Intravenous rehydration


Intravenous rehydration is the process by which sterile water solutions containing small amounts of salt or sugar are injected into the body through a tube attached to a needle which is inserted into a vein.


Intravenous rehydration is used to restore the fluid and electrolyte balance of the body due to illness, surgery, or accident. Electrolytes are salts (sodium, potassium, chloride, calcium, magnesium, phosphate, sulfate, and bicarbonate) that become ions when mixed with fluids in the body and blood and have the ability to conduct electricity. The body uses electrolytes to carry electrical impulses from cell to cell. Moderate to severe dehydration can interfere with the body's normal functioning. Restoration of fluids and electrolytes through intravenous means is the swiftest means to achieve fluid balance.


Fever , vomiting , and diarrhea can cause a child to become dehydrated fairly quickly. Infants and children are especially vulnerable to dehydration. Athletes who have over-exerted themselves in hot weather may also require rehydration with IV (intravenous) fluids. An IV for rehydration can be in place for several hours to several days and is generally used if a patient cannot drink fluids.

Basic IV solutions are made of sterile water with small amounts of sodium (an ingredient in table salt) or dextrose (sugar) supplied in bottles or thick plastic bags that can hang on a stand mounted next to the patient's bed. Additional mineral salts such as potassium and calcium, vitamins , or medications can be added to the IV solution by injecting them into the bottle or bag with a needle or injected directly into the IV line.


Patients receiving IV therapy need to be monitored to ensure that the IV solutions are providing the correct amounts of fluids and minerals needed. People with kidney and heart disease are at increased risk for over-hydration , so they must be carefully monitored when receiving IV therapy.

A child receiving fluids through an intravenous (IV) bag. ( Tom Stewart/Corbis.)
A child receiving fluids through an intravenous (IV) bag.
(© Tom Stewart/Corbis.)


The doctor orders the IV solution and any additional nutrients or medications to be added to it. The doctor also specifies the rate at which the IV will dispense the solution.

The IV solutions are prepared under the supervision of a pharmaceutical company, using sanitary techniques that prevent bacterial contamination, and come prepackaged. Additions to the IV solutions are supervised by a doctor or nurse. Just like a prescription, the IV is clearly labeled to show its contents and the amounts of any additives.

The skin around the area where the needle for the IV catheter is inserted is cleaned and disinfected. Once the IV catheter is in place, it is taped to the skin to prevent it from being dislodged. The IV line is then attached to the IV catheter. Any other IV lines can be added to the IV catheter.


Patients need to take fluids by mouth before an IV solution is discontinued. After the IV needle is removed, the site should be inspected for any signs of bleeding or infection.


There is a small risk of infection at the injection site that is usually treated topically. It is also possible that the IV solution may not provide all of the nutrients needed, leading to a deficiency or an imbalance, which would need to be corrected.

If the needle becomes dislodged, the solution can flow into tissues around the injection site rather than into the vein. This is called extravasation, or infiltration, and occurs in about half of pediatric IVs. In most cases, the patient reports a burning or stinging sensation at the site of the needle or IV catheter, especially when new IV fluids are started or the speed of the IV drip is increased. The tissues usually swell and become discolored, looking like a bruise. Usually, the IV catheter is removed and reinserted at another site.

If an IV has been in place for a long time or the child has had a medical condition that weakens the veins, the child may experience vein collapse. This occurs when the vein is not able to receive anymore intravenous fluid and forces the IV solution into the surrounding tissues. It can also occur if a thrombosis, or blood clot, forms in the vein at the IV catheter site.

A collapsed vein feels and looks much like a dislodged IV catheter. This can sometimes happen when the nurse has inserted a needle or IV catheter that is too big for the size of the vein. This isn't a misjudgement on the nurse's part. Standard sized needles are used and only rarely are extremely thin needles necessary. They may be needed in adult patients as well as children. If vein collapse occurs, the IV catheter should be removed and reinserted into a different vein, usually in another part of the body. For example, if a vein in the left arm collapses, the nurse can put a new IV catheter into the right arm.

Treatment for an extravasation or a collapsed vein are similar. A warm compress is usually applied to the injection site to reduce swelling. If there is sufficient injury at the injection site, general wound care is done to prevent infection and speed healing.

Parental concerns

Usually intravenous rehydration is very effective, allowing the child's body to return to its normal fluid equilibrium. Once the child can keep fluids down orally and urine output has returned to normal, then intravenous rehydration is discontinued. Most children don't relapse once they are home if they can continue taking fluids by mouth.

Intravenous rehydration should only be used for moderate to severe dehydration. It is not recommended for mild dehydration from stomach upset or flu. Oral products that restore fluid and electrolytes balance are better for hydrating a sick child who has been vomiting during an illness or after strenuous activity in extremely hot weather. Oral rehydration also does not require a hospital stay.

To reduce the risk of displacement of the needle when the IV catheter or needle is inserted, parents should help the child keep still. The child should also be careful when moving about so as not to dislodge the IV catheter, especially at night. Parents can also look at the injection site and report any discoloration they see. They should also encourage the child to report any burning or stinging around the IV catheter to the nursing staff.


Dextrose —A sugar solution used in intravenous drips.

Electrolytes —Salts and minerals that produce electrically charged particles (ions) in body fluids. Common human electrolytes are sodium chloride, potassium, calcium, and sodium bicarbonate. Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost all major biochemical reactions in the body.

Extravasation —To pass from a blood vessel into the surrounding tissue.

Sodium —An element; sodium is the most common electrolyte found in animal blood serum.

Thrombosis —The formation of a blood clot in a vein or artery that may obstruct local blood flow or may dislodge, travel downstream, and obstruct blood flow at a remote location. The clot or thrombus may lead to infarction, or death of tissue, due to a blocked blood supply.



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"Water, Electrolyte, Mineral, and Acid-Base Metabolism." In The Merck Manual. 16th ed. Rahway, NJ: Merck, 1992.


Atherly-John Y. C., et al. "A Randomized Trial of Oral vs Intravenous Rehydration in a Pediatric Emergency Department." Archives of Pediatric Adolescent Medicine. 156 (December 2002): 1240–3.

Camp-Sorrell, D. "Developing Extravasation Protocols and Monitoring Outcomes." Journal of Intravenous Nursing. 21, no. 4 (1998): 232-239.

Castellani, J. W., et al. "Intravenous vs. Oral Rehydration: Effects on Subsequent Exercise-Heat Stress." Journal of Applied Physiology 82 (Mar. 1997): 799–806.

Montgomery, L. A., Hanrahan, K. and K. Kottman. "Guideline for IV Infiltrations in Pediatric Patients." Pediatric Nursing 25, no. 2 (1999): 167–180.

Janie Franz Altha Roberts Roberts

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