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Course Sample:
RISK OF DEHYDRATION IN ADULTS Almost any major illness can alter fluid and electrolyte balance in the elderly. The aging adult has a multitude of clinical diagnoses that alter physiological responses in his/her body. He/she also has limited physiological reserves. So when acute or chronic illness strikes or worsens, the fluid and electrolyte balance is at risk. With aging, the physiological reserves in the body are decreased, and homeostasis becomes more precarious. An old person's body is simply less able to guard the water supply. With less water to work with, any disease or environmental stress causes a risk of dehydration. According to Phillips (1993), "Up to 25 percent of non-ambulatory geriatric patients are chronically mildly dehydrated ?" For all ages, and particularly the elderly, fluid balance is very important to health. The consequences of dehydration are serious. This module reviews the signs and symptoms of dehydration. THE FUNCTIONS OF FLUIDS Water has many important functions in the body. The first is as a solvent carrying fluid, oxygen and glucose to all cells of the body, and carrying waste products away from the body. A decrease in fluids means less fluid is available to circulate oxygen to the brain. Deprivation of oxygen to the brain causes severe mental and physiological changes. Thus, common side effects of an inadequate fluid intake are confusion and falls. With an adequate fluid intake, water flushes out waste products from the body. This is especially important to prevent bladder infections. Without adequate fluid intake waste products accumulate in the warm, moist atmosphere of the bladder and in time lead to a urinary tract infection. Another function of water is to assist with movement of the joints, including the spine. This is important for the elderly, who frequently have difficulty with joint movement due to chronic diseases such as arthritis, Parkinson's Disease and other diseases affecting their muscle and joint movement. Water also cushions the cells. A decrease in fluid status is a contributor in development of pressure sores. Dehydration causes decreased cushioning of cells, increasing the risk of pressure, resulting in a pressure ulcer. Water also acts as a solvent for the biochemical processes that take place in each cell of the body. Water provides fluids for digestion, including saliva, gastric, bile and pancreatic juices. Decreased fluid impairs the body's ability to carry out the necessary chemical actions, carry nutrients to the cells and carry waste products away from the cells. Fluid acts as a coolant for the body. Thus, a person with a fluid loss may have an elevated body temperature. SOURCES OF FLUID Water is found in: - Fluids such as water, gelatin (Jell-O), juices and other beverages.
- Fluids are found in foods. Most foods are 60-80 percent water. The exceptions are baked foods, fats and oils.
- Water also comes from the metabolic breakdown of food or oxidative metabolism.
Fluids come from drinking fluids orally, from foods that contain a high percentage of water, and from burning calories that provide fluid. There is one cc of fluid released for every calorie metabolized. This is called the water of oxidation. Foods that are fluid at room temperature are considered in fluid intake. This amount is usually 1500 cc. The fluid from food is about 700 cc, with 200 cc coming from the water of oxidation. The combined total of recommended fluid intake is 2400 cc. The obese adult has the same fluid requirement per kilogram of weight as the non-obese adult. The obese have excessive fat. Fat does not hold water. The obese adult has only 45 percent body water, as compared to the non-obese adult, who has 60 percent body water. (Loeb, 1994). Fluid losses in a day roughly balance the fluid intake of about 1500 cc. The losses from the skin and lungs are about 920-1000 cc. This fluid loss is called an insensible water loss because the resident is not aware of the fluid loss. Urinary losses account for a daily fluid loss of 500-1400 cc, and about 80-100 cc are lost daily through the stool. When there are abnormal fluid losses fluid balance can quickly become compromised. When abnormal fluid losses are accompanied by a suboptimal fluid intake, a serious deficit fluid balance results. Other sources of fluid losses include fever, diarrhea, bleeding, use of air fluidized beds, etc. There are three ways to calculate fluid requirements. ADULT FLUID REQUIREMENTS (Winkler, 1993) Calculations (assuming normal renal and cardiac function, and euvolemia [normal hydration status]). - 30 ml/kg body weight
- 1 ml/kcal intake (referring to enteral formula)
- 100 ml/kg for the first 10 kg, plus 50 ml/kg for the next 10 kg, plus 15 ml/kg for the remaining weight
Also, fluids with caffeine may not be the best choice. A list of fluids with their caffeine content is given below. Your facility's policy may be to not count coffee because of the caffeine content, but may allow cocoa and chocolate milk. CAFFEINE CONTENT OF BEVERAGES BEVERAGE | MG OF CAFFEINE | | Coffee, 5 oz. |
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