Structures abdominal pain workups with differential by quadrant and surgical consultation criteria. Use when assessing acute abdomen, determining imaging needs, or identifying surgical emergencies.
Structures abdominal pain workups with differential diagnosis by quadrant location, laboratory and imaging selection, and surgical consultation criteria for acute abdomen.
Why This Skill Exists
Abdominal pain is the most common chief complaint in US emergency departments, accounting for approximately 8% of all ED visits (11 million annually). The differential diagnosis spans over 50 conditions across multiple organ systems, and the diagnostic challenge is compounded by the fact that history and physical exam alone have limited sensitivity for surgical conditions — clinical accuracy for appendicitis, for example, ranges from 70-87% without imaging. Missed surgical emergencies (ruptured AAA, mesenteric ischemia, perforated viscus) carry mortality rates of 40-80% if treatment is delayed.
Overtesting is equally problematic: CT abdomen/pelvis exposes patients to 10 mSv of radiation (equivalent to ~500 chest X-rays), and contrast-induced nephropathy affects 1-6% of patients with renal insufficiency. This skill provides a systematic framework for efficient, accurate abdominal pain evaluation that avoids both undertesting and overtesting.
Checkpoint A: Pre-Draft Intake (Mandatory)
Related Skills
What is the location, onset, and character of the abdominal pain? (Default: document using OLDCARTS)
What are the patient's vital signs? (Default: full set; flag fever, tachycardia, hypotension)
Is the patient pregnant or of childbearing age? (Default: obtain beta-hCG for all females 12-55)
What is the patient's surgical history? (Default: document all prior abdominal surgeries — critical for adhesive obstruction)
What is the timing of last oral intake? (Default: relevant for NPO status if surgery likely)
Are there associated GI symptoms (nausea, vomiting, diarrhea, constipation, melena, hematochezia)? (Default: query and document each)
Are there urinary symptoms? (Default: query dysuria, frequency, hematuria)
What medications is the patient taking (NSAIDs, anticoagulants, immunosuppressants, steroids)? (Default: these mask examination findings)
Documents to Request
Complete vital signs with serial measurements
Prior abdominal imaging for comparison
Surgical history documentation
Medication list (NSAIDs, steroids, immunosuppressants mask peritonitis)
Small bowel obstruction with signs of strangulation (fever, tachycardia, localized tenderness, elevated lactate)
Incarcerated hernia not reducible
Cholecystitis with sepsis or gangrenous features
Step 4: Pain Management and Reassessment
Analgesic Approach
Administer analgesia early — withholding pain medication does NOT improve diagnostic accuracy (multiple RCTs confirm this)
IV opioids for severe pain: morphine 0.1 mg/kg or hydromorphone 0.015 mg/kg
IV acetaminophen 1g (opioid-sparing; safe in most abdominal conditions)
IV ketorolac 15-30 mg for renal colic (avoid if creatinine elevated, GI bleeding, or surgical candidate)
Antiemetics: ondansetron 4 mg IV
Serial Examination
Reassess and document abdomen after analgesia and after imaging results
Improvement with analgesia does not exclude surgical pathology
Worsening examination on reassessment = escalate urgency
Checkpoint B: Post-Draft Alignment (Mandatory)
Was the differential diagnosis organized by pain location and pattern?
Was beta-hCG obtained for all females of childbearing age?
Was imaging selection appropriate for the leading diagnosis (not reflexive CT for all complaints)?
Were surgical consultation criteria applied and consult obtained when indicated?
Was the patient reassessed after treatment and imaging with findings documented?
Quality Audit
Pain location and character documented with OLDCARTS framework
Complete vital signs including temperature documented
Beta-hCG obtained for all females of childbearing age
Differential diagnosis listed by anatomic location
Laboratory studies appropriate to the differential obtained
Imaging modality matches the suspected diagnosis (ultrasound for biliary, CT for appendicitis, etc.)
Surgical consultation obtained for peritonitis, free air, ischemia, or ruptured viscus
Pain management provided and documented with response
Serial abdominal examination documented with times
Lactate obtained if mesenteric ischemia or sepsis considered
NSAIDs/steroids/immunosuppressant use documented (mask peritoneal signs)
Disposition rationale documented with surgical clearance if applicable
Discharge instructions include specific return precautions for worsening pain, fever, vomiting
Guidelines
Always obtain beta-hCG in females of childbearing age presenting with abdominal or pelvic pain — ruptured ectopic pregnancy is the most dangerous missed diagnosis in this population.
Administer analgesia early and aggressively — the outdated practice of withholding pain medication to preserve the abdominal exam has been definitively disproven by multiple randomized controlled trials.
A normal lactate does not exclude mesenteric ischemia — lactate elevation is a late finding indicating bowel necrosis; CT angiography is the test of choice for early diagnosis.
Use ultrasound before CT for suspected biliary disease, suspected ovarian pathology, and suspected ectopic pregnancy — ultrasound is more sensitive, faster, and avoids radiation for these specific diagnoses.
Elderly and immunosuppressed patients present atypically — perforated appendicitis may present with minimal tenderness, and peritonitis may lack rebound or guarding in patients on steroids.
Abdominal pain "out of proportion to physical examination findings" is the classic presentation of mesenteric ischemia until proven otherwise — this phrase should trigger immediate CT angiography.
Serial examination is the most valuable diagnostic tool in undifferentiated abdominal pain — if the initial evaluation is non-diagnostic, reassess in 4-8 hours rather than discharge prematurely.
Document the patient's surgical history in detail — adhesive small bowel obstruction is the most common cause of SBO and occurs almost exclusively in patients with prior abdominal surgery.