Vomiting, Diarrhoea, Vomiting, Diarrhoea, Abdominal PainAbdominal Pain&&Fluid TherapyFluid Therapy

Department of PaediatricsCUHK

VomitingVomiting

vomiting– forceful ejection of gastric contents– often preceded by nausea and retching

possetting– gentle expulsion of gastric contents with swal

lowed air (“wind”)regurgitation

– similar to possetting, but larger lossretching

– laboured rhythmic respiratory activity that precedes vomiting

Mechanism of vomitingMechanism of vomiting

Vomiting process

• patent upper GI tract

• retro-peristalsis

• lower esophageal sphincter

relaxation

• contraction of abdominal

muscles and diaphragm

Causes of VomitingCauses of Vomiting

infection/inflammation• gastroenteritis

• viral• bacterial• toxin

• immunological• cow-milk• coeliac• food allergy

• inflammatory• appendicitis• mesenteric adenitis

GI obstruction• pyloric stenosis• intussusception• volvulus• strangulated hernia• Hirschsprung• tumour• post-operative ilieus

CNS irritation• infection• raised ICP• drugs / poisons• metabolites

Incompetent LES• possetting• reflux• hiatus hernia

DiarrhoeaDiarrhoea

Diarrhoea: increase in frequency (> 3 times) and change in character of stool (volume and liquidity)

Lead to rapid dehydration and progressive acidosis

Acute - within 2 weeks

Chronic or persistent - beyond 2 weeks

WHO: 2.6 episodes/child/year, global mortality 3.3 million/year

Infective gastroenteritisInfective gastroenteritis

Acute gastroenteritisAcute gastroenteritis

Morbidity in developed world, yet mortality in developing world

Complicated in developed world with secondary lactase deficiency

Complicated in developing world with recurrent episodes and malnutrition, like deficiency of zinc, vitamin A etc,

Especially affecting children < 2 years

Infective causes of diarrhoea and voInfective causes of diarrhoea and vomitingmitingViruses BacteriaRotavirus Enteroinvasive E. coliAdenovirus Camphylobacter jejuniCoronavirus Salmonella sp.Astrovirus Shigella sp.Calcivirus Vibrio choleraParvovirus Yersinia enterocoliticaEchovirus

Protozoa Bacterial toxinsGiardia lamblia Enterotoxic E. coliCrytosporidium Staphylococcus aureusEntamoeba histolytica Bacillus cereusMalaria Clostridium difficile

Bacterial GastroenteritisBacterial Gastroenteritis

Salmonella, E coli (EPEC, EIEC, EHEC, VTEC-0157), Shigella (neurotoxin), Yersinia, Campylobacter

Adherence and invasion of bacteria to gut structures

Bloody diarrhoea, Fever, Tenesmus, Severe or persistent symptoms

Antibiotic use, Clostridium(toxin is common in healthy newborn)

CholeraCholera

cause secretory diarrhoea

enterotoxin production leading to generation of intracellular cAMP (adenyl cyclase)

result in stimulation of the chloride channel leading to fluid and electrolytes secretion

could also cause increased production of prostaglandins

absorption of fluid and e- remains intact

Virus GastroenteritisVirus Gastroenteritis

Rotavirus attacks the villus epithelium of the small intestine

Norwalk virus - vomit

Enteric adenoviruses

increase in epithelial renewal with crypt proliferation, interfering the process of maturation

repair takes 4 - 5 days, affected by chronic protein-calorie malnutrition

Rotavirus gastroenteritisRotavirus gastroenteritis

Most common cause in infants and young children (6 - 12 months), occurs in winter

Within two days of exposure, low grade fever,anorexia, & vomiting lasting up to 48 hours. Watery diarrhea and cramps follow

Highly infective, resistant to drying and chlorine in tap water. Nosocomial outbreaks occur in hospital and nurseries

Fecal-oral transmission

Rotavirus gastroenteritisRotavirus gastroenteritis

Infect the villi of small intestine, causing damage to transport mechanisms, secondary lactase deficiency and malabsorption

Local IgA response, no life-long protection

Diagnosis by viral antigen detection

Self-limiting disease with complete recovery

Prevention by improving overall standard of nutrition and hygiene (handwashing, disposal of diapers), ?oral vaccine

Norwalk / Norwalk-like / Norwalk / Norwalk-like / NorovirusNorovirus

Norwalk virus was named after the strain that was responsible for an outbreak of gastroenteritis in a school in Norwalk, Ohio, USA

Recently approved name: Norovirus, a RNA virus

More common during cooler months

As of November 17, there were 41 reported cases of viral gastroenteritis caused by Norwalk-like virus, affecting about 1,000 persons and occurring in institutions like schools, child care centres and homes for the elderly.

* 截至二零零三年十月 Up to October 2003

二零零三年 * 受諾沃克類病毒影響人數Number of Persons Affected of Norwalk-like D

isease 2003*

安老院舍 Elderly home

48%

家居Home

5%

院舍Institutions

9%

幼兒中心Child care centre

10%

幼稚園Kindergarten

4%

小學Primary school

19%

中學Secondary school

4%

醫院 Hospital

1%

* 截至二零零三年十月。

*Up to October 2003

Norovirus gastroenteritisNorovirus gastroenteritis

Incubation 1 - 2 daysUsually self-limited, lasts 1 - 10 days

Symptoms• Vomiting• Diarrhoea• Fever• Abdominal cramps• Headache

Clinical Approach to a Clinical Approach to a child who presents with child who presents with vomiting or diarrhoeavomiting or diarrhoea

History: VomitingHistory: Vomiting

Onset• Present since birth ?• Present since weaning ?• Present since introduction of new food?• Sudden or gradual ?

Vomit• Size, frequency and timing to feed• Undigested food ? bile ? blood ? coffee-gro

und ?

History: DiarrhoeaHistory: Diarrhoea

Onset• Sudden or gradual ?

Stool• Volume, frequency and timing to feed• Loose, watery, rice watery• Blood, mucus, steatorrhoea

History:History:

Associated symptoms• Abdominal pain / Abdominal distension• Fever• Change in appetite / feeding habit• Weight loss ? or gain ?• General: playfulness, activities, urine outpu

t

Social history• Family members having vomiting / diarrho

ea• Recent traveling

ExaminationExamination

Full examination is necessary in all childrenGeneral examination

• Activity• Nutritional status• Weight and Height (and compare with prev

ious)• Temperature• Anaemia• Jaundice• Degree of dehydration• Cleft palate• Neurological

Mild Moderate Severe

Body weight <5% 5-10% > 10%General Appearance

Thirsty, Alert Thirsty, restless or lethargic

Drowsy, cold, sweating

Tears Present Absent Absent

Anterior Fontanelle

Normal Sunken Very sunken

Eyes Normal Sunken Very sunken

Tissue Turgor Normal Absent Absent

Mucous Membranes

Moist Dry Very Dry

Pulse Normal Rapid Rapid, weak, may be

impalpable

Urine flow Normal Reduced, concentrated

Oliguria

Blood pressure

Normal Normal or low Low, may be unrecordable

Fluid deficit 50ml/kg 60-90ml/kg 100ml/kg

In hypertonic dehydration, signs not prominent because of intracellular dehydration; skin of doughy consistency with abnormal behaviour

ExaminationExamination

Abdomen: Inspection• Distension

• Constipation• Gastroenteritis• Obstruction / Ileus• Coeliac Disease

• Surgical Scar

ExaminationExamination

Abdomen: Palpation• Local tenderness• Generalized tenderness• Guarding and rebound tenderness

• Peritoneal irritation• Masses

• Organomegaly• Pyloric mass• Sausage shaped mass

• Hernial orifices• Genitalia

ExaminationExamination

Abdomen: Auscultation• Bowel sounds

• Normal• Hyperactive: irritation, obstruction• Diminished, absent: paralytic ileus

Abdomen: Rectal examination• Anal fissures• Sphincter• Faeces• Blood• Masses

InvestigationsInvestigations

Ordered according to index of suspicion

• Examine stool for consistency, blood, mucus, and steatorrhoea

• Stool for bacterial culture and virus isolationPositive yield ~50%

• Commonest: rotavirus• Commonest bacterial: Salmonella

• Stool for Clostridial difficile toxin• Blood for cell counts, U&Es, culture

InvestigationsInvestigations

• Test feed for infant 2 to 10 weeks

• Examine urine for RBC, WBC and organism under microscope, urine for culture

• AXR: Supine, Erect for intestinal obstruction

• USG abdomen

TreatmentTreatment

RehydrationRehydrationRehydration fluid and electrolytes

• Oral glucose-electrolyte solution• Intravenous glucose-electrolyte solution• Nutritional treatment - continuation of bre

ast feeding (lactadherin), or formula feeding

Principles of fluid Principles of fluid replacement : replacement : volume requiredvolume required= maintenance + deficit + = maintenance + deficit + ongoing lossongoing loss

Daily fluid requirementDaily fluid requirement

Fluid First 10 kg 100 ml/kg/daySecond 10 kg 50 ml/kg/dayAfter first 20 kg 20 ml/kg/day

Increase by 10% per degree Celcius rise in body temperature

Electrolytes Sodium 3 mmol/kg/dayPotassium 2 mmol/kg/day

For a 25-kg boyDaily fluid requirement for a 25-kg boy

= 1000 ml + 500 ml + 100 ml = 1600 ml

Daily Na requirement = 75 mmolDaily K requirement = 50 mmol

Fluid deficit calculationFluid deficit calculation

Volume depleted = estimated % of dehydration x body weight

For a 25 kg boy with 10 % dehydrationVolume deficit (1 L water = 1 kg)

= 10% x 25 kg = 2.5 L

Fluid ongoing lossFluid ongoing loss

Most difficultMeasure stool output and volume of vomitus

Oral versus intravenous Oral versus intravenous fluid replacement therapyfluid replacement therapy

AAP Practice Parameter 1996AAP Practice Parameter 1996

ORS is the preferred treatment for fluid and electrolyte losses caused by diarrhoea in children who have mild to moderate dehydration

Use of cola, fruit juice and sports beverages is not recommended– Inappropriate electrolyte content– Too much carbohydrate

ORSORS

Commercially available ORS contain 45-50mmol/l of sodium– Best suitable for maintenance– Can also be used in mild to moderate dehydra

ted otherwise healthy children– Taste better than the saltier solution

WHO recommended ORS– High sodium content 90mmol/l– Suitable for secretory diarrhoea eg. Cholera

ORS Therapy in mild to ORS Therapy in mild to moderate dehydrationmoderate dehydration

50-100ml/kg ORS to be given over a 4-hour period

Replacement of stool (10ml/kg for each stool) and vomitus will require adding appropriate amounts of solution to the total

Administering in small but frequent amounts– 10 ml every two minutes = 500 ml over 4 hours

Labour intensive, time consuming

Intravenous fluid therapyIntravenous fluid therapy

Although oral rehydration is encouraged, clinician must be prepared to administer IV fluids who do not respond to oral regimen

Severely dehydrated or who are in a state of shock must receive immediate and aggressive intravenous fluid therapy

Phase I: Treat shock(0 - 30 minutes)

Phase II: Initial Rehydration(½ - 8 hours)

Phase III: Continued Replacement(8 - 24 hours)

10-20ml/kg 0.9% NaCl

Reassess

Improved

No Change

Measure plasma electrolytes

Calculate fluid deficit and maintenance

Review plasma electrolytes and fluid status

Initial replacement with saline-dextrose solution

Half the calculated fluid deficit plus maintenance

Replacement with saline-dextrose solution

Half the calculated fluid deficit plus maintenance

Sodium replacementSodium replacement

Sodium deficit in mmol required = (140 - [Na+] x 0.65 x body weight in kg)

• 0.65 is the volume of distribution of NaSodium replacement

= sodium daily requirement + sodium deficit

If due to water intoxication (iatrogenic, SIADH)• Restrict fluid

Treatment of metabolic Treatment of metabolic acidosisacidosis

For full correction of acidosis, NaHCO3 required (mmol)

= Base deficit x body weight x 0.3

In most cases, metabolic acidosis is self-corrected once dehydration corrected and hence effective circulation volume restored

In rare situation, half of the calculated required NaHCO3 may be given: watch out for Na overload and pulmonary oedema

Hypertonic dehydrationHypertonic dehydration

Difficult to assess degree of dehydration, unless the child in clinically shock (>10% dehydration)

The plan – Fluid resuscitation 10-20 ml/kg NaCl over first 1

hr– replace total fluid deficit plus maintenance slo

wly over 48-72 hours– To lower serum sodium slowly: 10mmol/L/da

y

Rapid correction may cause cerebral oedema

MonitorMonitor

Body weightVital signs, heart rate, blood pressure,

respiratory rateSubsidence of signs of dehydration Input and output chartsContinuous lossSerum electrolytes In severe cases blood glucose, blood gases,

osmolality

Antibiotics in special Antibiotics in special circumstancecircumstance

Salmonella GE in infantShigella with trimethoprim-sulfamethoxazoleCampylobacter with erythromycinCholera with tetracyclineAmoebic dysentery - giardiasis (metronidazole)NB: drug resistance, promote carrier state, worse

n the course of diarrhoea

RefeedingRefeeding

Children who have diarrhoea and are not dehydrated should continue to be fed regular diet

Children who require rehydration should be fed regular diet as soon as they have been rehydrated

Early feeding of regular diet does not worsen the course or symptoms of mild diarrhoea and may reduce the duration of diarrhoea modestly

RefeedingRefeeding

Avoid fatty foods and foods high in simple sugars

Rice, wheat, potatoes, bread and cereals (complex carbohydrate), lean meats, yogurt, fruits and vegetables are usually well tolerated

Most children who have diarrhoea will tolerate full-strength milk

Lactose-free formula may be used if secondary lactase deficiency is suspected

Antidiarrhoeal compoundsAntidiarrhoeal compounds

Decrease stool water and electrolyte lossesChange toward more formed stoolRelieve discomfortFalse sense of securityDelaying more effective therapyGenerally not recommended

Drugs that alter intestinal Drugs that alter intestinal motilitymotility

LoperamideDecreases transit velocity Increases the ability of gut to maintain fluidReduces stool losses, shortens the course of diar

rhoeaAssociates with serious adverse effect

– Lethargy, ileus, respiratory depression and coma

– Death has been reported

Drugs that alter secretionDrugs that alter secretion

Bismuth compounds, eg. Bismuth subsalicylate Inhibit intestinal secretionModest beneficial effectsDose of every 4 hours for 5 daysTheoretical risk of Reye syndrome from salicylat

e absorption

Drugs that absorb fluid and Drugs that absorb fluid and toxinstoxins

Kaolin-pectin, fiber, activated charcoal, attapulgite

Adsorb bacterial toxinsBind waterSerious toxic effects are not a concernEvidence of their efficacy has been contradictory

Agents that alter intestinal microfloAgents that alter intestinal microflorara

Patients with diarrhoea undergo reduction fecal flora, which leads to increased water losses

Lactobacillus sp.– Alter the bacterial colonization of the gut

therapeuticallyToxic effects are not a concernHowever efficacy of lactobacillus-compounds

in treating diarrhoea yet to be demonstrated

Treatment outcome/evaluationTreatment outcome/evaluation

hospitalization or notextent of investigationeffectiveness of rehydration (IV <=> PO)use of antimicrobials relief of symptoms - frequency of stools, duratio

n of diarrhoea, weight gainprevention strategy

• Public health measures - sanitation• Food preparation and storage• Promotion of breast feeding

Other common paediatric Other common paediatric gastrointestinal gastrointestinal conditionsconditions

Gastro-oesophageal refluxPyloric stenosisCyclic vomitingChronic diarrhoeaConstipationAcute abdominal pain

Gastro-oesophageal refluxGastro-oesophageal reflux

Small, effortless vomits of semi-digested milk soon after feeding

Common in infants because of• immature lower oesophageal sphincter• short intra-abdominal length of oesophagu

sUsually resolve by 1 year oldUsually mild but severe cases with complications:

• pulmonary aspiration• oesophagitis, peptic stricture• failure to thrive, feeding problems

Gastro-oesophageal refluxGastro-oesophageal reflux Investigation

– usually not required– 24-h oesophageal pH monitoring

• contrast study

Gastro-oesophageal refluxGastro-oesophageal reflux

management• often requiring no treatment• mild: positioning at 30° head-up prone & th

ickening agent• drugs enhancing gastric emptying• H2 antagonists• fundoplication

Pyloric StenosisPyloric Stenosis

hypertrophy of pyloruspresented between 2 and 7 weeks of ageM:F = 4:1presentation

• large, non-bilious, projectile vomiting after each feed

• dehydration, weight loss

Pyloric StenosisPyloric Stenosis

visible peristalsis “olive”-shaped mass at

right upper quadrant

Pyloric StenosisPyloric Stenosis

Investigation• ultrasonography & contrast study

antrum

thickened pyloricmuscle

elongated pyloriccanal

Pyloric StenosisPyloric Stenosis

Management

• fluid resuscitation• electrolyte correction

• hypochloraemic alkalosis with hypokalaemia

• Ramstedt’s pyloromyotomy

Persistent & Chronic VomitingPersistent & Chronic Vomiting

CNS: raised intracranial pressure• early morning vomiting• headache worsen on lying down

Appendicitis• uncommon before 3 years old• atypical presentation in retrocaecal and pe

lvic appendices

Persistent & Chronic VomitingPersistent & Chronic Vomiting

Cyclical vomiting• psychogenic, with stressful factors• of school age• prodromal symptoms: pale, withdrawn• associated with migraine

Anorexia or bulimia nervosa– adolescent– deranged body image– weight-fear– induced vomiting

Chronic DiarrhoeaChronic Diarrhoea

Birth to 6mo InfectionSecondary lactose deficiency

Persisting diarrhoeaCow’s milk intoleranc

eOther food intoleranceCystic fibrosisIn-born errorsAntuoimmune enteropa

thySurgery

Chronic DiarrhoeaChronic Diarrhoea

6mo to 1yr InfectionCoeliac diseaseGiardia lambliaSurgery

1+ years Post-infectionCoeliac diseaseGiardia lamblia

10+ years Inflammatory bowel disease

Chronic diarrhoeaChronic diarrhoea

Postinfectious diarrhoea - persistence of diarrhoea and failure to gain weight more than 7 days after admission

Due to disaccharide intolerance(brush-border damage), cow milk protein hypersensitivity(-lactoglobulin), persistent infection

Managed by soy-base formula, lactose-free formula, or semielemental diet

Chronic nonspecific diarrhoeaChronic nonspecific diarrhoea

“Toddler” diarrhoeaaffecting children 6 months to 2 yearsself-limitingpass 4 - 10 loose stool per daymay be intermittent, explosiveMay contain undigested foodNegative stool culture and reducing

substancesgrowth and development normal

Acute abdominal pain:Acute abdominal pain:“Does the child require “Does the child require emergency surgery?”emergency surgery?”

Signs of peritonism, appendicitis– Fever, localized tenderness, guarding, reboun

d tenderness, absent bowel sounds– The younger the child the more vague the sign

sSigns of obstruction

– Vomiting, abdominal distension, high pitch bowel sounds, empty rectum

Gastrointestinal bleeding– Haematemesis, bloody stool, “Current-jelly

” stool, malaena

Require early surgical referral

Abdominal cause but does not require immediate surgical referral

Systemic cause

AppendicitisPeritonitisIntussusceptionVolvulusStrangulated herniaTraumaGI Bleeding

GastroenteritisInfantile colicIngestionConstipationPeptic ulcerPancreatitis / mumpsCholecystitis / cholangitisUrinary tract infectionNephrotic syndromeHepatitisDysmenorrhoea

Any febrile illness but especially ENT infectionLower lobe pneumoniaAbdominal migraineDiabetic ketoacidosisSexual abusePorphyriaLead poisoningHenoch Scholein purpura