Gastroenteritis Flashcards
Define gastroenteritis.
Inflammation of the GI tract secondary to an infection by an enteropathogen.
Explain the aetiology/risk factors for gastroenteritis.
Bacterial in developing countries
Viral in developed countries
Most are notifiable. Lead to impaired absorption of water, electrolytes and sugars because of damage to mucosa or increase in secretory mechanisms.
What are common viral causes of gastroenteritis?
Most commonly rotavirus.
Others: adenovirus (type 40&41), calicivirus, coronavirus and astrovirus.
What are common bacterial causes of gastroenteritis?
Neurotoxin producing: Staphylococcus aureus and Bacillus cereus (reheated rice); cause severe vomiting shortly after ingestion, rarely cause diarrhoea.
Enterotoxin producing: Escherichia coli and Vibrio cholerae act directly on secretory mechanisms primarily by “d activation of cAMP and produce typical copious watery (rice water) diarrhoea. No mucosal invasion occurs.
Cytotoxin producing: Shigella dysenteriae, Vibrio parahaemolyticus, Clostridium difficile and enterohaemorrhagic E. coli result in enterocyte destruction, leading to bloody stools with inflammatory cells.
Mucosal invasion: Shigella, Campylobacter organisms and enteroinvasive E. coli cause mucosal destruction and inflammatory diarrhoea. Salmonella and Yersinia species invade the enterocytes but do not induce cell death so dysentery does not usually occur. However, bacterial translocation occurs via the lamina propria, causing enteric fever such as typhoid.
What is gastroenteritis associated with?
Poverty
Malnutrition
Lack of infrastructure
Bottle feeding
Abx use
Immunocompromised
Summarise the epidemiology of gastroenteritis.
On average, child in the UK experiences episodes twice a year. Billions of cases each year worldwide.
What are the presenting symptoms of gastroenteritis?
General: Pyrexia, anorexia, vomiting, abdominal pain and diarrhoea.
Specific: Features of diarrhoea (frequency/duration/character) and time-lapse between ingestion of food and symptoms may suggest infective organism.
What are some signs of gastroenteritis?
Assess level of dehydration.
Mild (<4%): No clinical signs
Moderate (>5%): Dry mucous membranes, increased skin turgor, cool peripheries, increased CRT
Severe (10%): Skin laxity, sunken eyes and fontanelle, impaired peripheral circulation, acidotic breathing, restlessness, lethargy and oliguria.
Extreme (10–15%): Anuric, shock or coma. Stool examination: Mucus, blood (streaks/large amounts).
What are some investigations for gastroenteritis?
General: Weight and temperature monitoring.
Bloods: FBC, U&Es, LFTs.
Stool: MC&S.
What is the management for gastroenteritis?
Mild-to-moderate – at home oral rehydration therapy (ORT) following European Society for Paeditric Gastroenterology (ESPGHAN) guidelines.
What is the management for mild dehydration?
Prevent dehydration: Continue breast-feeding and other milk feeds. Encourage fluid intake to compensate for increased gastrointestinal losses. Discourage fruit juices and carbonated drinks. Oral rehydration solution (ORS) as supplemental fluid if at increased risk of dehydration.
What is the management for clinical dehydration?
Oral rehydration solution (ORS): Give fluid deficit replacement fluids (50ml/kg) over 4 hours as well as maintenance fluid requirement. Give ORS often and in small amounts. Continue breast feeding. Consider supplementing ORS with usual fluids if inadequate intake of ORS. If inadequate fluid intake or vomitting persisitently, consider giing ORS via nasogastric tube.
If further deterioration or persistent vomiting, consider IV therapy for rehydration.
What is the mamagement of shock due to dehydration?
Intravenous therapy: Give rapid infusion of 0.9% sodium chloride solution. Repeat if necessary. If remains shocked, consider consulting paediatric intensive care specialist.
If signs/symptoms of shock improve, consider IV therapy for rehydration.
What is IV therapy for rehydration?
Replace fluid deficit and give maintenance fluids.
Fluid deficit is 100ml/kg (10% body weight) if initially shocked, 50ml/kg (5% body weight) if not shocked.
Give 0.9% saline, or 0.9% saline with 5% glucose.
Monitor plasma electrolytes, urea, creatinine and glucose. Consider potassium supplementation. Continue breast-feeding if possible.
What is the management after rehydration?
Give full strength milk and reintroduce usual solid food. Avoid fruit juices and carbonated drinks. Advise parents - diligent handwashing, towels used by infected child not to be shared, do not return to childcare facility or school until 48 hours after last episode.
