ORT in gastroenteritis

Question 1

Where in the world is ORT not used enough?

What are some barriers to using ORT?

Answer 1

In the developing world

Fear of iatrogenic hypernatremia
Lack of familiarity
Entrenched patterns of practice

Question 2

What is the scientific basis of ORT?

Answer 2

The science relies on the cotransport of glucose and sodium across the intestinal membrane.

• The sodium-potassium ATP pump on the basolateral membrane of the enterocyte provides the gradient that drives the process. The cotransport system is relatively intact in infective diarrhoea due to viruses or enteropathogenic bacteria, whether invasive or enterotoxigenic. Glucose enhances sodium and secondarily water absorption.
• Ideal glucose:sodium raio = 1:1

Question 3

What is in ORT in the WHO revised formula?

Answer 3

Sodium: 75 mmol/L
Potassium: 20 mmol/L
Chloride: 65 mmol/L
Glucose 75 mmol/L
Bicarbonate: 10 mmol/L

Question 4

What is the osmolarity of ORT?

Answer 4

245 most/L

Question 5

What are some of the controversies of ORT?

Answer 5

Hypernatremia after the use of OT in patients with non cholera diarrhoea
Some RCTs have shown that lower osmolarity could be better with decreased need for IV, lower stool volumes and less vomiting –> this caused recommendations of a new ORT with less osmolarity (311 –> 245)

Question 6

Why would you consider adding starch to ORT?

Answer 6

Adding short-chain glucose polymers (starch) such as rice and other cereals helps reduce the osmolarity while providing a favourable ratio of glucose to sodium. This may also add additional calories without increasing the osmotic load.

There is evidence to support its inclusion in patients with cholera and the benefit would be considerably lower in children with non-cholera diarrhoea

Question 7

Is there evidence for adding other substrates such as glycine, alanine, glutamine and zinc?

Answer 7

These have been investigated and there is no evidence for any of them except for zinc. Zinc can reduce the duration and severity of diarrhoea. You want to use 20 mg once daily of zinc.

Question 8

Is weight change an accurate indicator of degree of dehydration?

Answer 8

It is helpful, but it should always be corroborated by clinical signs because wight can be affected by many errors.

Question 9

What are the components of fluid therapy when treating a dehydrated child?

Answer 9

Rehydration
Replacement of ongoing losses
Maintenance

Question 10

What are some clinical signs of mild dehydration?

Answer 10

Mildly decreased urine output
Slightly increased thirst
Slightly dry mucous membranes
Slightly elevated heart rate

Question 11

What percentage weight loss does mild dehydration correlate to and how do you treat it?

Answer 11

5 %

ORT 50 ml/kg

Question 12

What are some clinical signs of moderate dehydration?

Answer 12

Decreased urine output
moderate increased thirst
dry mucous membranes
Elevated HR
Decreased skin turgor *
Sunken eyes*
Sunken anterior fontanelle *

Question 13

What percentage weight loss does moderate dehydration correlate to and how do you treat it?

Answer 13

5-10%

100 ml/kg ORT

Question 14

What are some clinical signs of severe dehydration?

Answer 14

Marked decrease or absent UO
Greatly increased thirst
Very dry MM
Greatly elevated HR
Decreased skin turbo
Very sunken eyes
Lethargy *
Cold extremities *
Hypotension *
Coma *

Question 15

What percentage weight loss does severe dehydration correlate to and how do you treat it?

Answer 15

IV resuscitation

Question 16

If there is hypernatremia, are there any special adjustments to the rehydration process? (2)
Why?

Answer 16

To do it slowly over 48-72 hours
To decrease the maintenance fluid by 25%
To avoid cerebral oedema

Question 17

Is vomiting a contraindication to ORT?

Answer 17

No, almost all children with vomiting respond to ORT, if given frequently and in small amounts.

Question 18

If the family do not have ORT at home, is it ok for them to use gatorade? What about plain water?

Answer 18

No, fluids containing non-physiological concentrations of glucose and electrolytes are discouraged because these drinks have a high carbohydrate content, low electrolyte content and high osmolarity.
Administration of hyperosmolar solutions may also produce osmotic diarrhoea

Plain water can lead to hyponatremia and hypoglycemia

Question 19

Is ORT evidence based?

Answer 19

Yes. There are two meta-analyses that show that ORT is as effective as, if not better than, IV therapy for rehydration of moderately dehydrated children.
There are also fewer adverse effects and shorter hospital LOS

Question 20

What are some contraindications of ORT?

Answer 20

Protracted vomiting
shock-like state
impaired consciousness
Paralytic ileus
monosaccharide malabsorption

Question 21

What are the benefits of early refeeding?

Answer 21

induces digestive enzymes
improved absorption of nutrients
enhanced enterocyte regeneration
promotes recovery of disaccharidases
reduces the duration of diarrhoea
maintains growth
improved nutritional outcomes

Question 22

Is powered ORT just as good?

Answer 22

Technically it is, but the risk of error is high. Error could result in hypoglycaemia and electrolyte abnormalities.