Rehydration in acute diarrhea

Jorge Amil DiasPorto, 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 Stool sodiumCholera 88.9 mMol/LETEC 53.7 mMol/LRotavirus 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• Skin turgor• Eyes• Mucous membranes• Tears• Respiratory rate• Heart rate

(>3” = iv resuscitation!)

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 non-

cholera 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

Trisodium citrate Potassium 20

dihydrate 2.9 Citrate 10

Total Osmolarity 245

Soft drinks

Brand AQUARIUS GATORADE NESTEACOCA-COLA

PEPSI-COLA

SPRITEFANTA

ORANGE

Na (mEq/L) 13 23.5 10 6 5 8 6

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

Soft drinks are NOT recommended for rehydration, specially in infants or small children

Alternatives to ORS?

• Home-made solutions?– Risk of variable composition and osmolality

• Fruit juice?– Benefit of potassium but content of fructose and

osmolality load

Coconut water 300.4 ± 5.9 Peach 257.8 ± 14.3 Apple (natural) 258.4 ± 25.8 Apple (bottled) 773.4 ± 72.6 Orange (natural) 536.7 ± 32.5 Pear (natural) 302.1 ± 27.3 Pear (bottled) 449.5 ± 9.2 Pineapple (natural) 292.5 ± 54.0 Pineapple (bottled) 725.1 ± 42.3 Grape (bottled) 1087.9 ± 44.5

Osmolality of fruit juices

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 lossesPrevious losses(rehydration)

Ongoing lossesOngoing losses(maintenance and

prevention of dehydration)

Normal lossesNormal losses

First 10 kgFirst 10 kgSecond 10 kgSecond 10 kgSubsequent kgSubsequent kg

100 ml/kg50 ml/kg20 ml/kg

Basic daily needsBasic daily needs

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

• 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

H2O

Na+

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!