We had a likelihood ratio EXTRAVAGANZA during our noon report last week with Dr. Lewis. Dr. Lewis presented a case of a patient who presented with subacute progressive fatigue, dyspnea on exertion and melena who was found to have a hgb in the 4’s (!) and MCV of 65 on presentation.
We reviewed the JAMA rational clinical exam article on severe upper GI bleed: https://jamanetwork.com/journals/jama/article-abstract/1105075
Likelihood ratio for symptoms of UGIB:
- Reported history of Melena : +LR 5.1-5.9
- Melenic stool on exam: +LR 25
- Serum BUN:Cr ratio >30: +LR 7.5
- Blood clots in stool: LR 0.05
Dr. Lewis shared another systematic review on diagnostic value of symptoms for colorectal cancer in primary care: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3080228/
Positive predictive value for symptoms:
Rectal bleeding: 8.1%
Abdominal pain: 3.3%
Rectal bleeding + weight loss: +LR 1.9
Rectal bleeding + change in bowel habits: +LR 1.8
Srygley FD, Gerardo CJ, Tran T, Fisher DA. Does this patient have a severe upper gastrointestinal bleed?. JAMA. 2012;307(10):1072-9.
Astin M, Griffin T, Neal RD, Rose P, Hamilton W. The diagnostic value of symptoms for colorectal cancer in primary care: a systematic review. Br J Gen Pract. 2011;61(586):e231–e243. doi:10.3399/bjgp11X572427