IBD Flashcards
IBD - PRICMCP?
P: dx date, symptoms: diarhoea, PR bleed, mucus, abdo pain, weight loss, obstruction.
Extraintestinal: skin (PG/EN), eye (conjunc/uveitis), joints (arthritis), liver (PSC, cirrhosis)
R: Smoking, FH IBD, GI infections
I: What is the extent of disease? - colonoscopy (maximal extent), if Crohn’s - gastroscopy, SB enterography (or CTE), fistulogram, EUA. Is patient on IBD colonoscopic surveillance?
C: check compliance then complications
UC: toxic megacolon, perforation, massive haemorhage, strictures, CRC
CD: fistulating disease, perianal abscess, SBO, gall stones, malabsorption, GI cancer
Extra-intestinal: VTE (ATIII def)
Complications of drugs: steroids, AZA/6-MP/TNFa sideFx
M: 5-ASA, AZA/6-MP/MTX, steroids, biologics. Any surgeries (colectomy, strictuloplasty, dilatation, EUA, seton). Cessation of smoking.
C: current symptoms (BO frequency, bleeding, pain…etc), frequency of FU, latest colonoscpy or SB imaging, no. of flare up last 12 months
Prognosis & insight
What are the DDx for colitis (7)?
- Infectious colitis
- Microscopic (collagenous / lymphocytic) colitis – tx with budesonide
- IBD
- Ischaemic colitis
- Radiation enteritis / proctitis / colitis
- Diversion colitis
- Toxic exposure (e.g. peroxide or gold)
What is your approach for investigating this patient with suspected IBD?
•T: Colonoscopy – macroscopic / microscopic diagnosis, Ab testing
- UC: cryptitis and crypt abscess. Continuous. pANCA +ve, ASCA -ve
- Crohn’s – granulomas. Skip lesions. pANCA –ve, ASCA +ve (specific, not sens)
•Exclude infection
- stool culture, viral PCR, ova, cyst and parasites, c.diff Ag and toxin genes
- If MSM → syphilis serology. Young – gonorrhoea + chlamydia rectal swab (PCR/NAAT)
- Immunocompromised: CMV, HSV serology, cryptosporidium, IGRA (CXR too)
•S: Hb (anaemia), inflammatory (WCC, CRP, ESR), AXR – bowel wall thickening (oedena), toxic mega colon, obstruction; MRE or CT
•T: as treatment baseline
- FBC, EUC, LFTs mainly
- AZA/6MP: HCV (ab), HBV (sAg, cAb), HIV, VZV, EBV*, TPMT*
- Anti-TNF/Biologics: above + CXR and IGRA
•S: screen complications
- Stricturing / fistulating Crohn’s (CT/MR fistulogram or EUA)
- CRC
- Mal-absorption
- Drug toxicity: AZA (pancreatitis), infection (all immSx / biologics)
What is your approach in managing patients who is on AZA/6MP not responding to treatment?
- Check compliance
- Thiopurine metabolites – key
- If absent 6-TGN + 6-MMP → non-compliance
- If low 6-TGN + 6-MMP both low → sub-therapeutic → ↑dose
- If high 6-MMP + low 6-TGN → thiopurine resistance → allopurinol
- If both therapeutic → need another drug
Explain 6-MP/AZA metabolism pathways. What is the mechanism for BM toxicity and Hepatotoxicity?
- AZA/6MP gets metabolised by 1 of the 3 enzymes that are in competition.
- Metabolism by TPMT produces 6-MMP: inactive form and responsible for hepatotoxicity (>5,700)
- Metabolism by XO produces 6-TA (inactive)
- Metabolism by HPRT produces the active form, 6-TGN – If level too high (>235): bone marrow toxicity, as it impairs purine synthesis
What constitute a severe UC in (Truelove-Whitt’s criteria)? (6)
BO >= 6/day (Fulminant if >10)
PR bleeding (+++)
Tachycardia (>90)
Temp (>37.5)
Abdominal tenderness
ESR >30, CRP >30, Anaemia <100
Management of acute flare up of UC? (6)
Immediate Mx
- IV fluids
- IV K+ and Mg+ depending on serum levels (hypo-K is common with diarrhoea + steroids due to MR action)
- IV steroids
- DVT prophylaxis
- Oral Vitamin D
- Topical mesalazine + steroids if tolerated
Follow-up
- At least BD review
- Early surgical review + stoma nurse (provide info pack)
- Daily AXR
•Stool chart
- Stool culture to exclude infection
- Consider unprepared limited flexi-sig → 2 biopsies to exclude CMV
Acute severe UC - initial IV Hydrocortisone - Still not responding (3 days) – what would you do?
- Consider 2nd line therapy (IFX or Cyclosporin)
- Discuss the need for colectomy (if no/worsening disease by day 3-5)
- If IFX or Cyclosporin started – daily bloods, AXR, BD review…etc. If no response by day 7 or curtailed response by day 10 → Surgery
Management for mild-mod UC?
Oral 5-ASA
Topical 5-ASA
If repeated episodes of flare - AZA/6MP
Index colonoscopy & determine surveillance frequency
Side effects of
Mesalazine
Olsalazine
Sulfasalazine (4)?
Mesalazine - minimal
Olsalazine - can worsen diarrhoea in active UC so only use as maintenance
Sulfasalazine: SJS, reversible male infertility, haemolytic anaemia, folate deficiency
Side effects of Azathioprine/6-MP (5)
Pancreatitis
Hepatotoxicity
BM toxicity (dose dependent)
Lymphoma risk (hence EBV serology)
Arthritis/Rash
What are the options for thiopurine refractory / steroid dependent/refractory UC?
- Anti-TNFs
- Vedolizumab (Entyvio) – integrin 𝛼4𝛽7 inhibitor
Colectomy – would it cure extraintestinal manifestations?
•NO. Ank Spond, liver disease, PG do not improve.
What is IPAA and what are the problems (2)?
- Ileal Pouch Anal Anastomosis (pan-proctocolectomy instead of ileostomy) – does give you intestinal continuity
- Problems = pouchitis (50% - Mx with Metronidazole), BO frequency norm is 4-8 times / day, minor incontinence in 20%
AZA/6MP/MTX and Anti-TNFs are currently used for Crohn’s. Things to check before starting (work-up)
General
- Baseline FBC, EUC, LFTS
- Hep B, C, EBV (due to lymphoma risk in sero-ves), VZV, HIV
- Update immunisations
- Papsmear
Specific
- AZA/6-MP: TPMT
- MTX: start folic acid
- Anti-TNFs: IGRA, CXR (TB), Anti-ds DNA and ANA
