Rehydration in acute diarrhea Jorge Amil Dias Porto, Portugal

Water and electrolyte movement across the intestinal mucosa K Hodges and R Gill, Gut Microbes, 2010

Stool electrolyte losses InfectionStool sodium Cholera88.9 mMol/L ETEC53.7 mMol/L Rotavirus37.2 mMol/L AM Molla et al. J Pediatr 1981

History of Oral Rehydration 1910 Intestinal absorption in patients with cholera Sellards, Phillip J Sci 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/litremmol/litre Sodium chloride2.6Sodium75 Glucose, anhydrous13.5Chloride65 Potassium chloride1.5Glucose, anhydrous75 Trisodium citrate Potassium20 dihydrate2.9Citrate10 Total Osmolarity245

Soft drinks BrandAQUARIUSGATORADENESTEA COCA- COLA PEPSI- COLA SPRITE FANTA ORANGE Na (mEq/L) K (mEq/L) 15< Glucose (mmol/L) Osmolality (mOsm/L) 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 water300.4 ± 5.9 Peach ± 14.3 Apple (natural)258.4 ± 25.8 Apple (bottled)773.4 ± 72.6 Orange (natural) ± 32.5 Pear (natural) ± 27.3 Pear (bottled) ± 9.2 Pineapple (natural) ± 54.0 Pineapple (bottled)725.1 ± 42.3 Grape (bottled) ± 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 – ml/kg/d Reassess regularly!

Fuid requirements Previous losses (rehydration) 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 Basic 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

H2OH2O 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!