Rehydration in acute diarrhea
Jorge Amil Dias
Porto, Portugal
jamildias@zonmail.pt
Water and electrolyte movement
across the intestinal mucosa
K Hodges and R Gill, Gut Microbes, 2010
K Hodges and R Gill, Gut Microbes, 2010
K Hodges and R Gill, Gut Microbes, 2010
Stool electrolyte losses
Infection
Cholera
ETEC
Rotavirus
Stool sodium
88.9 mMol/L
53.7 mMol/L
37.2 mMol/L
AM Molla et al. J Pediatr 1981
History of Oral Rehydration
1910 Intestinal absorption in patients with cholera
Sellards, Phillip J Sci
1953 186 patients with cholera treated without iv lfuids
Chatterjee, Lancet
1960’s Identification of glucose-solute co-transport
1971 WHO recommended the use of ORS
intestinal sodium co-transport
“Oral rehydration is potentially the most important
medical advance in the 20th century”
Lancet, 1978
Is This Child Dehydrated?
• The best measure of dehydration is the
percentage loss of body weight.
• Classification into subgroups with no or
minimal dehydration, mild or moderate
dehydration, and severe dehydration is an
essential basis for appropriate treatment
ESPGHAN/ESPID Guidelines, JPGN 2008
Assess Dehydration by Clinical History?
• Parental reports on dehydration symptoms are
low in specificity. They may not be clinically
useful.
• Parental report of normal urine output
decreases the likelihood of dehydration.
• Infants and young children with frequent high
output diarrhea and vomiting are most at risk.
ESPGHAN/ESPID Guidelines, JPGN 2008
Assess Dehydration Based on Signs and
Symptoms?
• Clinical tests for dehydration are imprecise.
• Historical points are moderately sensitive as a
screening test for dehydration.
• The best 3 individual examination signs for
assessment of dehydration are:
– prolonged capillary refill time
– abnormal skin turgor
– abnormal respiratory pattern
ESPGHAN/ESPID Guidelines, JPGN 2008
Items that reflect hydration
•
•
•
•
•
•
•
•
•
Urine output
General appearance
Capillary refill (>3” = iv resuscitation!)
Skin turgor
Eyes
Mucous membranes
Tears
Respiratory rate
Heart rate
Blood electrolytes?
• Electrolytes should be measured:
– In moderately dehydrated children whose history
and physical examination findings are inconsistent
with a straight diarrheal disease.
– in all severely dehydrated children.
– In all children starting intravenous (IV) therapy,
and during therapy, because hyper- or
hyponatremia will alter the rate at which IV
rehydration fluids will be given
Indications for admission
• Shock
• Severe dehydration (>9% of body weight)
• Neurological abnormalities (lethargy, seizures,
etc)
• Intractable or bilious vomiting
• ORS treatment failure
• Caregivers cannot provide adequate care at home
and/or there are social or logistical concerns
• Suspected surgical condition
Oral rehydration
• First-line therapy for the management of children
with AGE
• When oral rehydration is not feasible, enteral
rehydration by the nasogastric route is as
effective if not better than IV rehydration.
• Enteral rehydration is associated with
significantly fewer major adverse events and a
shorter hospital stay compared with IV therapy
and is successful in most children.
• Children who are able to receive oral rehydration
therapy (ORT) should not be given IV fluids.
Role of osmolality in ORS
• Lower osmolality increases water absorption
– (osmolar gradient)
• Hypertonic solutions (old WHO-ORS, Na+90 mmol/l)
may increase the risk of hypernatremia
• Current WHO (Na 75mmol/l) has a balanced
composition that is safe both for cholera and noncholera diarrhoea
Composition of WHO ORS
grams/litre
mmol/litre
Sodium chloride
2.6
Sodium
75
Glucose, anhydrous
13.5
Chloride
65
Potassium chloride
1.5
Glucose, anhydrous
75
Potassium
20
Citrate
10
Total Osmolarity
245
Trisodium citrate
dihydrate
2.9
Soft drinks
Brand
AQUARIUS
GATORADE
NESTEA
COCACOLA
PEPSICOLA
SPRITE
FANTA
ORANGE
Na (mEq/L)
13
23.5
10
6
5
8
6
Soft drinks are NOT recommended
for rehydration, specially in
infants or small children
K (mEq/L)
15
<1
3.37
1
0.9
1.2
3.4
Glucose
(mmol/L)
103.8
45
40.3
100.3
109
290.5
367.5
Osmolality
(mOsm/L)
406
330
326
509
571
703
859
Alternatives to ORS?
• Home-made solutions?
– Risk of variable composition and osmolality
• Fruit juice?
– Benefit of potassium but content of fructose and
osmolality load
Osmolality of fruit juices
Coconut water
Peach
Apple (natural)
Apple (bottled)
Orange (natural)
Pear (natural)
Pear (bottled)
Pineapple (natural)
Pineapple (bottled)
Grape (bottled)
300.4 ± 5.9
257.8 ± 14.3
258.4 ± 25.8
773.4 ± 72.6
536.7 ± 32.5
302.1 ± 27.3
449.5 ± 9.2
292.5 ± 54.0
725.1 ± 42.3
1087.9 ± 44.5
Fruit juice may affect duration of
diarrhea
N=90
S Valois et al Nutr J, 2005
Rehydration stages
• Compensate for previous losses
– Calculate fluid deficit
• Compensate for ongoing elevated losses
– Calculate 10ml/kg/liquid stool
• Compensate for basic needs
– 100-150ml/kg/d
Reassess regularly!
Fuid requirements
Previous losses
(rehydration)
Basic daily needs
Ongoing losses
(maintenance and
prevention of dehydration)
Normal losses
First 10 kg
Second 10 kg
Subsequent kg
100 ml/kg
50 ml/kg
20 ml/kg
ESPGHAN/ESPID guidelines on acute
diarrhoea
• Dehydration is the main clinical feature.
• Weight loss, prolonged capillary refill time, skin turgor, and
abnormal respiratory pattern are the best clinical signs.
• Microbiological investigations generally are not needed.
• Rehydration is the key treatment - apply as soon as possible.
• Low osmolality oral rehydration solution - offer ad libitum.
• Regular feeding should not be interrupted - carry on after
rehydration.
• Regular milk formulas are appropriate in the majority of cases.
ESPGHAN/ESPID Guidelines
• Drugs are generally not necessary.
• Selected probiotics may reduce the duration
and intensity of symptoms.
• Other drugs require further investigations.
• Antibiotic therapy is not needed in most cases
– May induce a carrier status (Salmonella).
– Antibiotic treatment mainly in shigellosis and in
the early stage of Campylobacter infection.
Pilars for treatment of acute diarrhoea
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•
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Oral rehydration solution over 3-4 h
Rapid reintroduction of normal feeding thereafter.
Breast-feeding should be continued as possible.
Hypotonic solution is safe and effective
Supplementation with oral rehydration solution.
Lactose-free formulae unjustified in the majority.
– If diarrhea worsens check stool pH and/or reducing substances
– Lactose-free formula if stool is acid and >0.5% red substances.
• Do not dilute formula
• Provide additional ORS to compensate for ongoing losses
• Do not use unnecessary medication
Enteral vs parenteral rehydration - Length of hospital stay
Enteral vs parenteral rehydration – duration of diarrhoea
Enteral rehydration is as effective if not better
than IV rehydration.
Enteral rehydration by the oral or nasogastric
route is associated with significantly fewer
major adverse events and a shorter hospital
stay compared with IV therapy and is successful
in most children
If iv fluids are necessary
• Check blood electrolytes
• Use isotonic saline solution (NaCl 0.9%) with
2.5% dextrose
• Possible alternative: half DD solution
• In case of hypernatremia, take additional care:
– Use 75% of calculated volume.
– Monitor serum Na+
– Aim at reducing Na + by 10mmol/l per day
Na+
H2O
Instruct caregivers for:
• Ongoing vomiting despite small fluid sips,
especially if associated with abdominal distension
or pain
• Persisting fever after 24 hours of ORT
• Increasing lethargy and failure to feed
• Deteriorating hydration and failure to pass urine
• Presence of blood in the stools
• Diarrhoea persisting for more than 1 week.
Oral rehydration
• May not reduce stool volume or duration of diarrhoea
• BUT saves lifes by preventing dehydration!
• Pro’s and Con’s of additional medication
– Cost
– Limited benefit
– Draw parents’ attention from the main intervention –
Rehydration!