedure lasts for a long time, it is best that the two people switch positions to be able to sustain the procedure. See also First Aid.

Theophylline

Theophylline, prescription drug used to treat asthma, a chronic disease of the respiratory system. It is also used to treat asthmalike symptoms in patients with emphysema, chronic bronchitis, and pulmonary (lung) disease. Theophylline is sometimes used to treat breathing problems in infants at risk for sudden infant death syndrome (SIDS). As a bronchodilator, the drug works by relaxing constricted muscles of the lung’s bronchi, the two branches of the trachea (windpipe) that lead to the lungs. It also opens blood vessels in the lungs, improving circulation.

Theophylline is available in capsule, tablet, and liquid form. All are taken orally, usually with food to prevent stomach irritation. Dosage in children under the age of 16 is based on body weight. Adult dosages usually start at 200 mg taken twice a day, which may be increased if needed. The maximum adult dose is 900 mg per day. Effectiveness is usually apparent within 48 to 72 hours.

Patients with peptic ulcers, seizure disorders, impaired liver or kidney function, high blood pressure, irregular heartbeat, or heart disease should use this drug with caution. Theophylline should not be used by breast-feeding women and should be avoided during pregnancy.

Side effects may include nausea or restlessness, especially when starting treatment with theophylline. Other possible side effects are diarrhea, headache, increased urination, insomnia, low blood pressure, or skin rash. Changes in heart rate, another possible side effect, should be checked by a doctor. Symptoms of overdose can include the side effects described above or more severe effects including high fever, convulsions, or coma.

Theophylline may interact adversely with the medication in a flu shot. It also may interact with cimetidine, ciprofloxacin, clarithromycin, doxycycline, erythromycin, phenytoin, propanolol, and birth control pills.

Brand Names: Slo-bid, Theo-dur

Bronchodilator

Bronchodilator, any of a group of drugs that expand the air passages (bronchial tubes) of the lungs. Bronchodilators are used to treat asthma, bronchitis, emphysema, and other diseases that affect the lungs. They relieve symptoms such as wheezing, shortness of breath, and coughing, and restore the patient’s ability to breathe comfortably.

Bronchodilators work in various ways. Some, such as albuterol, affect the sympathetic nervous system, dilating the walls of the bronchial tubes. Others, such as theophylline, interfere with the action of certain enzymes or cells within the lungs, relaxing the constricted muscles of the airway.

Many bronchodilators are inhaled through the mouth, especially those that provide immediate relief from an asthma attack. Some are taken orally in tablet or liquid form while others are injected into the skin. Inhaled bronchodilators are often prescribed with a dosage of 1 or 2 inhalations up to 4 times per day. A typical tablet dosage is 2 to 4 mg taken 3 to 4 times per day. Some bronchodilators begin to work within minutes of a dose. Others are not designed for immediate relief of symptoms and may take several weeks to take effect.

Patients taking bronchodilators are usually cautioned to avoid using other drugs to treat their symptoms, especially inhaled medications, unless a doctor advises otherwise. The effect of bronchodilators on pregnant women has not been well-studied in humans, although some types of bronchodilators produce birth defects in animals when administered in high doses.

Medical Transplantation

Medical Transplantation, transfer of a living tissue or organ to an injured or ill person to restore health or reduce disability. Over the past 45 years, surgeons have made great strides in their ability to implant organs in people who are seriously ill. At least 21 different organs—such as hearts, livers, and kidneys—and tissues—such as corneas and bone marrow—can now be successfully transplanted into patients who can then expect to survive for years or even decades. Improved surgical techniques are partly responsible for the success of organ transplants, but a more important factor is the development of drugs that can suppress the body’s rejection of the implanted organ without also leaving the patient highly susceptible to infections.

Kidneys are the most common organs to be transplanted. Kidneys remove waste products from the blood stream. If they fail, often as a result of diabetes mellitus or cancer, a person can die from the buildup of these toxic materials. The waste products can be removed artificially through a process called kidney dialysis, but the patient must be hooked up to the dialysis machine two to three times each week for as long as 12 hours at a time. Kidney transplants free the recipient from dependence on dialysis. If the kidney is rejected, the patient must go back on dialysis or receive another transplant.

Heart transplants are perhaps the most dramatic of all organ transplants because without a functioning heart, a patient cannot survive more than a few minutes. The heart is also more sensitive to a lack of blood than other organs, and can be preserved for only a few hours without damage.

Liver failure caused by cirrhosis, cancer, or hepatitis can be fatal. The liver is the only internal organ with the capacity to regenerate. This capacity provides the surgeon additional flexibility in treating liver damage. For instance, if the damage is not very severe, a temporary transplant can take over the liver’s function while the patient’s own liver recovers. It is also possible to remove part of a liver from a living donor and transplant it. After the surgery both the donor’s liver and the transplanted portion will grow to full size.

Lung transplants are used to replace a single diseased lung, and sometimes both lungs. In some cases lung disease has damaged the heart, and these cases may benefit from a combined heart-lung transplantation. Successful lung transplants are hampered by the difficulty in preserving a lung from a person who has recently died so that it is still viable by the time a proper recipient is found.

The most common tissue transplant is blood transfusion, commonly used to replace blood lost by a person in an accident or during surgery. Other tissues commonly transplanted include bone marrow, corneas, skin, bone, cartilage, tendons, and blood vessels.

Hemophilia

Hemophilia, hereditary blood disease characterized by the inability of blood to clot, or coagulate, leading to hemorrhage, or excessive bleeding, even from minor injuries. The disease is caused by an insufficiency or absence of certain blood proteins, called factors, that participate in blood clotting. The most common form, hemophilia A, is observed in 80 percent of hemophiliacs and is caused by a lack of factor VIII; in the second most common, hemophilia B (Christmas disease), factor IX is missing. The severity of hemophilia varies greatly. The bleeding may occur as excessive bruising or persistent bleeding after a simple cut. Hemorrhaging into joints and muscles can be disabling. Before the advent of modern therapy, the chance of survival to adulthood was poor.

About 80 percent of all cases of hemophilia have an identifiable family history of the disease; in other instances, it may be attributable to a spontaneous mutation of genes. Researchers recently discovered that the spontaneous mutation of the factor VIII gene in two children was due to the attachment of a foreign “jumping gene” (see Genetics) that disrupted the blood-clotting ability of the factor VIII gene. Inheritance is controlled by a recessive sex-linked factor carried by the mother on the X chromosome. A probability of one in two exists that each boy born to a normal male and a carrier female will be hemophiliac and the same chance that each girl of this union will be a carrier. Of the children of a hemophiliac male and a normal female, all the girls will be carriers and all the boys will be normal. Males cannot transmit the disability, and female carriers are free of the disease.

Prevention of injury is important for the patient with hemophilia. When bleeding occurs, replacement therapy may be necessary. Freshly frozen blood plasma can be used to treat mild forms of the disease. In severe cases, hemophiliacs can administer plasma extracts at home either in a freeze-dried form that is storable for six months at room temperature or for a year in the refrigerator; or else in a form called cryoprecipitate, a concentrate that is prepared from fresh blood and must be refrigerated. Cryoprecipitate and other types of concentrates are less likely to transport diseases such as hepatitis and acquired immunodeficiency syndrome (AIDS) because concentrates are prepared from the blood of a single donor, whereas plasma comes from large pools obtained from many donors. Screening of donors and heat treatment of plasma products have recently decreased the risk of disease transmission. The cloning of factor VIII by genetic engineering allowed the development of a completely safe replacement product that was approved by the Food and Drug Administration (FDA) for commercial production in 1992. Unfortunately, a high percentage of hemophiliacs have already been exposed to the AIDS virus.