Evidence indicates what minimally invasive tests should not be used to determine dehydration in older people.
Water-loss dehydration results from drinking too little fluid. It is common in older people, among whom it is associated with increased risk of many health problems. It is important to identify dehydration early before health and wellbeing are compromised. There are many simple, minimally invasive tests that are used and recommended to determine if older people are drinking enough water (fluid). These include skin turgor, dry mouth, urine colour, and bioelectrical impedance.
A team of Cochrane authors, based in Australia, France, Japan, the Netherlands, Palestine, Sweden, Switzerland, the United Kingdom, and United States, worked with Cochrane Kidney and Transplant Group to study the effectiveness of simple, minimally invasive tests to determine whether a people aged 65 years and over are drinking enough fluid.
The diagnostic test accuracy review evaluated 67 different tests; none were found to be consistently useful in determining whether older people were drinking enough or were dehydrated. There was sufficient evidence to suggest that some tests should not be used to indicate dehydration; these include dry mouth, feeling thirsty, heart rate, urine colour, and urine volume.
“Unfortunately no tests were found to be consistently useful in diagnosing dehydration in older people aged over 65 years. However, we did find sufficient evidence to determine what tests we should not be using in this population. Dry mouth, feeling thirsty, heart rate, urine colour, and urine volume all miss a high proportion of people with dehydration and wrongly label those who are adequately hydrated. These tests are sometimes relied on by healthcare professionals, so it is important they know they are not effective when used with older people,” said Lee Hooper, a researcher at the University of East Anglia, Norwich, UK and lead author of the Cochrane Review. “This review is also an important driver for research. There are a few tests which look promising, and a sequence of several tests may be better than any individual test. These tests should be studied further to establish if they are useful in specific older populations.”