Diarrhoea and Vomiting Flashcards
Important features in a history to assess a child with diarrhoea and vomiting:
Duration, frequency, volume, (any blood in the stools)
Current oral intake and usual feeding pattern
Passage of urine - no. of wet nappies, how heavy
History of fever and other red flag symptoms
Recent contact with someone with diarrhoea and vomiting, ingestion of contaminated food or water, recent travel abroad
Physical features of dehydration in an infant
Sunken anterior fontanelle Dry mucous membrane Tachycardia Reduced CR Reduced skin turgor
Most common causes of gastoenteritis
Rotavirus - most children under 5 will have rotavirus and develop immunity (causes gastroenteritis in 60% of children <2)
Adenovirus
Bacterial less common - Campylobacter jejuni
Causes of blood in stool associated with D and V in children
Campylobacter Rotavirus Intussusception E. Coli Shigella
What is intussusception?
Invagination of proximal bowel into a distal segment commonly involving invagination of ileum into caecum through the ileocecal valve.
Peak presentation is between 3 months to 2 years of age with history of paroxysmal, severe colicky pain when the child draws his/her legs up, pallor during the episodes of pain followed by recovery from the painful episodes and lethargy. The child may refuse to feed, have vomiting and pass characteristic red currant jelly stool containing blood and mucus.
Red flags associated with vomiting
Blood Bile Projectile vomiting Abdominal tenderness/distention Blood in stool Bulging fontanelle
Common causes of vomiting in children
Feeding issues
GORD
Gastroenteritis
Symptom:
Bile stained vomit
Possible Cause:
Intestinal obstruction
Symptom:
Haematemesis
Possible Cause:
Oesophagitis
Gastric ulcer
Oral or nasal bleeding and vomiting up swallowed blood
Symptom:
Projectile vomiting under 2 months of age
Possible Cause:
Pyloric stenosis
Symptom:
Abdominal distention/tenderness
Possible Cause:
Intestinal obstruction
Strangulated inguinal hernia
Surgical abdomen
Symptom:
Blood in stool
Possible Cause:
Gastroenetritis – salmonella or campylobacter
Intussusception
Symptom:
Severe dehydration and shock
Possible Causes:
Severe gastroenteritis
Systemic infection – UTI
Meningitis
Diabetes ketoacidosis
Symptom:
Bulging fontanelle/fits
Possible Cause:
Raised intracranial pressure due to meningitis/ hydrocephalus
Symptom:
Faltering growth
Possible Causes:
Gastroesophageal reflux
Coeliac disease
Chronic gastrointestinal conditions
Symptom:
Vomiting with paroxysmal cough
Possible Cause:
Whooping cough
Actions to take based on leucocytes and nitrites on urine dipstick
Leu - neg
Nitrites - neg - UTI unlikely
Leu - pos
Nitrites - pos - suggests UTI
Leu - neg
Nitrites - pos - prelim diagnosis of UTI(and vice versa), commence Abx await culture
(most commonly E. coli)
What is ORS?
Oral rehydration salts
Mix of glucose, electrolyes and salts to help the absorption of sodium via the sodium-glucose cotransporter, and in turn water is absorbed helping the body to rehydrate
Advice for a parent of a child with gastroenteritis
No IV therapy necessary
Diarrhoea usually last 5-7 days
Encourage usual fluid intake
Give 5ml/kg ORS after each passage of loose stool
Wash hands after nappy change and before preparing, serving or eating food
No nursery for 48 hours after last episode
Seek help if child becomes unwell, mottled skin, vomiting (shouldnt last longer than 3 days), decreased urine output/wet nappies, irritable/lethargic and cold extremities
Can you breastfeed during gastroenteritis?
Continue if tolerated
Reintroduced by 24 hours if stopped due to persistent vomiting
Usually reduces the risk of gastroenteritis, life saving in developing countries
Properties of breast milk
Anti infective
Secretory IgA - provides mucosal protection
Bifidus factor - promotes growth of lactobacillus bifidus which metabolises lactose to lactic acid and acetic acid. Low pH may prevent growth of GI pathogens
Lysozyme - bacteriolytic enzyme
Lactoferrin - iron binding protein inhibits growth of E.coli
Interferon - antiviral
Properties of breast milk
Cellular
Macrophages - phagocytic and synthesise lysozyme, lactoferrin, C3, C4
Lymphocytes - B cells synthesise IgA and T cells may offer delayed hypersensitivity response§
Properties of breast milk
Nutritional
Easily digested protein - whey to casein ratio 60:40
Lipid (rich in Oleic acid) - easy to digest and improves fat absorption
Calcium: phosphorus 2:1 - improves calcium absorption and prevents hypocalcaemic tetany
Low renal solute load - easily digestible and fat absorption
Iron 40-50% absortion
Long chain polyunsaturated fatty acids - important for retinal development
Viral gastroenteritis
Rotavirus
Enteric adenovirus 40 and 41
Calcivirus (including Norovirus)
Astrovirus
Bacteria gastroenteritis
Campylobacter jejuni C diff E. coli Salmonella Shigella Vibrio cholerae
Parasitic gastroenteritis
Giardia lamblia
Cryptosporidium
Pathology of diarrhoea
Caused by infective or inflammatory processes in the intestine which affect the secretory or absorptive function of enterocytes
Two primary mechanisms of infectious diarrhoea
Secretory
Mucosal invasion
Effects on secretion caused by infectious diarrhoea
↓ absorption
↑ secretion and electrolyte transport
Leads to watery stool
Caused by: cholera, E.coli, C diff, cryptosporidium (HIV)
Effects on colon due to mucosal invasion
Inflammation
↓ mucosal surface area and/or colonic reabsorption
↑ motility
Leads to blood in stools and ↑ in WBCs
Rotavirus, campylobacter, salmonella, shigella, Yersinia
What features associated with DandV suggests a different diagnoses
Fever Tachypnoea Altered conscious level Neck stiffness Bulging fontanelle in infants Non-blanching rash Blood and /or mucus in stool Bilious vomit Severe or localised abdominal pain Abdominal distension or rebound tenderness
Factors considered in assessing dehydration
Body weight (% loss) General appearance Skin turgor Tears Mucous membranes BP Urine flow Pulse Eyes Anterior fontanelle Fluid deficit
Risk of dehydration increased in:
Children younger than 1 year, particularly under 6 months of age
Low birth weight infants
If more than 5 loose stools and 2 episodes of vomiting in the previous 24 hours
Not offered or able to tolerate supplementary fluids before presentation
Malnourished children
Types of dehydration
Isonatremic – loss of sodium and water are proportional
Plasma sodium remains within normal range
Hyponatremic – intake of large quantity of water / hypotonic fluids, greater net loss of sodium than water, fall in serum sodium
Results in shift of water from extracellular to intracellular compartment causes brain oedema and marked extracellular dehydration and shock
Hypernatremic – water loss exceeds the sodium loss with resultant increase in plasma sodium concentration. This can happen when there is low sodium diarrhoea or high insensible water loss. There is shift of water from intracellular to extracellular compartment and therefore less signs of dehydration
Features of hypernatremic dehydration
Jittery movements Increased muscle tone Hyperreflexia Convulsions Drowsiness or coma
Investigations for diarrhoea
Stool microscopy and culture - indicated if:
- Recent travel abroad
- The diarrhoea is not improving by day 7
- Suspected septicaemia
- Blood and /or mucus in stool
Immunocompromised child
Blood culture – if starting antibiotics
U&E’s and glucose if dehydrated /starting intravenous fluids
Indications for IV fluid treatment
Shock - fluid bolus 20ml/kg 0.9% sodium (2nd bolus if shock persists)
Red flag symptoms or signs
Persistent vomiting
Hypoglycaemia
What is imperative before starting IV fluids
Weight and U&Es should be measured at least every 24 hours
Blood glucose
Degree of dehydration
Mild dehydration 50 ml/kg over 4 hours
Moderate dehydration 100 ml/kg over 4 hours
Ongoing losses (stool) 5- 10ml/kg
Reduce fluid intake when patient appears clinically hydrated
Breast or formula feeding can be continued and should not be delayed for more than 24 hours
Antibiotic treatment
Campylobacter – Erythromycin shortens the duration of illness and shedding of bacteria
Clostridium difficile – metronidazole or vancomycin
Nontyphoid salmonella, shigella , vibrio cholerae, Giardia, Yersinia and cryptosporidium
Key differential in acute appendicitis
Mesenteric adenitis, especially if there was a history of sore throat
What is Haemolytic Uraemic Syndrome?
Pathological Cause - E. coli 0157:H7
Triad of:
Mvgticroangiopathic haemolytic anaemia
Thrombocytopaenia
Acute renal failure (AKI)
Problem with primary haemostasis - platelet count will be low <150, bleeding time will increase
Atypical in adults
What type of anaemia is associated with HUS?
Normocytic anaemia
Haemolytic
Intravascualar
Extrinsic (extra-corpuscular)
Non-immune (negative Coomb’s test)
