Anesthesia

Dr. Malarvizhi is conferred “Best Doctor” award by Tamil Nadu Dr. MGR Medical University, Chennai on November 24, 2012.

Anesthesiologists – who are they and what do they do?

Before your operation you will meet an importanat specialist physician. This doctor has the critical responsibility for your welfare when you undergo surgery — your anesthesiologist. A vital member of the surgical team, the anesthesiologist is responsible for keeping you safe and comfortable during and after your operation.

Anesthesiologists are doctors who after completion of medical school do about 5 years of training in anesthesia. During their training, anesthesiologists are extensively trained in human physiology (how the body works), particularly the brain, heart, lungs, kidneys and liver. They become experts on the drugs that are used in anesthesia and intensive care medicine. Anesthesiologists give more intravenous drugs than all other types of physicians combined. Anesthesiologists are the only physicians with expert knowledge of the extremely potent drugs used to anesthetize people.

Anesthesiologists become familiar with all the different medical conditions and their implications for patients undergoing a wide variety of surgical procedures. They gain experience in the provision of anesthesia for all surgical procedures, on patients of all ages and in any state of health. By the end of their training they are perioperative physians and have become experts on anesthesia, resuscitation, critical care, and pain management. Perioperative medicine is the term used to describe your medical care before, during and shortly after your operation (as opposed to your surgical care, which is provided by your surgeon). It includes the preoperative assessment of your medical status, the provision of anesthesia, and the supervision of your recovery until you are transferred from the post anesthesia care unit.

Why is preoperative assessment by an anesthesiologist necessary?

Many factors influence the effect of the drugs used to provide anesthesia. Age, weight, pregnancy, race, alcohol, tobacco, prescription medication, street drugs, kidney and liver disease are just a few of these factors. In some conditions, certain anesthetic drugs should not be given at all.

Many medical conditions increase the risk of anesthesia. Heart disease is a common example.. Anesthesia and surgery may affect all the major systems of your body, and your anesthesiologist must know about any medical problems that you may have, so that anesthesia may be provided in the most appropriate way to maximize your safety and comfort.

The Pre-Anesthetic Assessment Clinic: Nowadays most patients come to the hospital on the day of their operation, and are seen by the anesthesiologist in the pre-anesthetic assessment clinic. They will review your medical history, examine you, and order any necessary laboratory tests He or she will make sure that any medical conditions, which might complicate your anesthetic, are being treated as well as possible. The different types of anesthesia appropriate for you will be explained, and any questions you have answered. You will be told which of your regular medications, if any, you should take on the day of surgery. Occasionally, the anesthesiologist will request an opinion from another specialist, such as a cardiologist, to help in your assessment. Very rarely, your operation may be postponed or cancelled because of the risks involved.

Sometimes, if you are physically fit and are having straightforward surgery, there will be no pre-arranged visit to the clinic. You will receive your pre-anesthetic assessment on the day of surgery. Occasionally patients are admitted to hospital one or more days before surgery and they are assessed in the hospital.

Will the pills I take interfere with the anesthetic drugs?

Any drugs you take, including those used for recreation, should be known by your anesthesiologist prior to your procedure, for interactions are always possible. However, modern anesthetic techniques allow you to continue to take your scheduled medications even prior to the operation, unless you are specifically advised not to do so. Please check with your hospital if in doubt.

Anesthesia – General, Regional or Local?

General anesthesia: General anesthesia may seem like being asleep but it’s quite different. During general anesthesia, your anesthesiologist keeps you in a state of carefully controlled unconsciousness, with a mixture of very potent drugs, so that the operation is painless. Many people think that this involves the injection of just one drug. Actually, most general anesthetics require the administration of somewhere between three and fifteen different drugs, depending on the complexity of the case. All intravenous drugs and anesthetic gases are administered in appropriate amounts so that the patient is completely unconscious during the surgery, but awake and pain free at the end.

Regional anesthesia: Regional anesthesia involves injecting local anesthetics through a needle, which the anesthesiologist places close to the nerve or nerves supplying the region of the body involved in the operation. The skin and tissues that the needle goes through are also numbed with local anesthetic so that there is minimal discomfort associated with placement of the needle. Local anesthetic drugs stop nerves from working temporarily, so that no sensation and/or movement in the area of the body supplied by the nerve(s) occurs. This type of anesthesia is also called a nerve block.

The most common type of regional anesthesia is spinal anesthesia. This can be used to anesthetize the abdomen and legs. Many other ‘regions’ of the body, such as an arm, can be safely and comfortably anesthetized. The effect of different local anesthetics lasts for different times, so the length of the anesthetic can be tailored to your operation. You may remain completely awake if you wish, but usually your anesthesiologist will administer a drug to make you relaxed and drowsy. At the end of the operation patients are transferred to the post anesthetic care unit awake, relaxed and pain free. They are usually very pleased with this type of anesthetic.

Local anesthesia: Local anesthesia refers to temporarily numbing a small area by injecting local anesthetic into the skin so that minor procedures like stitching cuts can be done painlessly.

The Post Anesthesia Care Unit (PACU)

This is where you go at the end of the operation to recover from the immediate effects of anesthesia and surgery. Nurses with special expertise will look after you. The anesthesiologist will supervise your medical care until you are stable enough to transfer out of this unit, either to go home after day surgery or to the ward if you are an inpatient. Your surgeon will also follow your progress in the PACU, and will be called to see you have any surgical problems.

Acute pain management: This is the treatment of pain that occurs temporarily after surgery or some other type of trauma. Anesthesiologists have developed its treatment to the point where it is possible to avoid severe pain in most circumstances, particularly after surgery.
The use of epidural analgesia, first developed for labor pain, has now been extended to a wide range of surgical procedures, such as major leg, abdominal and chest surgery. An ‘epidural’ allows patients to remain comfortable after these types of operations. A small amount of medication is continuously infused through the epidural catheter and numbs the painful area. Only several years ago, patients undergoing these operations would have been in extreme pain for several days after surgery. They would have required large amounts of narcotic drugs, such as morphine. These drugs made the patients sleepy, disorientated, and often extremely nauseated. It is impressive to see them now – alert, orientated, comfortable, and nausea free. They are able to get up sooner and this speeds recovery and reduces complications. Epidural analgesia is a major advance of modern medicine.

For patients whose pain control does not require epidural analgesia, a range of treatment is available. These treatments use combinations of non-narcotic drugs and/or nerve blocks to minimize the amount of narcotic medication needed to keep patients comfortable. Special pumps allow patients to control the amount of narcotic medication they get, according to how much pain they have.

Why can’t I eat or drink before surgery?

Inhaling vomited stomach contents into your lungs is called “aspiration”, and can be dangerous. Fortunately your body has an effective mechanism to stop this from happening. Unfortunately when you are unconscious this mechanism does not work, so it’s best that your stomach is empty when you have a general anesthetic. In emergency surgery when you may have eaten recently your anesthesiologist will take special precautions to reduce the risk of aspiration. Even if you are booked to have a regional anesthetic, it is important to follow the instructions about not eating and drinking, just in case it becomes necessary for you to have a general anesthetic.

What is an ‘epidural’?

The epidural space lies just outside the special covering or dura, which encloses the spinal canal. An ‘epidural’ is a type of regional anesthetic in which a needle is positioned between the bones of the spine to allow the anesthesiologist to insert a small plastic tube (or catheter) into the epidural space. The needle is then removed and local anesthetic is injected through the catheter. This local anesthetic moves (or diffuses) across the dura. into the spinal canal, and temporarily stops the spinal nerves from working, so that sensation and movement in the area supplied by the nerves does not occur. When the effect of the local anesthetic wears off, sensation and movement will return. If a weaker solution of local anesthetic is used, then only painful sensations will be blocked. This is very useful for controlling pain and is called epidural analgesia. Often continuous infusions of local anesthetic solutions are used, which allows the effect to be maintained as long as required. The catheter may be placed in the upper back (thoracic spine) or the lower back (lumbar spine), depending on where the effect is needed. This is a very useful and safe procedure, when performed with appropriate care by an experienced anesthesiologist.