Click Here

Thursday, April 10, 2008

Dehydration

Dehydration occurs when you lose more fluid than you take in and your body doesn't have enough water and other fluids to carry out its normal functions. If lost fluid remains unreplenished, you may suffer serious consequences.

Common causes of dehydration include intense bouts of diarrhea, vomiting, fever or excessive sweating. Inadequate intake of water during hot weather or exercise also may deplete your body's water stores. Anyone may become dehydrated, but young children, older adults and people with chronic illnesses are most at risk. Mild dehydration can cause symptoms such as weakness, dizziness and fatigue. Severe dehydration is a life-threatening medical emergency.

You can usually reverse mild to moderate dehydration by increasing your intake of fluids, but severe cases need immediate medical treatment. The safest approach is not to become dehydrated in the first place. You can do that by monitoring your fluid loss during hot weather, illness or exercise, and drinking enough liquids to replace what you lose.

Causes:
If you're an average adult, every day you lose more than 10 cups (close to 2.5 liters) of water simply by sweating, breathing and eliminating waste. You also lose electrolytes — minerals such as sodium, potassium and calcium that maintain the balance of fluids in your body. Normally, you can replenish what you've lost through the foods and liquids you consume, even when you're active.

But when you eliminate more water and salts than you replace, dehydration results — your system literally dries out. Sometimes dehydration occurs for simple reasons: You don't drink enough because you're sick or busy, or because you lack access to potable water when you're traveling, hiking or camping.

* Diarrhea, vomiting- Severe, acute diarrhea, that is, diarrhea that comes on suddenly and violently — can cause a tremendous loss of water and electrolytes in a short amount of time. If you have vomiting along with diarrhea, you lose even more fluids and minerals. Children and infants are especially at risk. Worldwide, more than 1.5 million infants and children die of dehydration resulting from diarrhea every year — 300 to 500 of them in the United States. Most of these deaths occur in the first year of life.
* Fever- In general, the higher your fever, the more dehydrated you may become. If you have a fever in addition to diarrhea and vomiting, you lose even more fluids.
* Excessive sweating- You lose water when you sweat. If you engage in vigorous activity and don't replace fluids as you go along, you can become dehydrated. Hot, humid weather increases the amount you sweat and the amount of fluid you lose. But you can also become dehydrated in winter if you don't replace lost fluids. Preteens and teens who participate in sports may be especially susceptible, both because of their body weight, which is generally lower than that of adults, and because they may not be experienced enough to know the warning signs of dehydration.
* Increased urination- This is most often the result of undiagnosed or uncontrolled diabetes mellitus, a disease that affects the way your body uses blood sugar and that often causes increased thirst and more frequent urination. Another type of diabetes, diabetes insipidus, is also characterized by excessive thirst and urination, but in this case the cause is a hormonal disorder that makes your kidneys unable to conserve water. Certain medications — diuretics, antihistamines, blood pressure medications and some psychiatric drugs — as well as alcohol also can lead to dehydration, generally because they cause you to urinate or perspire more than normal.
* Burns- Doctors classify burns according to the depth of the injury and the extent of tissue damage. Third-degree burns are the most severe, penetrating all three layers of skin, and often destroying sweat glands, hair follicles and nerve endings. People with third-degree burns or extensive first- or second-degree burns experience profound fluid loss, and the resulting dehydration can be life-threatening.

Symptoms:
Mild to moderate dehydration is likely to cause:
Dry, sticky mouth, Sleepiness or tiredness — children are likely to be less active than usual, Thirst, Decreased urine output — fewer than six wet diapers a day for infants and eight hours or more without urination for older children and teens, Few or no tears when crying, Muscle weakness, Headache, Dizziness or lightheadedness.

Severe dehydration, a medical emergency, can cause:
Extreme thirst, Extreme fussiness or sleepiness in infants and children; irritability and confusion in adults, Very dry mouth, skin and mucous membranes, Lack of sweating, Little or no urination — any urine that is produced will be dark yellow or amber, Sunken eyes, Shriveled and dry skin that lacks elasticity and doesn't "bounce back" when pinched into a fold, In infants, sunken fontanels — the soft spots on the top of a baby's head, Low blood pressure, Rapid heartbeat, Fever, In the most serious cases, delirium or unconsciousness.

Diagnosis:
Your doctor can often diagnose dehydration on the basis of physical signs and symptoms such as little or no urination, sunken eyes, and skin that lacks its normal elasticity and resilience when pinched. If you're dehydrated, you're also likely to have low blood pressure, especially when moving from a prone to a standing position, a faster than normal heart rate and reduced blood flow to your extremities.

To help confirm the diagnosis and pinpoint the degree of dehydration, you may have other tests, such as:
* Blood tests- These may be used to check your electrolytes, especially sodium and potassium; to look for signs of concentrated blood; and to evaluate how well your kidneys are working.
* Urinalysis- The color and clarity of your urine, the presence of carbon compounds (ketones) and your urine's specific gravity — that is, the mass of the urine as compared with equal amounts of distilled water — all help show whether you're dehydrated and to what degree. A high specific gravity, for example, indicates significant dehydration.

If it's not obvious why you're dehydrated, your doctor may order additional tests to check for diabetes and for liver or kidney problems.

Treatment:
The only effective treatment for dehydration is to replace lost fluids. The best approach to dehydration treatment depends on your age, the severity of your dehydration and its cause.

Treating dehydration in sick children
Your doctor can offer specific suggestions for treating dehydration in your child, but some general guidelines include the following:
Use an oral rehydration solution. Unless your doctor advises otherwise, use an oral rehydration solution such as Pedialyte for infants and children who have diarrhea, vomiting or fever. These solutions contain water and salts in specific proportions to replenish both fluids and electrolytes. They also contain glucose or another carbohydrate such as rice powder to enhance absorption in the intestinal tract. Oral rehydration products are readily available in most drugstores, and many pharmacies carry their own brands. Begin giving fluids early in the course of an illness instead of waiting until the situation becomes urgent.

In most developing countries, you can buy packets of a powdered oral rehydration solution, WHO-ORS, originally developed by the World Health Organization to treat diarrhea and dehydration in infants with cholera. Reconstitute the powder in water according to the directions on the package. Always boil the water first, remeasure the water, then add the powdered oral rehydration material.

Treating dehydration in sick adults
Most adults with mild to moderate dehydration from diarrhea, vomiting or fever can improve their condition by drinking more water. Avoid coffee, tea and other beverages that contain caffeine, as they may temporarily increase dehydration. Fruit juices and sodas can make diarrhea worse.

Treating dehydration in athletes of all ages
For exercise-related dehydration, cool water is your best bet. Sports drinks containing electrolytes and a carbohydrate solution also may be helpful. There's no need for salt tablets — too much salt can lead to hypernatremic dehydration, a condition in which your body not only is short of water but also carries an excess of sodium.

Treating severe dehydration
Children and adults who are severely dehydrated should be treated by emergency personnel arriving in an ambulance or in a hospital emergency room, where they can receive salts and fluids through a vein (intravenously) rather than by mouth. Intravenous hydration provides the body with water and essential nutrients much more quickly than oral solutions do — something that's essential in life-threatening situations.

No comments: