Management of Severe Dehydration

Maintenance Therapy

For patients with severe dehydration due to infectious diarrhea who cannot tolerate oral rehydration, the Infectious Diseases Society of America recommends 5% dextrose 0.25 normal saline with potassium chloride for maintenance after initial resuscitation with isotonic fluids 1
After initial resuscitation with isotonic fluids, dextrose-containing solutions can be used for maintenance in children with severe dehydration from diarrhea 1
The American Diabetes Association recommends beginning treatment with isotonic saline (0.9% NaCl) to restore intravascular volume, and once hemodynamically stable, switching to hypotonic solutions, with 0.45% NaCl as the preferred initial hypotonic solution 2
The induced change in serum osmolality should not exceed 3 mOsm/kg/h, as recommended by the American Diabetes Association 2

The use of 0.45% NaCl (half-normal saline) without dextrose is appropriate if the corrected serum sodium is elevated, according to the American Diabetes Association 3, 2
D5 (5% dextrose) IV solutions can be used to manage dehydration in older adults with elevated serum osmolality (>300 mOsm/kg or calculated osmolarity >295 mmol/L) who appear unwell, alongside oral fluid intake when possible, as recommended by Clinical Nutrition 4, 5
Appropriate formulations for D5 solutions include:
Formulation Description
Half-normal saline-glucose 5% D5 0.45% NaCl
40 g/L dextrose with 30 mmol/L NaCl
5% dextrose with 4 g/L NaCl
Two-thirds 5% glucose with one-third normal saline

Formulation	Description
Half-normal saline-glucose 5%	D5 0.45% NaCl
40 g/L dextrose with 30 mmol/L NaCl
5% dextrose with 4 g/L NaCl
Two-thirds 5% glucose with one-third normal saline

Intravenous administration of D5 solutions is recommended when rapid correction is needed or larger volumes are required 4
Subcutaneous administration is an effective alternative for mild-to-moderate dehydration in frail elderly patients, associated with fewer complications than the IV route and more suitable for community settings 4
Regular blood glucose monitoring is necessary to prevent hyperglycemia in elderly patients receiving D5 solutions 6
Serum electrolytes, especially in patients at risk for electrolyte disturbances, and fluid status should be monitored to prevent overload, which can precipitate pulmonary edema 6

D5 solutions should not be used as routine maintenance fluid in non-diabetic elderly patients, and should not be used for volume resuscitation in hypovolemic states or treatment of volume depletion, as isotonic solutions with electrolytes are preferred 4
Using D5W for volume depletion instead of isotonic solutions, failing to monitor glucose levels during D5 infusion, and not considering subcutaneous administration when appropriate are common pitfalls to avoid 4
D5 solutions can worsen cerebral edema in at-risk patients, and should be used cautiously in patients at risk for cerebral edema, as recommended by the Centers for Disease Control and Prevention, as published in the MMWR Recommendations and Reports 6
Avoid indiscriminate or excessive treatment with glucose in patients, as hyperglycemia may increase ischemic brain injury, as published in the BMJ 7

Ranitidine (50 mg diluted in 5% dextrose to 20 mL volume) can be used for infusion reactions, according to the Annals of Oncology 8
D5 1/2NS (5% Dextrose in Half-Normal Saline) is preferred IV fluid for patients with cerebral malaria requiring glucose supplementation, as recommended by the MMWR Recommendations and Reports 6