Oral rehydration therapy (ORT) is a type of fluid replacement used as a treatment

for dehydration. It involves drinking water mixed with sugar and salt, while continuing
to eat. When dehydration is severe, the therapy also includes supplemental zinc.
Caretakers are taught the signs of worsening dehydration. The World Health
Organization and UNICEF specify indications, preparations and procedures for ORT.
[1]

Since its introduction and development for widespread use in the latter part of the 20th
century, oral rehydration therapy has decreased human deaths from dehydration
in vomiting and diarrheal illnesses, especially in choleraepidemics occurring in
children. It represents a major advance in globalpublic health. It is on the World Health
Organization's List of Essential Medicines, a list of the most important medication
needed in a basic health system.
[2]

Prior to the introduction of ORT, death from diarrhea was the leading cause of infant
mortality in developing nations. Between 1980 and 2006, the introduction of ORT is
estimated to have decreased the number of infant deaths, worldwide, from 5 to 3
million per year.
[3][4]
However, in 2008, diarrhea remained the second most common
cause of death in children under five years (17 percent), (after pneumonia (19
percent)).
[5]
Moreover, by the same year, the use of ORT in children under five had
declined.
[6]

Medical uses[edit]
Oral rehydration therapy is a treatment for the symptoms of dehydration. ORT is less
invasive than the other strategies for fluid replacement, specifically intravenous (IV)
fluid replacement. Mild to moderate dehydration in children seen in anemergency
department is best treated with ORT.
ORT in combination with anti-nausea drugs is indicated for vomiting patients as a
strategy to be able to take fluid orally. In an emergency department setting, vomiting,
dehydrated patients take these drugs as soon as possible to enable taking fluid by
mouth sooner.
[7]

Persons taking ORT should eat within 6 hours and return to their full diet within 2448
hours.
[8]

Contraindications[edit]
ORT is contraindicated in the case of protracted vomiting despite proper administration
of ORT, worsening diarrhea in excess of fluid intake, onset of stupor or coma, or
intestinal blockage (ileus). Short-term vomiting is not a contraindication to receiving
oral rehydration therapy. In persons who are vomiting, drinking oral rehydration
solution at a slow and continuous pace will help the person not vomit.
[8]

Preparation[edit]
WHO and UNICEF jointly maintain official guidelines for the manufacture of ORS and
recommend various alternative preparations, depending on material availability.
Commercial preparations are available as either pre-prepared fluids or packets of oral
rehydration salts (ORS) ready for mixing with the fluid.
[9][10]

WHO/UNICEF's formula is 2.6 grams (0.092 oz) salt (NaCal), 2.9 grams (0.10 oz)
trisodium citrate dihydrateC
6H
5Na
3O
7,2H
2O, 1.5 grams (0.053 oz) KCl, 13.5 grams (0.48 oz) anhydrous glucose C
6H
12O
6 per litre of fluid.
[11]

A basic oral rehydration therapy solution is composed of salt, sugar, and water
in solution, made using a standard ratio and is appropriate for use in situations when
ORS must be prepared without the standard ingredients.
[12][13]

30 ml sugar : 2.5 ml salt : 1 liter fluid
6 teaspoons sugar : 0.5 teaspoon salt : 1 quart fluid
The Rehydration Project states, "Making the mixture a little too diluted (with more than
1 litre of clean water) is not harmful."
[14]

The optimal fluid is plain, clean water. However, fluids such as rice water, coconut
water, vegetable broth, yogurt, weak unsweetened tea, unsweetened fresh fruit
juice or even nonpotable water are recommended when plain, clean water is
unavailable. Water can be boiled or treated with chlorine. However, ORS
is not withheld on the basis of potentially unsafe water. Rehydration takes
precedence.
[1]

The molar ratio of sugar to salt should be 1:1 and the solution should not
be hyperosmolar.
[15]
The Mayo clinic suggests half a teaspoon of salt, six level
teaspoons of sugar and 1 litre (34 US fl oz) water.
[16]
The British Columbia health
service suggests sugar free fruit juice mixed with water in a ratio of 1:4.
[17]

Low-osmolarity oral rehydration salts[edit]


An ORS sachet is poured into a bottle
In 2003, clinical trials and comparisons with rice water led to a reduction in the
recommended osmolarity of ORS.
[18]
The guidelines were also updated in 2006. The
reduced osmolarity ORS has a total osmolarity of 245 mmol/L. This decreases
vomiting; decreases stool volume by about twenty-five percent; and the need for IV
therapy by about thirty percent. When the recommended osmolarity of ORS was
reduced from 311 mmol/L to 245 mmol/L, the concentration of glucose and sodium
chloride were reduced, while that of potassium and citrate remained the
same.
[19][20][21][22][23][24]

Administration[edit]
WHO/UNICEF guidelines suggest ORT should begin at the first sign of diarrhea in
order to prevent dehydration.
[25][26]

Babies are given ORT fluid from a dropper or a syringe. Infants under two are given a
teaspoon of ORT fluid every one to two minutes. Older children and adults take sips
from a cup. If the patient vomits, the carer waits a short time then persists with the
ORT.
[1](Section 4.2)

A key element of ORT is that water is still absorbed from the gastrointestinal tract into
the body, even with loss of fluid through diarrhea or vomiting. In the case of vomiting,
WHO recommends a pause of 510 minutes, then continuing to slowly administer the
fluid. In the case of diarrhea, WHO recommends giving children under two a quarter-
to a half-cup of fluid following each loose bowel movement and older children a half- to
a full cup. ORT is often given by parents or other family members in a home setting.
ORT is also given by aid workers and health care workers in refugee camps, health
clinics and hospital settings.
[27]

Mothers should remain with their children if at all possible. WHO recommends
continuing breastfeeding and perhaps even re-lactating if circumstances realistically
allow.
Associated therapies[edit]
Zinc[edit]
As part of oral rehydration therapy, WHO recommends supplemental zinc (10 to 20 mg
daily) for ten to fourteen days, to reduce the severity and duration of the illness and
make recurrent illness in the following two to three months less likely. Preparations are
available as a zinc sulfate solution for adults, a modified solution for children and in
tablet form.
[28]

Feeding[edit]
Continuing to feed the patient, when some appetite is present, speeds the recovery of
normal intestinal function, as well as supporting continued nutrition in children. Small
frequent meals are best tolerated (offering the child food every three to four hours).
Mothers should continue to breastfeed.
[1][29][30]
A child with watery diarrhea typically
regains his or her appetite as soon as dehydration is corrected, whereas a child with
bloody diarrhea often eats poorly until the illness resolves. Such children should be
encouraged to resume normal feeding as soon as possible. Once diarrhea is
corrected, WHO recommends giving the child one more meal a day for two weeks, and
longer if the child is malnourished.
[1]

Children with malnutrition[edit]
Dehydration may be overestimated in wasted children and underestimated
in edematous children.
[31]
Care of these children must also include careful
management of their malnutrition and treatment of other infections. Useful signs of
dehydration remain eagerness to drink, lethargy, cool and moist extremities, weak or
absent radial pulse (wrist), and reduced or absent urine flow. In children with severe
malnutrition, it is often impossible to reliably distinguish between some dehydration
and severe dehydration. A severely malnourished child who has signs of severe
dehydration but who does not have a history of watery diarrhea should be treated
for septic shock.
[1]

Since the previous ORS (90 mmol sodium/L) and the current standard reduced-
osmolarity ORS (75 mmol sodium/L) both have too much sodium and too little
potassium for the typical severely malnourished child, the Bangladesh Institute of
Public Health Nutrition recommends Rehydration Solution for Malnutrition (ReSoMal).
An exception is if the severely malnourished child also has severe diarrhea (in which
case ReSoMal may not provide enough sodium), in which case standard reduced-
osmolarity ORS (75 mmol sodium/L) is recommended.
[31]

The Bangladesh Institute of Public Health Nutrition further recommends that the IV
route not be used for rehydration except in cases of shock and then only with care,
infusing slowly to avoid flooding the circulation and overloading the heart. In addition,
with severe acute malnutrition, the usual signs of infection, such as fever, are often
absent, and infections are often hidden, and therefore recommended that all severely
malnourished children be treated with broad-spectrum antibiotics on admission.
[31]

WHO recommends rehydrating malnourished children slowly. Specifically, WHO
recommends 10 milliliters of ORS per kilogram body weight for each of the first two
hours (for example, a 9-kilogram child should be given 90 ml of ORS over the course
of the first hour, and another 90 ml for the second hour) and then continuing at this
same rate or slower based on the child's thirst and ongoing stool losses, keeping in
mind that a severely dehydrated child may be lethagic. If the child drinks poorly, a
nasogastric tube should be used. IV infusion should only be used for the treatment of
shock and then slowly to avoid over-hydration and heart failure. Increasing edema is a
sign of over-hydration.
[1]

Feeding should usually resume within 23 hours of starting rehydration, and food
should be given every 23 hours, day and night. As an example of an initial cereal diet
before a child regains his or her full appetite, WHO recommends combining 25 grams
skimmed milk powder, 20 grams vegetable oil, 60 grams sugar, and 60 grams rice
powder or other cereal into 1,000 milliliters water and boiling gently for five minutes. A
child should be fed 130 ml per kilogram of body weight during one day (for example, a
9-kilogram child should be given 1,170 ml of this initial food over the course of a day).
A child who cannot or will not eat this minimum amount should be given the diet by
nasogastric tube divided into six feedings. Later on, the child should be given cereal
made with a greater amount of skimmed milk product and vegetable oil and slightly
less sugar. As appetite fully returns, a child should be eating 200 ml per kilogram of
body weight per day (a 9-kilogram child should be given 1,800 ml of this modified
cereal over the course of a day). Zinc, potassium, vitamin A, and other vitamins and
minerals should be added to both recommended cereal products, or to the oral
rehydration solution itself. Some mothers exclusively breastfeed for the first six months
of an infant's life, and this has health advantages. WHO states, "In general, foods
suitable for a child with diarrhoea are the same as those required by healthy
children."
[1]

Antibiotics[edit]
WHO recommends that all severely malnourished children admitted to hospital should
receive broad spectrum antibiotics (for example, gentamicin and ampicillin). In
addition, hospitalized children should be checked daily for other specific infections.
[1]

Physiological basis[edit]


Intestinal epithelium (H&E stain)
Fluid from the body enters the intestinal lumen during digestion. This fluid
isisosmotic with the blood because it contains a high concentration of sodium(approx.
142 mEq/L). A healthy individual secretes 2030 grams of sodium per day into the
intestinal lumen. Nearly all of this is reabsorbed so that sodium levels in the
body remain constant. In a diarrheal illness, sodium-rich intestinal secretions are lost
before they can be reabsorbed. This can lead to a life-threateninghyponatraemia within
hours. This is the motivation for sodium and water replenishment in ORT.
[32]

Sodium absorption occurs in two stages. The first is via intestinal epithelial cells.
Sodium passes into these cells by co-transport via the SGLT1 protein. From the
intestinal epithelia cells, sodium is pumped by active transport via the sodium
potassium pump through the basolateral membrane into the extracellular space.
[33][34]

The sodiumpotassium ATPase pump at the basolateral cell membrane moves three
sodium ions into the extracellular space, while pulling into the cell two potassium ions.
This creates a "downhill" sodium gradient within the cell. SGLT proteins use energy
from this downhill sodium gradient to transport glucose across the apical membrane of
the cell against the glucose gradient. The co-transporters are examples of secondary
active transport. The GLUT uniporters then transport glucose across the basolateral
membrane. Both SGLT1 and SGLT2 are known as symporters, since both sodium and
glucose are transported in the same direction across the membrane.
The co-transport of glucose into epithelial cells via the SGLT1 protein requires sodium.
Two sodium ions and one molecule of glucose (as galactose) are transported together
across the cell membrane via the SGLT1 protein. Without sodium, intestinal glucose is
not absorbed. This is why oral rehydration salts (ORS) include both sodium and
glucose. For each cycle of the transport, hundreds of water molecules move into the
epithelial cell, slowly rehydrating the patient.
[32]

History[edit]
Definition[edit]
In the early 1980s, "oral rehydration therapy" referred only to the preparation
prescribed by the World Health Organization(WHO) and UNICEF. In 1988, the
definition changed to encompass recommended home-made solutions, because the
official preparation was not always readily available. The definition was again
amended in 1988 to include continued feeding as an appropriate associated therapy.
In 1991, the definition became, "an increase in administered hydrational fluids" and in
1993, "an increase in administered fluids and continued feeding".
[27]

Development[edit]


Refugee camp.
Over 2,500 years ago, Indian physician Sushruta described the treatment of acute
diarrhea with rice water, coconut water, and carrot soup.
[35]

Until 1960, ORT was not known in the West. Dehydration was a major cause of death
during the 1829 cholera pandemic in Russia and Western Europe. In 1831,William
Brooke O'Shaughnessy noted the loss of water and salt in the stool of cholera patients
and prescribed intravenous fluid therapy (IV fluids). The prescribing of hypertonic IV
therapy decreased the mortality rate of cholera from 70 to 40 percent. In the West, IV
therapy became the "gold standard" for the treatment of moderate and severe
dehydration.
[35]

In 1957 Indian physician Hemendra Nath Chatterjee published his results of treating
cholera patients with ORT.
[36]
However, he had not performed a controlled trial. Robert
A. Phillips attempted to create an effective ORT solution based on his discovery that,
in the presence of glucose, sodium and chloride become absorbable during diarrhea in
patients with cholera. Phillips did not succeed due to inadequate methodology.
[37]

In the early 1960s, biochemist Robert K. Crane discovered the sodium-glucose co-
transport mechanism and its role in intestinal glucose absorption.
[38]
This strengthened
belief in the concept that the intestinal mucosa is not disrupted in cholera and led to
understanding of the physiological basis of the effectiveness of ORT. In 1960, David R.
Nalin found that in adults, ORT given in volumes equal to that of the diarrhea, reduces
the need for IV fluid therapy by eighty percent.
[35][39]

In 1971, the Bengali people fought for independence from Pakistan. The fighting
displaced many people and an epidemic of cholera ensued. When IV fluid ran out in
the refugee camps, Dilip Mahalanabis, a physician, instructed his staff to distribute oral
rehydration salts (ORS) to family members and carers. Over 3,000 patients with
cholera received ORT in this way. The mortality rate was 3.6 percent with ORT and 30
percent with IV fluid therapy.
[35][37]

In 1980 the Bangladeshi nonprofit BRAC essentially developed a door-to-door and
person-to-person sales force to teach ORT. A task force of fourteen women, one cook
and one male supervisor traveled from village to village, assuming that the womens
numbers would protect them from the supervisor and the supervisor would protect
them from others. After visiting with women in the village, each evening they got
together and talked about what worked and what did not. They hit upon the method of
encouraging the women in the village to making their own oral rehydration fluid. They
used available household equipment, starting with a half a seer (half a quart) of water
and adding a fistful of sugar and a three-finger pinch of salt. Later on, the approach
was broadcast over television and radio and a market for oral rehydration salt packets
developed. Three decades later, national surveys have found that almost 90% of
children with severe diarrhea in Bangladesh are given oral rehydration fluid.
[40]

From 2006 to 2011, UNICEF estimated that worldwide about a third of children under 5
who had diarrhea received oral rehydration solution, with estimates ranging from 30%
to 41% depending on the region.
[41][42]

ORT is one of the principle elements of the UNICEF "GOBI FFF" program (growth
monitoring; ORT; breast feeding; immunisation; female education; family spacing and
food supplementation). The program aims to increase child survival in developing
nations through low-cost interventions.
[43]

Controversy and ongoing investigations[edit]
The ORS formulation has been criticised for not providing enough sodium for adult
cholera patients.
[47][48]

In Rwanda, a charity supplied the sports drink Gatorade, which is not compliant with
ORT in children and was accused of making them worse.
[49]
The president of
AmeriCares, the said charity, responded, "We stand by our decision to ship Gatorade
to Rwandan refugees. In the absence of potable water, Gatorade, with its electrolytes
and water, saved countless lives in a true triage situation."
[50]