Much of the practice of medicine is indirect. Doctors observe the outward appearance of patients to discover manifestations of disease. They use diagnostic equipment and laboratory tests to look at the patient's inner environment from the outside. They prescribe treatments based on their best judgment of the internal factors causing the patient's problems.
The practice of surgery is more intimate. Surgeons actually get inside the human body. They operate on patients to remove or correct diseased or damaged body parts. They replace a failing organ with a healthy or artificial one.
This close contact poses many risks for the patient, including excessive bleeding and infection. The practice of surgery has advanced over the decades to greatly reduce these dangers.
Any surgical procedure will cause bleeding. Surgeons cannot avoid slicing through blood vessels as they cut into skin and muscles. At the site of surgery, they must make other cuts in blood vessels and tissue to accomplish their task.
Patients who have major operations, such as heart surgery, lose large amounts of blood. Because blood carries vital oxygen and nutrients throughout the body, lost blood must be replaced. Approximately 14 percent of all surgical patients each year receive new blood through transfusions. These patients may receive transfusions of whole blood or specific components of the blood, such as oxygen-carrying red blood cells, infection-fighting white blood cells, or clot-inducing platelets.
In recent years, many patients became concerned about the safety of blood obtained from donors for transfusion. Their principal fear has been that the blood might be contaminated with human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). However, blood in blood banks is tested carefully for antigens produced by the body in response to HIV. According to the U.S. Centers for Disease Control and Prevention (CDC), only 1 percent of individuals with AIDS contracted the disease through a transfusion. In addition, almost all of these persons were infected with HIV before blood screening began in 1985. Many patients who have several months to prepare for surgery may donate some of their own blood ahead of time in case they need it during their procedure. This type of transfusion is known as autologous.
Infection may be a minor complication of surgery that clears up on its own without any treatment, or it may be a serious condition that requires antibiotics or surgery to get rid of infecting organisms. An infection may begin during surgery because infecting organisms have been transported into the patient on a surgical instrument. The operation itself may cause an organism that normally resides in one part of the body to move to an area where it is not welcome. Infection also may occur after surgery, in the surgical wound or the lungs, for example, because the immune system of the patient has been weakened and it cannot ward off infecting organisms.
Since the late 19th century, surgeons have been following what is known as aseptic technique to protect surgical patients from infection. The purpose of aseptic technique is to destroy or remove microorganisms from all objects that come in contact with the patient during surgery. All surgical instruments, the threadlike material used to close wounds (sutures), and the sponges that remove excess blood from the area of surgery are sterilized in an autoclave. The autoclave kills microorganisms by exposing them to steam under pressure. Using soap that contains an antiseptic, doctors and nurses carefully scrub their hands before surgery. They wear caps, gowns, masks, and gloves that have been sterilized to avoid any possible transmission of germs.
Surgery would not be possible without putting the patient to sleep or completely desensitizing a specific body part so the surgeon can operate without causing pain. Administering anesthesia to a patient is a complicated process. The anesthesiologist must consider the patient's condition, the type of surgery, the effects of the anesthetic agent, the procedures for administering the anesthetic, and the training and experience of the surgical team.
There are two principal types of anesthesia—general and local. General anesthesia makes the patient unconscious. General anesthetic agents may be given in the form of a liquid that is administered intravenously—directly into a vein. They also may be in a gaseous form that is inhaled into the lungs. The ideal general anesthetic is often a combination of drugs that should accomplish three things: sleep, pain relief, and muscle relaxation. Local anesthesia affects only a particular section of the body. Usually a local anesthetic is administered in an area near the spine to desensitize the nerves leading to the area of the operation. The patient is not unconscious during the procedure. Spinal anesthesia is valuable in emergency situations, when the patient's stomach may be full and vomiting is a risk during general anesthesia.
Recent advances in the administration of anesthetic drugs have improved the safety of surgery. One device, known as the pulse oximeter, assesses the amount of oxygen in the blood and sets off an alarm when the oxygen level is too low. Another, called the end-tidal capnograph, determines how much carbon dioxide the patient exhales; it can indicate if something is interfering with the patient's breathing while he or she is under general anesthesia.
The operations surgeons perform today are a far cry from the simple procedures that were done at the beginning of the 20th century. Modern-day operations are often highly complicated, involve many different organs, and require sophisticated equipment.
Since World War II, doctors have been trying to perfect transplantation surgery. The major obstacle to success was the natural tendency of the body's immune system to reject anything that is foreign to the body. Transplantation is possible today because drugs were discovered that could effectively suppress the immune system. These drugs allow the recipient of a transplanted organ to accept the new organ as his or her own. The most important of these drugs is cyclosporine. It has allowed many patients to live for years with transplanted organs. With the advent of cloning technology, one day in the near future a transplant patient may be able to "grow" a donor organ from his or her own cells, thus eliminating the danger of rejection altogether.
Heart disease afflicts more people in the United States than any other medical condition. Through surgical techniques, doctors can replace faulty valves that prevent blood from flowing through the heart. They can insert a pacemaker to regulate an irregular heartbeat. Inserting tiny, inflatable balloons can restore blood flow through blocked arteries.
Under high-powered microscopes, surgeons can reconnect breaks in the smallest of the body's structures. As a result, they can reattach severed limbs. Surgeons also can repair injuries to the tubes through which sex cells pass in the body, and thus restore fertility to both men and women.
Fire and ice.
Cancer surgery usually involves removal of the organ or tissue that contains tumors. In some instances, this type of surgery is either insufficient or unsuitable. For example, some patients have tumors that lie so deeply within the brain they cannot be reached by surgeons without damaging normal brain tissue. Other patients have tumors in the liver that cannot be removed because nearby blood vessels will cause excessive bleeding if doctors attempt surgery. Surgeons sometimes treat these patients with the heat of radiosurgery or the cold of cryosurgery.
Radiosurgery involves the administration of concentrated doses of radiation to precise locations in the body. Patients with brain tumors are placed under a metal head frame that pinpoints each site of cancer. Individual beams of radiation are directed to these sites through the head frame.
Cryosurgery applies liquid nitrogen to freeze and kill individual tumors. First, high-frequency sound waves are used to distinguish tumors from normal structures. Sound waves also help to guide the placement of thin probes into the tumors. Small vials of liquid nitrogen then are transported through the probes to the tumors, and the nitrogen is released. Cryosurgery is also used to control pain and blood loss and to reduce brain lesions.
Minimally invasive surgery.
Since the 1980s, an increasing number of surgeons have been performing minimally invasive surgery (keyhole operations). Keyhole surgery was named for the small incisions the surgeon makes in the body. Instead of one long cut, the surgeon does a series of three or four smaller cuts. Through one of the cuts, the surgeon can insert a laparoscope, a fiber-optic instrument with a light and a miniature camera. The camera transmits pictures of the patient's organs and tissues. Through the other cuts, the doctor inserts surgical instruments that he or she manipulates from outside the body. These instruments can cut and remove small portions of diseased or damaged organs.
Other flexible or rigid tubular instruments, including endoscopes, are used in this type of surgery to visually examine the interior of a body canal or organ. An endoscope can be inserted through one of the body's natural openings or through tiny incisions. Laparoscopes are inserted through a small incision in the abdominal wall.
For the patient, the advantages of minimally invasive surgery include less pain and blood loss and a shorter recovery period. This type of surgery is also usually less expensive to perform. The technique has been used to operate on the kidney, stomach, heart, spine, uterus, and ovaries. Laparoscopic surgery has also been effective in removing gallbladders and appendixes.
Offshoots of minimally invasive surgery—including robosurgery, in which robots help to perform operations, and telesurgery, a form of robosurgery in which operations are performed over a long distance—are under scrutiny. Early studies are evaluating robosurgery as a way to repair heart valves, remove gallbladders, repair fallopian tubes, and perform prostate surgery.
After surgery the patient must be carefully watched to be sure his or her body is mending as it should. The patient's pulse, blood pressure, and breathing are checked regularly for one or more hours after the operation. Body temperature is taken regularly to determine if there is any infection. The patient is observed to be sure he or she is waking up properly from the anesthetic.
Some patients need to be followed more closely, especially those who have had major surgery or who have particularly serious medical problems. Such patients are moved to the intensive-care unit (ICU), where they can be closely monitored while specialists make precise assessments.
The intensive-care unit in a hospital has many sophisticated machines that measure various body functions. An electrocardiograph records the pattern of the beating of the heart. Catheters, or tubes, that are placed in the bloodstream spot sudden changes in blood pressure. Bedside monitors are able to indicate how well the lungs are working.
Because of advancements in technology, many surgical procedures can be performed in outpatient or ambulatory surgery centers. These centers may be part of a hospital, or they may be in a separate building. They have the same types of equipment as a hospital operating room and use the same kind of aseptic procedures, but they do not have an ICU. Such centers provide orthopedic, ophthalmological, plastic, gynecological, and general surgery.
In these centers, for example, eye surgeons use lasers to operate on the eye. They need to apply a laser beam for only a few minutes to burn away a cataract or to reattach the back of the eye (retina) when it has become detached. Orthopedic doctors, or physicians who treat bones and muscles, perform arthroscopy in outpatient centers. Arthroscopy is the examination of a joint such as the knee or shoulder using an arthroscope. An arthroscope is similar to a laparoscope—it is a narrow device that has a light and a camera so the doctor can see the inside of the joint. The arthroscope is placed in the joint through a small cut in the skin. Gynecologists, who treat female patients, conduct many of their minor operations in outpatient centers. In U.S. community hospitals today, approximately 65 percent of the surgery is performed on an outpatient basis.
Before patients go to an outpatient center, they undergo laboratory tests and X rays to determine whether they are healthy enough to have an operation. These tests are done one or two days ahead of time in the doctor's office, the outpatient center, or a hospital. Patients come to the outpatient center a few hours before the operation to receive instructions about the procedure and to discuss what needs to be done after the operation. Immediately before surgery, patients are given a local or a mild general anesthetic. After surgery, patients are watched until doctors are sure it is safe to send them home. Many outpatient centers employ drivers who escort the patients home in a van.
The Emergency Room
One of the busiest areas in a hospital is the emergency room—where people seek immediate treatment for unexpected medical emergencies. Here, medical personnel are prepared to quickly examine and treat patients. In addition to the seriously ill, many people use emergency rooms for nonemergencies; this is largely a result of rising health-care costs and the growing percentage of Americans who lack family doctors and health insurance.
Visits to hospital emergency rooms have grown steadily, resulting in overcrowding and sometimes preventing medical personnel from treating serious problems in a timely manner. Hospitals are trying various methods to alleviate overcrowding. In some cases, staff members screen patients as soon as they enter the emergency department, directing those with mild problems to a separate area. Hospitals also are increasing the number of home-care programs for high-risk patients. In another attempt to take pressure off emergency rooms so that they can focus on true emergencies, primary-care centers have sprung up across the United States. At such centers, patients can obtain medical attention on a walk-in, no appointment basis. Some of these facilities are open daily.
The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies.
Copyright Information: Public domain information with acknowledgement given to the U.S. National Library of Medicine.