How We Diagnose the Cause of Acute Abdominal Pain in Adults

In a previous post (1) I discussed  many of the causes of acute abdominal pain and how we try to decide which of those causes is most likely.

We decide which tests to order for diagnosis depending on what we think is the most likely cause of the pain.

We start out, after asking the patient the history with the vital signs (pulse, blood pressure, respiratory rate, and oxygen saturation [pulse oximetry]. An abnormality in any of these signs may make us want to watch the patient more closely or up-triage him or her. (2)

Then we perform a physical examination and palpate (meaning press gently on) the abdomen to see if there is an part of the abdomen that is especially tender.

Next, we order laboratory tests. Many doctors order more or less the same set of lab tests regardless of what they think the cause is.

Typically the doctor will order a complete blood count, a complete metabolic profile, a urinalysis, an amylase and lipase, and, if the patient is a woman of reporductive age, a serum pregnancy test.

Nowadays, if we think that the cause of a patient’s abdominal pain may be serious (meaning that it possibly needs immediate medicines or surgery), we usually order imaging tests.

And the imaging tests we order depend on what we think is the most likely cause of the abdominal pain.

A search of the American College of Radiology Appropriateness Criteria relating to acute abdominal pain yields a good set of imaging protocols (3) that are organized in the way that doctors approach  abdominal pain.

The topics found in the search include: Acute abdominal pain and fever or suspected abdominal abscess, Acute pancreatitis, acute onset flank pain—suspect stone disease, left lower quadrant pain—suspect acute diverticulitis, right lower quadrant pain—suspect appendicitis, acute pelvic pain in the reproductive age group, Crohn’s Disease, right upper quadrant pain, renal failure, and jaundice.
Note: Suspect Small-bowel obstruction did not appear on the search list but it should have and so is included below.

The doctor will decide on the most likely cause of the acute abdominal based on the patient’s history, physical examination, and laboratory studies and then probably ordering imaging test that are listed in the various ACR appropriateness criteria listed below. [Notes (4) through (13)].

In upcoming posts, I’ll discuss specific causes of acute abdominal pain in greater detail.

(1) An Approach to Causes of Acute Abdominal Pain In Adults available at http://www.tomwademd.net/2012/02/02/an-approach-to-the-causes-of-acute-abdominal-pain-in-adults/

(2) The Emergency Severity Index: A Five Level Triage Tool Available for Download available at http://www.tomwademd.net/2012/01/26/the-emergency-severity-index-a-five-level-triage-tool-available-for-download/

(3) A List of ACR Appropriateness Criteria for acute abdominal pain available at
http://acsearch.acr.org/TopicList.aspx?topic_all=’%22acute*%22+and+%22abdominal*%22+and+%22pain*%22’&topic_any=&connector=+And+&cid=193   

(4) Acute Abdominal Pain and Fever or Suspected Abdominal Abscess ACR Appropriateness Criteria. Date of origin: 1996. Last review date 2008. Available at http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/AcuteAbdominalPainandFeverorSuspectedAbdominalAbscessDoc1.aspx

(5) Acute Onset flank pain—Suspicion of Stone Disease ACR Appropriateness Criteria
Date of origin: 1995. Last review date: 2011.  Available at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonUrologicImaging/AcuteOnsetFlankPainSuspicionofStoneDiseaseDoc1.aspx

(6) Left Lower Quadrant Pain—Suspected Diverticulitis ACR Appropriateness Criteria. Date of origin: 1996. Last review date: 20ll  http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/LeftLowerQuadrantPainDoc8.aspx

(7) RLQ Pain Suspected Appendicitis ACR Appropriateness Criteria. Date of origin 1996. Last review date: 2010. Available at     http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonPediatricImaging/Othertopics/RightLowerQuadrantPain.aspx

(8) Acute Pelvic Pain in the Reproductive Age Group ACR Appropriateness Criteria.
Date of oirign: 2008. Last review date: 2011.  Available at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonWomensImaging/AcutePelvicPainintheReproductiveAgeGroup.aspx.

(9) Crohn’s Disease ACR Appropriateness Criteria. Date of origin: 1998. Last review date: 2011.
Available at:
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/CrohnsDiseaseDoc5.aspx.

(10) Right Upper Quadrant Pain ACR Appropriateness Criteria. 
Date of origin: 1996. Last review date: 2010. Available at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/RightUpperQuadrantPainDoc13.aspx.

(11) Renal Failure ACR Appropriateness Criteria: Date of origin 1995. Last review date: 2008.
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonUrologicImaging/RenalFailureDoc15.aspx.

(12) Jaundice ACR Appropriateness Criteria. Date of origin: 1996. Date of last review: 2008. Available at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/JaundiceDoc7.aspx.

(13) Suspected Small-bowel obstruction  ACR Appropriateness Criteria. Date of origin: 1996. Last review date: 2010. Available at:
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonGastrointestinalImaging/SuspectedSmallBowelObstructionDoc15.aspx.

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