1. SAQ 9

2. SAQ 9
A 24 yo man with a 6 yr Hx of Crohns disease presents with 12hrs of worsening abdominal pain, fever and vomiting.
BP 90/60 HR Temp 38.7

3. List 6 possible causes for this presentation
List 5 abdominal complications of Crohns disease
List & Justify 5 investigations in this pt
Compare Crohns disease & Ulcerative Colitis

4. List 6 possible causes for this presentation
Crohns disease related
Exacerbation with complication
Complicated by Rx (steroids/immunosuppresion)
Non Crohns causes of abdominal sepsis
Uncomplicated causes of abdo pain are NOT going to score marks
Appendicitis/biliary colic/UTI

5. List 6 possible causes for this presentation
All the differentials should relate to the STEM if possible
Only if you have exhausted abdominal causes should you venture away from the abdomen.

6. List 6 possible causes for this presentation
Crohns disease related
Acute flare of Crohns with
perforation & peritonitis
Fistulae/abscess
Obstruction/ischaemia/perf/peritonitis
Urosepsis from enterovesical fistula or inflammatory mass causing ureteric obstruction
Peptic ulcer (steroid use) with perforation/peritonitis
Non Crohns causes of abdominal sepsis
Appendicitis with perforation/peritonitis
Ascending cholangitis
Pancreatitis
Infective (bacterial) colitis

7. List 5 abdominal complications of Crohns disease
Fistulae
Strictures
Perforation
Abscess
Bowel obstruction
Colorectal Ca
The Symptoms of Crohns are NOT complications

8. List & Justify 5 investigations in this pt
FBE
U+E/RF
VBG
CRP/ESR
Blood cultures
Stool MCS
Urine MCS
LFT/lipase
AXR US
CT abdo
CXR
MRI

9. Points to consider when asked to justify or provide a satisfactory rationale
when and why you would perform the test(s)
What you would be looking for
Test utility/ or likely yield
Clinically relevant information

10. Features of an unsuccessful answering
Investigtion without adequate explanation
Eg FBE signs of infection
Listing investigations in a self evident fashion
Eg U+ E to check for electrolyte abnormalities
CRP/ESR – inflammatory markers
Investigations showing no clinical perspective
Eg CXR for pneumonia in this pt
Omitting key investigations
Writing “Baseline” as justification for investigations

11. Investigations Bedside Laboratory Imaging BSL Stool MCS
Hypoglycemia with poor caloric intake
Stool MCS
white blood cells (WBCs), occult blood, routine pathogens, ova, parasites, and Clostridium difficile toxin. These studies should also be used to rule out infectious etiologies during relapses and before the initiation of immunosuppressive agents
FWT urine (+ MCS)
Urosepsis from vesicoenteric fistula or inflammatory mass causing ureteric obstruction
Laboratory
VBG
Increased lactate with bowel ischaemia
Metabolic acidosis septic shock/ischaemic bowel
U+E
Na/K/Cl/BC changes with persistent vomiting
Prerenal impairment with severe dehydration
FBE
WCC >20 or <4 favors bacterial sepsis
Leukocytosis from inflammation/abscess/steroid rx
Hb : anaemia from chonic inflammation/Fe malabsorption/chronic loss
LFTs
Transient increase with inflammation vs persisting elevation with sclerosing choleangitis
Hypoalb indicates suboptimal crohns treatment
CRP/ESR
Markers of acute disease activity, monitor response to Rx
Used to risk stratify likelyhood of complications & CT need
Imaging
CT abdo
bowel wall thickening, bowel obstruction, mesenteric edema, abscesses, or fistulae
Serial radiation exposure is a concern / only used if markers of disease activity indicate
MRI
Better at evaluating perianal & pelvic disease/abscess/fistulae
AXR (+ CXR)
Free gas (perforation)
Dilated loops/AF levels (SBO)/thumbprinting bowel wall/wall thickening/dilation

12. Compare Crohns disease & Ulcerative Colitis
Characteristics
Crohns disease
Ulcerative Colitis
distribution
Mouth-anus
colon
pathology
Transmural/skip lesions
Mucosal/continuous
radiology
String sign /thumbprinting
Fistula/strictures
Leadpipe colon/toxic megacolon
Cancer risk
Increased vs gen pop
Higher than crohns
Presentation
bleeding
occasional
Very common
obstruction
common
seldom
fistulae
Rare/none
Weight loss
significant
mild
Perianal disease