What is the appropriate management for a patient with leukocytosis and abdominal pain?

Management of Leukocytosis (WBC 23) with Abdominal Pain

Obtain urgent CT abdomen/pelvis with IV contrast immediately to identify the source of infection or surgical pathology, as leukocytosis of this magnitude with abdominal pain indicates high likelihood of serious intra-abdominal pathology requiring source control. 1

Immediate Diagnostic Workup

Laboratory Testing

• Beyond the complete blood count, obtain C-reactive protein (CRP), comprehensive metabolic panel, urinalysis with culture, and blood cultures if fever is present 1
• WBC count alone is insufficient to discriminate urgent from non-urgent diagnoses, but a WBC >23,000 with abdominal pain warrants aggressive investigation 2
• Lymphopenia (<1.4 × 10⁹/L) combined with eosinopenia (<0.04 × 10⁹/L) and neutrophilia >9.0 × 10⁹/L has 94.9% specificity for severe infectious or surgical pathology 3
• CRP ≥5 mg/dL has high specificity for postoperative complications and intra-abdominal pathology, though normal CRP does not rule out serious disease 4

Imaging Strategy

• CT abdomen/pelvis with IV and oral contrast is the study of choice, providing 95% sensitivity and 94% specificity for identifying surgical causes 4, 1
• Ultrasound should be performed first only if right upper quadrant pathology (cholecystitis) is suspected, but CT should follow if ultrasound is non-diagnostic 1, 5
• Plain radiography has no role in the workup due to lack of added value beyond clinical assessment 2

Critical Differential Diagnoses to Consider

High-Priority Surgical Conditions

• Appendicitis (including perforated): Leukocytosis may be absent in 24-57% of cases, but WBC 23,000 suggests complicated disease 4
• Intra-abdominal abscess: Collections >3 cm require percutaneous drainage plus broad-spectrum antibiotics covering gram-negatives and anaerobes 4, 1
• Bowel perforation or obstruction: Requires emergent surgical consultation 1
• Acute cholecystitis: Early laparoscopic cholecystectomy (within 7 days) is definitive treatment 1

Infectious Medical Conditions

• Spontaneous bacterial peritonitis (if cirrhosis/ascites present): Diagnostic paracentesis is mandatory if ascites present; ascitic fluid PMN >250 cells/mm³ requires immediate empiric antibiotics 4
• Obstructive pyelonephritis: If imaging shows hydronephrosis with perinephric stranding, emergent urinary decompression via percutaneous nephrostomy or ureteral stent is lifesaving 1
• Inflammatory bowel disease complications: Abscesses in Crohn's disease require drainage if >3 cm; antibiotics alone may suffice for smaller non-drainable abscesses without fistula 4

Immediate Management Actions

Within First Hour

• Start empiric broad-spectrum antibiotics after obtaining blood cultures if sepsis is suspected (fever, hypotension, altered mental status) 1
• For suspected intra-abdominal infection, use third-generation cephalosporin (cefotaxime 2g IV q8h or ceftriaxone 1-2g IV daily) plus metronidazole 4
• Fluoroquinolones may be used but resistance patterns have changed due to widespread prophylactic use 4
• Administer IV fluids, correct electrolyte abnormalities, and provide VTE prophylaxis with low molecular weight heparin 4

Surgical/Interventional Consultation

• Arrange immediate surgical consultation if imaging reveals perforation, bowel obstruction, or findings requiring operative intervention 1
• Interventional radiology consultation for percutaneous drainage if fluid collections >3 cm are identified 1
• Diagnostic laparoscopy has higher sensitivity and specificity than any radiological assessment when diagnosis remains unclear 4

Special Populations and Pitfalls

Immunocompromised Patients

• Transplant recipients may have normal or low WBC despite serious infection; CRP is more reliable than WBC count in this population 4
• In liver transplant patients with appendicitis, median WBC was only 7,500 cells/mm³ versus 12,500 in non-transplanted patients, but CRP was significantly elevated (6.1 vs 0.8 mg/dL) 4

Cirrhotic Patients

• Alcoholic hepatitis can mimic spontaneous bacterial peritonitis with fever, leukocytosis, and abdominal pain 4
• Elevated ascitic fluid PMN must be presumed to represent SBP regardless of peripheral leukocytosis 4
• Empiric antibiotics can be discontinued after 48 hours if all cultures remain negative 4

Common Pitfalls to Avoid

• Never delay imaging based on "reassuring" vital signs—WBC 23,000 with abdominal pain mandates imaging within hours 1
• Do not rely on leukocytosis alone to guide antibiotic decisions; obtain imaging first to identify source requiring drainage 4, 1
• Antibiotics should not be routinely administered for abdominal pain unless superinfection or abscess is identified on imaging 4
• Opioid analgesia should be provided as it decreases pain intensity without affecting diagnostic accuracy 2

Antibiotic Duration and Monitoring

• Clinical improvement should occur within 3-5 days; if not, repeat imaging to assess adequacy of source control 4
• Five days of antibiotic therapy is as efficacious as 10 days for adequately drained intra-abdominal infections 4
• Monitor CRP and procalcitonin for antibiotic de-escalation decisions 4