Abdominal Bloating

 

Abdominal bloating is felt by patients as a feeling of fullness, tightness or distension in the abdomen. Bloating is different to abdominal swelling, where the abdomen is actually increased in size, although both of these features may be present. 

Abdominal bloating is quite common and in the majority of cases will not be caused by anything serious. Excessive gas due to dietary factors, irritable bowel syndrome (IBS) or difficulty absorbing certain foods are amongst the most common causes. If your abdominal bloating is prolonged, severe, or if you have other worrying symptoms (e.g. diarrhoea, constipation, weight loss or bleeding) it is extrememly important you see your doctor so they can exclude serious conditions (e.g. cancer).

Abdominal bloating refers to a sensation of fullness or a sense of abdominal enlargement. It is often due to disturbance in the normal function of the gastrointestinal tract, causing an increase in intestinal gas.

Gas in the intestine is a mixture of numerous different components which can be increased by swallowing too much air, excess production, or impaired absorption due to obstruction. Excess gas causes bloating as well as other gas symptoms such as flatulence or burping.

If the abdomen is visibly distended in association with bloating, it is more likely that there is an organic, rather than functional, cause of the symptom. Bloating is frequently associated with abdominal pain that may be relieved by passing gas or bowel motions.

Abdominal bloating may be a feature of a number of disorders, the majority of which are not serious and result from changes in gastrointestinal function. Possible common causes are:

Diet

Your body takes a long time to break down and expel fat from the body. Too much fat in your diet can cause episodes of bloating. Other foods can cause bloating due to the formation of extra gas. These foods include cabbage, cauliflower, baked beans and salads.

Malabsorption syndromes

A number of disorders exist where the body cannot break down and absorb certain components of food. In these cases, the remaining food products can produce extra gas due to certain chemical reactions, or due to the good bacteria in the bowel trying extra hard to break these foods down. Lactose intolerance, coeliac disease and other food intolerances are examples of disorders that cause bloating by these mechanisms.

Air swallowing

If you swallow large amounts of air, your bowel has trouble absorbing or removing it all from the body fast enough. This means more will stay within the bowel lumen and cause the sensation of a full bowel. Anxiety or nervousness, eating quickly, gulping food or beverages, drinking through straws and chewing gum can all cause you to swallow increased amounts of air.

Irritable bowel syndrome 

Irritable bowel syndrome is a common disorder where patients have alternating episodes of constipation and diarrhoea. Abdominal bloating is one of the key features of this diagnosis.

Partial bowel obstruction

A blockage at some point in the intestines will impair the mechanical transit of food and may lead to bloating.

Constipation

Constipation is characterised by a reduction in the frequency of bowel motions, and may cause bloating.

Menstruation

Bloating is common in women at the time of menstruation, or as part of a premenstrual stress disorder.

Other causes

Very rarely, your bloating may be due to a more serious condition, so it often pays to discuss your symptoms with a doctor. The following conditions are less common but don't want to be missed:

Ascites: Sometimes you may feel bloated due to the accumulation of fluid within the abdominal cavity, called ascites. This is often the result of liver disease. Tumours: Very occasionally, you may feel bloated because there is a tumour present within your abdomen, of the ovaries, liver, stomach or elsewhere. The present of a lump or swelling should alert you to the possibility of a tumour or cancer. Infection: Certain parasitic disorders can cause abnormal dilatations of the colon (megacolon) associated with symptoms of bloating.

If you experience abdominal bloating, it is important to see your doctor to make sure there is nothing serious present. In particular, if you have symptoms of diarrhoea, constipation, weight loss or bleeding from anywhere in the gastrointestinal tract (vomiting blood or bloody or dark stools), there is a greater possibility that something more serious is present rather than just a functional problem.

When you see your doctor, you should be prepared to answer detailed questions about:

Duration of the bloatingYour dietThe relationship of the bloating to certain foodsIf you're a female, any change in bloating during the menstrual cycleAny other associated symptomsAny past medical historyCurrent medications

Your doctor will then examine you, paying particular attention to palpating your abdomen for any masses or swelling. Your doctor will also tap your belly to identify any fluid present. Listening to bowel sounds can help your doctor determine if there is an obstruction. The doctor may perform a rectal examination if you have other bowel symptoms.

If your bloating is due to a functional problem, such as an inability to tolerate dairy products or wheat, examination is likely to be normal. Your doctor may suggest trials of certain diets to determine if it is a particular food triggering your symptoms.

Investigations are needed in some patients, particularly when the other serious symptoms are present. Your doctor may refer you for the following:

Radiography: Plain x-rays of your abdomen can tell if it is blocked in certain places. Ultrasound or CT scans: May be done if the doctor suspects ascites (fluids) or a mass. Colonoscopy: Involves inserting a long tube (with a light and a camera on the end of it) into the rectum (back passage). The doctor can then look at the inside of the bowels to make sure there are no tumours (e.g. colon cancer). Barium enema  

If a specific cause is suggested (e.g. lactose intolerance), special trial diets or further diagnostic testing (e.g. lactose tolerance test) may be required. Coeliac disease may be diagnosed by a series of blood tests looking for certain antibodies.

The treatment of bloating mainly depends on the underlying cause of the symptom. Your doctor would have performed a number of necessary tests to exclude serious problems. Treatment then focuses on a number of diet and lifestyle changes:

Avoid carbonated beverages. Avoid chewing gum as this predisposes to air swallowing. Avoid foods that are difficult to digest or that cause increased amounts of gas (e.g. brussel sprouts, cabbage, beans and lentils). Be careful of your sources of fibre. Patients with IBS often need increased amounts of fibre to relieve their symptoms, however, some types of fibre such as psyllium (in Metamucil) can exacerbate bloating. You should discuss your choice of fibre supplements with a pharmacist. Eat small, frequent meals at a reasonable pace (slowly). Drinking fennel tea may help your symptoms.

In some patients, over-the-counter medications such as simethicone, beano and activated charcoal can help gas symptoms. Your doctor may suggest a trial of some of these, but unfortunately they have only modest benefits and do not work in all patients.

For more information on nutrition, including information on types and composition of food, nutrition and people, conditions related to nutrition, and diets and recipes, as well as some useful videos and tools, see Nutrition. 

Abraczinskas D, Goldfinger SE. Intestinal gas and bloating [online]. Waltham, MA: UpToDate; 2006 [cited 25 July 2006]. Available from: URL link Glickman R. Abdominal swelling and ascites. In: Braunwald E, Fauci AS, Kasper DL, et al. Harrison's Principles of Internal Medicine (16th edition). New York: McGraw-Hill Publishing; 2006. [Book]Lehrer JK, Lichtenstein GR. Irritable bowel syndrome [online]. Omaha, NE: WebMD eMedicine; 2005 [cited 25 July 2006]. Available from: URL linkLongmore M, Wilkinson I, Rajagopalan S. Oxford Handbook of Clinical Medicine (6th edition). Oxford: Oxford University Press; 2004. [Book]Abdominal bloating [online]. Bethesda, MD: National Institutes of Health Medline Plus; 2004 [cited 25 July 2006]. Available from: URL link Szarka L, Levitt M. Belching, bloating and flatulence [online]. Bethesda, MD: American College of Gastroenterology; 2006 [cited 25 July 2006]. Available from: URL link

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Energy Expenditure Calculator

Reference
Panel on Macronutrients & Standing Committee for the Scientific Evaluation of Dietary Reference Intakes. Energy. Chapter 5. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids (Macronutrients), National Academy of Sciences. 2005. [cited 2009, June 6], Available from http://www.nap.edu/catalog/10490.html

This tool needs Javascript enabled to run.

The formula for calculating how many Calories you burn while exercising is:
Calories = 0.0175 * weight (kg) * MET * duration (minutes)

For example:
A man who weighs 85 kilograms and swam for 30 minutes would burn:
Calories = 0.0175 * 85 * 7 * 30
Calories = 0.0175 * 85 * 210
Calories = 0.0175 * 17850
Calories = 312.375

Dancing Ballroom (fast) or squareJogging (10-min 1 mile : 1.6 kilometres)

This information will be collected for educational purposes, however it will remain anonymous.

For more information on fitness and exercise, including stretches, types of exercise, exercise recovery and exercise with health conditions, as well as some useful videos, see Fitness and Exercise.  

For more information on nutrition, including information on types and composition of food, nutrition and people, conditions related to nutrition, and diets and recipes, as well as some useful videos and tools, see Nutrition.   

Created: 1/7/2009


This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Blood Pressure Calculator

Normal
Your blood pressure should be rechecked within 2 years or earlier depending on your risk of developing cardiovascular disease. Your General Practitioner can advise you about this risk and also on lifestyle risk reduction.High-Normal
Your blood pressure is elevated. It should be rechecked within 12 months or earlier depending on your risk of developing cardiovascular disease. Your General Practitioner can advise you about this risk and also on lifestyle risk reduction.Grade 1 (mild) Hypertension
Your blood pressure is elevated. It should be confirmed within 2 months. Your General Practitioner should advise you about lifestyle risk reduction and/or medication to lower your blood pressure.Grade 2 (moderate) Hypertension
Your blood pressure is elevated. It should be confirmed within 1 month and you may also need to see a specialist in this time. Your General Practitioner can advise you about lifestyle risk reduction and/or medication to lower your blood pressure.Grade 3 (severe) Hypertension
Your blood pressure is elevated. It should be confirmed within 1 week and you may also need to see a specialist in this time. Your General Practitioner can advise you about lifestyle risk reduction and/or medication to lower your blood pressure.Isolated systolic hypertension
Your systolic blood pressure is elevated. Depending on the level it needs to be confirmed within a certain time (140-159mmHg - 2 months; 160-179mmHg - 1 month; >180mmHg - 1-7 days).You may also need to see a specialist. Your General Practitioner can advise you about lifestyle risk reduction and/or medication to lower your blood pressure.Isolated systolic hypertension with widened pulse pressure
Your blood pressure is elevated. It should be confirmed within 1 week and you may also need to see a specialist in this time. Your General Practitioner can advise you about lifestyle risk reduction and/or medication to lower your blood pressure.Hypotension
Your blood pressure is lower than normal. Your General Practitioner will ask you about symptoms that you may be experiencing and determine if you require treatment or further investigation.

You must have Javascript enabled to use this tool.

This information will be collected for educational purposes, however it will remain anonymous.

For more information on blood, blood types, blood tests, and blood donation and transfusion, see Blood.

For more information on high blood pressure, including investigations and treatments, as well as some useful animations, videos and tools, see Hypertension (High Blood Pressure).  

Created: 24/2/2010


This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Lumbar Puncture (Cerebrospinal Fluid Examination)

A lumbar puncture is a procedure that is used to examine the cerebrospinal fluid (CSF). The cerebrospinal fluid is the fluid which circulates around the brain and membranes around the brain and spinal cord (the meninges). It is mainly used in aiding diagnoses pertaining to infection, inflammatory diseases and traumatic injuries. It can also be used therapeutically and for anaesthesia, however this document is mainly concerned with the investigative use of a lumbar puncture.

To begin with the procedure is usually carefully explained to the patient, including the risks and benefits. In experienced hands, a lumbar puncture is a relatively safe procedure. Proper positioning of the patient is extremely important. The patient is asked to lie on their side, with their back toward the examiner and then curl into a ball. This involves the patient flexing their neck and lower spine, whilst drawing up their thighs toward their chest. The shoulders and pelvis should be vertically aligned without forward or backward tilt. In approximately 94% of individuals the spinal cord terminates at the level of the L1 vertebrae. In the further 6% of individuals the spinal cord can extend to the L2-L3 interspace. Therefore a lumbar puncture is generally performed at or below the L3-L4 interspace. As a general anatomical rule, the line drawn between the posterior iliac crests often corresponds closely to the level of L3-L4. The interspace is selected after palpation of the spinous processes at each lumbar level.Once the area for needle insertion has been ascertained, the examiner puts on a mask and sterile gloves - this decreases the risk of infection. The skin is then cleansed with alcohol and usually an iodine based disinfectant and the area is draped with a sterile cloth. A local anaesthetic, commonly 1% lignocaine, is injected into the subcutaneous area - this should be ideally done at least 5 minutes prior to insertion of the lumbar puncture needle.The lumbar puncture needle is typically a 20 - 22 gauge needle and it is inserted into the target area and slowly advanced. The bevel of the needle is maintained in a horizontal position (with the flat portion of the bevel pointing up) and it should be parralel to the direction of the dural fibers. In most cases the needle is advanced 4 - 5cm before the subarachnoid space is reached - this is characteristically recognized by a sudden decrease in resistance and sometimes a 'popping' sound may be heard. Once a subarachnoid space has been reached, a manometer can be attached to the needle to record the opening pressure. Fluid is then usually obtained for collection. Fifteen millilitres of CSF is usually sufficient for a sample. The fluid is then taken and may be analysed for a number of parameters (according to the clinical presentation) including: cell count with differential protein and glucose concentrations culture - bacterial, fungal, mycobacterial and viral smears - gram stains and acid-fast bacilli smear antigen tests and serology (e.g. cryptococcal antigen, latex agglutination, limulus lusate tests) PCR (polymerase chain reaction) tests to amplify DNA or RNA of micro-organisms antibody tests immunoelectrophoresis cytology or cell studiesSome normal values for CSF parametes are as follows: Glucose 2.22-3.89mmol/L Lactate 1-2mmol/L Protein 0.15-5g/L Red Blood Cells 0 IgG 0.009-0.057g/LThe minor risks and complications associated with a lumbar puncture include backache, post lumbar puncture headache, radicular pain and numbness. Major complications that rarely occur include infection, haemorrhage, damage to the spinal cord or nerve roots and herniation of cerebral tissue in patients with pre-existing increased intracranial pressure.



This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

GORD: Managing the Symptoms

Gastro-oesophageal reflux disease (GORD or GERD) is a common and chronic gastrointestinal disorder. Nearly 80% of the population will experience symptoms of reflux at some stage in their lives. GORD is associated with prolonged exposure of the lower oesophageal mucosa to gastric contents, leading to symptoms of heartburn, regurgitation (feeling like the stomach contents are coming back up) and waterbrash (excess saliva in the mouth). Symptoms are often made worse by lying flat, are related to meals (especially fatty foods), and may be worsened by hot liquids or alcohol.

The severity of your symptoms does not always correspond to how badly your oesophagus is scarred or damaged. It is therefore important that you see a doctor so your condition can be properly investigated. GORD often requires life-long and regular use of anti-reflux therapies.

Treatment tends to pursue three main aims:

Healing the damage to the oesophagus;Preventing complications such as Barrett's oesophagus, strictures (narrowing), and oesophageal cancer; andAlleviating your symptoms and improving your quality of life.

In general, a step-wise approach is used in the management of GORD symptoms. Usually you will be trialled on simple lifestyle measures, and then slowly have more aggressive treatments added if your symptoms don't improve.

Before starting anti-reflux therapies, it is important that other causes of similar symptoms have been excluded. In particular, cardiac chest pain from angina can present quite similarly to reflux. Failure to treat an underlying heart problem could have serious consequences.

If your GORD is mild it is likely that you will respond satisfactorily with simple lifestyle changes and over-the-counter antacids. In many cases, people are able to control their own symptoms and do not necessarily need to see a doctor. It is quite common for people to go to the doctor only when their symptoms become so severe that they interfere with daily functioning. However, it is important that you realise that reflux symptoms may be a marker of more serious underlying conditions. GORD can cause nasty complications, including oesophageal cancer, which need to be monitored throughout your treatment. In general, the longer you have symptoms of reflux, the greater risk you have for additional complications.

There are a number of symptoms that may suggest more serious problems and require urgent investigation. These are referred to as "alarm symptoms". It is important to see your doctor so they can conduct further investigations if you notice any:

Difficulty swallowing; Pain when swallowing;Blood in your vomit;Dark, tarry stools (melaena); Weight loss; Anaemia: You may notice you are more pale (particularly in the skin creases and conjunctiva of the eyes), or fatigue more easily.

Lifestyle changes

Lifestyle changes that can help manage GORD symptoms include:

Losing weight (if you are overweight); Elevating your head in bed; Avoiding lying down or sleeping for 3 hours after a meal; Reducing alcohol consumption; Quitting smoking;Avoiding fatty foods and foods that typically trigger symptoms, such as: Avoiding medications that trigger your reflux symptoms (discuss with your doctor).

Although some of these lifestyle changes can be difficult to achieve, they are excellent therapies as they are low cost and have few side effects. These measures are recommended for virtually everyone with GORD and should be continued even when using other therapies.

Over-the-counter and antacid therapy

Depending on the severity of your symptoms, your doctor may prescribe medications or recommend over-the-counter (OTC) preparations. These may be needed for a short time while you have symptoms or on a long-term basis, depending on the features of your symptoms.

Many people self-treat themselves with over-the-counter medications. These include simple antacids and alginates. Antacids work by neutralising the gastric acid so that it is no longer damaging to the oesophagus. Alginates, on the other hand, work by forming a thick gel coating on the surface of the stomach contents to stop them from refluxing. Lots of studies have confirmed these agents produce rapid symptom relief, but their effects only last for a short time so they need to be taken frequently. Furthermore, these treatments do not change the underlying amount of acid secretion or prevent complications, so they may be a more temporary measure.

Histamine-2 receptor antagonists (H2RA) such as cimetidine (e.g. Tagamet) and ranitidine (e.g. Zantac) are also available over-the-counter. These agents have been proven in clinical trials to reduce gastric acid levels. The different drugs of this class vary slightly in their potencies and onset of action. H2RAs can be taken before activities known to trigger reflux, such as eating heavy meals or exercising, to prevent the onset of symptoms.

Antisecretory medications

Suppressing the amount of acid produced in the stomach has been shown to be the most successful treatment for GORD. Proton pump inhibitors (PPIs) work by inhibiting a special enzyme on the surface of acid-producing cells in the stomach. This blocks acid production and reduces the overall level of acid in the stomach. PPIs are considered the most effective medications for symptom relief and may be used in nearly all cases, except perhaps if your disease is very mild. PPI medications are available via a prescription from your doctor.

PPI drugs available in Australia include:

Pantoprazole (Somac); Rabeprazole (Pariet); Omeprazole (Losec);Esomeprazole (Nexium);Lansoprazole (Zoton).

Clinical trials have confirmed that these medications treat symptoms such as heartburn, acid regurgitation and painful swallowing. They are effective in approximately 80% of patients. PPIs are able treat symptoms and heal oesophageal damage more rapidly than any other therapy available. There is still debate over which PPI is the most effective, so different doctors may prescribe different medications based on their experience.

If you have severe reflux, you will probably be treated long-term with a PPI medication. Often the maintenance dose is smaller than that prescribed in an acute period of symptoms. If you are on long-term treatment and suddenly stop taking your medication, it is likely you will experience a recurrence or relapse in your symptoms. Even with adequate therapy, it is not uncommon to have some occasional flares of symptoms. PPI medications should be taken before meals, as prescribed by your doctor. Usually the daily dose will be split into a morning and evening dose.

PPI medications are generally well tolerated and tend to have few side effects. However, the following adverse effects may occasionally occur (in approximately 5 out of 100 patients taking these medications):

Most side effects are only mild and temporary during the start of treatment. A more serious side effect of vitamin B12 deficiency has been reported, but this is exceedingly rare. Overall, PPIs are excellent medications in terms of efficacy and minimal side effects. Perhaps the only factor limiting more widespread use is cost, as some of the agents can be quite expensive.

Prokinetic medications

Some drugs such as metoclopramide and domperidone (Motilium) may be used as add-on therapies to help control symptoms. These agents work by enhancing the contractions of the stomach and increasing its rate of emptying. This essentially reduces the contents of the stomach so that less is available to reflux back into the oesophagus, thus reducing damage. 

Surgery

Surgery is usually only used in cases of very severe reflux symptoms, particularly in younger patients who would otherwise need long-term drug therapy to manage symptoms. Approximately 80% of patients undergoing surgery will demonstrate improvement in symptoms. However, controversy exists over the long-term effectiveness of this mode of treatment, and indications for surgery are less clear-cut than for other types of treatment.

Endoscopic therapy

Occasionally reflux symptoms may be treated endoscopically by inserting a tube down the throat and either sewing, burning or injecting damaged areas of the mucosa (lining). Unfortunately the long-term efficacy of these treatments is unknown so their role is limited to a very select number of patients. In addition, endoscopic treatment can cause significant complications such as pain, gastrointestinal injury and short-term dysphagia.

Reflux is a very common condition in children but the symptoms are often non-specific. To date there is no ideal method of diagnosing or treating the problem in infants and children. However, you may gain some comfort from knowing that the symptoms of reflux are extremely common and that the condition is not due to any fault on your part. Often simple reassurance from a medical practitioner is helpful in improving both your and your child's quality of life.

As demonstrated above, there are many different treatments available for symptoms of reflux. Unfortunately there is limited experience with these therapies in children. Therefore when considering treatment for your child it is very important that you consider the potential side effects of the medications. You should remember that mild reflux is generally not a serious condition and that your child is otherwise well and healthy.

In most cases, symptoms of reflux will resolve spontaneously by approximately 12 months of age. Your doctor can help explain the condition more so that you understand that it is usually better for your child NOT to have extensive investigations or multiple drug therapies. This will avoid unnecessary side effects from unnecessary treatments.

Some management options for reflux symptoms in children are:

Reassurance and education: Learning more about your child's condition can allay some of your fears about the seriousness of the condition. Support groups such as RISA can help provide reassurance and educational materials; Posturing: There is some evidence that being in certain positions while feeding increase the incidence of reflux. Laying your child prone (on their stomach) with their head slightly elevated during feeding is associated with the least amount of reflux. It can be helpful to keep your child upright for about half an hour after feeds. However, caution should be taken positioning your child on their stomach, as there is an increased risk of SIDS;Dietary treatment: Milk thickeners and thickened feeds can reduce regurgitation, but there is limited evidence that they reduce reflux. Infants with mild acid reflux may respond well to simple thickening of their feeds; Alginates: There is limited experience with antacids in infants, but they may have some benefit in improving symptoms of mild GORD. However, side effects on bone metabolism (including rickets), diarrhoea and constipation can occur from these medications; Proton pump inhibitors: These are the recommended treatments for severe reflux in children. These treatments can cause side effects which should be discussed with your doctor. The pros and cons of treatment should be weighed up on an individual basis.

Children with very severe reflux symptoms and persistent vomiting can develop more serious complications such as failure to thrive and malnutrition. In these cases, more drastic measures may be required such as feeding through a nasogastric tube (a tube passed through the nose and down into the stomach, through which nutrient-rich puréed foods can be fed) or, very rarely, surgery.

For more information on acid reflux and heartburn and related investigations, treatments and supportive care, see Acid Reflux and Heartburn.

Biddle W. Gastroesophageal reflux disease: Current treatment approaches. Gastroenterol Nurs. 2003;26(6):228-36. [Abstract]DeVault KR, Castell DO. Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease. Am J Gastroenterol. 2005;100(1):190-200. [Abstract | Full text]Goyal R. Diseases of the esophagus. In: Braunwald E, Fauci AS, Kasper DL, et al. Harrison's Principles of Internal Medicine (15th edition). New York: McGraw-Hill Publishing; 2001. [Publisher]Ip S, Bonis P, Tatsioni A, et al. Comparative effectiveness of management strategies for gastroesophageal reflux disease [online]. Rockville, MD: Agency for Healthcare Research and Quality (AHRQ), US Department of Health and Human Services; 13 December 2005 [cited 10 June 2007]. Available from: URL link Kumar P, Clark M (eds). Clinical Medicine (5th edition). Edinburgh: WB Saunders Company; 2002. [Publisher] Somac [online]. MIMS Online; 2003 [cited 10 June 2007]. Available from: URL link Tutuian R. Castell DO. Management of gastroesophageal reflux disease. Am J Med Sci. 2003;326(5):309-18. [Abstract]Vandenplas Y. Gastroesophageal reflux: Medical treatment. J Pediatr Gastroenterol Nutr. 2005;41 Suppl 1:S41-2. [Full text] 

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Exercise: Cardio Training

Cardio training is a form of exercise that makes the heart beat a little faster. This includes walking, running, football and tennis. Dr Joe Kosterich talks about the purpose of cardio training, the importance of exercise, and the need to start small.

When people think of exercise, the one that generally comes to mind is cardio training. Cardio training is short for cardiovascular training, so it's a form of exercise that causes our heart to beat a little bit faster, causes the blood to pump around, and gets us to breathe a little bit more quickly.

Obvious sorts of cardio training are walking, running, bike riding and swimming. Most sports, with the exception of things like weight lifting and rifle shooting, are cardio type exercises. So football, cricket, tennis and even golf, to a degree, are all cardio type exercises and sports.

Cardio training is really, really important as the heart is an important part of the body. The brain is really important as well, but you probably hear a lot more about heart attacks than most other forms of diseases. And like most parts of the body, if you use it in the right way and look after it, it will keep you going for longer.

So with cardio training, what are we trying to do? We're trying to get the heart a little bit stronger and more resilient. How do we do that? By basically stressing it a little bit - stressing it to the degree that we get it to work a little bit harder. It's always those last two reps or that last 50 metres that pushes you that little bit further. So in looking to build up a cardio regimen, we're looking to improve our stamina, fitness and overall energy capabilities. This happens gradually. Nobody who's run a marathon has ever gone out and done it the first day - they've built it up over time. Swimmers who excel at 1,500 metres haven't started doing that the first day - they probably started at 25 or 50 metres.

So for those of you who haven't been doing much exercise, you need to start at a small level. For some of you who haven't done exercise for a long time, you may want to check with your doctor and have a little bit of a check-up before starting out. But for most people, if you start out at a low level, away you can go.

Walking is a really good form of exercise. You don't have to raise a major sweat, but you do want to be walking at a pace that is a little bit quicker than just ambling to the letter box. Power walking was very popular for a while and is still a reasonable form of exercise, but just walking itself hits all the buttons in terms of cardio exercise.

Other things we spoke of before, jogging and running are quite good as well. Swimming is an excellent form of cardio exercise. For those who don't like walking or running and perhaps have problems with their joints, walking through water is also a very good form of exercise. Bike riding is fine and you can do that out and about, or you can do it on an exercise bike at the gym, or in front of the TV if you're that way inclined. All of these are good forms of exercise. 

Now, a lot of cardio games or sports - like squash, tennis, football, basketball, the list goes on - are good forms of exercise. If you haven't done them for a while, you need to be training for them. There's often been an executive in particular who hasn't played squash for 15 years, decides they want to get fit, tears out on the squash court and suddenly has problems with a heart attack because they haven't done the preparation or the training. So it's really important that if you want to do sports like that, that you do some cardio exercise.  

Start at a low level, at something that's appropriate to you. If you're not quite sure where to start, have a chat to your doctor. A physio or personal trainer may be able to guide you on the exercise specifics, but for almost everybody you can start at a level of comfort and gradually build up. How do you know you're building up? Your walking distance goes further. You can go the same distance as last week and not feel quite as tired - that's the signal to go a little bit further.

For most people, aim for some cardio exercise 3-4 times a week if you can and for a minimum of 30-40 minutes per day. By the end of it, you raise a little bit of a sweat. You don't have to be drenched with sweat if that's not your thing, but you do need to have known that you've done a little bit of work. If you have, that's going to stand your health in a really good stead in general, and your cardiac system (which is your heart) in particular.

For more information on fitness and exercise, including stretches, types of exercise, exercise recovery and exercise with health conditions, as well as some useful videos, see Fitness and Exercise.

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Cardiac MRI (Magnetic Resonance Imaging)

MRI stands for magnetic resonance imaging, a diagnostic technique that uses harmless radio waves rather than x-rays to create images.

Cardiac magnetic resonance imaging (CMR) is currently the most accurate and reproducible technique for imaging the heart. It has outstanding image resolution and intrinsic tissue contrast. CMR is safe, non-invasive, and does not expose patients to ionising radiation. Sometimes a contrast dye is injected into the veins to highlight certain features that would not otherwise be visible. 

MRI is a safe and painless means of looking inside the body without using radiation. Detailed pictures of the body can be produced by using a large magnet, radio waves, and a computer, often providing information that could not be obtained from other investigations (e.g. x-rays or ultrasound).

 

The body is made up of small particles called atoms. Hydrogen atoms, a major component of water, make up 95% of your body. Normally, the hydrogen atoms within your body spin around at random. However, when a patient lies within the bore (the central tunnel) of a large, strong magnet, the same hydrogen atoms naturally line up and all spin in the same direction. When a radio wave is passed through the body, it causes the hydrogen atoms to give off signals. The scanner detects these signals and, with the aid of a computer, they are reconstructed into images of the body.

Until recently, clear pictures of the beating heart could not be obtained due to the heart's constant movement. To overcome this, cardiac MRI uses ECG gating. This allows the scanner to coordinate the pictures with the movement of the heart.

Patients are asked to change into a medical gown. As the magnetic field will damage credit cards, mobile phones and any electronic equipment, these must be left outside the scan room, along with all jewellery and clothing with metal (e.g. zips or jean rivets). The machine will make loud knocking noises while scanning, so patients are often provided with head phones which act as ear protectors and allow them to listen to music during the procedure. The patient lies down on a sliding 'table' and ECG electrodes are attached, before they are moved into the scanner.

The scan can last from 30 minutes to an hour. Patients may be asked to hold their breath for 10-20 seconds during some imaging sequences. The patient should remain motionless in order to produce a clear picture. Throughout the examination, radiographers are able to communicate with the patient via intercom to ensure that the patient is informed and comfortable.

There are several contraindications to MRI. In particular, patients who have implanted medical devices (e.g. pacemakers or defibrillators, cochlear implants, cerebral aneurysm clips), or who may have iron fragments in their eyes, are not suitable for MRI investigation. Orthopaedic pins, mediastinal clips, coronary stents, and the majority of artificial heart valves are safe to scan.

There are no known risks from undergoing MRI during pregnancy. However, as with any medical investigation, a patient who suspects that she is pregnant should seek advice on the risks versus benefits of undergoing the investigation.

Around 4% of patients will suffer from claustrophobia to a degree that will not allow them to tolerate a MRI scan. This can be reduced to < 2% by sedating with oral or IV benzodiazepines.

There is also the risk of patients being injured if they forget to remove pieces of metal from their person or clothing. If sedation is required, there are associated risks of overmedication. If a contrast dye is used, there is a small risk of an allergic reaction, although this risk is very low.

The MRI scan is a painless and safe scan that produces clear images of the body, from any angle. The pictures are clearer than those obtained by most other techniques, including both echo and SPECT scanning. It uses no radiation and therefore eliminates the substantial x-ray doses of cardiac CT scans.

Cardiac MRI is useful in a wide variety of cardiac conditions. It can demonstrate the structure and function of cardiac chambers, and help quantify the flow of blood through the cardiac valves. It is particularly valuable for assessing abnormal heart muscle (cardiomyopathy) and the damage done by previous heart attacks.

While MRI provides a very high standard image, it is time consuming and more expensive than some other investigations. Very obese patients may not be able to fit comfortably within the MRI machine, and patients with severe heart failure may struggle to lie flat for the duration of the test. Some patients will suffer from claustrophobia to a degree that will not allow them to tolerate a MRI scan. In patients with very fast heart rates, or frequent irregular beats, ECG gating can prove unreliable.

Although not yet widely available in many regions of Australia, cardiac MRI is an established technique in many countries for the diagnosis and management of diseases of the cardiovascular system.

The uses of a cardiac MRI include:

Aortic disease

Cardiac MRI accurately displays the size and shape the aorta. The lack of radiation makes cardiac MRI ideal for repeated examinations, such as the evaluation of patients with Marfan's syndrome and aortic dilatation, or serial review of coarctation as is seen in the image on the right. Cardiac MRI can also be used for the quantification and characterisation of cholesterol plaques in the major arteries.

Ischaemic heart disease

There are multiple approaches to detecting coronary artery disease by cardiac MRI. Blood flow can be assessed at rest and under stress to demonstrate significant coronary blockages. Due to the higher resolution, cardiac MRI may be able to detect smaller areas of ischaemia than would be visible by nuclear scanning. This high resolution also allows detection of wall motion abnormalities, which may affect the heart's function.

Cardiac MRI can be used for determining the presence, size and location of a heart attack by the technique of delayed enhancement. Delayed enhancement accurately defines myocardial scar, and provides a reliable method to assess the likelihood of recovery of heart function after bypass surgery. It can also be helpful in deciding the cause of heart failure. Coronary arteries can be visualized by cardiac MRI, and coronary stenoses can be demonstrated. It is also possible to assess the flow within the coronary arteries.

Cardiomyopathy

While echocardiography is still the mainstay of diagnosis in cardiomyopathies, cardiac MRI can be used to demonstrate the abnormalities in heart muscle and function, particularly those associated with cardiomyopathies. In particular, cardiac MRI is useful in the diagnosis and follow-up of arrhythmogenic right ventricular dysplasia.

Cardiac masses

Echocardiography remains the initial diagnostic tool for the assessment of cardiac masses, particularly thrombus or tumour. Unlike an echocardiogram, cardiac MRI can easily differentiate between these two diagnoses. It is also useful in the classification of cardiac tumours.

Valvular heart diseases

Cardiac MRI can now be used to clearly assess valvular heart diseases (e.g. narrowed or leaky heart valves), and any damage they have caused to the heart.

Pericardial disease

The pericardium is a fibrous sack that surrounds the heart. An MRI can show any changes to the structure of this sack, and help decide the difference between diseases of the pericardium and of the heart muscle.

Congenital heart diseases

Cardiac MRI is used to give detailed information about the structure and function of the heart in cases where there have been problems with the heart's development. A cardiac MRI can also be used to give an idea of how and where blood is flowing, which can often be very complicated.

Other

CMR is useful in a wide variety of other cardiac diseases, including left ventricular non-compaction, infiltrative cardiomyopathy and myocarditis. In siderotic cardiomyopathy, caused by iron deposition, myocardial biopsy can be avoided by the use of cardiac MRI.

(Kindly reviewed by Dr JF Younger FRACP MRCP, BHF Cardiac MRI Unit, Department of Academic Cardiology, Leeds General Infirmary, Leeds, West Yorkshire, UK.) Anderson LJ, Holden S, Davis B, et al. Cardiovascular T2* magnetic resonance for the early diagnosis of myocardial iron overload. Eur Heart J. 2001; 22: 2171-9. Bellenger NG, Davies LC, Francis JM, et al. Reduction in sample size for studies of remodelling in heart failure by the use of cardiovascular magnetic resonance. J Cardiovasc Magn Reson. 2000; 2: 271-8. Cesare ED, Giordano AV, Cerone G, et al. Comparative evaluation of TEE, conventional MRI and contrast-enhanced 3D breath-hold MRA in the post-operative follow-up of dissecting aneurysms. Int J Card Imaging. 2000; 16: 135-47. Chernoff D, Stark P. Principles of magnetic resonance imaging [online]. UpToDate. [cited 13 July 2006]. Available at URL: http://www.uptodate.com Fayad ZA, Nahar T, Fallon JT, et al. In vivo magnetic resonance evaluation of atherosclerotic plaques in the human thoracic aorta: a comparison with transesophageal echocardiography. Circulation. 2000; 101: 2503-9. Hornak JP. The basics of MRI, 2006 [online]. The Centre for Imaging Science. [cited 12 July 2006]. Available from URL: http://www.cis.rit.edu/ htbooks/ mri/Kanal E, et al. ACR White Paper on Magnetic Resonance Safety: ACR Magnetic Resonance Safe Practice Guidelines. American College of Radiology, 2004. Kim RJ, Wu E, Rafael A, et al. The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction. N Engl J Med. 2000; 16: 1445-53. Klein C, Nekolla SG, Bengel FM, et al. Assessment of myocardial viability with contrast enhanced magnetic resonance imaging: Comparison with positron emission tomography. Circulation. 2002; 105: 162-7. Magnetic Resonance Imaging: Body [online]. Radiology Info. Radiological Society of North America, 2006 [cited 12 July 2006]. Available at URL: http://www.radiologyinfo.org/ Magnetic Resonance Imaging: Cardiac [online]. Radiology Info. Radiological Society of North America, 2006 [cited 12 July 2006]. Available at URL: http://www.radiologyinfo.org/Mahrholdt H, Goedecke C, Wagner A, et al. Cardiovascular magnetic resonance assessment of human myocarditis: A comparison to histology and molecular pathology. Circulation. 2004; 109: 1250-8. McCrohon JA, Richmond DR, Pennell DJ, et al. Isolated non-compaction of the myocardium: A rarity or missed diagnosis? Circulation. 2002; 106: e22-3. Pennell DJ, Sechtem UP, et al. Clinical indications for cardiovascular magnetic resonance (CMR): Consensus Panel Report. Journal of Cardiovascular Magnetic Resonance. 2004; 6(4): 727-65.Plein S, Greenwood JP, Ridgeway JP, et al. Assessment of non-ST segment elevation acute coronary syndromes with cardiac magnetic resonance imaging. J Am Coll Cardiol. 2004; 44(11): 2173-8. Reimer P, Parizel PM, Stichnoth FA (editors). Clinical MR Imaging: A Practical Approach (2nd Edition). Heidelberg, Springer-Verlag, 2003. Schwitter J, Nanz D, Kneifel S, et al. Assessment of myocardial perfusion in coronary artery disease by magnetic resonance: A comparison with positron emission tomography and coronary angiography. Circulation. 2001; 103: 2230-5.



This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

What Are Drugs? (Introduction to Pharmacology)

The study of drugs or chemicals and the effects they have on living animals is called pharmacology. Pharmacology explains what drugs are, what they do to body functions and what the body does to them. Pharmacology also explains why a person may experience side effects when they take drugs and why there is such a wide spectrum of differences between drug actions in different people.

Everyone at one stage or another in life will rely on a pharmaceutical product, whether it is for themselves, a friend or a family member. Therefore it is useful to have a basic understanding of pharmacology.

A drug is a chemical that interacts with proteins in the body to affect a physiological function. This is the general idea behind all medicine. Once these chemicals are absorbed into the systemic circulation they bind with certain proteins and this changes the functioning of the cell slightly. For example, anticancer drugs bind to proteins on the surface of cancer cells this stimulates the cells to die. In this case cell death is the physiological action of the drug.

No drugs are specific to interacting with just one type of cell or one type of protein and this is what causes side effects. Again using an anticancer drug as an example, the medication works by binding to very rapidly dividing cells, such as cancer cells, however hair cells are also rapidly dividing and that is why one of the side effects of anticancer drugs is hair loss.

The chemical in the drug that affects physiological functioning is the active ingredient of the drug. For most drugs, the amount of chemical needed to cause an effect is very small, often as small as 5 micrograms; this is 0.005% of a gram! As you can imagine this is too small to package and handle, these ingredients are very expensive and giving out little amounts like that will cause most of the drug to be lost and wasted. Therefore most of the drugs that we take are also comprised of inactive ingredients  that work to fill out the drug. Inactive ingredients are, as the name suggests, ingredients that have no effect on the functioning of cells, namely lactose, dyes and gluten. If the drug needs to be taken orally, the inactive ingredients also work to bind the drug together and lubricate the drug so it is easy to swallow.

So the inactive ingredients are the fillers, binders and lubricants of the drug whereas the active ingredient is the very small amount of chemical that reacts with the body to produce an effect.

Our bodies are largely controlled by proteins. Proteins exist in many different forms in the body and have many different functions. Each protein has a specific function and is quite specific to the cell type that it acts on. For example, there are specific types of proteins called receptors. Receptors are embedded on the cell surfaces, there are different receptors for different types of cells. A liver cell will have different receptors than a cardiac cell. The receptor binds to other proteins and chemicals on the outside of the cell and this in turn creates a change in the functioning of the cell.

Proteins also act as drug targets. In order for a drug to exert an effect it needs to be bound to a protein. This can be thought of as a lock and key system; where the drugs are the key and the protein is the lock. Once the drug is bound in this lock and key mechanism it can have one of two main influences over the cell. It can produce a change in response or it can stop a normal response of the cell.

Drugs that produce a change in the cell functioning are called agonists. Drugs that stop a normal function of the cell are called antagonists.

Once the drug is bound to a protein it exerts a therapeutic effect on the body, this is the pharmacodynamics of a drug. There is an enormous list of different drugs and their actions in the body. Below are links to just some of the major treatment areas.

Pharmacokinetics is the study of what happens to drugs once they enter the body. The main stages include:

Each drug will have a unique bioavailability. This is the amount of drug available to have an effect on the biological system. A drug's bioavailability is determined by its pharmacokinetics. For example, some drugs are poorly absorbed as they do not cross cell membranes as quickly or as effectively as others and so less of the drug will pass into the systemic circulation where it needs to be in order to have an effect.

The proportion of the drug that does pass into the circulation is called the drug-plasma concentration. When a drug is absorbed into the circulation, the plasma concentration will increase until it reaches a peak and then as the drug is metabolised this plasma concentration will decline until the entire drug has been metabolised and then excreted from the body. Depending on the characteristics of the drug some will reach the peak plasma concentration quicker than others or be metabolised faster and so on.

Each drug has a range of dosages that can effectively treat a condition while still remaining safe. That is, the range between the lowest dose that has a positive effect, and the highest dose before the negative effects outweigh the positive effects. This is known as the therapeutic window the drug. This can vary substantially between different types of drugs. For example, one drug could be safe and efficacious anywhere between 5mg to 20mg of whereas another could have the therapeutic window between 15mg and 20mg.

Many of the reasons that we see such a wide and diverse range of efficacies of drugs across people are that drugs work differently in different people. A drug will usually produce the same qualitative effect across individuals, that is to say that it will produce the same end result and the same side effects but the quantity of these effects will be different. So some people may experience a shorter action of the drug or a more intense side effect.

This variation is due mostly to differences in pharmacokinetics and pharmacodynamics between ethnicity, age, genetic makeup and disease state.

Ethnicity

There are quite substantial differences in drug metabolism between people of different ethnicities. Asians are usually more sensitive to most drugs than Caucasians and Caucasians are more sensitive then afro-carrabeans.

Age

Elimination of the drug from the body is directly influenced by age. Newborns and elderly experience the effects of drugs for longer and the drug takes a lot longer to be eliminated from the body.

Newborns

When babies are born to term, their renal function is very quick to establish similar levels to adults within one week after birth. If the baby is born prematurely it can take 8 weeks or more to reach the level of enzymes necessary. If drugs are given before the renal function is at this level, the drug elimination from the body takes a lot longer and so do the effects of the drugs.

Elderly

Renal filtration rate begins to decline at 20 years of age and by 50 years of age it has declined by 50%. This again will affect the elimination of drugs from the body.

Genes

The differences in our genes are also an important determinant of variability in what our bodies to do the drugs.

Disease state

There are many different disease states that affect pharmacokinetics. In fact most diseases will affect pharamcokinetics to some degree and this is for your doctor to determine and consider when prescribing medication. Diseases of the liver and kidneys will affect drug metabolism and excretion whereas diseases of the gastroenterological systems will affect the absorption of drugs. Receptors, the blood-brain barrier, blood, heart and skin are just some other areas that, if affected by disease, can impair the therapeutic action of drugs.

During pregnancy the process of drug elimination from the body becomes very complicated. The increased cardiac stress put on the mother's body enables the kidneys to increase their filtration rate. This is the opposite for the growing baby; the drugs that cross the placenta to the foetus will be eliminated very slowly as the kidneys and liver are not fully developed. Taking medication anytime during pregnancy can affect the growing foetus but the first trimester is the high risk zone.

As a result, when a woman is pregnant their doctor has an especially difficult job in weighing up the risks versus benefits of prescribing a drug. Not only must the patient's risk benefit be determined but also the risk for the developing foetus. Determining foetal risk from drug exposure is near impossible due to the lack of scientific data in the area.

That said, there is a list of drugs that are known to be harmful to a developing baby and these are called teratogens, examples of these are alcohol and cigarette smoke. Teratogens must be strictly avoided during pregnancy. If you are in doubt as to whether a medication you are taking could be teratogenic always check with your doctor.  

When weighing up the risks of prescribing medication the therapeutic decision is not the sole responsibility of the doctor but also the mother. Mothers will be made aware of the possible risks of the treatment and, through discussions with their doctor and family can decide for themselves whether they want to take the medication.

As a guide all drugs have been assigned a pregnancy category. The pregnancy categories describe the relative risk associated with the medication by summarising the information that is available to date. Each category puts into perspective the potential reliability of the information by describing the number of women that have been pregnant or of childbearing age that have taken the medication and the observable effects on the developing foetus. The categories provide an invaluable tool for weighing up the risk-benefit for doctors and patients.

Breastfeeding can expose a feeding child to toxicity due to the medication the mother is taking. The relative risk of toxicity through breast milk can be estimated by a doctor by weighing up the dose of the medication given, the amount from this that could be potentially excreted in breast milk and finally the potential dosage the infant will absorb systemically from the milk they ingest. Similar to the issue of medicating during pregnancy, large clinical trials have not been conducted in breastfeeding mothers and therefore the evidence is not available to support any certainty that the child will not be affected. If the mother needs to take medication which is known to be risky for children then the mother should not breastfeed her child. 

Most pharmaceutical products cannot be purchased without a prescription from a doctor. That said, there are quite a number of non-prescription or over-the-counter (OTC) drugs available that do not need clearance from a doctor in order to purchase and use. Depending on the particular medication, some OTC medicines can be found in supermarkets, convenience stores and petrol stations or can be purchased online. Buying medicines over the counter can be advantageous in that it allows the consumer to self-medicate minor health problems giving more of the power and control of health conditions to the individual.

There are disadvantages involved with non-prescription medications. As OTC drugs do not require a doctor's visit they have the potential to mask more serious medical issues. OTC drugs can also be associated with misuse and dependence.

Dependence on OTC medication is prevalent in society. The majority of consumers who do become dependent initially purchase OTC medication with the intention of treating a minor health issue but without proper guidance find it difficult to cease use of the drug. Only a small proportion of consumers purchase OTC with the intention to misuse the medication.

Before purchasing any over the counter medication it is advised that you speak to your pharmacist about the benefits, risks and appropriate use of the medication. Therefore it is wise that you purchase the medication from a community pharmacy rather than a supermarket.

e-pharmacies are online pharmacies where only non-prescription drugs can be purchased and delivered. Although this may seem like an easy option, a consumer cannot be sure they are receiving all the information they need in order to make an informed decision about whether to take the drug or whether further information is required. While some internet sites provide very accurate and comprehensive information there are some that provide poor quality information and do not identify possible drug interactions. Most OTC drugs are safe to use when used properly however it is always best to speak to your pharmacist or trained pharmacy assistant about dosing, drug interactions and other options.

An important point to note is that medications need to be suited to the individual, this is the area that pharmacists and doctors are trained to assess. When in doubt always ask a trained healthcare professional.

Polypharmacy is the use of multiple drugs at once for different reasons. This occurs most frequently in the elderly who need to take many different types of drugs a day. Drugs can be affected by the pharmacodynamics or pharmacokinetics of the other drug. For example a pharmacodynamic reaction would be if drug X works to decrease heart rate it may affect the distribution of drug Y due to the decrease in blood pressure. A pharmacokinetic reaction would be if both drugs are metabolised in the liver and therefore need to compete with the metabolisation enzymes.

The side effects associated with some medications are more detrimental than the disease state they are treating. It is in these situations when you and your doctor must work together to determine the risk and benefit profile of taking the medication. In order to completely determine the risks you MUST tell your doctor which medications you are taking concomitantly, including herbal supplements, any allergies you have and any previous adverse effects you have experienced from medication. 

Make sure you are aware of all the medications you are taking, what they are for and the risks associated with each. If the side effects are severe you may not want to continue with the treatment. Ask your doctor if there are any alternatives and if not discuss the consequences of not taking the medication. However, never stop a medication without the advice of your doctor.

Developing pharmaceutical products is an extremely expensive and long process, costing billions of dollars and taking over a decade to produce one drug! There are three main stages in the drug development process. These are:

Laboratory methods: this includes testing the newly formed/discovered molecule on cell cultures (these are cells in dishes in labs not within living organisms) and then animals (usually either rats or mice).Clinical trials: firstly on healthy human volunteers then moving onto patients undergoing medical treatment.Socioeconomic methods: assessment of the drug in the community, the adverse effects, the family of the patient's response, the healthcare costs etc.

Each stage of the process must pass strict safety and efficacy testing before the medicine can progress. Throughout all stages the scientists are determining the benefits versus risks of the new drug. For every drug there will be side effects and adverse effects in some patients. In order to determine whether the drug will have an overall benefit, the proportion of patients that respond positively to the treatment must be compared to the number of patients that respond negatively. So for example in a clinical trial sample of 1000 patients, if 996 patients experience a significant improvement in quality of life and 4 patients experience an adverse drug reaction, more than likely  the benefit outweighs the risk in this case. If 550 patients significantly improve and 450 patients experience adverse drug reactions the drug is not likely to be marketed. This of course depends on the nature and severity of the adverse events. 

Once the drug has been determined to be safe, effective and a significant cost-benefit it may be produced, marketed and distributed to the public. In Australia, the authority that makes the overruling decision is the Therapeutic Goods Administration (TGA).

Rang HP, Dale MM, Ritter JM, Moore PK. Pharmacology 5th ed. Elsevier Science; London: 2003.Vadja FJE. Generic substitution in epilepsy: A controversial issue. [online] The Epilepsy Report 2006. [cited March 2009] PDF available from: URL: http://www.epilepsyaustralia.net/Epilepsy_Information/Treatment_options/Treatment_options.aspx#GenericJones AW, Holmgren A, Kugelberg FC. Concentrations of scheduled prescription drugs in blood of impaired drivers: considerations for interpreting the results. Therapeutic Drug Monitoring. 2007; 29(2):248-60.Xie HG, Frueh FW. Pharmacogenomics steps toward personalised medicine. Personalized Medicine. 2005; 2(4): 325- 37.Bloche G. Race-Based Therapeutics. N Engl J Med. 2004: 351(20): 2035-7.Camí J, Farré M. Mechanisms of disease: Drug Addiction. N Engl J Med 2003; 349:975-86.Briggs GG, Freeman RK, Yaffe S. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. 8th Ed. Lippincott Williams & Wilkins; Philadelphia: 2008.Bedouch P, Allenet B, Grass A et al. Drug-related problems in medical wards with a computerized physician order entry system. Journal of Clinical Pharmacy and Therapeutics. 2009; 34: 187-95. McBride AJ, Pates R, Ramadan R, McGowan C. Delphi survey of experts' opinions on strategies used by community pharmacists to reduce over-the-counter drug misuse. Addiction. 2003; 98(4):487-97.Bessell TL, Anderson JN, Silagy CA, Sansom LN, Hiller JE. Surfing, self-medicating and safety: buying non-prescription and complementary medicines via the internet Quality & Safety in Health Care. 12(2):88-92, 2003.

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Moving more may lower stroke risk

Here’s yet another reason to get off the couch: new research findings suggest that regularly breaking a sweat may lower the risk of having a stroke.

A stroke can occur when a blood vessel in the brain gets blocked. As a result, nearby brain cells will die after not getting enough oxygen and other nutrients. A number of risk factors for stroke have been identified, including smoking, high blood pressure, diabetes and being inactive.

For this study, published in the journal Stroke, Michelle N. McDonnell, Ph.D., from the University of South Australia, Adelaide and her colleagues obtained data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. REGARDS is a large, long-term study funded by the NIH National Institute of Neurological Disorders and Stroke (NINDS) to look at the reasons behind the higher rates of stroke mortality among African-Americans and other residents living in the Southeastern United States.

“Epidemiological studies such as REGARDS provide an important opportunity to explore race, genetics, environmental, and lifestyle choices as stroke risk factors,” said Claudia Moy, Ph.D., program director at NINDS.

Over 30,000 participants supplied their medical history over the phone. The researchers also visited them to obtain health measures such as body mass index and blood pressure. At the beginning of the study, the researchers asked participants how many times per week they exercised vigorously enough to work up a sweat. The researchers contacted participants every six months to see if they had experienced a stroke or a mini-stroke known as a transient ischemic attack (TIA). To confirm their responses, the researchers reviewed participants’ medical records.

The researchers reported data for over 27,000 participants who were stroke-free at the start of the study and followed for an average of 5.7 years. One-third of participants reported exercising less than once a week. Study subjects who were inactive were 20 percent more likely to experience a stroke or TIA than participants who exercised four or more times a week.

The findings revealed that regular, moderately vigorous exercise, enough to break a sweat, was linked to reduced risk of stroke. Part of the protective effect was due to lower rates of known stroke risk factors such as hypertension, diabetes, obesity and smoking.

“Our results confirm other research findings but our study has the distinct advantage of including larger numbers, especially larger numbers of women as well as blacks, in a national population sample so these provide somewhat more generalizable results than other studies,” said Virginia Howard, Ph.D., senior author of the study from the School of Public Health, University of Alabama at Birmingham.

The researchers also looked at the data according to gender. After the researchers accounted for age, race, socioeconomic factors (education and income) and stroke risk factors, the results revealed that men who exercised at least four times a week still had a lower risk of stroke than men who exercised one to three times per week. In contrast, there was no association between frequency of exercise and stroke risk among women in the study. However, there was a trend towards a similar reduction in stroke risk for those who exercised one to three times a week and four or more times a week compared to those who were inactive.

“This could be related to differences in the type, duration, and intensity of physical activity between men and women,” said Dr. Howard. “This could also be due to differences in the perception of what is intense physical activity enough to work up a sweat.”

The results should encourage doctors to stress the importance of exercise when speaking with their patients, Dr. Howard said.

“Physical inactivity is a major modifiable risk factor for stroke. This should be emphasized in routine physician check-ups along with general education about the benefits of exercise on stroke risk factors including high blood pressure, diabetes and being overweight or obese,” she said.

The study suggests that men should consider exercising at least four times a week. 

REGARDS will continue to assess stroke risk factors to look for long-term patterns in the study population. “Findings from this study, including the current physical activity results, will ultimately help us to identify potential targets for immediate intervention as well as for future clinical trials aimed at preventing stroke and its consequences,” said Dr. Moy.

Source National Institue of Neurological Disorders and Stroke

Article Date: 23/7/2013

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Future doctors unaware of their obesity bias

Two out of five medical students have an unconscious bias against obese people, according to a new study by researchers at Wake Forest Baptist Medical Center. The study is published online ahead of print in the Journal of Academic Medicine. 

"Bias can affect clinical care and the doctore-patient relationship, and even a patient's willingness or desire to go see their physician, so its crucial that we try to deal with any bias during medical school," said David Miller, M.D., associate professor of internal medicine at Wake Forest Baptist and lead author of the study.

"Previous research has shown that on average, physicians have a strong anti-fat bias similiar to that of the general population. Doctors are more likely to assume that obese individuals won't follow treatment plans, and they are less likely to respect obese patients than average weight patients," Miller said. 

Miller and colleagues conducted the study as part of their efforts to update the medical school's curcciculum on obesity. The goa was to measure the prevalence of unconscious weight related biases among medical students and to determine whether the students were aware of those biases.

The three-year study included more than 300 third-year medical students at a medical school in southeastern United States from 2008 through 2011. The students were geographically diverse, representing at least 25 differemt states and 12 countries outside the United States.

The researchers used a computer program called the Weight Implicity Association Test (IAT) to measures students' unconscious preferences for "fat" or "thin" individuals. Students also answered a survey assessing their conscious weight preferences. The authors determined if the students were aware of their bias by seeing if their IAT results matched their stated preferences.

Overall, 39 percent of medical students had a moderate to strong uncoscious anti-fat bias as compared to 17 percent who had a moderate to strong anti-thin bias. Less than 25 percent of students were aware of their biases.

"Because anti-fat stigma is so prevalent and a significant barrier to the treatment of obesity, teaching medical students to recognise and mitigate this bias is crucial to imrpoving the care for the two-thirds of American adults who are now overwight or obese," Miller said. "Medical schools should address weight bias as part of a comprehensive obesity curriculum."

While this study did not address which teaching strategies are most effective, Miller said that a prerequisite to combating prejudice is to first acknowledge its existence. At Wake Forest Baptist, all third-year medical students in the family medicine clerkshop must complete the online IAT, and then participate in an in-class discussion of their experience with bias. In addition students must accept that their bias could affect their actions and adopt new strategies to mitigate bias, he said.

(Source: Wake Forest Baptist Medical Center: Journal of Academic Medicine)

For more information on obesity, health and social issues, and methods of weight loss, as well as some useful tools, see Obesity and Weight Loss.
Article Date: 22/6/2013

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Major weight loss tied to microbes

Scientists at Harvard may have new hope for people struggling with obesity.

A study conducted in collaboration with researchers at Harvard-affiliated Massachusetts General Hospital hints at a future where doctors could deliver the weight-loss benefits of gastric bypass surgery without the surgery. In a study described in a 27 March paper in Science Translational Medicine, researchers found that the surgery caused drastic changes to microbes in the guts of mice. When those microbes were transferred into the guts of sterile mice, the result was rapid weight loss.

"Simply by colonising mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight — about 20 percent as much as they would if they underwent surgery," said Peter Turnbaugh, a Bauer Fellow at the Faculty of Arts and Sciences' Center for Systems Biology, and one of two senior authors of the paper.

As striking as the results were, they weren't as dramatic as they might have been.

"In some ways we were biasing the results against weight loss," Turnbaugh said, explaining that the mice used in the study hadn't been given a high-fat, high-sugar diet to increase their weight beforehand. "The question is whether we might have seen a stronger effect if they were on a different diet."

"Our study suggests that the specific effects of gastric bypass on the microbiota contribute to its ability to cause weight loss, and that finding ways to manipulate microbial populations to mimic those effects could become a valuable new tool to address obesity," said the other senior author, Lee Kaplan, director of the Obesity, Metabolism & Nutrition Institute at MGH.

"We need to learn a good deal more about the mechanisms by which a microbial population changed by gastric bypass exerts its effects, and then we need to learn if we can produce these effects — either the microbial changes or the associated metabolic changes — without surgery," added Kaplan, an associate professor of medicine at Harvard Medical School. "The ability to achieve even some of these effects without surgery would give us an entirely new way to treat the critical problem of obesity, one that could help patients unable or unwilling to have surgery."

Turnbaugh warned that it could be years before the research contributes to treatment, and that any procedure tied to it would likely not be for someone looking to lose those stubborn last 10 pounds. Rather, the technique may one day help dangerously obese people who want to lose weight without the trauma of surgery.

"It may not be that we will have a magic pill that will work for everyone who's slightly overweight," he said. "But if we can, at a minimum, provide some alternative to gastric bypass surgery that produces similar effects, it would be a major advance."

While there had been hints that the microbes in the gut might change after bypass surgery, the speed and extent of the change came as a surprise.

In earlier experiments, researchers had shown that the guts of both lean and obese mice were populated by varying amounts of two types of bacteria — firmicutes and bacteroidetes. When mice undergo gastric bypass surgery, however, it "resets the whole picture," Turnbaugh said.

"The post-bypass community was dominated by proteobacteria and verrucomicrobia, and had relatively low levels of firmicutes," he said. What's more, Turnbaugh said, those changes occurred within a week of the surgery, and were lasting — the altered gut microbial community remained stable for months afterward.

There is plenty left to uncover about what exactly is driving the weight loss in mice, the researchers said.

"A major gap in our knowledge is the underlying mechanism linking microbes to weight loss," Turnbaugh said. "There were certain microbes that we found at higher abundance after surgery, so we think those are good targets for beginning to understand what's taking place."

In fact, he said, the answer may not be the specific types of microbes, but a by-product they excrete.

In addition to changes in the microbes found in the gut, researchers found changes in the concentration of certain short-chain fatty acids. Other studies have suggested that those molecules may be critical in signaling to the host to speed up metabolism.

"To some degree, what we're learning is a comfort for people who have an issue with their weight, because more and more we're learning that the story is more complicated than just how much you exercise and how much you eat," Kaplan said.

(Source: Harvard University : Science Translational Medicine)

For more information on obesity, health and social issues, and methods of weight loss, as well as some useful tools, see Obesity and Weight Loss.
Article Date: 12/4/2013

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Does This Medication Make Me Gain Weight?

(LifeWire) - In addition to poor diet and lack of exercise, one other culprit has been blamed for contributing to obesity: medication. Some of the most widely prescribed drugs in the United States -- for common conditions like diabetes, migraines, high blood pressure, depression and bipolar disorder -- have been found to cause weight gain.

Medications That Can Contribute to Weight Gain

Medication can add pounds to your figure in several ways:

Metabolism changes: Some drugs change the body's metabolism, and calories are burned more slowly.

Corticosteroids: Corticosteroids are known to stimulate appetite while reducing the body's ability to absorb glucose, which can promote fat deposits in the midsection.

Beta-blockers: Beta-blockers can cause shortness of breath and fatigue, making it difficult for patients taking them to exercise.

Calcium channel blockers: Calcium channel blockers taken for high blood pressure can cause users to retain water.

Antipsychotic medications: Drugs used to treat psychiatric conditions and mood disorders, like depression and bipolar disorder, are among those most closely associated with weight gain. It is so common with drugs like Paxil (paroxetine), Zoloft (sertraline), Clozaril (clozapine), Seroquel (quetiapine), Zyprexa (olanzapine) and Risperdal (risperidone) that researchers have called it "an epidemic within an epidemic."

As a result, the FDA has, since 2004, required manufacturers of certain antipsychotic medications to add a warning statement to doctors prescribing these drugs. The warning outlines the increased risk of diabetes and hyperglycemia that can result from use of the drugs.

Side Effects of Weight Gain

How much weight is gained varies from patient to patient and from drug to drug. Some patients may gain a few pounds over the course of a year; others experience weight gains in excess of 100 pounds in a matter of months. Because many of these drugs are taken for chronic conditions, their use over a period of several years can contribute to substantial weight gains patients often experience.

In addition to the emotional and social dimension of weight gain, patients can also experience serious health conditions -- diabetes, high blood pressure, osteoarthritis, metabolic syndrome, high cholesterol -- that are created or made worse by added weight.

Perhaps the most serious result of drug-induced weight gain is that many patients stop taking their medication or decide on their own to switch to a lower dosage. As a result, potentially serious underlying health conditions may go untreated. Lack of compliance with a drug regimen because of weight gain has been cited as a particular problem with patients taking antipsychotic and antidepressant drugs.

Some healthcare providers proactively tell their patients about the potential for weight gain when prescribing certain drugs and advise the patients to moderate their diet and increase their aerobic exercise to offset any weight increases.

Alternative Medications

All patients, regardless of condition, should talk to their healthcare provider before stopping medication or changing doses.

In many cases, your doctor may be able to recommend a drug that works just as well without the added pounds. Or, your doctor may decide to prescribe an additional drug to treat any weight gain you might experience.

Sources:

"2004 Safety Alert: Zyprexa (Olanzapine)." fda.gov. 22 Mar. 2004. Food and Drug Administration. 27 Feb. 2009 .

Deshmukh, Rashmi and Kathleen Franco. "Managing Weight Gain as a Side Effect of Antidepressant Therapy." Cleveland Clinic Journal of Medicine 70:7 (2003): 614-23. 27 Feb. 2009 .

Fenton, Wayne S. and Mark R. Chavez. "Medication-Induced Weight Gain and Dyslipidemia in Patients With Schizophrenia." American Journal of Psychiatry 163 (2006): 1697-704. 27 Feb. 2009 .

"Prescription Drugs That Cause Weight Gain." Johns Hopkins Health Alert. Jun. 2008. Johns Hopkins Medicine. 27 Feb. 2009 .

Simpson, MM, et al. "Weight Gain and Antipsychotic Medication: Differences Between Antipsychotic-Free and Treatment Periods." Journal of Clinical Psychiatry 62:9 (2001): 694-700. 27 Feb. 2009 .

LifeWire, a part of The New York Times Company, provides original and syndicated online lifestyle content. Marc Lallanilla is a New York-based freelance writer and editor. He has written extensively on health, science, the environment, design, architecture, business, lifestyle and travel.

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

How Many Calories Should I Eat?

Q: How many calories should I eat? I am a 32-year-old man.

A: That answer varies a little based on your lifestyle. It also depends on whether you are hoping to simply avoid weight gain or you want to lose weight. A male between the ages of 31 and 35 who is sedentary -- meaning you get less than 30 minutes a day of moderate physical activity -- can consume roughly 2,200 calories per day and maintain your weight, according to USDA recommendations. If you are active, you can consume between 2,400 and 3,000 calories daily without experiencing weight gain.

You can calculate your BMR (basal metabolic rate) using a simple math formula and factor in your own personal activity level. If you want to lose weight (and save yourself some math), check out Calories Needed for Goal Weight at About.com's Calorie Count. Simply enter your current weight and your goal weight to find out your caloric recommendations.

If you do want to lose weight, most people find it most comfortable to cut a set number of calories (around 250-500) per day, rather than making drastic dietary changes. Another option is to burn more calories with exercise, or, ideally to do a combination of both (e.g. cut 250 from your diet and burn an extra 250 with activity). As a rule of thumb, 3,500 calories is equal to one pound, so if you cut or burn a total of 500 calories daily, you could lose one pound a week, which is a safe rate at which to lose.

The following resources can help you understand your caloric needs a little better:

About.com's Calorie Count offers a way for you to enter your personal information to find your daily calorie expenditure. The site also offers free tools to track your caloric intake throughout the day with an online food diary and keep up with your "burn" (the calories you use up).

You may also find mypyramid.gov helpful.

Losing weight by cutting calories isn't just about eating less, but also getting the most "bang" for you calorie buck. It's important to educate yourself on nutrition and healthy food choices. After all, if you're only going to "spend" a certain number of calories each day, you'll want to use them on the most healthful, nutritious foods.

Source:
MyPyramid.gov. Inside the Pyramid - How many discretionary calories can I have?. 11 Sept 2008.

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More

Basal Metabolic Rate

Definition: Basal metabolic rate (BMR) refers to the minimum amount of energy -- in the form of calories -- that your body requires to complete its normal functions, such as breathing, breaking down food, and keeping your heart and brain working. Age, gender, weight, and physical activity directly effect on basal metabolic rate.

BMR varies from person to person and increases with your amount of muscle tissue. Exercising increases your BMR, and it can stay raised after 30 minutes of moderate physical activity. Many people's BMR stays increased for approximately 48 hours following exercise.

Common Misspellings: basil metabolic rateBasal metabolic rate is typically reduced as we age.

Weight Loss Glossary

View the original article here

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

Read More