Fluid balance is normally maintained by thirst
perception, the kidneys and hormones comprising of antidiuretic hormone (ADH),
atrial natriuretic hormone (ANH), and the renin-angiotensin-aldosterone system.
Age-related changes, diseases (especially those that
result in vomiting or diarrhea) and drugs can lead to fluid and electrolyte
imbalance. In elderly, this could result
in inability to bear stress and increase susceptibility to disease. It could
also result in low sodium levels, with subsequent falls, unsteadiness, and
should be explained the importance of maintaining adequate hydration with
proper electrolyte balance.
Elderly individuals often do not drink
enough water. It could be due to a lesser tendency to be thirsty or they could
avoid water so as to keep their urinary incontinence under control. They may
also find it difficult to access water due to disease and/or disability. Elderly
people with Alzheimer's disease are at a particular risk for developing fluid
Elderly people are often treated with multiple
medicines. These medications could also affect their fluid balance. These
include diuretics that increase urine output, ACE inhibitors, some
antipsychotic drugs and antidepressants.
suggest that doctors should be aware of this increased susceptibility in
elderly to fluid and electrolyte imbalance. They have also encouraged doctors
and hospital pharmacists to monitor the elderly to prevent serious consequences
of this imbalance.
Zagaria MA. Drug- and Age-Related Changes in Sodium and Water
Regulation. US Pharm. 2011; 36(6):30-33.