GI Infections Tutorial

Question 1

Case 1 - 78F

Nursing home resident
Day 4 post emergency open left inguinalhernia repair for small bowel obstructure
PMH = T2DM, recurrent UTIs
Ex-smoker
Mobilises w/ stick

Ward round =
6x watery diarrhoea overnight, mild abdominal pain
Observations: T 376, HR 89, BP 108/72, Sats 96% on air
Moderate abdominal distension, mild generalised tenderness on palpation
Dry oral mucosa, reduced skin turgor
On co-amoxiclav day 4

What investigations would be done next?

Answer 1

Urine
WCC
K+, Mg+, phosphate 
Creatinine
INR and APTR
LFTs
Albumin
CRP

Question 2

Investigations revealed:

Urine – leucocytes 1+
 WCC 16.4, Hb 12.1
 K+, Mg+ & Phosphate - normal, Creat 170
 INR & APTR Normal
 LFTs Normal,  Albumin 16
 CRP 98

What are some potential differential diagnoses to explain her current onset of diarrhoea and generalised tenderness?

Answer 2

Infectious Diarrhoea = 
Clostridium difficile
Klebsiella oxytoca
Clostridium perfringens
Salmonella spp

Non-infectious diarrhoea =
Antibiotics side effect
Post-infectious irritable bowel syndrome 
Inflammatory bowel disease
Microscopic colitis
Ischaemic colitis
Coeliac disease

Question 3

Is it likely to be an infectious or non-infectious cause?

Answer 3

Infectious = raised WCC, CDP albumin etc. = characteristic for infections

Likely C. diff = common HAI

Question 4

What fr dry oral mucosa and reduced skin turgor suggest?

Answer 4

Dehydration

Question 5

What is the management for a C. Diff infection?

Answer 5

Infection control
The patient is moved into a side room

Discontinue inciting antibiotic agents
Co-amoxiclav is stopped

Management of fluids, nutrition & diarrhoea

Question 6

How do you distinguish severe and non severe C. diff. infection?

Answer 6

Non-severe infection
WCC<15, Creat <150

Severe infection
WCC>15, Creat >150

Question 7

What is fulminant colitis?

How does it present clinically?

Answer 7

Most severe manifestation

Hypotension or shock, ileus, toxic megacolon

Question 8

What is the management for non-severe disease?

Answer 8

Antibiotic therapy with oral vancomycin or fidaxomicin or metronidazole

Role of Faecal Microbiota Transplantation (FMT)

Question 9

What is the management to severe disease or fulminant colitis?

Answer 9

Antibiotic therapy, supportive care and close monitoring

Early surgical consultation

Question 10

Does the patient have a severe or non-severe infection?

Answer 10

Severe - her WCC is above 15, her creatinine is above 150

Question 11

How is the patient managed and treated?

Answer 11

The patient is started on oral vancomycin and is closely monitored

Question 12

On day 7, nurses note a streak of blood in the stool

On examination:
Generalised abdominal tenderness, worsening distension
HR 135, BP 95/64, T 379

Investigations show: 
WCC 24.7
Hb 11.4
K+ 3.1
Creat 263
Alb 12
CRP 304

What are the management options?

Answer 12

Medical therapy = antibiotics, IV fluid resuscitation & inotropic support

Supportive management

Surgical interventions

Question 13

What is 1st line treatment for fulminant colitis with toxic megacolon?

Answer 13

Medical therapy with antibiotics and supportive management

Transfer to ICSU

Question 14

What is done in ICU for fulminant colitis with toxic megacolon?

Answer 14

IV fluid resuscitation & inotropic support

Question 15

What are the indications for surgery?

Answer 15

Colonic perforation

Necrosis or full-thickness ischaemia

Intra-abdominal hypertension or abdominal compartment syndrome

Clinical signs of peritonitis or worsening abdominal exam despite adequate medical therapy

End-organ failure

Question 16

What is Pseudomembranous colitis and what are its main features?

Answer 16

Most often associated with C. difficile infection

Manifestation of severe colonic disease

Characteristic yellow-white plaques that form pseudomembranes on the mucosa

Confirmed on endoscopy +/- biopsy

Question 17

Case 2 - 26F, otherwise healthy
3 months history of diarrhoea (4x / day) with rectal bleeding
Associated urgency and mucous secretion
PMH = nil
SH = ex-smoker, stopped 9 months ago
No recent travel 

Examination shows: soft abdomen, tenderness in left iliac fossa
H2 = 80, BP = 115/70, Temp = 36.9

What investigations would be done next?

Answer 17

Hb 
WCC 
Neut 
Platelets 
Urea, Creatinine
CRP 
LFTs 
Coagulation

Question 18

Investigations reveal:
Hb 120
WCC 12
Neut 7
Platlets 400. 
Ur 5, Cr 70 
CRP 50 
LFTs – Normal
Coagulation- Normal

What are the differential diagnoses for bloody diarrhoea?

Answer 18

Infectious = 
Clostridium difficile
Shigella
E. Coli
Salmonella spp

Non-infectious =
Inflammatory bowel disease
Haemorrhoids
Post-infectious irritable bowel syndrome 
Microscopic colitis
Ischaemic colitis
Coeliac disease

Question 19

UC (ulcerative colitis) can be divided by severity nito mild, moderate and severe

How are they each classified?

Answer 19

Mild = 4 x BMs/day, no systemic toxicity, normal ESR/CRP, mild symptoms

Moderate = > 4x BMs/day, mild anaemia, mild symptoms, minimal systemic toxicity, nutrition maintained and no weight loss

Severe = > 6 BMs/day, severe symptoms, systemic toxicity, significant anaemia, increased ESR/CRP and weight loss

Question 20

How do you assess UC severity?

Answer 20

Different scopes including clinical disease activity index, Montreal classification and Trulov & Witt scores

Question 21

What are the management options for UC?

Answer 21

Steroids

5 ASA

Immune suppressants
Azathioprine
Methotreaxate

Biologic therapy

Others –diet, FMT, antibiotics, probiotics, novel agents

Question 22

What are BMs?

Answer 22

Bowel movements