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Three Part Question

In [patients presenting with acute abdominal pain] does [a normal C-reactive protein] exclude [serious abdominal pathology]

Clinical Scenario

A 20 year old male patient presents with an acute abdomen. You wonder if any laboratory tests could aid your management of this patient. CRP has been proven to show inflammation and you wonder if it is a useful test for this patient.

Search Strategy

MEDLINE (1950 – 2008) and EMBASE
[(exp abdominal pain OR Abdominal pain.mp OR exp acute abdomen OR acute abdomen.mp) AND (exp C-reactive protein OR C-reactive protein.mp OR CRP.mp)AND (exp diagnosis OR Diagnosis.mp)] LIMIT to humans and english language

Search Outcome

214 articles, of which 1 was a meta-analysis and 6 other articles which were not included in this meta-analysis were also found to be relevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses

Comment(s)

CRP is a helpful test when assessing a patient with acute abdominal pain. It is far more sensitive than specific and seems to be a better indicator of severe disease. Alone it can not be used successfully in making a diagnosis. However, when combined with certain other clinical signs, particularly leukocytosis, it becomes a far more accurate test. This is something that requires more research. CRP is a good diagnostic aid in acute abdominal pain as long as it is used with consideration of these facts.

Clinical Bottom Line

CRP is a helpful diagnostic tool. However, alone it cannot rule out serious abdominal pathology

References

1. Tepel J, Sommerfeld A, Klomp HJ, Kapischke M, Eggert A, Kremer B. Prospective evaluation of diagnostic modalities in suspected acute appendicitis. Langenbecks Arch Surg 2004 Jun;389(3):219-24
2. Chi CH, Shiesh SC, Chen KW, Wu MH, Lin XZ. C-reactive protein for the evaluation of acute abdominal pain. Am J Emerg Med. 1996 May;14(3):254-6.
3. Hallan S, Asberg A. The accuracy of C-reactive protein in diagnosing acute appendicitis--a meta-analysis. Scand J Clin Lab Invest. 1997;Aug;57(5):373-80.
4. Andersson RE, Hugander AP, Ghazi SH, Ravn H, Offenbartl SK, Nyström PO, Olaison GP. Diagnostic value of disease history, clinical presentation and inflammatory parameters of appendicitis. World J Surg 1999 Feb;23(2):133-40.
5. Erkasap S, Ates E, Ustuner Z, Sahin A, Yilmaz S, Yasar B, Kiper H. Diagnostic value of interleukin-6 and C-reactive protein in acute appendicitis. Swiss Surg. 2000;6(4):169-72.
6. Yildirim O, Solak C, Koçer B, Unal B, Karabeyoğlu M, Bozkurt B, Aksaray S, Cengiz O. The role of serum inflammatory markers in acute appendicitis and their success in preventing negative laparotomy. J Invest Surg. 2006 Nov-Dec;19(6):345-52.
7. Salem TA, Molloy RG, O'Dwyer PJ. Prospective study on the role of C-reactive protein (CRP) in patients with an acute abdomen. Ann R Coll Surg Engl 2007 Apr;89(3):233-7.