Nerve Blocks, Miracle in Pain Relief

Nerve blocks are used in the diagnosis and treatment of some painful conditions, and to provide pain relief during many conditions.

What drugs are used?
The most common drugs are local anaesthetic agents, which block all types of nerve conduction. They prevent pain and may also prevent movement in the area until the block wears off.
A variety of local anaesthetic drugs is available:
Bupivacaine ("Marcaine", "Sensorcaine") is a common longer-acting anaesthetic, widely used for epidurals, spinals and other blocks;
Cocaine is still used as a local anaesthetic in special cases;
Lidocaine (also called "Xylocaine","Lignocaine") is the most common of the short-acting local anaesthetics, and is used in many procedures;
Mepivacaine is similar to Lidocaine.
Ropivacaine is a new longer-acting agent which appears to be safer than Bupivacaine; and
Tetracaine is used mainly for spinals.
Other drugs may be added to the local anaesthetic, including epinephrine (adrenaline), to decrease bleeding, and sodium bicarbonate, to decrease the acidity of the drug, in an attempt to make it work faster.
For spinals and epidurals, narcotic painkillers such as morphine and fentanyl can be used, usually in addition to a local anaesthetic.
Will it hurt?
Most local and regional anaesthetic techniques involve using a syringe and needle to inject drugs in the correct place. Unfortunately, this can often be uncomfortable, and the local anaesthetic may sting during injection. Most patients consider this discomfort a small price to pay for pain relief during and after surgery.
During the operation, patients may still be able to feel touch and pressure. Occasionally (e.g. during delivery of a baby by Caesarean Section), patients may feel tugging. But patients should not feel pain during the operation.
Will it work?
When the right amount of the right drug is injected in the right place, it will eventually work and provide good pain relief. The problem areas are usually putting the drug in the right place and waiting long enough for it to work. In some cases, the correct spot is easy to identify (e.g. spinal anaesthesia) while, in other cases (e.g. epidural, sciatic nerve block), it is harder to find the correct spot. Most blocks take 5-20 minutes to work.
Commonly used blocks are usually 90-99% likely to work, depending on the type of block and the skill of the anaesthetist.
What are the potential side effects and/or complications?
In general, local or regional anaesthesia is very safe, and usually safer than a general anaesthetic. However, the potential for side effects or complications exists with any form of anaesthesia.
The most common side effect of a block is a temporary weakness or paralysis of the affected area. This is often useful to the surgeon, and wears off after a while.
The complications that may arise depend on the specific block. They usually occur when the local anaesthetic is injected in the wrong place. If a large volume (10-20 mls.) of local anaesthetic is injected into a vein by mistake, it may cause convulsions and even cardiac arrest. This is why physicians always inject local slowly; sucking back on the syringe to check the local is not going into a vein. Major nerve blocks are safe when performed by physicians trained in the technique, and in resuscitation, in an area equipped with oxygen, suction, drugs, and other essential equipment.
Why choose a local or regional anaesthetic?
Surveys indicate that anaesthetists would often choose local anaesthesia if they required surgery themselves, for the following reasons:
local anaesthesia avoids some of the risks and unpleasantness, such as nausea and vomiting, which sometimes occurs with general anaesthesia;
local anaesthesia often lasts longer than the surgery, providing pain relief for several hours after the operation;
local anaesthesia may reduce blood loss; and
some patients feel more "in control" when they are awake during surgery.

BLOCKS FOR VARIOUS PARTS OF THE BODY
Local infiltration for cuts and small procedures
For small cuts and the removal of small skin lesions, local anaesthetic is injected around the site. This may require several injections, but it is usually simple, safe and effective.
Blocks for eye surgery
The idea of having an eye operation while awake seems unpleasant to many patients. However, it is actually one of the best and most successful types of local anaesthesia. With the latest advances in cataract surgery, the operation is being done with smaller incisions, requiring less anaesthetic. For some operations, only eye drops are required. Other procedures require local anaesthetic to be injected around or behind the eye.
Very rare complications include: injecting into the fluid surrounding the brain, causing seizures; puncturing the eye; or a blood clot forming behind the eye, which may delay surgery.
Blocks for hand and arm surgery
Various types of block can be used:
Local infiltration. Injection of local anaesthesia around a cut or for a small operation works well and is very safe.
Blocks of individual fingers, or of nerves at the wrist are also safe and reliablle.
Intravenous Regional Blocks. A tourniquet is put around the upper arm. Local anaesthetic is put into a vein in the hand to numb the arm. This works well, but after about 40 minutes to an hour, the tourniquet becomes painful. Sometimes a second, lower tourniquet solves this problem. The anaesthetist has to be careful to ensure that the tourniquet remains inflated until the local anaesthetic is absorbed into the tissue.
Axillary block. This involves blocking the major nerves as they enter the arm, usually by placing a needle in the arm pit. A small electrical shock may be used to help find the right position to inject the local anaesthetic.
Spinal and epidural anaesthesia
Spinal anaesthesia involves putting local anaesthetic in the patient's back to "freeze" the lower part of the body. It is usually very safe and effective. It may be associated with less blood loss, and less risk of dangerous blood clots, than general anaesthesia.
Spinal anaesthesia is suitable for many procedures in the lower half of the body. Common uses for spinal anaesthesia include:
Caesarean section
hernia repair
hip and knee surgery
transurethral resection of prostate (TURP)
most procedures on the foot or leg
In general, spinal anaesthesia provides excellent pain relief during all these procedures. Patients may feel some stretching or tugging during delivery of the baby by Caesarean section, or during handling of the bowels in a hernia repair. Major orthopaedic surgery may include cutting bone and hammering to insert artificial joints, and some patients dislike the noise and/or vibration this causes. Spinal anaesthesia is especially useful during TURP surgery, as it allows the patient to detect side effects of the washing solution used in the bladder (it makes their vision fade temporarily) and it encourages clotting in the cut blood vessels.
Technically, there are two types of "spinal" anaesthesia: true spinal, or "intrathecal" anaesthesia, and epidural or extradural anaesthesia.
The first technique involves injecting local anaesthetic into the CSF, the fluid which surrounds the spinal cord. This produces a very intense nerve block very quickly, with only a small amount (half teaspoon) of local anaesthetic. The major disadvantage of a spinal anaesthetic is a drop in blood pressure, caused by temporary blockage of the nerves that control blood flow into the legs, so that blood collects in them. This can be treated with intravenous liquids and drugs, if necessary.
Headaches after spinal anaesthesia used to be a major problem. Now, with the use of very small specially-designed needles, headaches are very rare. If they occur, they can be treated with rest, adequate liquids to drink, simple pain-killers such as Paracetamol or Tylenol, and if necessary by an procedure called an "epidural blood patch".
Epidural or extradural anaesthesia uses a larger volume of anaesthetic, positioned in the fat and veins further away from the spinal cord. This block takes effect more slowly, which can be an advantage in some cases. For example, an epidural is less likely to produce a severe drop in blood pressure than a true spinal block. The other major advantage is that a small tube or catheter can be placed in the epidural space to allow the block to be continued over a period of hours or days, while a true spinal block only lasts a few hours.
The major disadvantage of epiduralanalgesia is that larger amounts of local anaesthetic are used (about 20 mls.) which can cause serious complications if they are put in the wrong place. In a vein, the local anaesthetic may cause convulsions or cardiac arrest. In the CSF, it may spread too high, which may stop the patient breathing. Fortunately, all of these complications can usually be treated by an anaesthetist, without long-lasting problems.
Pain relief in labour
If relaxation and breathing exercises prove ineffective, nitrous oxide ("laughing gas") or narcotics (demerol, pethidine, morphine) may help. However, epidural analgesia is the most effective form of pain relief in labour, and it can even be extended for use in forceps delivery or Caesarean section.
A small, sterile plastic tube is placed in the patient's back by an anaesthetist. Local anaesthesia is inserted, providing pain relief. Sometimes narcotic pain killers are added for increased effect. Pumps can be used to keep the epidural "topped up".
Side effects may include temporary weakness in the legs, difficulty passing urine, and/or a decrease in blood pressure.
Rare complications may include headache, decreased breathing, and/or seizures. Cases of paralysis may occur as a result of: injecting the wrong drug; a clot or infection in the epidural space; and/or inadequate treatment of complications, but this is an exceedingly rare complication.
Women who have epidurals in labour may be more likely to have forceps deliveries or Caesarean sections. They may also be more likely to have backache after delivery than women who did not have epidurals.
Epidural analgesia may avoid the potential complications of an emergency general anaesthetic, and is especially useful for women with high blood pressure, twins, or breech presentation.
Other types of nerve block
There is a wide variety of other nerve blocks, including blocks at the ankle, around the groin, in the buttocks, underneath ribs and in various locations on the face. Nerve blocks are also used in the diagnosis and treatment of some painful conditions, such as the use of epidural steroid injections for some types of back pain.
CONCLUSION
All medical procedures have risks and benefits. For many operations, the risk/benefit ratio for local or regional anaesthesia is better than for general anaesthesia. Patients should ask whether their operations can be done under local or regional anaesthesia, and discuss this issue with their physicians.

DISCLAIMER: This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Health Mirror, the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

In case of any queries feel free to contact Dr Anil K Dhull

How can nicotine be good for me?

By now the health hazards of smoking and tobacco use are well known. Smoking is the chief preventable cause of death in the United States and a major contributor to many types of cancer, heart disease and other serious or potentially fatal conditions. Cigarettes are also expensive, addictive and they leave a bad odor. However, medical researchers have begun to show interest in one of the most reviled components of cigarettes -- nicotine. And they're interested in this potent, powerfully addictive substance for its health benefits.
Over the past decade, new research has taught us more about how nicotine affects the brain and the body. Some of it is good news -- for example, a lower incidence of Alzheimer's disease in smokers. Research has pointed to a compound called acetylcholine as the reason. Nicotine is structurally similar to acetylcholine, a naturally-occurring compound that serves as a neurotransmitter. Nicotine binds to nerve receptors and makes nerve cells fire more frequently. In one study, a group of Alzheimer's patients were given nicotine patches, while another received a placebo. Those with nicotine patches maintained their cognitive abilities longer and sometimes even recovered lost cognitive function. A follow-up study indicated that nicotine may also boost cognitive abilities in elderly people who aren't suffering from Alzheimer's but who are experiencing the typical mental decline associated with old age.
Nicotine is the highly addictive substance found in tobacco that gives users a buzz. It may also have some health benefits.
The transformation with nicotine happened when the nicotine patch was introduced. Intended to help smokers quit, the nicotine patch also opened up a whole new way of studying the drug. Suddenly scientists had a reliable delivery system -- one without the numerous carcinogens found in cigarettes -- that could be standardized across various studies. A 1982 study revealed that patients with ulcerative colitis had fewer flare-ups when taking nicotine. However, side effects proved nicotine to be a poor long-term treatment.

In 2000, a study performed at Stanford revealed surprising results about nicotine's effects on blood vessels. Contrary to popular opinion, the study showed that nicotine actually boosts the growth of new blood vessels. The discovery may lead to new treatments for diabetes. Many people with severe diabetes experience poor circulation, which can lead to gangrene and ultimately, limb amputation.

Researchers from the Scripps Research Institute published a study in 2002 that revealed a connection between nornicotine -- a chemical found in tobacco and also created when the body breaks down nicotine -- and a reduction of Alzheimer's symptoms. However, nornicotine is toxic, pointing to the need for a nontoxic substitute.

­­In 2006, Duke scientists found that people with depression who were treated with nicotine patches reported a decrease in their depressive feelings. The results were perhaps not surprising for a drug associated with imparting a "buzz." However, the research also showed a direct link between nicotine and an increase in the release of dopamine and serotonin, two vital neurotransmitters. A lack of dopamine or serotonin is a common cause of depression.

Warning: Cigarette smoking & tobacco chewing are injurious to health.

In Case of any queries please contact Dr Anil K Dhull

How Caffeine Works

Around 90 percent of Americans consume caffeine in one form or another every single day. More than half of all American adults consume more than 300 milligrams (mg) of caffeine every day, making it America's most popular drug by far. The caffeine comes in from things like coffee, tea, cola, chocolate, etc.
Have you ever wondered what it is that makes caffeine so popular? What does this drug do that causes its use to be so widespread? In this article, you will learn all about caffeine. ­
The caffeine from your morning coffee changes your ­brain's chemistry.

What is Caffeine?
Caffeine is known medically as trimethylxanthine, and the chemical formula is C8H10N4O2. When isolated in pure form, caffeine is a white crystalline powder that tastes very bitter. The chief source of pure caffeine is the process of decaffeinating coffee and tea.
Medically, caffeine is useful as a cardiac stimulant and also as a mild diuretic (it increases urine production). Recreationally, it is used to provide a "boost of energy" or a feeling of heightened alertness. It's often used to stay awake longer -- college students and drivers use it to stay awake late into the night. Many people feel as though they "cannot function" in the morning without a cup of coffee to provide caffeine and the boost it gives them.
Caffeine is an addictive drug. Among its many actions, it operates using the same mechanisms that amphetamines, cocaine, and heroin use to stimulate the brain. On a spectrum, caffeine's effects are more mild than amphetamines, cocaine and heroin, but it is manipulating the same channels, and that is one of the things that gives caffeine its addictive qualities. If you feel like you cannot function without it and must consume it every day, then you are addicted to caffeine.

Q: How is caffeine used medically?
A: Medically, caffeine is useful as a cardiac stimulant and also as a mild diuretic (it increases urine production).

Caffeine in the Diet
Caffeine occurs naturally in many plants, including coffee beans, tea leaves and cocoa nuts. It is therefore found in a wide range of food products. Caffeine is added artificially to many others, including a variety of beverages. Here are the most common sources of caffeine for Americans:
· Typical drip-brewed coffee contains 100 mg per 6-ounce cup. If you are buying your coffee at Starbucks or a convenience store or drinking it at home or the office out of a mug or a commuter's cup, you are consuming it in 12-, 14- or 20-ounce containers. You can calculate the number of milligrams based on your normal serving size.
· Typical brewed tea contains 70 mg per 6-ounce cup.
· Typical colas (Coke, Pepsi, Mountain Dew, etc.) contain 50 mg per 12-ounce can. Things like Jolt contain 70 mg per 12-ounce can.
· Typical milk chocolate contains 6 mg per ounce.
· Anacin contains 32 mg per tablet. No-doz contains 100 mg per tablet. Vivarin and Dexatrim contain 200 mg per tablet.
By looking at these numbers and by knowing how widespread coffee, tea and cola are in our society, you can see why half of adults consume more than 300 mg of caffeine per day. Two mugs of coffee or a mug of coffee and a couple of Cokes during the day are all you need to get you there. If you sit down and calculate your caffeine consumption during a typical day, you may be surprised. Many people consume a gram or more every single day and don't even realize it.

Caffeine and Adenosine
Why do so many people consume so much caffeine? Why does caffeine wake you up? By understanding the drug's actions inside the body you can see why people use it so much.
As adenosine is created in the brain, it binds to adenosine receptors. The binding of adenosine causes drowsiness by slowing down nerve cell activity. In the brain, adenosine binding also causes blood vessels to dilate (presumably to let more oxygen in during sleep).
To a nerve cell, caffeine looks like adenosine. Caffeine therefore binds to the adenosine receptor. However, it doesn't slow down the cell's activity like adenosine would. So the cell cannot "see" adenosine anymore because caffeine is taking up all the receptors adenosine binds to. So instead of slowing down because of the adenosine level, the cells speed up. You can see that caffeine also causes the brain's blood vessels to constrict, because it blocks adenosine's ability to open them up. This effect is why some headache medicines like Anacin contain caffeine -- if you have a vascular headache, the caffeine will close down the blood vessels and relieve it.
So now you have increased neuron firing in the brain. The pituitary gland sees all of the activity and thinks some sort of emergency must be occurring, so it releases hormones that tell the adrenal glands to produce adrenaline (epinephrine). Adrenaline is the "fight or flight" hormone, and it has a number of effects on your body:
· Your pupils dilate.
· Your breathing tubes open up (this is why people suffering from severe asthma attacks are sometimes injected with epinephrine).
· Your heart beats faster.
· Blood vessels on the surface constrict to slow blood flow from cuts and also to increase blood flow to muscles. Blood pressure rises.
· Blood flow to the stomach slows.
· The liver releases sugar into the bloodstream for extra energy.
· Muscles tighten up, ready for action.
This explains why, after consuming a big cup of coffee, your hands get cold, your muscles tense up, you feel excited and you can feel your heart beat increasing.

Caffeine and Dopamine
Caffeine also increases dopamine levels in the same way that amphetamines do (heroine and cocaine also manipulate dopamine levels by slowing down the rate of dopamine re-uptake). Dopamine is a neurotransmitter that, in certain parts of the brain, activates the pleasure center. Obviously, caffeine's effect is much lower than heroin's, but it is the same mechanism. It is suspected that the dopamine connection contributes to caffeine addiction.
So you can see why your body might like caffeine in the short term, especially if you are low on sleep and need to remain active. Caffeine blocks adenosine reception so you feel alert. It injects adrenaline into the system to give you a boost. And it manipulates dopamine production to make you feel good.
The problem with caffeine is the longer-term effects, which tend to spiral. For example, once the adrenaline wears off, you face fatigue and depression. So what are you going to do? You take more caffeine to get the adrenaline going again. As you might imagine, having your body in a state of emergency all day long isn't very healthy, and it also makes you jumpy and irritable.
The most important long-term problem is the effect that caffeine has on sleep. Adenosine reception is important to sleep, and especially to deep sleep. The half-life of caffeine in your body is about 6 hours. That means that if you consume a big cup of coffee with 200 mg of caffeine in it at 3:00 PM, by 9:00 PM about 100 mg of that caffeine is still in your system. You may be able to fall asleep, but your body probably will miss out on the benefits of deep sleep. That deficit adds up fast. The next day you feel worse, so you need caffeine as soon as you get out of bed. The cycle continues day after day.
This is why 90% of Americans consume caffeine every day. Once you get in the cycle, you have to keep taking the drug. Even worse, if you try to stop taking caffeine, you get very tired and depressed and you get a terrible, splitting headache as blood vessels in the brain dilate. These negative effects force you to run back to caffeine even if you want to stop.

In Case of any queries, contact Dr Anil K Dhull

How do antibiotics work?

Antibiotics work to kill bacteria. Bacteria are single-cell organisms. If bacteria make it past our immune systems and start reproducing inside our bodies, they cause disease. We want to kill the bacteria to eliminate the disease.
An antibiotic is a selective poison. It has been chosen so that it will kill the desired bacteria, but not the cells in your body.
Certain bacteria produce chemicals that damage or disable parts of our bodies. In an ear infection, for example, bacteria have gotten into the inner ear. The body is working to fight the bacteria, but the immune system's natural processes produce inflammation. Inflammation in your ear is painful. So you take an antibiotic to kill the bacteria and eliminate the inflammation.
An antibiotic is a selective poison. It has been chosen so that it will kill the desired bacteria, but not the cells in your body. Each different type of antibiotic affects different bacteria in different ways. For example, an antibiotic might inhibit a bacterium's ability to turn glucose into energy, or its ability to construct its cell wall. When this happens, the bacterium dies instead of reproducing. At the same time, the antibiotic acts only on the bacterium's cell-wall-building mechanism, not on a normal cell's.
Antibiotics do not work on viruses because viruses are not alive. A bacterium is a living, reproducing lifeform. A virus is just a piece of DNA (or RNA). A virus injects its DNA into a living cell and has that cell reproduce more of the viral DNA. With a virus there is nothing to "kill," so antibiotics don't work on it.

DISCLAIMER: This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Health Mirror, the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

In case of any queries feel free to contact Dr Anil K Dhull

Basics of Anaesthesia

INTRODUCTION
Many patients, and even some physicians, automatically assume that surgery requires general anaesthesia, and that the patient should be asleep during surgery. This is not true. Many procedures can be performed on awake patients, using local or regional anaesthesia. This not only avoids the risks and unpleasantness sometimes associated with general anaesthesia, but may also provide specific benefits such as reduced blood loss and better postoperative analgesia.
Patients are often concerned about having surgery under a local or regional anaesthetic. These concerns are not usually justified by the facts. The more patients understand the reasons for, and the benefits of, local or regional anaesthesia, the more likely they are to choose this type of anaesthetic. Unfortunately, in these days of cost-cutting and same day surgery, patients may never get the opportunity to discuss their anaesthetic options with an anaesthetist in detail prior to surgery. In the rush to get through a busy operating list the anaesthetist may, unfortunately, decide that it is quicker and simpler just to put the patient to sleep, rather than enter into the discussion and education necessary to allow the patient to make an informed choice about the most appropriate type of anaesthesia.
Patients are becoming more involved as consumers of health care. They are actively seeking out information about treatment choices, and some are turning to the Internet as a source of medical information. This site is dedicated to patients who want to learn more about local and regional anaesthesia. However, they must understand that this article provides background information only. The final decision about the best type of anaesthetic depends on the specific operation, patient, surgeon, and anaesthetist involved.
If you are faced with the possibility of needing surgery in the future, chances are you will need some type of anaesthesia to go along with it. There are many different types of anaesthesia. Which one you will need depends on a variety of factors such as the type of surgery you are having and your state of health. Some surgical procedures require only an injection of local anaesthesia into the incision area. Other procedures cannot be performed unless you are completely anesthetized -- unconscious and unaware of pain.

The Basics
Anaesthesia is divided into four basic categories:
· general anaesthesia
· regional anaesthesia
· local anaesthesia
· sedation
Each type of anaesthesia has an effect on a part of the nervous system, which results in a depression or numbing of nerve pathways. General anaesthesia affects the brain cells, which causes you to lose consciousness. Regional anaesthesia has an effect on a large bundle of nerves to a particular area of the body, which results in losing sensation to that area without affecting your level of consciousness. Local anaesthesia causes you to lose sensation in a very specific area.
Some of the drugs that produce general anaesthesia in large doses can be used to produce sedation, or "twilight sleep" in lower doses. Sedation can be given in many ways. A common example of an anesthetic gas that is used for sedation is nitrous oxide or laughing gas.
If you are scheduled to have surgery, you may be told not to eat anything for eight hours. It is very important that you follow whatever instructions you are given for not eating or drinking anything prior to surgery. Why? Because when you are given anaesthesia, you lose the ability to protect your lungs from inhaling something you're not supposed to inhale. When you are awake, you can usually swallow saliva and food without choking because part of the swallowing mechanism involves a reflex that results in covering the opening into the lungs. When you are anesthetized, you lose that reflex. So, if you have any solids or liquids in your stomach, they could come up into your mouth and be inhaled into your lungs. The result could be very serious lung damage.
Sleep is a state of reduced consciousness, depressed metabolism, and little activity of the skeletal muscles. Strong stimuli such as loud noise, bright light or shaking can arouse the sleeper. Consciousness is being clearly aware of yourself and your environment.
Unconsciousness is when you are completely or partially unaware of yourself and your environment, or you don't respond to sensory stimuli.
Conscious sedation is caused when an anesthesiologist administers depressant drugs and/or analgesics in addition to anaesthesia during surgery. Consciousness is depressed and you may fall asleep, but are not unconscious.

General Anaesthesia
General anesthetics produce an unconscious state. In this state a person is:
· unaware of what is happening
· pain-free
· immobile
· free from any memory of the period of time during which he or she is anesthetized
It is not completely clear exactly how general anesthetics work at a cellular level, but it is speculated that general anesthetics affect the spinal cord (resulting in immobility), the brain-stem reticular activating system (resulting in unconsciousness) and the cerebral cortex (seen as changes in electrical activity on an electroencephalogram).

General anaesthesia can be administered as an inhaled gas or as an injected liquid. There are several drugs and gases that can be combined or used alone to produce general anaesthesia. The potency of a given anesthetic is measured as minimum alveolar concentration (MAC). This term describes the potency of anesthetic gases. (Aveolar is the area in the lung where gases enter and exit the bloodstream via the capillary system). Technically, MAC is the alveolar partial pressure of a gas at which 50 percent of humans will not move to a painful stimulus (e.g. skin incision). Injected liquid anesthetics have a "MAC equivalent" which is the blood concentration of the liquid anesthetic that provides the same effect. Using MAC as a guideline, the amount of anesthetic given to a patient depends on that particular patient's needs.
When anesthetics reach the bloodstream, the drugs that affect the brain pass through other blood vessels and organs so they are often affected too. Therefore, patients must be carefully monitored. The anesthesiologist continuously monitors the patient's heart rate, heart rhythm, blood pressure, respiratory rate, and oxygen saturation. Some patients may have even more extensive monitoring depending on their health and which type of procedure or surgery they are having.

Most adults are first anesthetized with liquid intravenous anesthetics followed by anesthetic gases after they are asleep. Children, however, may not like having an injection or intravenous catheter placed in them while they are awake. Therefore, they often breathe themselves to sleep with anesthetic gases given through a mask.
What is local or regional anaesthesia?
Anaesthesia means the absence of sensation. Regional anaesthesia means blocking the nerve supply to part of the body, such as an arm, so the patient cannot feel pain in that area. Local anaesthesia, strictly speaking, means putting local anaesthetic ("freezing") around the affected area to make it pain free. However, many people use the phrase loosely to include regional anaesthesia.
Local Anaesthesia
Local anaesthesia involves numbing a small area by injecting a local anesthetic under the skin just where an incision is to be made. When used alone, this type of anaesthesia has the least number of risks. Local anesthetics are thought to block nerve impulses by decreasing the permeability of nerve membranes to sodium ions. There are many different local anesthetics that differ in absorption, toxicity, and duration of action.
One of the most commonly used local anesthetics is lidocaine (Xylocaine). Lidocaine can be administered as an injection or placed topically on mucous membranes. Another topical anesthetic is cocaine. Cocaine is primarily used to anesthetize the nasal passages for surgical procedures. A topical anesthetic that is gaining popularity for anesthetizing the skin prior to painful procedures, such as injections, is known as eutectic mixture of local anesthetics (EMLA) cream which contains lidocaine and prilocaine. This white cream is placed on the skin and then covered with an occlusive dressing for approximately one hour to obtain a good numbing effect. In addition, EMLA can be used to numb the skin prior to giving injections or pulling superficial splinters.

Regional Anaesthesia
Regional anaesthesia is so named because a "region" of the body is anesthetized without making the person unconscious. One example of this is spinal anaesthesia, which is often used on women during childbirth. A local anesthetic is injected into the spinal fluid and causes a loss of sensation of the lower body. Spinal anaesthesia can be used for surgery on the legs or lower abdomen (below the bellybutton).
Epidural anaesthesia is similar to spinal anaesthesia in that a patient loses sensation in the legs and lower abdomen, but instead of injecting the local anesthetic into the spinal fluid, the anesthetic is injected into a space outside the spinal canal called the epidural space. A small tube or catheter can be placed into this space and a local anesthetic can be infused (fed) through the tube for hours, days, or even weeks. This type of anaesthesia can be used for surgery with larger doses of anesthetic, or for chronic pain relief with lower doses of anesthetic. Regional anaesthesia techniques can be used to block very specific areas such as one foot, one leg, one arm, or one side of the neck. In these cases, a smaller group of nerves is blocked by injection of the local anesthetic into a specific area. For spinals and epidurals, narcotic painkillers such as morphine and fentanyl can be used in addition to a local anesthetic.

Sedation
Some of the drugs that produce general anaesthesia in large doses can be used to produce sedation or "twilight sleep" in lower doses. Sedation can be given in many ways. A common example of an anesthetic gas that is used for sedation is nitrous oxide or laughing gas. Liquid sedating drugs are usually given by injection but some can also be given by mouth. Ketamine and Versed are examples of sedating drugs that can be given by injection or by mouth. The oral route is particularly useful for sedating children who do not like injections.
Children who refuse to drink medications may also receive sedation through the rectum via a small, lubricated tube or via the nasal route by spraying it into the nose. Regional and local anaesthesia can be combined with sedation to make patients more comfortable during a procedure in which general anaesthesia is not necessary, or when general anaesthesia may be too large a risk for the patient.

How is it used?
Local or regional anaesthesia can often be used to prevent pain during surgery. Sometimes it is used by itself, with no other medications, so that the patient remains wide awake during surgery. It can also be combined with sedative drugs to make the patient relaxed or sleepy during surgery.
Sometimes local or regional anaesthesia is used in addition to a general anaesthetic (i.e., in patients who are asleep during surgery). This is done to reduce the stress associated with surgery, to allow a lighter level of anaesthetic during surgery, and to provide pain relief after surgery.
Inhaled Anesthetics
Many adults may remember having ether for their anesthetic when they were young. Ether is an inflammable anesthetic that is no longer used in the United States. Today, the commonly used inhaled anesthetics are nitrous oxide (also known as laughing gas), sevoflurane, desflurane, isoflurane and halothane.
Why do we have so many different kinds of gases? Because each gas has its own special properties. For example, sevoflurane and halothane are easy to inhale while desflurane is very irritating to inhale and has a shorter duration of action. If you need to breathe yourself to sleep, halothane or sevoflurane would be easiest to inhale. If a very short-acting anesthetic is needed, the anesthesiologist can switch to desflurane after you fall asleep. Nitrous oxide is easy to inhale, but when used alone is not potent enough to be a complete general anesthetic. However, it can be used alone for sedation, or combined with one of the other inhaled anesthetics or injected liquid anesthetics for general anaesthesia.
These gases have different effects on other organs as well. For example, halothane may cause the heart rate to slow down and the blood pressure to decrease while desflurane may cause the heart rate to speed up and the blood pressure to increase. How do these inhaled anesthetics reach the brain? When an anesthetic gas is inhaled into the lungs, the blood that travels through the lungs carries the anesthetic gas to central nervous system cells. The rate at which the bloodstream takes up the anesthetic is dependent on many factors including the concentration of the inspired gas, the rate of flow of the gas from the anaesthesia machine, the solubility of the gas in blood, the rate and depth of breathing, and the amount of blood the heart pumps each minute in the person breathing the gas.
An important property of anesthetics is reversibility. When the surgery is over, the anesthesiologist wants to shut off the anesthetic and have the patient wake up from the anesthetic-induced sleep. Once the anesthetic gas is turned off, the blood stream brings the gas back to the lungs where it is eliminated. The more soluble the gas is in blood, the longer it takes to eliminate. Nitrous oxide and desflurane are the shortest-acting anesthetic gases because they are the least soluble in blood.

Injected Anesthetics
A liquid anesthetic drug is delivered to the brain by injecting it directly into the bloodstream, usually through an intravenous catheter. Examples of injected drugs are barbiturates, propofol, ketamine, and etomidate, as well as larger doses of narcotics (such as morphine) and benzodiazepines (Valium-like drugs). These drugs quickly reach the brain and their effect is dependent on several factors including the volume in which the drug is distributed in the body, the fat-solubility of the drug, and how quickly the body eliminates the drug.
A commonly used injected barbiturate anesthetic is sodium thiopental, also known as Pentothal. This drug is fat-soluble and acts very quickly. If you receive sodium thiopental and then you are asked to count backward from 100 after the drug is injected, you probably won't remember counting past 95. Some injected anesthetics are used in low doses for sedation. A small dose of a narcotic or a benzodiazepine like Valium or Versed can significantly decrease anxiety. These drugs are used in these doses either as a premedication prior to general anaesthesia or as "twilight sleep" or sedation when used in conjunction with local or regional anaesthesia.

DISCLAIMER: This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Health Mirror, the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.
In case of any queries please feel free to contact Dr Anil K Dhull

Amnesia

Amnesia is the loss of memory and the inability to form new memories. It can be a temporary or permanent condition. The causes of amnesia range from brain damage to severe anxiety.

Retrograde Amnesia

This type of amnesia usually follows any severe head injury that produces unconsciousness. The patient is not able to recall what happened immediately before the accident, the accident itself, or some of the events of the recovery period. In most cases, this type of amnesia is not significant because no other memory is affected and no treatment is needed.

Korsakoff Syndrome

An inability to record new memory along with a defect in recent memory, usually accompanied by confabulation (storytelling of fabricated events), is known as Korsakoff syndrome. It can be caused by head injury, stroke, encephalitis (inflammation of the lining of the brain), deficiency of vitamin B, cancer of the brain, or poor blood supply to memory tissue or pathways in the brain. However, heavy drinking of alcohol, with resultant brain damage, is commonly the cause. Although there may be little or no loss of memory or skills that were acquired before the disease began, the person with Korsakoff syndrome cannot effectively learn new skills or remember recent events. To hide this loss, from themselves as well as from others, patients may create experiences to take the place of the missing experiences. Sometimes the stories are so convincing that Kors-akoff patients appear normal. Treatment of Korsakoff syndrome is limited to treating the condition that caused it. Permanent brain damage may make it incurable. Frequently, however, the condition will disappear with time, especially if it was caused by a concussion (a swelling in the head that puts pressure on the brain).

Psychological Amnesia

Amnesia of psychological origin is less common than other forms of amnesia. A man disappears from home, job, and family; he travels to a new place and assumes a new identity -- all without being aware that anything has changed. After days or weeks, he "awakens," becomes his old self, and wonders what happened. There is no memory of the period of amnesia.Anxiety is the cause of this type of amnesia. The person is faced with an intolerable situation of high emotional stress or pain. To protect itself, the mind forgets the anxieties and everything related to them.Treatment may not be necessary for amnesia, since most affected persons recover without help. However, if the problem that caused the amnesia still remains, it must be faced and solved. Family therapy and change of work or activities may help. Hypnosis may be used to bring back the memory of the "lost days" and unlock the ideas and feelings that caused the original flight from home and self.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of healthmirror nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

In Case of any Queries, please feel free to contact Dr Anil K Dhull

How Alcohol / Beer Works

What is Alcohol?
In order to understand alcohol's effects on the body, it is helpful to understand the nature of alcohol as a chemical, so let's take a look...
Here are several facts:
· Alcohol is a clear liquid at room temperature.
· Alcohol is less dense and evaporates at a lower temperature than water (this property allows it to be distilled -- by heating a water and alcohol mixture, the alcohol evaporates first).
· Alcohol dissolves easily in water.
· Alcohol is flammable (so flammable that it can be used as a fuel).

Alcohol can be made by three different methods:
· Fermentation of fruit or grain mixtures. This is often followed by distillation of fermented fruit or grain mixtures (Spirits such as whiskey, rum, vodka and gin are distilled.)
· Chemical modification of fossil fuels such as oil, natural gas or coal (industrial alcohol)
· Chemical combination of hydrogen with carbon monoxide (methanol or wood alcohol)
In 1997, Americans drank an average of 2 gallons (7.57 liters) of alcohol per person. This translates roughly into one six-pack of beer, two glasses of wine and three or four mixed drinks per week (see MMWR: Apparent Per Capita Ethanol Consumption for details). About 35 percent of adults don't consume alcohol, so the numbers are actually higher for those who do -- alcohol is an amazingly popular social phenomenon.If you have ever seen a person who has had too much to drink, you know that alcohol is a drug that has widespread effects on the body, and the effects vary from person to person. People who drink might be the "life of the party" or they might become s­ad and droopy. Their speech may slur and they may have trouble walking. It all depends on the amount of alcohol consumed, a person's history with alcohol and a person's personality.
How Beer Works
Have you ever wondered what "malt" really is, and how you get malt from barley? And what about hops, and why do we need yeast? Barley, water, hops and yeast -- brewers combine these four simple ingredients to make beer.
But it's not just a matter of mixing the right amount of each ingredient and voila!...you have beer. A complex series of biochemical reactions must take place to convert barley to fermentable sugars, and to allow yeast to live and multiply, converting those sugars to alcohol. Commercial breweries use sophisticated equipment and processes to control hundreds of variables so that each batch of beer will taste the same.
In this article, we'll learn how events like Prohibition and World War II influenced the taste of the beer we still drink today. Then we'll take a tour through a regional brewery, the Carolina Brewing Company, to learn how they make beer, picking up some of the amazing technology and terminology of beer making along the way.
People have been brewing beer for thousands of years. Beer especially became a staple in the Middle Ages, when people began to live in cities where close quarters and poor sanitation made clean water difficult to find. The alcohol in beer made it safer to drink than water.

In the 1400s in Germany, a type of beer was made that was fermented in the winter with a different type of yeast. This beer was called a lager, and, in part due to Prohibition, a variation of this type of beer is dominant in the United States today.
For 13 years, starting in 1920, a constitutional amendment banned the production of alcoholic beverages in the United States. Before Prohibition, America had thousands of breweries producing many different types of beer. But Prohibition forced most breweries out of business. By the time the laws were repealed in 1933, only the largest breweries had survived. These breweries sought to brew a beer with universal appeal so that it could be sold everywhere in the country. And then came World War II. With food in short supply and many of the men overseas, breweries started brewing a lighter style of beer that is very common today. Since the early 1990s, small regional breweries have made a comeback, popping up all over the United States, and variety has increased.

What's in Beer
As we learned in the introduction, there are four main ingredients in beer: barley, water, hops and yeast. Each has many complexities. We'll start with malted barley.
Malted BarleyBarley is the seed of a grain that looks a lot like wheat. Before barley can be used to make beer, it must be malted, which involves a natural conversion process.
First, the barley must be allowed to germinate, or start to sprout. This is done by soaking the barley in water for several days, and then draining the barley and holding it at about 60 degrees Fahrenheit (15.5 C) for five days. This allows the husk to open and barley to start to sprout -- at this point it is called green malt. Like all seeds, the barley contains nutrients that can sustain the growing seed until it can produce its own nutrients using photosynthesis. During the germination process, enzymes released by the plant convert these nutrients (which are starches) into sugars that can feed the plant while it grows. The key to the malting process is to stop the germination of the barley at a point when the sugar-producing enzymes are present but most of the starch is still unconverted. Eventually, these enzymes will produce the sugars that will feed the yeast to make the alcohol in the beer.
Malted barley
After this natural process has released the enzymes, the green malt is dried by gradually raising the temperature. The intensity of the malt flavor and color depends on how high the temperature is raised during the drying process. One final step must be completed -- removing any small roots that formed during germination -- and the malted barley is ready to begin the brewing process. Most breweries buy barley that has already been malted to their specifications.
Hops
The hops used to make beer are the flower of the hop vine, which is a member of the hemp family (Cannabaceae). Hops are closely related to another member of the hemp family that you may have heard of -- cannabis, or marijuana, although hops do not have the psychoactive effects associated with marijuana.
Hops contain acids, which give beer its bitterness, as well as oils that give beer some of its flavor and aroma. Adding hops to beer also inhibits the formation of certain bacteria that can spoil the beer.
There are many different kinds of hops, each of which gives a different taste, aroma and amount of bitterness to the beer it is used in. In the United States, hops are grown mainly in Washington state. Hops are also grown in Germany, Southern England and Australia.
Yeast is the single-celled micro-organism that is responsible for creating the alcohol and carbon dioxide found in beer. There are many different kinds of yeasts used to make beer; and just as the yeast in a sourdough starter gives sourdough bread its distinctive flavor, different types of beer yeast help to give beer its various tastes.
There are two main categories of beer yeast: ale yeast and lager yeast. Ale yeast is top fermenting, meaning it rises near the surface of the beer during fermentation, and typically prefers to ferment at temperatures around 70 F (21 C). Lager yeasts are bottom fermenting. They ferment more slowly and prefer colder temperatures, around 50 F (10 C).
Brewing
The Mash
The mash is the process that converts the starches in the malted barley into fermentable sugars. At the Carolina Brewery, they start by crushing the malted barley between rollers to break up the kernel.
There is a fine tradeoff in the rolling process: the more the kernel is broken up, the more sugars can be extracted from the grains; but if it is broken up too much, the husk that surrounds the kernel may get broken down, which can cause a stuck mash. If the kernel is broken up just enough, then when the mash is finished, the whole husks form a filter bed that captures any solids from the liquid; but if the husks are broken down too much, they clog up and don't let the liquid through -- a stuck mash.
Next, the crushed grains pass through a feed pipe into the mash-lauter-tun. This insulated vessel has a device called a hydrator, which sprays heated water onto the grains as they enter. This eliminates any dry spots in the mash -- dry spots mean wasted sugars. The wet grains stay in the mash-lauter-tun for an hour. Since the vessel is insulated, the temperature stays at around 150 F (65 C).
The mash-lauter-tun
The purpose of the mash is to convert the starches in the malted barley into fermentable sugars to be used in the next step of the brewing process. Starches are strings of many glucose molecules chained together -- these chains must be broken down into chains of only two or three glucose molecules before they can be fermented. We learned earlier that the malted barley contains enzymes, which can convert the starches.
There are two different types of enzymes in the malted barley: alpha-amylase and beta-amylase. The alpha enzymes break up the long chains of starches by splitting them in half. The beta enzymes break down the starches by chopping them off a couple at a time from the ends of the chain. Only if these two enzymes work together can the conversion be accomplished in a reasonable amount of time. There is a catch though: The alpha enzymes are most active at 149 to 153 F (65 to 67 C), and the beta enzymes are most active at 126 to 144 F (52 to 62 C). So the temperature and duration of the mash must be carefully controlled to get a good conversion.
The last steps needed to complete the mash are lautering and sparging. The liquid is drained from the bottom of the mash-lauter-tun and then recirculated to the top so that it is filtered through the husks of the spent grains. Additional heated water is then poured over the grains -- a process called sparging -- to make sure all of the sugars are removed.
The mash is an amazing process. Before the mash starts, the grains don't taste at all sweet, but the liquid that is drained off from the grains at the end of the mash is very sweet and sticky. This liquid, which now contains mostly fermentable sugars, goes on to the boil.
The Wort The next step in the beer brewing process is called the boil. At the end of the boil we will have a finished wort (pronounced wert).
To start, the liquid from the mash is put into a huge brew kettle. The one used at the Carolina Brewery holds more than 600 gallons (2,270 L). It is a steam jacketed brew kettle. This kettle has double walls with a gap between them through which steam is circulated. This provides very even heating, since both the bottom and the sides are heated. The temperature is raised until the liquid comes to a vigorous rolling boil, and it is held there for 90 minutes.
A boiling wort
At the beginning of the boil, hops are added. These are called the boiling hops, and their job is to add bitterness to the beer. The acids that produce bitterness in the beer are not easy to extract from the hops, which is why they need to be boiled for up to 90 minutes. The oils that produce the hop flavor and aroma are very volatile and evaporate quickly, so the boiling hops only contribute bitterness to the beer -- the flavor and aroma are added later.
Depending on what type of beer is being brewed, more hops may be added near the end of the boil -- these are called finishing hops. Generally, hops that are added about 15 minutes before the end contribute flavor to the beer. Hops added just a few minutes before the end contribute aroma to the beer. The oils in the hops that give the beer a distinctive hop smell are the most volatile, so these hops really just need to steep in the hot wort for a few minutes, like tea leaves, to extract the oils. Some of the beers brewed at the Carolina Brewery get finishing hops added at three different times. In order for each batch of beer to taste the same, exactly the same amount of the same type of hops must be added at exactly the same time during each boil.
Separating the Solids
Before the wort can go on to the next step, all of the solids must be separated from the liquid. This is done in a very neat way. The wort is pumped from the kettle, and forced back into the kettle through a jet nozzle. This flow of liquid causes a whirlpool to form; and if you've ever stirred tea leaves in a cup, you know that they move to the center of the whirlpool. When this whirlpool forms in the brew kettle, all of the hops and other solids move to the center. The pump is then turned off, and over the next 20 minutes the whirlpool gradually stops and the solids settle to the bottom, forming a fairly solid cone.
The whirlpool pump that swirls the beer
When the wort is drained, the solids stay in the kettle. Next, the wort must be cooled down to the proper temperature for the yeast. This is done in a liquid-to-liquid heat exchanger. The wort is circulated through one set of tubes while chilled water is circulated through another set. The tubes with hot wort running through them transfer heat to the tubes holding the chilled water.
Heat exchanger
The cooling water is chilled first, so that the volume of water that is required to cool down one entire batch of wort is about equal to the volume of wort. The cooling water ends up at a temperature of about 170 F (76 C), and is stored in an insulated tank and used to brew the next batch of beer. This way both the water and the heat energy are saved.
Hot and cold water storage tanks
It is important to cool the wort quickly so that the yeast can be added right away and fermentation can begin. This reduces the chance of contamination by stray yeasts floating around in the air.
Fermentation
Fermentation is the process by which yeast converts the glucose in the wort to ethyl alcohol and carbon dioxide gas -- giving the beer both its alcohol content and its carbonation. To begin the fermentation process, the cooled wort is transferred into a fermentation vessel to which the yeast has already been added. If the beer being made is an ale, the wort will be maintained at a constant temperature of 68 F (20 C) for about two weeks. If the beer is a lager, the temperature will be maintained at 48 F (9 C) for about six weeks. Since fermentation produces a substantial amount of heat, the tanks must be cooled constantly to maintain the proper temperature.
Fermentation tanks
These fermentation tanks hold more than 2,400 gallons (9,085 L), which means that it takes four batches of wort to fill one tank. Since fermentation takes at least two weeks, the capacity of the brewery is limited by how many tanks they have.
When the wort is first added to the yeast, the specific gravity of the mixture is measured. Later, the specific gravity may be measured again to determine how much alcohol is in the beer, and to know when to stop the fermentation.
The fermenter is sealed off from the air except for a long narrow vent pipe, which allows carbon dioxide to escape from the fermenter. Since there is a constant flow of CO2 through the pipe, outside air is prevented from entering the fermenter, which reduces the threat of contamination by stray yeasts.
When fermentation is nearly complete, most of the yeast will settle to the bottom of the fermenter. The bottom of the fermenter is cone shaped, which makes it easy to capture and remove the yeast, which is saved and used in the next batch of beer. The yeast can be reused a number of times before it needs to be replaced. It is replaced when it has mutated and produces a different taste -- remember, commercial brewing is all about consistency.
While fermentation is still happening, and when the specific gravity has reached a predetermined level, the carbon dioxide vent tube is capped. Now the vessel is sealed; so as fermentation continues, pressure builds as CO2 continues to be produced. This is how the beer gets most of its carbonation, and the rest will be added manually later in the process. From this point on, the beer will remain under pressure (except for a short time during bottling).
When fermentation has finished, the beer is cooled to about 32 F (0 C). This helps the remaining yeast settle to the bottom of the fermenter, along with other undesirable proteins that come out of solution at this lower temperature.
Now that most of the solids have settled to the bottom, the beer is slowly pumped from the fermenter and filtered to remove any remaining solids. From the filter, the beer goes into another tank, called a bright beer tank. This is its last stop before bottling or kegging. Here, the level of carbon dioxide is adjusted by bubbling a little extra CO2 into the beer through a porous stone.
How Yeast Makes Alcohol and Carbon Dioxide
When the yeast first hits the wort, concentrations of glucose (C6H12O6) are very high, so through diffusion, glucose enters the yeast (in fact, it keeps entering the yeast as long as there is glucose in the solution). As each glucose molecule enters the yeast, it is broken down in a 10-step process called glycolysis. The product of glycolysis is two three-carbon sugars, called pyruvates, and some ATP (adenosine triphosphate), which supplies energy to the yeast and allows it to multiply. The two pyruvates are then converted by the yeast into carbon dioxide (CO2) and ethanol (CH3CH2OH, which is the alcohol in beer). The overall reaction is:
C6H12O6 => 2(CH3CH2OH) + 2(CO2)

Bottling, Kegging and Homebrewing
The most important thing about the bottling and kegging process is to keep the beer from being contaminated by stray yeasts, and to keep oxygen away from the beer. These are the main things that can reduce the shelf-life of beer.
The ways that the beer is transferred into bottles and kegs is pretty similar; but bottling has a few extra steps, so we'll talk about bottling.
The bottling line at the Carolina Brewery can fill up to 100 12-oz (355 ml) bottles of beer every minute. To start the process, the empty bottles are loaded onto the bottling line, where they are first rinsed with a chlorine solution, and then blasted with CO2 to remove the solution.
Bottle rinse -- this section of track inverts the bottles, rinses them with a cleaning solution, dries them with CO2 and then flips them back over.
Next, the bottles enter a turret-like mechanism that can hold 12 bottles at once. Each bottle rides around the turret once. During its ride, the bottle is purged with CO2 several times before it is filled. The bottles are pressurized with CO2 so that when the beer is forced into the bottles under pressure it doesn't foam up too much. After the beer has been added to the bottles, the pressure is slowly relieved until the beer is at ambient pressure. As each filled bottle leaves the turret, an empty one takes its place.
Bottle filling station
Next comes the capping machine -- but now there is a little bit of air space at the top of the bottle that needs to be purged. To do this, the bottle is passed under a very narrow, high-pressure jet of water that hits the beer, causing it to foam up and drive the air out of the bottle. The cap is then applied before any air can re-enter the bottle.

Bottle capping machine
After the cap is applied, the outside of the bottle is rinsed to remove any beer that may have foamed out during the process.

Bottle rinsing -- note the foam in the bottle
Surprisingly, the most difficult part of the bottling process is applying the label to the bottle. Getting a label to stick to a cold wet beer bottle is no easy trick.
The labels are fed into the labeling machine, which has a spinning device that rolls glue onto the labels and then sticks them to the bottles as they pass by. If all goes well, the label will be properly positioned, smooth and well-adhered.
Labeling machine
A special inkjet printer squirts the date onto the label as it moves past the print head. The date the beer was bottled and also a "best before" date (three months after the bottling date) are printed on the label.
Label printer

Homebrewing If this all sounds very complicated, then you might be wondering how people ever manage to brew their own beer. But as you may have gathered, most of the complexity of the brewing process is due to the need for a commercial brewery to turn out beer that tastes exactly the same batch after batch, year after year.
A typical set of homebrewing equipment
Most homebrewers have no such requirement -- it doesn't matter if the beer tastes exactly the same each time they make it. There are so many different types of beer to brew that many homebrewers never make the same type of beer twice anyway.
At homebrewing stores you can buy malt extract, which is the fermentable sugars extracted from the mash. That eliminates one fairly complicated step (although it is entirely possible to do a mash in your home). A basic set of homebrewing equipment consists of:
· Fermentation vessels (a bucket or glass water jug)
· Various hoses for siphoning beer from one container to another or to fill bottles
· An airlock so that carbon dioxide can escape the fermentation vessel but air cannot get in
· Some cleaning equipment for washing your fermenters, bottles and hoses
· Floating thermometer
· Floating hydrometer
· Bottle capper
· Funnel
All of these supplies and any ingredients you need are available at homebrewing stores, and are sometimes packaged as a kit.

Sources
·"Alcohol, tobacco among worst drugs." CNN.com. Mar. 23, 2007.http://www.cnn.com/2007/HEALTH/03/23/drugs.report.ap/index.html
·"Annual Causes of Death in the United States." Drug War Facts.http://www.drugwarfacts.org/causes.htm
·"New 'matrix of harm' for drugs of abuse." Bristol University. Mar. 23, 2007.http://www.bris.ac.uk/news/2007/5367.html
· Nutt, David, et al. "Development of a rational scale to assess the harm of drugs of potential misuse." The Lancet, 2007; 369:1047-1053.http://www.thelancet.com/journals/lancet/article/ PIIS0140673607604644/fulltext
·"Scientists want new drug rankings." BBC News. Mar. 23, 2007.http://news.bbc.co.uk/1/hi/health/6474053.stm?ls
· HSW team http://recipes.howstuffworks.com/alcohol1.htm
· Photo courtesy: Carolina Brewing Company

For further queries please feel free to contact Dr Anil K Dhull