There are three main categories of anesthesia: general, regional and local. Each has many forms and uses.
In general anesthesia, you are unconscious and have no awareness or other sensations. There are a number of general anesthetic drugs. Some are gases or vapors inhaled through a breathing mask or tube and others are medications introduced through a vein. During anesthesia, you are carefully monitored, controlled and treated by your anesthesiologist, who uses sophisticated equipment to track all your major bodily functions. A breathing tube may be inserted through your mouth and frequently into the windpipe to maintain proper breathing during this period. The length and level of anesthesia is calculated and constantly adjusted with great precision. At the conclusion of surgery, your anesthesiologist will reverse the process and you will regain awareness in the recovery room.
In regional anesthesia, your anesthesiologist makes an injection near a cluster of nerves to numb the area of your body that requires surgery. You may remain awake, or you may be given a sedative. You do not see or feel the actual surgery take place. There are several kinds of regional anesthesia. Two of the most frequently used are spinal anesthesia and epidural anesthesia, which are produced by injections made with great exactness in the appropriate areas of the back. They are frequently preferred for childbirth and prostate surgery.
In local anesthesia, the anesthetic drug is usually injected into the tissue to numb just the specific location of your body requiring minor surgery, for example, on the hand or foot.
Yes, in certain situations. Some operations can be performed using different anesthetic procedures. Your anesthesiologist, after reviewing your individual situation, will discuss any available options with you. If there is more than one type of anesthetic procedure available, your preference should be discussed with your anesthesiologist in order for the most appropriate anesthetic plan to be made.
Beginning Phase A great deal besides surgery takes place between the beginning of your anesthesia and your return to consciousness in the Post Anesthesia Care Unit. Your anesthesia probably will be started with an "induction agent"; a common one with which you may be familiar is sodium thiopental (Pentothal). You may have heard that this induction agent is used as a "truth serum"; that is a myth. The real truth is that thiopental is used basically during the first step (induction) of your anesthesia when you "drift off to sleep" and lasts only a few minutes.
In order to keep you anesthetized, your anesthesiologist administers and regulates additional and more potent medications that are necessary to maintain your anesthesia for the rest of the procedure. Some of these medications are injected into your veins and others, such as nitrous oxide, are inhaled through your lungs because they are gases. Inhaled gases are administered to patients who receive general anesthesia with "oxygen" being the most important gas. These gases are administered either through a mask or a special breathing tube which is inserted into your windpipe (trachea) depending upon your surgical procedure and physical condition.
Middle Phase Exactly which medications will be administered to you during anesthesia will be determined by your physical responses and how they will be affected by the type of surgery you are having and by your medical status. Therefore, your anesthesiologist will carefully tailor your anesthetic just for you. Some of these medications will be the actual anesthetic agents that help you to remain unconsciousness and experience no sensations, while others are administered to regulate your vital functions such as heart rate and rhythm, blood pressure, breathing, and brain and kidney functions.
Your anesthesiologist constantly is monitoring, evaluating and regulating your critical body processes because they can change significantly during the operation due to the stress and reflexes from surgery itself, the effects of the anesthetic medications and your medical condition. For example, in most operations specialized equipment is used to actually control the patient's every breath. (This is because certain medications temporarily decrease breathing capability, which is further reduced by necessary muscle relaxants.)
Your anesthesiologist also is responsible for and will treat any medical problem which you may develop during surgery such as a blood pressure problem. However, your anesthesiologist wants to help prevent any medical problems by using and interpreting today's sophisticated monitoring equipment and knowing when and how to treat your body's responses to surgery.
Recovery Phase When surgery is completed, the recovery phase is carefully timed and controlled. Anesthetic agents are discontinued and new medications may be given to reverse the effects of those administered previously. Body temperature, breathing, blood pressure, and other functions begin to normalize. Before your total recovery, you may receive some medications to decrease postoperative discomfort. All of this is calculated precisely under the supervision of your anesthesiologist to permit you to return to consciousness in the recovery room unaware of what has occurred during the operation.
Because anesthesia and surgery affect your entire system it is important for your anesthesiologist to know as much about you as possible.
You already realize that your anesthesiologist is responsible for your anesthesia to make you comfortable, but in addition, he or she is also responsible for your medical care during the entire course of surgery. Therefore, it is important to know exactly what medical problems you have and any medications you have been taking recently since they may affect your response to the anesthesia. You also should inform your anesthesiologist about your allergies, any hard drug or alcohol usage, and past anesthetic experiences.
Your anesthesiologist must be very familiar with your medical condition so that the best anesthetic and medical care may be provided throughout your operation. This important knowledge will allow your anesthesiologist, as a doctor, to continue your current medical management into surgery which will help prevent complications, and expedite diagnosis and treatment of any medical problems should they occur. Your continued medical management during surgery is necessary to help facilitate your speedy recovery.
Cigarettes and alcohol affect your body just as strongly and sometimes more than any of the medically prescribed drugs you may be taking. Because of their various effects on your lungs, heart, liver and blood, to name a few, cigarette or alcohol consumption can change the way an anesthetic drug will work during surgery, so it is crucial to let your anesthesiologist know about your consumption of these substances. This is also true, especially true, for so-called "street drugs"-marijuana, cocaine, amphetamines and the rest. People are sometimes reluctant to discuss these things, but it is worth remembering that such discussions are entirely confidential between you and your doctor. Your anesthesiologist's only interest in these subjects is in learning enough about your physical condition to provide you with the safest anesthesia possible. So, in this case honesty is definitely the best policy, and the safest one.
All operations and all anesthesia have some small risks, and they are dependent upon many factors including the type of surgery and the medical condition of the patient. Fortunately, adverse events are very rare. Your anesthesiologist takes precautions to prevent an accident from occurring just as you do when driving a car or crossing the street.
The specific risks of anesthesia vary with the particular procedure and the condition of the patient. You should ask your anesthesiologist about any risks that may be associated with your anesthesia.
To help anesthesiologists to provide the best and safest patient care possible, national standards have been developed by the American Society of Anesthesiologists to enhance the safety and quality of anesthesia. Specific standards already have been developed regarding patient care before surgery, basic methods of monitoring patients during surgery, patient care during recovery, and for conduction anesthesia in obstetrics. New standards continue to be developed to further ensure patient safety. These standards, along with today's sophisticated monitoring and anesthesia equipment as well as improved medications and techniques, have contributed enormously toward making anesthesia safer than ever before.
Frequently, people requiring surgery may also have some underlying condition such as diabetes, asthma, heart problems, arthritis or others. Having taken your medical history prior to the operation, your anesthesiologist has been alerted and will be well prepared to treat such conditions during surgery and immediately after. As doctors, anesthesiologists are uniquely suited to treat not only sudden medical problems related to surgery itself, but also the chronic conditions that may need attention during the procedure, because their medical training involves a firm grounding in the principles of internal medicine and critical care.
For most procedures it is necessary for you to have an empty stomach so that the chances of regurgitating any undigested food or liquids is greatly reduced. Some anesthetics suspend your normal reflexes so that your body's automatic defenses may not be working. For example, your lungs normally are protected from objects, such as undigested food, from entering them. However, this natural protection does not occur while you are anesthetized. So for your safety you may be told to fast (no food or liquids) before surgery. Your doctor will tell you specifically whether you can or cannot eat and drink and for how long. In addition, the anesthesiologist may instruct you to take certain medications with a little water during your fasting time. For your own safety, it is very important that you follow these instructions carefully about fasting and medications; if not it may be necessary to postpone surgery.