At the Time of an Operation

Many older people undergoing surgery have multiple health problems, and some may be very frail. These people often need special assistance during surgery. Special equipment (for example, step stools or grab bars) or extra personnel can help people with limited mobility move safely from the bed to a stretcher or from the stretcher to an operating table. People who feel pain during movement (for example, those with a hip fracture) can be given a drug to relieve pain (analgesic) before they are moved. A pillow or cushion can be placed under the person's knees to relieve stress on back muscles while on the operating table. Foam padding can be placed in a way that relieves or reduces pressure on vulnerable points of the body, such as bony prominences of the hips or the spine. Arms and legs can be positioned to avoid injury. In addition, the skin, which is much more fragile in older people, needs to be protected. Restraining devices, monitoring devices, and tape can tear or rub the skin, causing sores.

Monitoring

During surgery, the monitoring of blood pressure, heart rate and rhythm, breathing, the balance of body fluids, and urine output is similar in people of all ages. But monitoring of older people must often be more vigilant, in part because of their greater likelihood of having chronic diseases that can increase risks during surgery. Death rates among older people undergoing surgery have dropped steadily in recent years, due in part to improved tools for monitoring vital body functions during surgery. Additional monitoring of older people may include measurements of body temperature and the amount of oxygen in the blood.

Temperature in central parts of the body (core body temperature) is monitored—usually with a special probe in the esophagus or rectum—during long operations. In many older people, core body temperature is lower and more difficult to maintain than in younger people. For older people, the body's normal mechanisms to increase body temperature (for example, shivering) demand more oxygen and energy. Therefore, specific steps are taken to maintain a reasonable body temperature. These measures include using special warming systems, using warmed fluids that are given intravenously, maintaining adequate operating room temperature, and minimizing the amount of time that body organs are exposed to room temperature. Despite these measures, older people may lose significant body heat during surgery. If this occurs, doctors make every effort to rewarm the body as soon as possible.

The amount of oxygen in the blood is generally monitored with a device called an oximeter, which typically is placed on a finger or earlobe.

Anesthesia

Anesthesia is prevention of pain through the use of drugs (anesthetics) that cause a temporary loss of sensation or deep relaxation. With increasing age, the body undergoes changes that affect the type and amount of anesthetics that can be used. The use of anesthetics creates more risks for older people compared with younger people, in part because older people take longer to recover from the effects of the drugs. Also, the likelihood of developing side effects from anesthetics and the severity of side effects tend to increase.

Anesthesia is provided in several ways, some of which are safer than others. Local anesthesia blocks sensation in a very limited area. An anesthetic is injected as close as possible to the area to be operated on. Local anesthesia is commonly used for cataract surgery, placement of a heart pacemaker, and repair of certain types of hernias. When surgery involves the skin, an anesthetic is sometimes sprayed on the skin surface. With local anesthesia, mild sedatives may be added if needed, an approach called monitored anesthesia. Local anesthesia is generally the safest form of anesthesia. Occasionally, however, someone is allergic to the drug used or develops some other unexpected reaction.

Regional anesthesia blocks sensation in a specific region; thus, regional anesthesia involves a larger area than local anesthesia. For example, in an operation to repair or replace a joint, such as the hip or knee, anesthetic drugs may be injected very close to the spinal cord to numb the nerves going to the leg. By injecting anesthetics into nerves near the arm pit, a surgeon may be able to operate on an arm. Regional anesthesia poses more risk than local anesthesia but far less than general anesthesia.

General anesthesia produces temporary loss of consciousness, loss of memory of the events immediately before loss of consciousness, pain relief, and muscle relaxation. General anesthesia is the riskiest type of anesthesia but is often essential for surgery. A general anesthetic generally is given as a gas. If surgery is brief, an anesthesiologist may administer the gas through a mask. For longer operations, a tube is inserted into the trachea, and the person is connected to a ventilator (a machine that does all or some of the breathing for a person). Sometimes, a general anesthetic is administered by injection. This technique, however, is usually reserved for very brief procedures.

Anesthesiologists have many drugs to choose from. They try to select the safest drug for a particular person and his disorder. Whenever possible, they avoid using drugs with so-called anticholinergic effects. Drugs with anticholinergic effects block the action of acetylcholine, which is a substance that helps carry messages between nerves or from a muscle to a gland. Anticholinergic effects are particularly vexing in older people, causing confusion, blurred vision, constipation, dry mouth, light-headedness, and an inability to start or continue urinating.