What is the management of acute abdomen?

Management of Acute Abdomen

The management of acute abdomen requires prompt surgical intervention within 12-24 hours of symptom onset to decrease morbidity and mortality rates, with laparoscopy being the preferred approach in hemodynamically stable patients. 1

Initial Assessment and Diagnosis

Clinical Evaluation

• Alarming clinical signs requiring immediate attention:

  • Tachycardia ≥ 110 beats per minute
  • Fever ≥ 38°C
  • Hypotension
  • Respiratory distress with tachypnea and hypoxia
  • Decreased urine output 1
  • Combination of fever, tachycardia, and tachypnea (highly predictive of anastomotic leak or staple line leak) 1

• Key symptoms to evaluate:

  • Persistent vomiting and nausea (may indicate internal hernia, volvulus, gastrointestinal stenosis, intestinal ischemia) 1
  • Acute abdominal pain pattern and location
  • Abdominal tenderness and rigidity 2

Diagnostic Workup

1. Laboratory tests:

   • Complete blood count
   • Comprehensive metabolic panel
   • C-reactive protein
   • Lactate levels
   • Blood cultures (if sepsis suspected)

2. Imaging:

   • Contrast-enhanced CT scan is the most reliable diagnostic tool for acute abdomen, particularly in immunocompromised patients 1
   • Administration of both oral and IV contrast is fundamental for accurate diagnosis 1
   • Ultrasound is useful as initial investigation and in pregnant patients or those with contraindications to CT 3
   • MRI may be considered in pregnant patients to avoid radiation exposure 1

3. Specific testing based on clinical suspicion:

   • In patients with diarrhea, test for Clostridioides difficile and its toxin 1
   • Consider specific microbiologic tests only if clinically indicated 1

Treatment Algorithm

1. Hemodynamic Stabilization

• Aggressive fluid resuscitation
• Vasopressors if needed
• Broad-spectrum antibiotics for suspected infection/sepsis

2. Surgical Management Decision

• Immediate surgical exploration is mandatory in:

  • Hemodynamically unstable patients with peritonitis 1
  • Patients with signs of perforation or ischemia 1
  • Patients with toxic megacolon or fulminant colitis 1

• Timing: Surgery is mandatory within the first 12-24 hours to obtain good outcomes and decrease morbidity and mortality rates 1

3. Surgical Approach

• Laparoscopy is the preferred approach in hemodynamically stable patients 1
• Open surgery may be necessary in unstable patients or those with extensive disease

4. Damage Control Surgery Considerations

• Damage control surgery with open abdomen should be considered in:

  • Hemodynamically unstable patients with intra-abdominal infection source
  • Extensive intestinal ischemia
  • Massive hemoperitoneum
  • Severe peritonitis with septic shock
  • Abdominal compartment syndrome 1

• Indications for open abdomen:

  • Abbreviated laparotomy due to severe physiological derangement
  • Need for deferred intestinal anastomosis
  • Planned second look for intestinal ischemia
  • Persistent source of peritonitis (failure of source control)
  • Extensive visceral edema with risk of abdominal compartment syndrome 1

5. Specific Disease Management

Clostridioides difficile Colitis

• Initial medical management with antibiotics and bowel rest
• Surgical intervention for fulminant colitis or perforation
• Consider total colectomy or diverting loop ileostomy with colonic antibiotic lavage 1

Neutropenic Enterocolitis

• Non-operative treatment with broad-spectrum antibiotics and bowel rest
• Surgery only for perforation or ischemia 1

Cytomegalovirus Colitis

• Antiviral therapy, broad-spectrum antibiotics, and bowel rest
• Surgery only for toxic megacolon, fulminant colitis, perforation, or ischemia 1

Acute Cholecystitis

• Laparoscopic cholecystectomy as soon as possible after diagnosis
• Percutaneous cholecystostomy for patients unfit for surgery 1

Special Considerations

Immunocompromised Patients

• Higher threshold for surgical intervention
• Consider atypical presentations and opportunistic infections
• Multidisciplinary approach involving infectious disease specialists 1

Post-Bariatric Surgery Patients

• Lower threshold to operate if radiological findings are inconclusive but patient presents with acute abdominal symptoms and/or persistent tachycardia 1
• Assess all anastomoses after LRYGB, the remnant stomach, and excluded duodenum 1

Common Pitfalls to Avoid

1. Delayed diagnosis and intervention - can significantly increase morbidity and mortality
2. Failure to recognize atypical presentations - especially in immunocompromised or elderly patients
3. Overreliance on imaging - clinical judgment remains paramount despite advances in technology 4
4. Inadequate resuscitation before surgical intervention
5. Inappropriate surgical approach - choosing open surgery when laparoscopy would be more beneficial, or vice versa

Remember that mortality increases for every hour that passes without specific treatment in acute abdomen cases 5, making timely diagnosis and intervention crucial for improving outcomes.