Gastro - Diarrhoea

Question 1

Define diarrhoea

Answer 1

No one definiition
WHO: passage of >3 loose or liquid stols per day
Brit Gastro Soc : passages of more than 200g stool per day
Bristol chart - passage of type 6 or 7

Question 2

Incidence of diarrhoea in ICU

Answer 2

25-50%

Question 3

Causes of diarrhoea?

Answer 3

Infective and non-infective

Infect
Bacterial - e.coli, salmonella, shigella, c.jejuni, c.diff
Viral - noro/rotaviruses
Fungal - candida
Protozoa - cryptospiridia, giardia

Non infect
IBD - chrohns, UC
Drugs - enteral feed, Abx, Mg, laxative, chemo, NSAIDS
Mesenteric ischeamia
Short gut
Intolerance - Coeliac, lactose Bacterial overgrowth - bile salt malabsorption
Post ileus

Question 4

Types of diarrhoea

Answer 4

4 types:
Osmotic, Secretory, Inflammatory, Dysmotility

Osmotic
Failure to abosrb osmotically active solutes - water stays in gut Enteral feed

Secretory Increased secretion into the gut and reduced absorption —> large vol.
Enterotoxins, cholera, laxatives

Inflammatory Loss of integrityt of GI mucose due to inflammation, impaired absorption IBD

Dysmotility Rapid trasnsit time, water and electrolyte load oveywhelms absorption in colon
Recover from ileus

Question 5

Issues with diarrhoea in ICU

Answer 5

Patient:
Infection
Pressure sores
Need for a flexi seal

Organisational
Workload
Infecton control to other patietns

Question 6

What is c.diff

Answer 6

Anaeorobic
Spore forming
Gram positive
Bacillus
Makes two toxins
A: enterotoxin, causes fluid sequestriation in bowel
B: cytotoxin, detected in the CDT test

Common and serious nosocomial infection, usually when gut flora eradicated —> broad spec
spores not killed by alochol gel

Question 7

Risk factors for CDT

Answer 7

Age > 60
Broad spec Abx use
Underlying malignancy
Albumin < 25g/L
Renal/pulmonary disease
PPI use

Question 8

Approach to a patient testing positive for c.diff

Answer 8

Investigate and send samples
Isolate patient, tell ICT
Full barrier precautions, use soap and water
Tx. Oral or iv metronidazole or oral vanc

Question 9

Progression of c.diff

Answer 9

Fulminant pseudomembranous colitis in 20%
Mortality here is 20%
Risk of toxic megacolon and perf

Question 10

Managing patient with Diarrhoea

Answer 10

ABCDE etcHx and O/E —> travel hx, sources of infection, drug use, immuno, systemic feature abdominal pain

Ix - FBC, U&E, LFT, CRP, Coag, Blood gas, blood cultures
Stool sample - MC&S, CDT, Virology, cysts and parasites
Radiology - Abdo film, CXR erect, CT abdo pelcvis
Flexi sig/colon —> caution risk of perf

Question 11

When is surgical review indicatedf

Answer 11

Immunosupressed patients
Significant tenderness
Raised WCC
Organ dysfunction

Question 12

Treatment of diarrhoea?

Answer 12

Largely supportive
Maintain hydration, correct electrolytes and acid base

If approrpiate
- Abx
-Feed associated
- change of feed, add fibre
if infection excluded —> lopirimide
Flexi seal
Infection control measures

Question 13

What are some of the causes of a Toxic Megacolon

Answer 13

Infective causes:
- Clostridium difficile infection
- Cytomegalovirus colitis (in immunosuppressed patients)
- Salmonella/shigella/campylobacter infection
Inflammatory bowel disease (e.g. ulcerative colitis)
Intra-luminal obstruction (e.g. tumour) with perforation and peritonitis (less likely in
the context of diarrhoea)