April 6, 2026
Dehydration by Degrees: The Case for Targeted IV Hydration in Long-Term Care
By Steven Merahn, MD
Chronic subclinical hypohydration in SNF residents is real, measurable, and consequential — and the clinical and regulatory framework for addressing it already exists. This article is a response to Nursing Home Parenteral Therapies: Clinical Guidance and Payment Considerations in last month’s Caring for the Ages.
Recent collegial discussions about preventive intravenous hydration in skilled nursing facilities raised legitimate questions about appropriate use, documentation, and oversight. But when discussion shifts from dialogue to categorical dismissal of IV hydration as a “scam,” it conflates misuse with evidence-based targeted application—and risks harm to a population whose vulnerability to inadequate hydration is well established in the clinical literature.
The Physiology of the Problem
The basic science of fluid physiology in aging is not controversial. Older adults experience a progressive decline in total body water—from roughly 60% in young adults to 45–50% in those over 75 years of age—along with diminished thirst perception, reduced renal concentrating ability, and blunted osmoreceptor sensitivity. These changes create chronic vulnerability to voluntary dehydration or subclinical hypohydration even among residents who can drink thin liquids.1,2
The critical point is that frail elderly adults can experience cellular dehydration despite normal or even expanded extracellular volume.3 The ability to drink, therefore, does not equate to adequate intake to replace intracellular losses. Residents with cognitive impairment, depression, appetite-suppressing medications, or dependence on staff frequently fail to meet the conservative 1,500 mL/day intake threshold. Observational studies document mean daily intake of only 1,000–1,200 mL in substantial proportions of nursing home residents — well below physiologic need.4-6
The Dehydration Cascade
The “dehydration cascade” describes how chronic mild intake deficits accumulate into progressive clinical consequences on the path to acute dehydration. A deficit of just one ounce per day over 30 days yields roughly a 2% body water deficit in a 70 kg individual — sufficient to produce measurable physiologic effects yet often invisible on standard laboratory panels.7
Compensatory shifts of fluid from intracellular to vascular compartments normalize osmolarity and suppress both thirst and antidiuretic hormone release, paradoxically impeding self-correction. The resulting consequences are well documented: hydration status is independently associated with urinary tract infection risk, nephrolithiasis, constipation, orthostatic hypotension, cognitive decline, falls, pressure injury, and hospitalization.8-11 These outcomes are precisely what the Centers for Medicare & Medicaid Services (CMS) tracks as quality measures, generating far greater cost and suffering than an individualized, targeted hydration intervention.
What the Regulatory Framework Actually Says
The CMS RAI Manual explicitly recognizes dehydration and fluid-electrolyte imbalance as clinical diagnoses requiring individualized care planning, not conditions that can be managed by assuming oral access equals adequate intake.12 The RAI specifically supports IV fluids “if needed to prevent dehydration…,” and the 2024 LTC Surveyor Guidance reinforces this.13
Intermittent fluid boluses in this context do not treat acute dehydration. Rather, they re-equilibrate fluid compartments at hydration levels that oral intake alone often cannot achieve in frail residents, helping prevent decompensation.
The INTERACT Dehydration Care Pathway structures this decision process by documenting oral intake, vital-sign trends, weight change, and urine characteristics before escalation, and it explicitly includes IV or subcutaneous hydration when oral approaches prove insufficient.14 A resident with documented intake of 800–1,000 mL/day, recurrent UTIs, constipation, and new mood or participation changes presents a coherent case for supplemental hydration. Labeling such a care plan fraudulent simply because it triggers legitimate case-mix reimbursement misreads both protocol and physiology.
Fraud Versus Clinical Practice
Concern about indiscriminate, protocol-driven infusion without individualized justification is legitimate. However, that concern should not obscure the question of whether selected, documented, indication-driven IV hydration belongs in skilled nursing facility (SNF) care.
Neither the False Claims Act nor CMS medical-necessity standards prohibit IV hydration in SNFs. They require individual indication and documentation — a standard entirely achievable in routine practice.
The clinical decision—including assessment of need, evaluation of contraindications, documentation of medical necessity, and monitoring—rests with the ordering practitioner and the facility’s medical director. Attributing responsibility to vendors misconstrues the regulatory structure governing these services and the roles of each party in the care continuum. For lower-acuity situations, hypodermoclysis offers an evidence-supported alternative with minimal procedural risk.15,16
A Defensible Clinical Standard
Identifying residents for whom preventive IV hydration is appropriate requires careful evaluation, progressive use of less-invasive interventions first, and clear documentation of medical necessity. Any clinical algorithm should be grounded in CMS guidance and existing evidence and evaluated against four core criteria:
- Chronic low fluid intake despite targeted oral hydration efforts
- Conditions or medications that interfere with intake or predispose to intake or fluid imbalance
- Clinical conditions known to be caused or exacerbated by water deficits
- Absence of contraindications to IV hydration
The appropriate response to reimbursement abuse is rigorous documentation, medical-director oversight, and targeted auditing—not wholesale rejection of a physiologically grounded intervention for residents whose vulnerabilities make adequate oral hydration genuinely difficult.
Preventive IV hydration, when carefully deployed, represents evidence-based application of an established regulatory framework and a response to one of the most preventable causes of avoidable hospitalization in long-term care. Conflating entrepreneurial abuse with legitimate clinical practice ultimately does a disservice to residents for whom chronic hypohydration is real, measurable, and—with appropriate clinical attention—addressable.
References
1. Kenney WL, Chiu P. Influence of age on thirst and fluid intake. Med Sci Sports Exerc. 2001;33(9):1524–1532.
2. Mack GW, et al. Body fluid balance in dehydrated healthy older men. J Appl Physiol. 1994;76(4):1615–1623.
3. Ritz P et al. Chronic cellular dehydration in the aged patient. J Gerontol A Biol Sci Med Sci. 2001;56(6):M349-M352. doi:10.1093/gerona/56.6.m349
4. Gaspar PM. Water intake of nursing home residents. Image J Nurs Scholarship. 1999;31:257–261.
5. Hodgkinson B, Evans D, Wood J. Maintaining oral hydration in older adults. J Adv Nurs. 2003;44:583–593.
6. Namasivayam-MacDonald AM, et al. Inadequate fluid intake in long term care residents. Geriatr Nurs. 2018;39(3):330–335.
7. Hooper L, Abdelhamid A, Attreed NJ, et al. Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people. Cochrane Database Syst Rev. 2015;(4):CD009647.
8. Manz F, Wentz A. Good hydration for prevention of chronic diseases. Nutr Rev. 2005;63(6 Pt 2):S2–S5.
9. Beck AM, Seemer J, Knudsen AW, Munk T. Narrative review of low-intake dehydration in older adults. Nutrients. 2021;13(9):3142.
10. Edmonds CJ, Foglia E, Booth P, Fu CHY, Gardner M. Dehydration in older people: a systematic review. Arch Gerontol Geriatr. 2021;95:104380.
11. Xiao H, Barber J, Campbell ES. Economic burden of dehydration among hospitalized elderly. Am J Health Syst Pharm. 2004;61:2534–2540.
12. Centers for Medicare & Medicaid Services. Long-Term Care Facility Resident Assessment Instrument 3.0 User’s Manual (RAI Manual v1.18). CMS; 2024.
13. Centers for Medicare & Medicaid Services. LTC Surveyor Guidance 2024 (QSO-25-07-NH). CMS; 2024.
14. Ouslander JG, et al. The INTERACT quality improvement program. J Am Med Dir Assoc. 2014;15(3):162–170.
15. Remington R, Hultman T. Hypodermoclysis to treat dehydration. J Am Geriatr Soc. 2007;55(12):2040–2042.
16. Slesak G, et al. Subcutaneous and intravenous rehydration in geriatric patients. J Am Geriatr Soc. 2003;51(2):155–160.
Dr. Merahn is the founder of LTC Provider Care in Bingham Falls, MI, and a strategic advisor to a purveyor of IV hydration solutions in long-term care settings.