Phase 2 - GI Flashcards
(204 cards)
Infective causes of diarrhoea
Intraluminal infectionSystemic infectionTypically VIRAL:1. Rotavirus (main in kids)2. Norovirus (main in adults)Also TRAVELLER’S diarrhoea (can be caused by a variety of things esp EHEC)
Non-infective causes of diarrhoea
CancerRadiationChemicals- Poisoning- sweeteners- medications Inflammatory bowel diseaseIBS / malabsorptionEndocrine/hormonal eg ThyrotoxicosisAnatomical e.g. post colesectomy
Evaluation for acute diarrhoea is warranted in individuals with which symptoms?
- persistent FEVER, - BLOODY diarrhoea,- severe ABDO PAIN, - symptoms of VOLUME DEPLETION (eg, dark or scant urine, symptoms of orthostasis/postural hypotension), - HISTORY of IBD, - immunosuppression
Relevant history for diarrhoea
- ONSET/duration- CHARACTERISTICS of stool- Food/drink- Travel- IMMUNE status (immunocompromised can be affected by stuff normal immune people aren’t affected by)- Unwell contacts- Hobbies + FRESH WATER- ANIMAL contact- MEDS (recent - C. DIFF?)
What food is particularly related to which pathogen (+ inc. period + associated symptoms)
- Take-aways (lots of microbes/toxins)- Warm rice - BACILLUS CEREUS (1-6hr - toxin) - PROFUSE VOmiting- Meat/BBQ - campylobacter spp, (24-72hr) - PROFUSE DIARRHOEA + SEVERE abdo pain - clostridium perfringens (12-24hr) - Diarrhoea + COLICKY abdo pain- Poultry/eggs - Salmonella spp (16-48hr) - Diarrhoea + some abdo pain- SHELLFISH - NOROVIRUS, - V. parahaemolyticus - salmonella enterica serotype Typhi- FINGER FOODS - STAPH AUREUS (1-6hr - pre-formed toxin) - SEVERE vomiting + FEVER
Which mirobes are associated with fresh water/swimming
CryptosporidiumGiardiaAeromonas
Which animals are particularly associated with diarrhoea causing pathogens
Reptiles - salmonellaPuppies - campy
Characteristic symptoms of small bowel diarrhoea (esp proximally)
watery, large volume- cramping, bloating, flatulence
Characteristic signs/symptoms colonic diarrhoea
frequent, small volume, painfulMay contain blood, mucusOft associated feverCan see RBCs + inflammatory cells in stool microscopy
Function of action of cholera toxin
Exports chloride into lumen - water follows-> v. watery rice water stools
What does oral rehydration for diarrhoea consist of
1L water with 6 level teaspoons of sugar and 1/2 a level teaspoon of salt- need sugar to give energy for active transport
Typical site of campy diarrhoea pain; what are it’s late onset complications
Periumbilical - mimics acute appendicitisComplications - Guillan Barre Syndrome and reactive arthritis
Site of pain in yersinia spp diarrhoea and Complications.
RLQ painYersinia septicaemia - in IMPAIRED IMMUNITY or IRON-OVERLOAD states
Which antibiotics in particular can predispose to C. difficile
CLINDAMYCINCo-amoxiclav (penicillins)Ciprofloxacin (quinolones)Cephalosporins:- CEFUROXIME- CEFTRIAXONE- CEFALEXINAny BROAD SPECTRUM antibiotics
Virulence factors of C. diff
SPORE-formingToxinGram +veAnaerobic
When does C. diff infection typically start
During/up to 1 MONTH after antibiotics course
Natural history of C. diff infection
Asymptomatic carriage (or -> watery diarrhoea)-> fulminant disease with severe colitis -> toxic megacolon (potentially)toxin producing C. diff can cause psudomembranous colitis - layer of dead cells creating a membrane-esq
Management of C. diff
- stop inciting antibiotic as soon as possibleContact precautions/hand hygiene (hand washing > alcohol - c. diff spores not killed by alcohol)Antibiotics:- METRONIDAZOLE- VANCOMYCINStool transplant
Investigations for diarrhoea
STOOL TESTS:- microscopy (blood/pus)- CULTURE- Ova, cysts and parasites x3- Toxin detection (C difficile)PCR: Multi-pathogen molecular panels (use primers for specific pathogens - typically for viruses, C. diff, campy)Blood tests:- Culture- Raised Inflammatory markers (ESR/CRP) - possible infection * Alongside anaemia = IBD/cancer- EOSINOPHILIA = PARASITES * Alongside anaemia - think hookworm- may test vomit- Electrolytes + creatinine (won’t necessarily aid diagnosis but important)Endoscopy/biopsy if necessary
Indications for testing for diarrhoea
Severe illnessBloody diarrhoea/mucusHigh risk (>70, immunocomp, IBD, pregnant)Prolonged (>1 week)Public health concerns
Diarrhoea red flags (may become severe, complications etc.)
DehydrationElectrolyte imbalance- RENAL FAILUREImmunocompSevere abdo painCANCER RISK FACTORS:- >50 y/o- chronic diarrhoea- weight loss- blood in stool- family history
What is Zollinger Ellison syndrome
GASTRIN SECRETING TUMOUR - causes a triad- pancreatic tumour- gastric acid hypersecretion- Widespread Peptic ulcers
GI red flags
Think ALARMSAnaemiaLoss of weightAnorexia (loss of appetite)Recent onset of progressive symptoms (it’s always low-level been there but it recently got worse)MASSES/MELENA (or any other GI BLEEDING)Swallowing difficulties (DYSPHAGIA)and >55 y/o- points to GI cancer
What causes enteric fever
Salmonella Enterica subtypes Typhi and Paratyphi