Gastroenteritis Flashcards
(28 cards)
Toxin Mediated Food Poisoning
Onset 1-6 hours after exposure
Diarrhoea >few hours, ado pain and fever
Resolves in 6-10 hours
Can be a significant problem in the elderly with co-morbidities
Non-Infectious Causes of Diarrhoea
GI bleed Ischaemic gut Diverticulitis Endocrine disorders Numerous drugs Fish toxins Withdrawal
Presenting Clinical Syndromes of Food Poisoning
Acute Enteritis = D&V, fever, abdominal pain
Acute Colitis = Bloody diarrhoea, fever, abdominal pain
Enteric Fever like Illness = Fever, rigors, abdominal pain, little diarrhoea
Most Common Causes of Bloody Diarrhoea
Infection - campylobacter, shigella, E.Coli O157, amoebiasis
IBD
Malignancy
Ischaemia
Guillain-Barre Syndrome
40% of cases preceded by campylobacter
Tingling feet, then progressive paralysis of legs, arms and body
Poss. associated with autoimmune response
Appearance on Abdominal X-Ray
Thumbprinting Colitis
Dilated Bowel
Typhoid Carrier
Imported
Food or water
Human carrier
Typhoid Presentation
Enteric Fever Like Illness:
Asymptomatic
Mild bacteraemia
Enterocolitis
Typhoid Diagnosis
BLOOD CULTURES
Stool and urine cultures
Typhoid Treatment
Ciprofloxacin or chloramphenicol (resistance)
Azithromycin or ceftriaxone
Key Features of History Taking
Diarrhoea = frequency, nocturnal diarrhoea, colour and consistency, blood
Associated Symptoms = abdo pain, vomiting, fever
Family members/colleagues with similar symptoms
Occupation
Pets and animal contact
Travel abroad
Medications = recent antibiotics, PPIs
Key Features of Examination
Fever Skin rashes Dehydration signs Abdominal tendernes, distension RECTAL EXAM
Investigations
Stool microscopy (parasites) Stool culture (bacteria) Stool toxin (C.diff) Blood cultures (salmonella) PCR (viral) FBC (WCC for severity of CDI) U&Es AXR
Assessing Severity
Co-morbidities Fever Rigors Shock Blood in stools Abdo pain Number of stools/24 hours Colonic dilatation Lab results: WCC, renal function
Assessing Severity of C.diff Infection
Pseudomembranous colitis, toxic megacolon or ileus/colonic dilatation
WCC >15
Creatinine >1.5x baseline
Persisting symptomatic CDI despite two treatments
Complications of Bacterial Enteritis - Intestinal
Severe dehydration and renal failure
Acute colitis, toxic dilatation
Post infective irritable bowel (v common, lasts 4-6 weeks)
Transient secondary lactase intolerance
Complications of Bacterial Enteritis - Extra Intestinal
Bacteraemia leading to sepsis +/- metastatic infection Reactive arthritis Meningism Neurological (GB syndrome) Haemolytic uraemic syndrome
Treatment of Gastroenteritis
Antibiotics are generally not indicated Oral rehydration (or IV fluids if needed) ?Anti-spasmodics, Anti-motility drugs (avoid in elderly/young)
Indications for Antibiotics
Enteric fever (TYPHOID) Shigellosis (non sonnei species) Sometimes enterotoxigenic E.coli Cholera C.diff diarrhoea Giardiasis Ameobiasis Invasive salmonellosis
C.diff - Pathogenesis
Broad spectrum antibiotics kill normal gut flora
C.diff forms spores which are resistant
Destruction of normal flora allows C.diff to dominate and multiply
C.diff - Host Risk Factors
Over 65 Immunosuppression PPI use Hospitalisation, long term care facilities Previous CDI
C.diff - Prevention
Isolation and treatment of symptomatic patients
Reduction in use of broad spectrum, 4 C antibiotics
Treatment of asymptomatic carriers
C.diff - At Risk Patients for Recurrence
Elderly Antibiotics after initial CDI treatment Prolonged hospitalisation of stay in LTCF Defective immune response to toxin A Gastric acid suppression
C.diff - Drivers
Broad spectrum antibiotic therapy 4 Cs Long duration of therapy Vulnerable population Route of therapy makes no difference Total amount of antibiotic use Antibiotics in absence of infection
