Dehydration is the leading cause of death among children across the globe. In fact it is the dehydration that occurs as a result of diarrhea that is the killer in high risk groups like infants and children. The focus is therefore more often on diarrhea than on dehydration. Most, if not all of these deaths are preventable had the dehydration been managed and treated appropriately. Unfortunately there are a number of factors that hampers the proper treatment of dehydration with a lack of knowledge being of the leading factors.
What is dehydration?
Dehydration is a state where there is a net fluid loss as a result of more fluid being lost than fluid taken in. We lose fluid throughout the day, through sweat, urine, the air we exhale and in our stool. However, our daily fluid intake ensures that we never lose more fluid than we are taking in. When the fluid intake is too great the kidneys will pass out the excess fluid. Similarly when the fluid intake is too low the kidneys will preserve fluids. Overall the body should have enough fluid to maintain an inner state of balance known as homeostasis. In dehydration however, the fluid loss exceeds the fluid intake to the point that the fluid volume in the body consistently decreases.
With this fluid loss, there is also a loss of electrolytes (salts). Collectively the loss of fluid and electrolytes can disturb the various biochemical processes in the body and even impair organ function. Eventually it can lead to death. The use of oral rehydrating solutions (ORS) is the best option for preventing and treating dehydration as it replaces both fluids and electrolytes in the optimum concentration. An ORS is not necessary for daily use as water alone will suffice. However, when the risk of dehydration is great like during diarrheal illnesses, an ORS can make the difference between life and death.
Causes of Dehydration
The daily loss of fluid through sweat, urine, air and stool does not usually lead to dehydration unless a person cannot or does not consume sufficient fluid in a day. Normally the fluid loss is slow but can speed up when in hot environments and with strenuous physical activity due to profuse perspiration. However, in other conditions like with diarrhea the fluid loss is rapid and normal patterns for fluid intake are not sufficient to meet the fluid loss. Even the body’s best efforts to preserve water loss like reducing urine output and sweat production will not suffice.
The causes of dehydration therefore include:
- Gastroenteritis is the inflammation of the stomach and bowels often due to viruses and bacteria. It is among the most common cause of dehydration. Fluid loss occurs through vomiting and diarrhea.
- Fever leads to fluid loss through the profuse perspiration but often febrile illnesses affect appetite and eating/drinking. Therefore there is also insufficient fluid intake at the same times as the fluid loss.
- Heat stroke is the most severe form of heat illness. Dehydration is at the most severe at this point. Apart from heat waves, heat stroke can even occur indoors when the environmental heat is extreme or the body’s cooling mechanism is inefficient.
- Burns can lead to dehydration due to fluid loss through the wounds. The damaged skin cannot prevent fluid loss in the way health skin can. The extent of fluid loss depends on the extent and degree of burns.
- Thyroid overactivity results in fluid loss from profuse perspiration and often there is diarrhea as well.
- Diabetes mellitus is associated with polyuria (large volume urine output with frequent urination). Fluid loss may speed up significantly during diabetic emergencies like diabetic ketoacidosis.
- Mouth and throat problems like a sore mouth (stomatitis) or sore throat (pharyngitis) may limit fluid intake due to the pain and discomfort.
- Diabetes insipidus is a condition where the kidneys do not respond properly to the hormone ADH. As a result the kidneys cannot preserve fluids as necessary. Large amount of fluid loss therefore occurs in the urine.
- Diuretics (substances that promote fluid loss) which may include prescription medication, alcohol and certain illicit substances can also lead to dehydration although the fluid loss is often not as rapid as in other causes.
Signs and Symptoms
Very mild dehydration may not present with any symptoms. In fact many of the early symptoms are often ignored as it does not cause any significant discomfort or debility.
- Increased thirst although sometimes this thirst sensation may be impaired.
- Dry mouth often with low volume sticky saliva.
- Dry skin which becomes shriveled with severe dehydration
- Dry eyes with reduced tear production evident when crying.
- Reduced urine output (less frequent urination and small quantity).
- Headache (refer to dehydration headache)
- Sunken eyes with severe dehydration.
- Low blood pressure, rapid heart rate and rapid breathing.
- Delirium or unconsciousness.
- Fever may arise with dehydration as well as being a cause.
Why does death occur?
Severe untreated dehydration can lead to a coma and death. There are many ways in which death can occur due to dehydration. These complications to some extent depend on the time period over which dehydration occurs and is further influenced by the method of fluid loss as well as any pre-existing diseases. Complications of dehydration that may be deadly include:
- Irreversible hypovolemic shock.
- Kidney failure.
- Intractable seizures.
Sometimes the complication itself is not fatal but may lead to other events that could be life-threatening. Cerebral edema is another complication that may be associated with dehydration. It occurs when there is rapid rehydration in order to treat dehydration. Fluid may accumulate in the brain (cerebral) thereby causing swelling (edema). Some brain cells can burst and if cerebral edema is extensive it can be life-threatening.
Treatment of Dehydration
Dehydration can be easily treated and prevented. However, the treatment measures need to be implemented promptly. Any person who is at risk of dehydration should commence with the appropriate measures even if there are no signs of dehydration. The main way to treat dehydration is through oral rehydration therapy. This involves the use of oral rehydrating solutions (ORS). Commercial varieties can be easily purchased and are the best option as it has the optimal concentration of fluid and electrolytes. Alternatively home-made ORS can also be used.
However, there are instances where an ORS may not be viable. Firstly a person who is vomiting or unconscious cannot drink an ORS and therefore IV fluid administration. Secondly in severe dehydration it is important to ensure rapid rehydration and once again IV fluid administration may be the better choice. Furthermore if there are other complications that require hospitalization then IV fluid administration is often the preferred choice since the patient is in the hospital setting and can be appropriately monitored.
Other measures to treat dehydration depends on the cause of the fluid loss. This may include placing a person in a cool room for a heat stroke, using antidiarrheal agents for persistent chronic diarrhea, using antidiabetic medicines for diabetes-related fluids loss and so on. Medical treatment should always be sought for moderate to severe dehydration although mild dehydration can be easily treated at home.