---
name: evaluating-abdominal-emergencies
language: en
description: Structures abdominal pain workups with differential by quadrant and surgical consultation criteria. Use when assessing acute abdomen, determining imaging needs, or identifying surgical emergencies.
tags:
  - analysis
  - emergency-medicine
  - surgical
metadata:
  author: casemark
  practice_areas:
    - Emergency Medicine
  document_types:
    - Evaluation Report
  skill_modes:
    - Analysis
    - Assessment
---

# Evaluating Abdominal 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)

1. What is the location, onset, and character of the abdominal pain? (Default: document using OLDCARTS)
2. What are the patient's vital signs? (Default: full set; flag fever, tachycardia, hypotension)
3. Is the patient pregnant or of childbearing age? (Default: obtain beta-hCG for all females 12-55)
4. What is the patient's surgical history? (Default: document all prior abdominal surgeries — critical for adhesive obstruction)
5. What is the timing of last oral intake? (Default: relevant for NPO status if surgery likely)
6. Are there associated GI symptoms (nausea, vomiting, diarrhea, constipation, melena, hematochezia)? (Default: query and document each)
7. Are there urinary symptoms? (Default: query dysuria, frequency, hematuria)
8. 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)
- Lab results: CBC, BMP, lipase, hepatic panel, lactate, urinalysis, beta-hCG
- Prior ED visits for abdominal complaints

---

## Step 1: Differential Diagnosis by Quadrant

### Right Upper Quadrant (RUQ)

| Diagnosis | Key Features | Workup |
|-----------|-------------|--------|
| Acute cholecystitis | RUQ pain, positive Murphy sign, fever | RUQ ultrasound (sensitivity 88%, specificity 80%); CBC, hepatic panel |
| Choledocholithiasis | RUQ pain, jaundice, elevated bilirubin/ALP | MRCP or EUS if ultrasound equivocal; GI consult for ERCP |
| Ascending cholangitis (Charcot triad) | RUQ pain + fever + jaundice | Blood cultures, emergent ERCP; add hypotension + AMS = Reynolds pentad |
| Hepatitis | RUQ pain, elevated transaminases (>1000 suggests viral/toxin) | Hepatic panel, hepatitis serologies, toxicology |
| Hepatic abscess | Fever, RUQ pain, recent travel or biliary disease | CT with contrast, blood cultures |

### Right Lower Quadrant (RLQ)

| Diagnosis | Key Features | Workup |
|-----------|-------------|--------|
| Appendicitis | Periumbilical pain migrating to RLQ, anorexia, low-grade fever | CT abdomen/pelvis (sensitivity 98%); Alvarado score ≥7 highly suggestive |
| Ovarian torsion | Sudden severe unilateral pelvic pain, nausea | Pelvic ultrasound with Doppler (sensitivity 85-90%); gynecology consult |
| Ectopic pregnancy | Missed period, vaginal bleeding, pelvic pain, positive hCG | Transvaginal ultrasound; quantitative hCG; if ruptured → emergent OR |
| Mesenteric adenitis | RLQ pain in young patient, often viral prodrome | CT may mimic appendicitis; clinical observation |

### Left Upper Quadrant (LUQ)

| Diagnosis | Key Features | Workup |
|-----------|-------------|--------|
| Splenic infarct/rupture | LUQ pain, history of hematologic disorder, trauma | CT with IV contrast |
| Gastric ulcer perforation | Sudden epigastric/LUQ pain, peritonitis | Upright CXR (free air), CT if CXR negative |
| Pancreatitis | Epigastric/LUQ pain radiating to back, nausea, vomiting | Lipase (>3× upper limit), CT for complications if no improvement at 48-72h |

### Left Lower Quadrant (LLQ)

| Diagnosis | Key Features | Workup |
|-----------|-------------|--------|
| Diverticulitis | LLQ pain, fever, leukocytosis; common in age >50 | CT abdomen/pelvis with IV contrast (sensitivity >95%) |
| Sigmoid volvulus | Elderly, institutionalized, chronic constipation, distension | Abdominal X-ray (bent inner tube sign); CT confirms; rectal tube decompression |
| Ovarian pathology | Unilateral pelvic pain, menstrual irregularity | Pelvic ultrasound, beta-hCG |

### Diffuse / Periumbilical

| Diagnosis | Key Features | Workup |
|-----------|-------------|--------|
| Small bowel obstruction | Colicky pain, vomiting, distension, prior surgery | CT abdomen/pelvis; look for transition point |
| Mesenteric ischemia | Severe pain out of proportion to exam, AFib, age >60 | CT angiography; lactate (late finding); vascular surgery consult |
| Ruptured AAA | Sudden severe pain, pulsatile mass, hypotension, age >60, male | Bedside ultrasound (if stable); emergent OR if unstable (do NOT delay for CT) |
| Peritonitis | Rigid abdomen, guarding, rebound, involuntary guarding | Surgical consult immediately; imaging secondary to clinical diagnosis |

---

## Step 2: Laboratory and Imaging Selection

### Standard ED Abdominal Lab Panel
- CBC with differential (leukocytosis, anemia, bandemia)
- BMP (creatinine for contrast, electrolytes for vomiting)
- Hepatic function panel (AST, ALT, ALP, total bilirubin, albumin)
- Lipase (>3× ULN diagnostic for pancreatitis)
- Lactate (>2.0 mmol/L concerning for ischemia or sepsis)
- Urinalysis (UTI, stones, hematuria)
- Beta-hCG (all females of childbearing age — non-negotiable)
- Type and screen if surgical intervention likely

### Imaging Decision Framework

| Clinical Scenario | First-Line Imaging | Notes |
|-------------------|-------------------|-------|
| RUQ pain, suspected biliary | RUQ ultrasound | Do NOT order CT first for biliary disease |
| RLQ pain, suspected appendicitis | CT abdomen/pelvis with IV contrast | Ultrasound first in pediatric, pregnant, or young thin females |
| Suspected bowel obstruction | CT abdomen/pelvis with IV contrast | X-ray has poor sensitivity for partial SBO |
| Suspected renal colic | CT abdomen/pelvis without contrast | Low-dose CT protocol preferred; ultrasound first if pregnant |
| Suspected AAA | Bedside POCUS (if unstable → OR) | CT angio if stable and diagnosis uncertain |
| Female pelvic pain | Pelvic ultrasound (transvaginal) | Always obtain beta-hCG first |
| Suspected free air | Upright CXR → CT if CXR negative | CT is more sensitive than X-ray |

---

## Step 3: Surgical Consultation Criteria

### Immediate Surgical Consult Required

- **Peritonitis:** diffuse tenderness with involuntary guarding, rigidity, or rebound
- **Free air** on imaging (perforated viscus)
- **Bowel ischemia** suspected (pain out of proportion to exam, elevated lactate, CT findings)
- **Ruptured AAA:** hypotension + pulsatile mass + abdominal/back pain
- **Ruptured ectopic pregnancy:** positive hCG + free fluid + hemodynamic instability
- **Testicular torsion:** sudden onset scrotal pain, absent cremasteric reflex, high-riding testis (urology consult — do not delay for imaging if >6 hours)

### Urgent Surgical Consult (within hours)

- Appendicitis confirmed on CT
- Complicated diverticulitis (abscess, perforation, fistula)
- 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)

1. Was the differential diagnosis organized by pain location and pattern?
2. Was beta-hCG obtained for all females of childbearing age?
3. Was imaging selection appropriate for the leading diagnosis (not reflexive CT for all complaints)?
4. Were surgical consultation criteria applied and consult obtained when indicated?
5. 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

1. 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.
2. 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.
3. 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.
4. 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.
5. Elderly and immunosuppressed patients present atypically — perforated appendicitis may present with minimal tenderness, and peritonitis may lack rebound or guarding in patients on steroids.
6. 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.
7. 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.
8. 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.