Gastroenteritis Flashcards
Define gastroenteritis?
acute inflammation of lining of GI tract-> nausea, vomiting, diarrhoea, and abdominal discomfort
infectious colitis= swelling and irritation of colon
outline the aetiology of gastroenteritis?
Caused by viruses, bacteria, protozoa or toxins contained in contaminated food or water (faecal-oral route)
what are the risk factors for gastroenteritis?
exposure to contaminated food or water sources
close contact with infected people
poor hygiene
extreme ages
HIV infection
organ transplantation
chronic ilness
what key questions should be asked for diagnosing gastroenteritis?
ASK ABOUT TRAVEL, PEOPLE AROUND HAVING SIM SYMP, SPEC TIME FROM STARTING
give examples of viruses , bacteria and protoctists that cause gastroenteritis?
which virus is likely to cause outbreaks of D + V in institutions with elderly?
norovirus
what organism is likely to be the cause of a uni student having watery diarrohea?
campylobacter jejuni
what organism is likely to cause rapid onset diarrhoea after a meal?
Staph Aureus ( toxins produced) Bacilus cereus
which organism is likely to be cause of elderly on antibiotics with explosive diarrhoea?
pseudomembranous colitis: C difficile
which organism is the cause of traveller’s diarrhoea?
E. coli
what are tuberculosis and yernia associated with? and what can they mimic?
RIF pain and travel
both mimic ileo-caecal crohn’s
which organisms cause bloody diarrhoea ( dysentry)
CHESS
which organisms are associated with improperly cooked meats?
S.aureus, C. perfringens
Which organisms are associated with old rice?
B cereus, S aureus
which organisms are associated with milk and cheese?
Listeria and campylobacter
which organisms are associated with canned foods?
botulinism
summarise the epidemiology of gastroenteritis?
common
serious cause of morbidity in the developing world
what are the possible complications of gastroenteritis?
Dehydration
Electrolyte imbalance
Prerenal failure (due to dehydration)
Secondary lactose intolerance (particularly in infants)
Sepsis and shock
Haemolytic uraemic syndrome (associated with toxins from E. coli O157)
Guillain-Barre Syndrome may occur weeks after recovery from Campylobacter gastroenteritis
NOTE: botulism can lead to respiratory muscle weakness or paralysis
what are the presenting symptoms of infective colitis?
abdo discomfort
diarrhoea
N and V
bloody/purulent/mucoid stools
severe abdo cramping
fever
tenesemus
what are the presenting symptoms of gastroenteritis?
Sudden onset nausea, vomiting, anorexia
Viral gastroenteritis presents more with upper GI symp like N+V rather than D
DIARRHOEA (bloody or watery)
Note – dysentery is any type of gastroenteritis which causes bloody diarrhoea
Abdominal pain or discomfort
Fever and malaise
how is the onset of symptoms caused by toxins different to symptoms caused by bacterial/ viral/ protozoal infection?
Toxins = early (1-24 hours)
Bacterial/viral/protozoal = 12+ hours
what are the signs of gastroenteritis on physical examination?
Diffuse abdominal tenderness
Abdominal distension
Bowel sounds are often INCREASED
In SEVERE gastroenteritis: pyrexia, dehydration, hypotension and peripheral shutdown
IMPORTANT: ANY DIARRHOEAL CONDITION CAN LEAD TO DEHYDRATION so assess and address the patient’s hydration status immediately
what are the appopriate investigations for gastroenteritis?
Bloods: FBC, blood culture (identify bacteraemia), U&Es (dehydration)
C diff causes raised WCC
Stool MC&S: faecal microscopy and analysis for toxins (particularly for the toxin causing pseudomembranous colitis (C. difficile toxin))
AXR or ultrasound: exclude other causes of abdominal pain (e.g. bowel perforation)
Sigmoidoscopy: usually unnecessary unless inflammatory bowel disease needs to be excluded
what is the treatment for c difficile
Isolate
Oral metronidazole 10-14 days
- cause a disulfiram-like reaction (nausea, vomiting, flushing, discomfort, hangover-like symptoms) to alcohol so avoid alcohol during treatment
If refractory: vancomycin
generate a mangement plan for gastroenteritis?
Bed rest – should stay at home until D+V cleared for 48h
Fluid and electrolyte replacement with oral rehydration solution (contains glucose and salt)
IV rehydration may be necessary in those with severe vomiting/ pts with signs of hypovolaemia (e.g. Tachy, low BP)
Most infections are self-limiting (so will go away with time)
Antibiotic treatment (ciprofloxacin or azithromycin) is only used if severe or immunocompromised or if infective agent has been identified by a stool culture
if botulinim toxin is present due to clostridium botilinum, what is the treatment?
treat with botulinum antitoxin (IM) and manage in ITU
what is the prognosis for gastroenteritis?
good prognosis-> most cases are self limiting
