What is the appropriate management for a patient presenting with generalized abdominal pain?

Management of Generalized Abdominal Pain

For patients presenting with generalized abdominal pain, obtain immediate vital signs and perform focused abdominal examination, followed by CT scan of the abdomen and pelvis with IV contrast as the preferred initial imaging modality, with management decisions driven by hemodynamic stability and imaging findings. 1, 2

Immediate Assessment

Vital Signs and Red Flags

• Check for tachycardia, fever >38°C, hypotension (SBP <90 mmHg), respiratory distress, or decreased urine output—these indicate potential surgical emergency requiring immediate intervention 2, 3
• Hemodynamically unstable patients (hypotension, tachycardia >120 bpm, altered mental status) require immediate IV fluid resuscitation with crystalloids and urgent surgical consultation before completing diagnostic workup 1, 2
• Mortality increases 2-12% with each hour of delayed treatment once acute abdomen is present 3

Focused Physical Examination

• Assess specifically for peritoneal signs: guarding, rigidity, rebound tenderness, or absent bowel sounds—any of these mandate immediate surgical consultation 1, 2, 3
• Document pain location, but recognize that generalized pain requires whole abdomen/pelvis imaging rather than location-specific protocols 1
• In elderly patients (>65 years), maintain high suspicion even with minimal findings, as they frequently present with atypical symptoms and normal laboratory values despite serious pathology 1, 2

Laboratory Workup

Essential Initial Tests

• Complete blood count to detect leukocytosis (>11,000/μL suggests infection/inflammation) 2, 4
• Comprehensive metabolic panel including liver enzymes, bilirubin, creatinine, and electrolytes 2, 4
• Serum lipase (more specific than amylase for pancreatitis) 4
• Mandatory pregnancy test (β-hCG) in all women of reproductive age before any imaging 1, 2, 4
• Lactate level if concerned for bowel ischemia or sepsis (>2 mmol/L concerning, >4 mmol/L critical) 2, 4

Additional Tests Based on Clinical Suspicion

• Urinalysis for urinary tract infection or nephrolithiasis 4
• Blood cultures if fever present and sepsis suspected 4
• C-reactive protein as inflammation marker 5

Imaging Strategy

Primary Imaging Modality

CT scan of abdomen and pelvis with IV contrast is the preferred initial imaging for generalized/nonlocalized abdominal pain 1, 2, 5

• CT changes diagnosis in 49-54% of patients and alters management in 42-53% of cases 1
• CT increases diagnostic certainty from 70.5% pre-scan to 92.2% post-scan 1
• Scan the entire abdomen and pelvis—limiting coverage based on symptoms misses pathology in 67% of abnormal cases 1

Alternative Imaging

• Ultrasound as first-line only in pregnant patients, followed by MRI if additional imaging needed (avoid CT radiation exposure) 2, 5
• Plain abdominal radiographs have minimal diagnostic value and should NOT be routinely ordered except when bowel obstruction strongly suspected 2, 5
• CT angiography specifically if mesenteric ischemia suspected (acute onset severe pain, lactate elevation, atrial fibrillation) 1

Important Imaging Caveats

• Repeat CT after initially negative scan has low yield (drops to 5.9% by fourth scan) unless new clinical factors emerge like leukocytosis or worsening APACHE-II scores 1
• CT has 64% negative predictive value for upper abdominal pain, commonly missing gastritis, duodenitis, and early pancreaticobiliary inflammation 1
• Reduced segmental bowel wall enhancement on CT is 100% specific for bowel infarction—this finding requires immediate surgical exploration 1

Management Algorithm

Surgical Emergency (Immediate Intervention)

Patients with ANY of the following require emergency surgical consultation before completing full workup: 1, 2, 3

• Peritoneal signs (guarding, rigidity, rebound)
• Hemodynamic instability despite fluid resuscitation
• Free air on imaging (perforation)
• CT findings of bowel ischemia/infarction
• Septic shock (lactate >4, hypotension, altered mental status)

Stable Patients with Identified Pathology

Intra-abdominal abscess: 1

• Abscesses >3 cm: percutaneous drainage plus IV antibiotics
• Abscesses <3 cm: IV antibiotics alone may suffice
• Antibiotic duration: 4 days if immunocompetent and adequate source control; up to 7 days if immunocompromised or critically ill

Perforated viscus (gastric/duodenal): 1

• Laparoscopic or open repair with omental patch for small perforations
• Distal gastrectomy for large perforations near pylorus
• Conservative management only if patient unfit for surgery due to severe comorbidities

Small bowel perforation/obstruction: 1

• Segmental resection with primary anastomosis if viable bowel
• Resection with delayed anastomosis at second-look laparotomy if ischemic
• Stoma creation if critically ill or friable tissue precludes anastomosis

Empiric Antibiotic Therapy (When Indicated)

Do NOT routinely administer antibiotics—only give when infection/abscess suspected 2

For stable, immunocompetent patients with adequate source control: 1

• Piperacillin-tazobactam 4 g/0.5 g IV q6h OR 16 g/2 g continuous infusion
• If beta-lactam allergy: Eravacycline 1 mg/kg IV q12h OR Tigecycline 100 mg load then 50 mg IV q12h

For septic shock or critically ill: 1

• Meropenem 1 g IV q6h by extended infusion
• OR Doripenem 500 mg IV q8h by extended infusion
• OR Imipenem-cilastatin 500 mg IV q6h by extended infusion
• OR Eravacycline 1 mg/kg IV q12h

Special Population Considerations

Elderly Patients (>65 years)

• Maintain extremely high index of suspicion—laboratory tests frequently normal despite serious infection 1, 2
• Lower threshold for imaging and surgical consultation 2
• Atypical presentations are the norm, not the exception 2, 5

Women of Reproductive Age

• Always obtain pregnancy test before imaging—this is non-negotiable 1, 2, 4
• Consider ectopic pregnancy, ovarian torsion, pelvic inflammatory disease in differential 2
• If pregnant, use ultrasound first, then MRI if needed—avoid CT 2, 5

Immunocompromised Patients

• Signs of abdominal sepsis may be completely masked 1, 2
• Diagnosis frequently delayed with higher mortality 1
• Lower threshold for imaging and broader antibiotic coverage 1, 2

Critical Pitfalls to Avoid

• Never rely solely on laboratory tests without imaging—many surgical conditions require CT for definitive diagnosis 2, 5
• Never delay surgical consultation in patients with peritonitis or septic shock—mortality increases hourly 1, 2, 3
• Never skip pregnancy testing in women of reproductive age—ectopic pregnancy can be fatal if missed 2, 4
• Never assume elderly patients with normal labs are fine—serious pathology often present despite reassuring tests 1, 2
• Never order plain radiographs routinely—they have minimal diagnostic value except for suspected obstruction 2, 5
• Never limit CT coverage to "save radiation"—this misses 67% of pathology outside the targeted area 1

Disposition Decisions

Admit to Hospital

• Severe pain requiring parenteral analgesia 2
• Hemodynamic instability 2
• Peritoneal signs 2
• Any suspected surgical condition 2
• Imaging findings requiring intervention or close monitoring 2

Discharge with Close Follow-up

• Stable vital signs, benign examination, and negative or non-urgent imaging findings only 2
• Ensure 24-48 hour follow-up arranged 2
• Provide explicit return precautions for worsening pain, fever, vomiting, or inability to tolerate oral intake 2