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ColonoscopyNot the cure for Acute Lower GI Bleeding
Liz O’GormanSurgical InternCork University Hospital
• Acute – within 24 hours
• LGIB in Irish Healthcare System- Diverticular Bleed- Angiodysplasia
- IBD/Colitis- Neoplasia- Rectal Trauma- Iatrogenic
Aim of Colonoscopy is to diagnose and treat bleeding sources
I will discuss:
1. Limitations of colonoscopy
2. Risks of colonoscopy
3. Better alternative options
Why not perform Colonoscopy?
• Long standing debate
• Numerous studies tried to address this question
• No gold standard test for acute LGIB
AIM = treat and diagnose bleeding source
• 1 – need to identify source
• 2 – facilities to implement treatment
Limitations of Colonoscopy
1. Bowel Preparation
• Unique to endoscopic interventions
• Cleansing bowel of stool and blood imperative to diagnosis
• Unprepped- caecum in 55-70% Chaudry at al- reduced identification of bleeding sites Tada et al- increased risk of perforation Strate et al
• Diverticular bleeds- multiple subtle bleeding sites- active bleeding identified 21% Jensen et al, 2000- aggressive bowel prep
• Green at al, 2005- 62-64% endoscopic view rated poor to fair
2. Stigmata of Haemorrhage• Diagnostic interventions alone do not alter rebleeding and operative rates
• Variable reports of identification- 7.7% – 43 % Angtuaco et al, 2001; Schmuelewitz et al, 2003
• Bleeding intermittent- difficult to differentiate fresh blood from old blood and stool
• 20% haematochezia secondary to Upper GI bleed - Jensen et al, 1998; Laine et al 2010
3. Your Environment• Not all centres have same access to on call colonoscopy
• Trained personel- trained nursing staff- endoscopy suite / OT- anaesthetist if pt unstable
• Waiting for prep – increases likelihood of out of hours colonoscopy
• Strate et al, 2003- median time from admission to colonoscopy 17hours for LGIB
managed with urgent colonoscopy
Risks
1. Perforation
• Low: 0.3-1.3%
• Catastrophic with high mortality– patient already compromised
2. Volume Shifts
• Rapid bowel preps
• Haemodynamically compromised patients
• Renal compromise and electrolyte imbalances Goldman et al,1982
• Left ventricular dysfunction- exacerbation of symptoms and ECF volume overload
Alternatives
Angiography
• Diagnostic and therapeutic• Superselective embolisation
• Meta-analysis J GI Surg 2005 Khanna A et al- Diverticular Bleed 85% success
*if fails < 2 days- Non-diverticular Bleed 50% success
* if fails < 2 days
CT Angiography
• Triage prior to angiography (avoid risks associated with intervention)
• ALL patients with a suspected, known or previously treated AAA- ? Aortoenteric fistula
• Bleeding of 2cc/sec
Radionucleotide Scintigraphy
• Radiolabelled RBCs (99mTc)
• Identifies LGIB site in up to 78% of cases
• Bleeding of 0.2 cc/sec
• No intervention risks
Summary• Colonoscopy
- difficult to reach caecum without aggressive bowel prep- difficult to identify bleeding source even with bowel prep- prep associated electrolyte disturbances and volume shifts- risk of perforation- median time from admission 17hours ? acute
• Alternatives- CT / CT Angio / Radionucleotide Scans
BOTTOM LINE
•Colonoscopy diagnostically poor in acute LGIB
• You can not treat something you can not diagnose
•Acute lower GI bleeding usually stops without intervention
Thank You