What is the recommended IV fluid treatment for moderate to severe dehydration?

From the Guidelines

For moderate to severe dehydration, the recommended IV fluid treatment is isotonic crystalloid solutions, primarily 0.9% normal saline or lactated Ringer's solution, administered at an initial bolus of 20 mL/kg over 10-20 minutes, as recommended by the 2017 Infectious Diseases Society of America clinical practice guidelines 1. This approach is supported by the guidelines which state that isotonic intravenous fluids such as lactated Ringer’s and normal saline solution should be administered when there is severe dehydration, shock, or altered mental status and failure of ORS therapy 1. The use of isotonic solutions is preferred because they expand the intravascular space effectively without causing significant fluid shifts between compartments. Key considerations in the management of dehydration include:

• Monitoring of electrolyte abnormalities, particularly sodium, potassium, and bicarbonate, and correcting them as needed 1
• Assessing the patient's hydration status frequently to monitor the adequacy of replacement therapy 1
• Using the 4-2-1 rule to calculate maintenance fluids based on the patient's weight (4 mL/kg/hr for the first 10 kg, 2 mL/kg/hr for the next 10 kg, and 1 mL/kg/hr for each additional kg)
• Being cautious of signs of fluid overload, especially in patients with cardiac or renal compromise 1. Overall, the goal of therapy is to restore intravascular volume, improve tissue perfusion, and correct electrolyte imbalances.

From the Research

IV Fluid Treatment for Dehydration

The recommended IV fluid treatment for moderate to severe dehydration varies depending on the type of dehydration and the patient's condition.

• For children with mild-to-moderate dehydration, oral rehydration therapy (ORT) using commercially available oral solutions containing 45-75 mEq/l of Na(+) is recommended 2.
• For children with severe dehydration, intravenous fluids, 60-100 ml/kg of 0.9% saline in the first 2-4 h to restore circulation, are recommended 2.
• Oliguric patients with severe acidosis should receive a physiological dose of bicarbonate to correct blood pH level to 7.25 2.
• The optimal choice of infusate should be guided by the cause of hypovolemia, the cardiovascular state of the patient, the renal function, as well as the serum osmolality and the coexisting acid-base and electrolyte disorders 3.
• Balanced salt solutions, such as Lactated Ringer's, may be preferred in some patient populations 4.
• Maintenance fluid therapy with saline, dextrose-supplemented saline, or lactated Ringer's solution has different effects on metabolic balance, and a personalized fluid therapy is advised 5.
• Subcutaneous infusion of fluids (hypodermoclysis) provides a better opportunity to treat mild to moderate dehydration in the nursing home and at home 6.

Types of Dehydration

• Isotonic dehydration is best treated with 5% dextrose in 0.45% saline containing 20 mEq/l KCl over 24 h 2.
• Hyponatremic dehydration is best treated with 0.9% saline and 0.45% saline alternately in a 1:1 ratio in 5% dextrose containing 20 mEq/l KCl over 24 h 2.
• Hypernatremic dehydration is best treated with 5% dextrose in 0.2% saline containing 20 mEq/l KCl over 2-3 days to avoid cerebral edema 2.

Considerations for IV Fluid Treatment

• The use of crystalloids, such as normal saline, should be considered, as most colloids and human albumin are associated with increased adverse effects and high cost, respectively 3.
• Lactated Ringer's infusate should not be given in patients with severe metabolic alkalosis, lactic acidosis with decreased lactate clearance, or severe hyperkalemia, and in patients with traumatic brain injury or at risk of increased intracranial pressure 3.
• The bedside critical care nurse must understand the properties of various intravenous fluids and their corresponding impact on human physiology 4.