Lack of proper hydration is important in all age groups, but the elderly and the very young are particularly vulnerable. An example was seen in France during the summer of 2003, when, as temperatures soared to 104°F, over 15,000 people died of heat–related ailments over a three week period. For people over 65 years of age, the mortality rate rose by 60%. The deaths were attributed to dehydration and heat stress, sometimes with respiratory and cardiac complications.
Chronic hydration deficits in the elderly are highly prevalent, in part because the body’s natural thirst mechanism is blunted with aging. Ailments such as difficulty swallowing, lack of mobility, fear of incontinence, the use of diuretics or diminished cognition and dementia can also play a role. Common conditions that may result from inadequate hydration include urinary tract infections, sudden drops in blood pressure, recurrent falls due to dizziness and fainting (often resulting in fractures), pneumonia, skin infections and pressure sores.
It is estimated that the incidence of chronic under– and dehydration in elderly nursing home residents is as high as 33%, and as high as 7% among all otherwise healthy people over the age of 65. The morbidity and mortality associated with hydration deficits in the elderly result in costs to the healthcare system in the billions of dollars per year range. Much of the cost to the U.S. healthcare system results from the more than a quarter of a million U.S. hospital admissions each year for which volume depletion (dehydration) is the primary diagnosis.
Infants and the very young are susceptible to dehydration primarily as a result of vomiting and diarrhea associated with gastro–intestinal disorders. Approximately 5% of all pediatric hospital admissions in the U.S. result from dehydration and, worldwide, dehydration associated with diarrheal illness is the largest single killer of children under the age of five.
In health care, the ability to conveniently and cost–effectively measure and monitor hydration status, and therefore better manage it, will reduce costs and improve the quality of care.