Saturday, 23 July 2011

Making Anesthesia Safe

Published in "Panorama"

Anesthesia is safe

Death as a direct result of anesthesia may occur in about 2 or 3 out of every million cases. In fact, a person is more likely to incur death or injury at home, performing normal daily activities, than from anesthesia, say Drs.Tim Cooper, Chief of Anesthesia, American Hospital, Dubai and John George Emmatty, Al Rafa Poly Clinic, Dubai.

Modern medication, techniques of anesthesia, as well as approach to anesthesia and consequent surgery have enhanced the procedures, making them highly safe and effective. Even in emergencies, every patient is evaluated by an anesthesiologist before surgery, concur, the doctors. Dr.Cooper reveals, “Here, particularly in American Hospital, we have a clinic that runs every afternoon where we see all the patients prior to their surgery. We always try to get the maximum information from them, review their medical records and medical history to ascertain if they are under medication for problems like diabetes, hypertension, and so on. Following this evaluation of the patient we make a note of these factors and discuss the anesthetic procedure with them in terms of the medication we’d use, the possible effects from it, et al.”

Preparing the patient for anesthesia and surgery is as important as the procedures themselves. Unlike in earlier times when patients undergoing surgery were required to fast from the evening of the day prior to surgery, present day treatment requires patients to fast 6 hours for solid foods and 2-3 hours for clear liquids like water or apple juice, prior to administering of anesthesia. “We follow the guidelines for fasting as laid down by the American Society of Anesthesiologists,” says Dr.Cooper.

“Fasting is a must because there is always a small risk of stomach contents injuring the lungs when a patient receives anesthesia or sedation. The possibility that a patient will vomit during the anesthetic is increased if there is food in the stomach. Vomiting during anesthesia is dangerous because the stomach contents spill into the respiratory tract, leading the patient to choke on it. In case of elective surgery, if the patients have not adhered to this measure, we postpone the operation,” explains Dr. Emmatty. Dr.Cooper adds, “In emergencies where it is possible that the patient is brought in with a full stomach, we take special precautions to prevent stomach contents spilling into the lungs, to make sure the patient doesn’t suffer complication of vomiting.”

How is anesthesia administered and what is the basis on which the selection of mode is made? “There are different ways of administering anesthesia,” explains Dr.Cooper. “Decision on the mode is made through a process of evaluation of different factors including the patient’s medical profile, his age, the type of surgery to be performed, the kind of facilities and infrastructure available in the hospital. We make sure that everything works together, to give the finest result to the patient. In anesthesia, the sensitivity of the patient to the medication, goes up with increasing age and consequently the dose that you need to give to the patient, goes down with increasing age.”

Does the patient’s gender influence choice or dose of anesthetic? “Generally speaking,” says Dr.Cooper, “the sensitivity of the medication is not much greater among women than men. The commonest and the most difficult problem that we face is the one with nausea after anesthesia because this has a definite sex bias, being commoner in women, especially with gynaecological surgeries.”

However, Dr.Cooper points to an interesting cultural difference in the area of anesthetics. “In my practice, I usually find that Western patients require a higher dose of anesthetics than some of the Eastern patients who haven’t been exposed to medication and I find the Eastern patients are much more tolerant of pain. It is incredible how different nationalities tolerate the anesthetic process differently!”

What then are the modes of administering anesthesia? Three kinds of anesthesia may be used depending primarily upon the nature of surgery to be performed. Local anesthesia is a process whereby the local anesthetic is infiltrated into the tissue about the surgery, explains Dr.Cooper. And it is often used for minor surgery that do not last beyond 45 minutes and is simple in nature. Surgery to remove corn, nail excisions, small tumours or cysts all under this category, says Dr.Emmatty.

“In Regional Anesthesia,” says Dr.Cooper, “the object is to inject the local anesthesia around the nerves that go to the surgical area so that no pain gets transmitted to the brain. Regional anesthesia may be either spinal or epidural, depending upon the place where the anesthetic medicine is injected. However, an epidural may be often the preferred mode since its effect may be made longer lasting, for days. That is, it can maintain the pain-free state in the patient for days unlike a spinal anesthesia where we can’t get more than 2 hours of pain-free state, normally.”

Regional anesthesia is often used for surgery on the arms, legs, lower abdomen and lower extremities and during childbirth, adds Dr. Emmatty. The patient may choose to remain awake or sleep lightly with the help of sedatives administered through an IV catheter.

Is a regional anesthetic painful when administered? Regional anesthetics are given by placing the medicine in specific locations near nerves through a needle. An experienced and skilled anesthesiologlist performs the process and will often administer a sedative and an analgesic to relax the patient and reduce the pain.

Dr.Cooper points to an interesting fact pertaining to the UAE. “We find a perceptible change in the Anesthesia procedure in the area of Obstetrics. Epidurals are on the increase all the time in this part of the world. While in Saudi Arabia, nearly all the Caesarian section are done with general anesthesia, we perform 90% of our Caesarian with an epidural or spinal anesthetic. The reason we do it is because, we believe, as statistics show, that it is safer for the mother and the baby. The mother can breastfeed the baby, father can be present right away and the amount of pain killers is much less.”

General Anesthesia involves making the patient unconscious for the duration of the surgery and is most often used for more extensive surgery, such as heart, brain or chest surgery. “The idea is to relax his muscles and paralyse his respiratory muscles and have the artificial respirator breathe for him. If you knock the patient out with the anesthesia but do not knock out the respiration, he might come back to normal any time, should there be an under-dose of the anesthetic. Once the surgery is completed, we antidote the anesthetic medication and remove him off the respirator, allowing him to resume normal breathing,” says Dr. Emmatty.

“However,” explains Dr.Cooper, “the possibility of over-dose or under-dose is extremely rare with the kind of modern monitoring equipments that most hospitals have in dealing with these situations. Also, whether a person’s breathing is deliberately stopped, depends to a large extent on the surgery being undertaken. It is not necessary for every anesthetic that the patient be put on a respirator. Patients are allowed to breathe on their own since they have the monitoring equipment which constantly indicates whether they’re breathing well, if their system is sufficiently oxygenated and whether the carbon dioxide level is okay, if the vital signs – pulse, blood pressure and heart rate are fine.”

What are the possible side effects of anesthesia? Very rarely, patients may have allergies to the local anesthetic, says Dr.Cooper. “Also, very rarely, you can give too much of the medication so that it gets absorbed into the system, making the patient a bit drowsy.” The most common side effects are sore throat, nausea and headache, says Dr.Emmatty. Children may feel temporarily disoriented when they wake up. With spinal and epidural anesthetics, passing of urine may be temporarily difficult. Nausea and vomiting may be other side effects but these are becoming more and more rare with modern anesthetics.

What are the possible complications from any form of anesthesia procedure? Dr.Cooper emphasizes, “Every type of anesthesia has a list of complications that goes along with it.
Complications of either epidural or spinal anesthesia are quite rare. It may be safer because the patient remains conscious and is better able to protect the windpipe from aspiration if vomiting occurs. However, in very rare instances, there is a possibility of reaction to the local anesthetic, injection of medicine into a blood vessel, causing loss of consciousness, drop in blood pressure, etc.”

Dr.Cooper continues, “Having said that, close monitoring of our patients during surgery allows us to tailor each patient's anesthetic to fit his needs as best we can, so complications are very, very rare. The complications basically relate to the type of anesthesia used. If you look at General Anesthesia where the patient goes off to sleep, 70% of the complications are related to the airway – either the ability of the patient to breathe for himself or not getting adequate oxygen or not clearing the carbon dioxide from the system. But all these problems can be dealt with because of the monitoring equipments which signal any problem, should it arise.”

Explaining the choice of anesthesia, Dr.Cooper adds, “There is no doubt that for certain operations, example, big abdominal ones, an epidural will make the patient’s early recovery from surgery much easier, faster because the patient wont have to receive a lot of narcotics or other medication for pain. 70% of the complications from General Anesthesia are related to the airway and so if you do not use general anesthesia, you’re removing a high number of chance of complication. So an epidural or spinal anesthesia is very good for certain procedures because the airway is maintained by the patient. Ideally, a leg or hip operation for very heavy patients, asthmatics, if done with regional anesthetics, would not interfere with their breathing.”

Are there conditions where risk from epidural may be greater than any other form of anesthesia? “Yes”, confesses Dr. Cooper. “There are certain reasons why we cannot do an epidural on some patients and general anesthesia may be preferred. These include:
1. a person who is in a state of shock.
2. a patient who has an infection, either in the back or a systemic infection around the body.
3. any patient who has a problem with blood clotting.
4. patients with neurological disorders, like multiple sclerosis.
5. patients who refuse an epidural.

To do an epidural or spinal, says Dr.Cooper is a very technical procedure and it requires the medication to be placed very precisely in the right place in the right dose. And some patients can be more difficult than others to place these.

“Test” doses for epidurals are given by some anesthesiologists. Why is this done and does it minimize the complications from regional anesthesia? The practice remains a controversial one, says Dr.Cooper. “A “test” dose is only for epidurals and it involves giving a very small dose of the local anesthetic, usually with adrenaline. The patient’s heart rate is observed. The administration should be always with a very small dose and observing the patient before giving a larger dose.”

Is it true that anesthetics bring on liver problems? Dr.Cooper is assuring, “In modern anesthe3tics, liver problems as a result of the anesthetic drug is extremely rare and also extremely difficult to diagnose. There was a time when Halothane was used, and is still used around the world in different countries, which can potentially be toxic to the liver. Here, at the American Hospital, we no longer use Halothane. So modern general anesthetics do very little harm to the liver. However, if you have pre-existing liver disease, then you have to be very careful with all anesthetics because the drugs take far longer to clear from the liver.”


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