Response to Questions-10/31/06
I'm a bit new to the workings of the blog site, so I apologize for missing your questions in response to my first posting. Let me make up for that by answering each of the questions.
1. When you mentioned taking care of seven patients over the weekend, I wondered what is the largest amount of patients an anesthesiologist can handle in one day?
The number of patients that I care for in any given day depends on the length of the surgeries and the help that I have. Let me explain. Anesthesiologists often work as the director of an "anesthesia team". The anesthesiologist (who is a physician, a doctor) may supervise residents (physicians who are learning to be anesthesiologists), nurse anesthetists (nurses trained to perform anesthesia), and anesthesiologist assistants (a physician assistant trained to perform anesthesia). We are permitted to supervise up to 4 anesthetists or 2 residents at one time, but this depends on the complexity of the surgery and the medical condition of the patient. Sometimes the operation is so difficult and the patient is extremely ill. In this situation, I would work together with a resident or an anesthetist on only the one patient. When caring for healthy patients having relatively basic surgical procedures, I may be responsible for 4 patients having surgery at the same time (in 4 different operating rooms). When this is the case, I am constantly available to help if there is an unexpected problem and am always present for the most difficult parts of the anesthesia.
Some operations, like brain surgery or a liver transplant, are very complex and may take 10 to 18 hours to complete. Others can last only 10 or 15 minutes.
Therefore, on some days, I may care for only 1 patient, while on others, there may be many.
2. What other techniques are involved in anesthesiology, because you mentioned anesthesiologists use medications and other techniques?
When most people think of anesthesia, they only think about "going to sleep" for the surgery. This is called general anesthesia. But, there are other possible kinds of anesthesia that can be used for some procedures. Many women have epidural anesthesia when they deliver their baby. This anesthetic technique numbs the lower portion of the body so that the women does not have pain during childbirth, and this allows the mother to be awake to experience the delivery. Local anesthesia may be used for small procedures such as sewing up a cut or taking out a small tumor in the skin. With this form of anesthesia, a local anesthetic, a drug that blocks the pain sensation from traveling through nerves, is injected into the skin around the incision or cut. In the area where the local anesthetic was injected, there is no pain when the area is cut or sewed up. During this kind of anesthesia, the patient can be awake or may be sedated (made sleepy) by giving other medications. Another form of pain relief for surgery is a regional anesthetic. With this, a local anesthetic is injected with a needle near a nerve. The local anesthetic blocks the nerve from working and the area of the body supplied by the nerve feels no pain. This technique can be used for surgery on an arm or leg. Again, the patient may be awake during the surgery or could choose to receive sedation.
One of the benefits of the techniques that use local anesthesia is that there is relief of pain for several hours after surgery. There are many different local anesthetic drugs that can be used and some can relieve pain for up to 12 hours after surgery.
3. Why is it that the anesthesia does not shut down the whole body since it is injected into the blood stream?
First, I must tell you that we don't completely understand how general anesthetic drugs produce their effect, that is, anesthesia. There are many types of drugs that can produce general anesthesia. Some are liquids that are injected into the bloodstream while others are gases that are breathed into the lungs and enter the bloodstream through the air in the lungs. Because there are many different kinds of drugs that produce anesthesia, scientists are trying to find a unifying mechanism that is similar with all of these drugs.
One important concept with all drugs or medications is that they all have many effects on the body. Some of these are the desired effects (general anesthesia in this case) while some are "side effects" that may be hazardous. In developing anesthetic drugs, scientists find chemical substances that produce the desired effect (anesthesia) and have little risk for unwanted or dangerous effects. General anesthetics produce "sleep" by working mainly on the cells of the brain (neurons) and spinal cord. When the anesthetic drug combines with special parts of the neurons (receptors), the brain and spinal cord neurons temporarily stop working and the result is general anesthesia. When the anesthetic drug is allowed to go away ( be removed or inactivated by the body), the neurons begin to function normally again and the patient wakes up.
4. You mentioned using anesthesia to keep people from feeling pain. How do you know the right dosage?
Since all people are different (age, sizes, weight, general health), each patient will require a different amount of anesthesia. There are some rough guidelines for dosage, but that is only a starting point. Many people don't realize that general anesthetic drugs are continuously administered during surgery to keep the patient asleep. The drugs only work for a short time, so that if we didn't keep giving them, the patient would quickly wake up. (That's the secret as to how we can wake the patient up at the end of sugery, that is, we turn off, stop administering, the anesthetic drug.)
As anesthesiologists, we have a three year residency training program, and it is during that time that we learn to give the right amount of anesthetic drug to each patient. Someone from the anesthesia care team (see above) is always with the patient during anesthesia and surgery, and he/she is continuously giving the anesthetic drug. When we see that the patient needs more, we can give a larger dose. It is a process of "titration" or finding the right amount based on the individual patient's need at the time.
5. What is the longest time anybody has ever been under anesthesia, and what is the longest suggested amount of time they could safely be under?
The longest anesthetic and surgical procedure that I have participated in was 24 hours. One of the main problems with these extremely long surgeries is not from the anesthesia but relates to the patient being immobile (lying still) for such a long time. General anesthesia is not the same as being asleep. When you sleep at night, every few minutes you move and change position. Under general anesthesia, when the patient is completely still, there is a constant pressure on the skin and muscles that are being pushed against the bed. Over a long period of time, the pressure prevents blood from easily flowing into the areas with pressure on them, and the cells may begin to die. We try to prevent the pressure injuries by placing soft padding on these at risk areas.
Anesthesia has been continuously administered to patients for several days, not for surgery, but to treat some specific medical problems. Unfortunately, I could not find any information regarding a record for the longest anesthetic.
Till next time,
Dr Berry