| Anaesthesia & Critical Care |
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Dept. of Anaesthesia & Critical Care: Dr.Nishikanta P - MD(Anaesthesiology) Dr.Rojen - DA Dr.Kennedy Tayenjam - MD(Anaesthesiology) Anaesthesia has traditionally meant the condition of having sensation (including the feeling of pain) blocked or temporarily taken away. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. There are four main types. 1.Local: numbs one small area of the body. You stay awake and alert. The type of anesthesia your doctor chooses depends on many factors. These include the procedure you are having and your current health. Types of anesthesia Anesthesia can be categorized by the degree to which it suppresses consciousness and protective reflexes. Larger procedures often require greater amounts of anesthesia. From least to most, levels of anesthesia include: local, conscious sedation, regional and general. Determining the best choice for you depends on the anticipated nature and duration of the procedure, as well as your medical and psychological health. Discuss your options with your doctor. 1.Local anesthesia: It is used to block pain in a specific part of your body, allowing you to remain fully alert. The area that is anesthetized is usually small and superficial. Typically, a local anesthetic is used for dental work, skin biopsies or stitching up a cut. Sometimes a local anesthetic is used for a more extensive procedure in people for whom general or regional anesthesia is inadvisable. For local anesthesia, an anesthetic is injected at or near the site of the procedure. The injection numbs the area to pain and any other sensation. Local anesthetics are generally of short duration. They come in different forms, including injections, sprays and ointments. Only rarely do they cause an allergic reaction. 2.Conscious sedation: Conscious sedation or intravenous (IV) sedation is used to relax you and make you feel sleepy. It generally includes intravenous administration of pain medication and a mild sedative to minimize any discomfort. These medications also cause temporary forgetfulness, so you may not remember what happens during the procedure. Even though you may not remember anything that occurs during conscious sedation, you remain awake enough during that time to respond to questions and retain your protective reflexes. For example, if secretions accumulated in your throat, you would swallow or cough. This type of anesthesia is used for procedures such as colonoscopy, an exam of your colon and rectum. Conscious sedation is also frequently combined with regional anesthesia. 3.Regional anesthesia: It is used to block sensation in a particular region of your body, such as the lower half of your body, an eye, or an arm or leg. As with local anesthesia, you remain conscious during regional anesthesia. Often regional anesthesia is combined with conscious sedation, so you might not remember any of the procedure. The anesthetic is injected around a single nerve or a network of nerves that serve the area involved in the surgical procedure. You receive the injection, which is generally painless, while lying on your back or side, or sitting. To eliminate pain in the lower half of your body, spinal, epidural or caudal anesthetics may be injected near your spinal cord. These forms of anesthesia are often used for pelvic operations and for leg and hip surgery. Epidural anesthesia is often used during childbirth. The main advantage of regional anesthesia is that it provides a high level of anesthesia to a selected region of the body while having little effect on other areas, such as your heart, lungs and brain. In regional anesthesia, your protective reflexes remain intact. An additional benefit of regional anesthesia is that it helps control postoperative pain. That means you may require less pain medication after surgery and can avoid the nausea and grogginess that often result from those medications. 4.General anesthesia: It is used for more extensive procedures or for procedures that aren't amenable to regional anesthesia. The medications used in general anesthesia are given intravenously or by inhalation. The drugs circulate in your bloodstream to all areas of your body, including your brain. They can suppress all of your protective reflexes, such as coughing, gagging and even breathing. Consequently, a general anesthetic requires the use of a mask or breathing tube while you're asleep. Because general anesthetics affect all areas of your body, such as the heart and lungs, side effects from the medications are more common. However, most are temporary and can be managed by your medical team. HOW IT WORKS When you hurt, pain signals travel up the spinal cord, through your nervous system, and to the brain. The medicines used during local and regional anesthesia temporarily blocks nerve signals in the area, so you don't feel the pain. General anesthesia shuts down the brain's pain-processing center, so your body doesn't recognize the pain signals. RISKS All types of anesthesia carry some risk, although major side effects and complications are uncommon. Local anesthesia is the safest. General anesthesia affects the entire body, so side effects are more common. However, complications due to anesthesia have dropped dramatically over the last 25 years. This is due to better anesthetic drugs and better monitoring techniques. Risks from any type of anesthesia include: Risks from local and regional anesthesia include: Risks from general anesthesia may include: Delirium is most common in older adults. Studies have linked general anesthesia to long-term problems in mental function in older adults who have certain types of surgery, such as open heart surgery. The complication is called postoperative cognitive dysfunction (POCD).
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