Oral Rehydration Therapy
"The discovery that sodium transport and glucose transport are coupled in the small intestine so that glucose accelerates absorption of solute and water (is) potentially
the most important medical advance this century."
British Scientific Journal
5th August, 1978
ORT is the giving of fluid by mouth to prevent and/or correct the
dehydration that is a result of diarrhoea. As soon as diarrhoea begins, treatment using
home remedies to prevent dehydration must be started. If adults or children have not been
given extra drinks, or if in spite of this dehydration does occur, they must be treated
with a special drink made with oral rehydration salts (ORS).
The formula for ORS
recommended by WHO and UNICEF contains:
Reduced osmolarity ORS
Reduced osmolarity ORS
Trisodium citrate, dihydrate
Magic Bullet: The History
of Oral Rehydration Therapypdf 39 pages 7.4 mb.
by Joshua Nalibow Ruxin
Med Hist. 1994 October; 38(4): 363–397.
The Oral Rehydration Therapy
The Canadian Journal of Paediatrics 1994; 1(5): 160-164
Oral rehydration therapy with an inexpensive glucose and electrolyte solution as
promoted by the World Health Organization has reduced substantially the number
of deaths from dehydration due to diarrhea. In addition, recent research
suggests that these solutions have advantages over conventional therapy. Yet,
oral rehydration therapy has not been used extensively in developed countries.
Acute gastroenteritis is one of the most common illnesses affecting infants and
children in Canada and the world. The average child under age 5 experiences 2.2
diarrheal episodes per year.1 Treatment from resulting dehydration accounts for
an estimated 200,000 hospitalizations per year in the U.S.2 with comparable
rates occurring in Canada. Worldwide as many as 4,000,000 children per year die
as a result of gastroenteritis and resulting malnutrition. Prolonged diarrhea
and malnutrition are a primary cause of morbidity and mortality in Canadian
Oral rehydration therapy (ORT), using a simple, inexpensive, glucose and
electrolyte solution promoted by the World Health Organization (WHO) has reduced
the number of deaths from dehydration due to diarrhea by about a million per
year.1,3 In spite of its efficacy, ORT has not been used extensively in
developed countries. Recent research, summarized in this report, suggests that
the use of oral rehydration solutions have advantages over conventional therapy.
In an effort to encourage the use of ORT, a simple approach to rehydration is
Oral rehydration takes advantage of glucose-coupled sodium transport,4 a process
for sodium absorption which remains relatively intact in infective diarrheas due
to viruses or to enteropathogenic bacteria, whether invasive or enterotoxigenic.
Glucose enhances sodium, and secondarily, water transport across the mucosa of
the upper intestine.5 For optimal absorption, the composition of the rehydration
solution is critical. The amount of fluid absorbed depends on three factors: the
concentration of sodium, the concentration of glucose and the osmolarity of the
luminal fluid. Maximal water uptake occurs with a sodium concentration from 40
to 90 mmol/L, a glucose concentration from 110 to 140 mmol/L (2.0 to 2.5 g/100
mL) and an osmolarity of about 290 mOsm/L, the osmolarity of body fluids.6
Increasing the sodium beyond 90 mmol/L may result in hypernatremia; increasing
the glucose concentration beyond 200 mOsm/L, by increasing the osmolarity of the
solution, may result in a net loss of water. CHO to Na ratio should not exceed
2:1 in these solutions.
For practical purposes in Canada, rehydration can be accomplished using
solutions with higher sodium, i.e., 75-90 mmol/L. These are termed rehydration
solutions (ORS). Prophylaxis of dehydration and maintenance involve solutions
with 45-60 mmol/L of sodium. These are termed maintenance solutions. High sodium
rehydrating solutions used to treat acute dehydration may be used for
maintenance by giving the solution alternately on a 1-to-1 basis with a
no-sodium or low-sodium fluid such as water, low CHO fluids, or breast milk. The
high sodium ORS should not be used as the sole fluid intake for maintenance of
hydration. Fruit juices and pop are not efficacious because of their high
carbohydrate concentration, osmolarity and the inadequate sodium concentration.7
Individualized dietary management of the patient during acute diarrhea is the
key and should be emphasized.
Oral rehydration and maintenance solutions presently in use, although effective
in rehydration, do not decrease stool volume because of the relatively high
osmolarity of the glucose which they contain. The challenge, therefore, is to
provide adequate glucose to the sodium pump without increasing the osmolarity of
the rehydration solution.
This has been done successfully by substituting short chain glucose polymers
(starch) from rice and other cereals for glucose in the oral rehydration
mixture.8 In field trials in developing countries,8,9 ORS containing glucose
polymers, primarily from rice and corn, were found not only to be as effective
in correcting dehydration as glucose-based ORS, but also to offer the additional
advantage of reducing the amount and duration of diarrhea by 30%, thereby
reducing morbidity and costs of treatment and increasing acceptability. The
effectiveness in diarrhea typical of North America may be less marked, i.e.,
reducing stool output by 18%.
Defined short-chained glucose polymers from rice may also be safe and effective
in the treatment of acute diarrhea.10 Wapnir et al11 found that a solution
containing 30 g/L of rice syrup solids (180 mOsm/L) resulted in 40% more water
absorption than a similar solution which contained 20 g/L of glucose (230 mOsm/L).
A clinical study with solutions containing rice-syrup solids confirmed their
efficacy in the rehydration of infants with acute diarrhea. Further, such
solutions decreased stool output, and promoted greater absorption and retention
of fluid and electrolytes than did a glucose-based solution.12
Amino acids have also been suggested as additives to ORS. The addition of
alanine alone to the WHO oral rehydration solution (ORS) was not found to give
additional benefits.13 However, Khin-Maung-U and Greenough8 found that alanine,
added to a glucose polymer-based ORS, decreased the amounts of stool by a
further 10% to 40%. Nevertheless, these are not currently recommended by WHO.
Rice-based corn and lentil-based oral rehydration solutions have been
extensively tested and may eventually be made available.
Along with improved oral rehydration solutions have come advances in the field
of early refeeding. Fasting has been shown to prolong diarrhea. This may be due
to undernutrition of the bowel mucosa which delays the replacement of mucosal
cells destroyed by the infection. Although there is general agreement that
breast-feeding should continue in spite of diarrhea,14 early refeeding with a
lactose-containing formula is usually well tolerated.15 Early refeeding should
commence 6-12 hours into therapy.
On the basis of these findings and recent recommendations, 16 the following
principles should be followed in treating diarrheal disease:
Fluid therapy should include the following three elements: rehydration,
replacement of ongoing losses, and maintenance.
Fluid therapy is based on an assessment of the degree of dehydration present.
Principles are as follows:
No dehydration - If diarrhea is present, but urinary output is normal, the
normal diet and breast-feeding may continue at home with fluid intake dictated
by thirst. High osmolarity fluids such as undiluted juices should be avoided,
and maintenance oral electrolyte solution (Na 45-60 mmol/L) offered "ad libitum."
Mild - If symptoms and signs are limited to decreased urinary output and
increased thirst, mild dehydration is suspected. Assessment and treatment under
close supervision are indicated. Rehydration consists of ORS or maintenance
solution 10 mL/kg/hr with reassessment at 4-hour intervals. Breast-feeding
continues. Early refeeding with the child's customary formula at the usual
concentration is recommended. Extra ORS or maintenance solution (e.g., 5-10 mL/kg)
may be given after each stool if diarrhea persists.
Moderate - If at least two of the following signs, sunken eyes, loss of skin
turgor ("tenting" of abdominal skin lasting less than 2 seconds), or dry buccal
mucous membranes are present, moderate dehydration is diagnosed and rehydration
consisting of ORS 15-20 mL/kg/hr with direct observation and reassessment at
4-hour intervals. If dehydration is corrected, therapy for ongoing losses and
maintenance are continued as outlined above. If not, treatment is repeated as
indicated by clinical signs or symptoms.
Severe - If, in addition to signs of moderate dehydration, there is rapid
breathing, lethargy, coma, a rapid thready pulse or "tenting" of the skin
lasting more than 2 seconds, severe dehydration and shock are present. Blood
pressure should be measured. Prompt intravenous therapy is indicated with rapid
infusion of saline plasma or colloid sufficient to replete blood volume (10-20
mL/kg over 30 minutes may be necessary). Intraosseous infusion should be used if
an intravenous line cannot quickly be inserted.
General comments. Vomiting is not a contraindication to ORT. ORS should be given
slowly but steadily to minimize vomiting. Fluids may be administered by nasogastric tube if required. The child's clinical condition should be
frequently assessed. A child should never be kept on ORS fluid alone for more
than 24 hours. Early refeeding should begin within 6 hours. A full diet should
be reinstituted within 24 to 48 hours, if possible.
There are certain contraindications to the use of ORT:
Protracted vomiting despite small, frequent feedings
Worsening diarrhea and an inability to keep up with losses
Stupor or coma
As ORS can be administered easily by a properly instructed parent, and because
dehydration can be corrected quickly, it lends itself well for use in an
outpatient department or nursing station. At the end of 4 hours, the child can
either be sent home on maintenance therapy or, if dehydration persists, be
observed for further therapy. Intelligent use of ORT can decrease hospital
admissions, an important consideration in a time of decreasing hospital budgets.
Although in our society intravenous therapy is often considered more convenient
than ORT, clinicians should feel more comfortable as they become more accustomed
to the use of ORT.
TABLE 3: Simplified ORT protocol in mild to moderate rehydration
|next 6-8 hours
|Reassessment at 4-hour intervals
There are many different equations for calculating administration rates in oral
rehydration. ORT may be given in amounts equal to
fluids calculated for intravenous administration. Alternately, fluids may be
delivered by nasogastric tube
Dehydration accompanying infantile gastroenteritis should be treated with early
oral rehydration and early refeeding strategies.
Infants with gastroenteritis should be offered maintenance solution to prevent
dehydration. Parents and daycare centres should keep maintenance solution on
hand in anticipation of episodes of infectious diarrhea.
ORS and maintenance solutions and instructions in their use should be made
available at reasonable costs.
Medical facilities should have ORT protocols available for staff and patients.
Antidiarrheal drugs, antibiotics and antiemetic therapy are rarely indicated in
gastroenteritis in childhood and should be discouraged.
Home-made oral rehydration solutions are discouraged since serious errors in
formulation have occurred.
Infants with mild to moderate dehydration should be treated under medical
supervision with ORT in preference to intravenous rehydration.
Infants with severe dehydration should initially be treated with intravenous or
Breast-fed infants with dehydration should be given ORT in conjunction with
Early refeeding should commence as soon as vomiting has resolved, approximately
Non-lactose containing formulae or milks may be used if diarrhea and abdominal
cramps persist beyond expected 5- to 7-day course suggesting clinical lactose
Further initiatives to encourage ORT use by patients and professionals should be
Oral Rehydration Therapy (ORT)
Wikipedia, the free encyclopedia
Oral rehydration therapy, (also called ORT, oral
rehydration salts or solutions (ORS), or oral electrolyte),
is a simple, cheap, and effective treatment for
dehydration, caused by e.g.
It consists of a
of salts and other substances such as
which is administered orally. It is used around the world, but is most
important in the
World, where it saves millions of children from
their leading cause of death.
ORT was developed in the late
International Centre for Diarrhoeal Disease Research in
Bangladesh (then East Pakistan), for the treatment of cholera. The
Indo-Pakistani War of 1971 provoked a public health emergency in the
refugee camps set up to house those fleeing the violence. With cholera
spreading rapidly and death rates rising, the head of a medical centre in
one of the camps instructed his staff to distribute Oral Rehydration Salts
(ORS). In the refugee camps where ORS was being used the death rate was only
3%, compared to 20–30% in those camps using only intravenous fluid therapy. In 2002,
David R. Nalin, and
Nathaniel F. Pierce were awarded the first
Pollin Prize for Pediatric Research, in recognition of their work in
and 2000, ORT
decreased the number of children under five dying of diarrhea from 4.6
million worldwide to 1.8 million—a 60% reduction. According to
Lancet (1978), ORT is "potentially the most important medical
discovery of the 20th century".
Today, the total production is around 500 million ORS
year, with the
children's rights agency
distributing them to children in around 60
developing countries. ORS represents a cheap and effective way of
reducing the millions of deaths caused each year by diarrhea.
Oral rehydration therapy is widely considered to be the best
method for combating the
dehydration caused by
Various diseases cause damage to the
allowing water to flow from the blood into the intestine, depleting the body
of both fluid and
electrolytes. This may be
In the human body, water is absorbed and secreted passively; it follows
the movement of salts, based on a principle called
So, in many cases,
is caused by intestine cells secreting
sodium) and water following passively along.
Simply drinking water is ineffective for 2 reasons: (1) the large
intestine is usually secreting instead of absorbing water, and (2)
electrolyte losses also need compensating. As such, the standard
treatment is to restore fluids
intravenously with water and salts. This requires trained personnel and
materials which are not sufficiently available in the
However, it was discovered that the body can absorb a simple
containing both sugar and salt. The dry ingredients can be mixed and
packaged, and then the solution can be prepared and delivered by people with
minimal training. One diarrhea mechanism (like in
which is a very dangerous form of profuse diarrhea), is an
enterotoxin interfering with
G-proteins. However, water can still be absorbed by cAMP-indepentent
mechanisms, like the
SGLT-transporter (sodium and glucose transporter, of which 2 types
exist). This is achieved by combining
Oral rehydration can be accomplished by drinking frequent small amounts
of an oral rehydration salt solution.
It is important to rehydrate with solutions that contain electrolytes,
electrolyte disturbances may be avoided. Sugar is important to improve
absorption of electrolytes and water, but if too much is present in ORS
diarrhea can be worsened. Oral rehydration does not stop diarrhea, but
keeps the body hydrated and healthy until the diarrhea passes.
There are several commercially available products but an inexpensive
home-made solution consists of 8 level
of sugar and
1 level teaspoon of
salt mixed in 1
water. A half cup of
orange juice or half of a mashed
be added to each liter both to add potassium and to improve taste. If
commercial solutions are used, true rehydration solutions should be used and
sports drinks should be avoided (especially in younger children) as
these solutions contain too much sugar and not enough electrolytes.
One standard remedy is the
glucose-based Oral Rehydration Salts (ORS) solution. WHO/UNICEF ORS solution
|Reduced osmolarity ORS
||Reduced osmolarity ORS
|Trisodium citrate, dihydrate
In the human body, the
plasma osmolality is about 285 mOsm/l.
An inexpensive home-made solution consists of
A half cup of orange juice or half of a mashed banana can be added to
each liter to add potassium and improve taste.
If commercial solutions are used, true rehydration solutions should be
sports drinks should be avoided (especially in younger children) as
these solutions contain too much sugar and not enough electrolytes.
The amount of rehydration that is needed depends on the size of the
individual and the degree of dehydration. Rehydration is generally adequate
when the person no longer feels thirsty and has a normal urine output. A
rough guide to the amount of ORS solution needed in the first 4-6 hours of
treatment for a mildly dehydrated person is:
- Up to 5 kg (11 lb): 200 – 400 ml
- 5-10 kg (11-22 lb): 400 – 600 ml
- 10-15 kg (22-33 lb): 600 – 800 ml
- 15-20 kg (33–44 lb): 800 – 1000 ml
- 20-30 kg (44-66 lb: 1000 – 1500 ml
- 30-40 kg (66-88 lb): 1500 – 2000 ml
- 40 plus kg (88 lb): 2000-4000 ml
Adults and children with dehydration who are not vomiting can be allowed
to drink these solutions in addition to their normal diet. People who are
vomiting should be fed small frequent amounts of ORS solution until
dehydration is resolved. Once they are rehydrated, they may resume eating
normal foods when nausea passes.
Vomiting itself does not mean that oral rehydration cannot be given. As
long as more fluid enters than exits, rehydration will be accomplished. It
is only when the volume of fluid and electrolyte loss in vomit and stool
exceeds what is taken in that dehydration will continue. When vomiting
occurs, rest the stomach for ten minutes and then offer small amounts of ORS
solution. Start with a teaspoonful every five minutes in children and a
tablespoonful every five minutes in older children and adults. If output
exceeds intake or signs of moderate to severe dehydration occur, medical
assistance should be sought.
Oral Rehydration Therapy - A Brazilian Experience
updated: 10 November, 2012