Journal: Journal of pain & palliative care pharmacotherapy
This integrative systematic review examined the physiology and clinical impact of dehydration in patients with advanced, life-limiting illness near the end of life.
Across seven included studies, the evidence suggests that so‑called “terminal dehydration” is often a regulated, adaptive process rather than a straightforward fluid deficit. Key physiological observations included:
- Relatively stable serum electrolytes despite reduced fluid intake
- Activation of the renin–angiotensin–aldosterone system, indicating homeostatic adjustment
- Limited correlation between biochemical markers and subjective thirst
- Bioelectrical impedance findings consistent with progressive intracellular dehydration linked to overall catabolic decline
Clinically, higher volumes of artificial hydration were associated with more respiratory secretions, edema, and agitation. In contrast, lower hydration levels tended to correlate with greater comfort and fewer secretion-related complications. There was little evidence that artificial hydration improved thirst, delirium, or overall symptom burden.
Overall, the review supports viewing terminal dehydration as a largely adaptive physiological response in the dying process, with uncertain symptomatic benefit and potential harms from routine artificial hydration in this setting.