What does bilateral peritonitis mean and what is the recommended acute management?

Bilateral Peritonitis: Definition and Acute Management

"Bilateral peritonitis" is not standard medical terminology—peritonitis is by definition a diffuse process affecting the entire peritoneal cavity, not lateralized to one side, and requires immediate resuscitation, broad-spectrum antibiotics within the first hour, and urgent surgical source control to prevent mortality.

Understanding the Term

• The term "bilateral peritonitis" likely reflects confusion with anatomical descriptors, as peritonitis describes inflammation of the peritoneal membrane lining the entire abdominal cavity 1
• Peritonitis is classified by etiology (primary, secondary, tertiary) rather than anatomical location 2, 3
• Secondary peritonitis is the most common form, resulting from gastrointestinal tract perforation or loss of integrity, causing peritoneal contamination with endogenous bacteria 2, 3

Immediate Recognition and Diagnosis

Clinical Presentation

• Abdominal pain and tenderness occur in 74-95% of patients, typically with rebound tenderness and guarding indicating peritoneal irritation 1
• Abdominal rigidity strongly suggests peritonitis and demands immediate intervention 1
• Tachycardia (62.5% of patients) and fever >38.5°C (38% of patients) are common 1
• Hemodynamic instability with hypotension, lactic acidosis, oliguria, and altered mental status indicates septic shock 1

Diagnostic Workup

• CT scan has the highest sensitivity and specificity for detecting peritonitis, showing free fluid, free air, bowel wall thickening, and pericolic inflammation 1
• Obtain blood cultures and ascitic fluid analysis (if present) before initiating antibiotics 1
• Leukocytosis with left shift (band neutrophils >20%), elevated CRP, elevated lactate, and increased creatinine are common laboratory findings 1

Acute Management Algorithm

Step 1: Immediate Resuscitation (Within First Hour)

• Establish IV access and begin aggressive fluid resuscitation for hemodynamic stabilization 1
• Initiate broad-spectrum empiric antibiotics within the first hour in critically ill patients—delays significantly increase mortality 1
• Obtain blood cultures before antibiotics, but never delay antibiotic administration for culture collection 1

Step 2: Antibiotic Selection

For Community-Acquired Secondary Peritonitis:

• Use third-generation cephalosporins (cefotaxime 2g every 8 hours) plus metronidazole for anaerobic coverage 1, 4
• Alternative regimens include piperacillin-tazobactam or ertapenem covering E. coli, Klebsiella, Streptococcus species, and anaerobes 1, 4

For Hospital-Acquired/Nosocomial Peritonitis:

• Use broader-spectrum antibiotics with anti-ESBL and anti-Pseudomonal coverage due to higher risk of multidrug-resistant organisms 1
• Consider imipenem plus amikacin as reference treatment 4
• Add empirical antifungal therapy (fluconazole) for hospital-acquired peritonitis due to high risk of Candida species (28.9% of cases) 1, 3

Step 3: Surgical Source Control (Urgent)

Timing is Critical:

• Perform surgical source control immediately upon diagnosis—delays beyond 24 hours significantly increase mortality 1
• Operating room latency ≥60 hours is an independent predictor of need for relaparotomy and death 1

Surgical Objectives:

• Resection or suture of perforated viscus 1
• Removal of infected organs 1
• Debridement of necrotic tissue 1
• Drainage of abscesses and fluid collections 1
• Repair of traumatic perforations with primary anastomosis or diversion 1

Damage Control Surgery:

• Consider in physiologically deranged patients with ongoing sepsis to prevent abdominal compartment syndrome 1
• Open abdomen may be necessary for unstable patients with diffuse contamination 1

Step 4: Non-Operative Management (Highly Selective)

Only consider if ALL criteria met:

• Hemodynamically stable 1
• Responding to antibiotics 1
• Limited disease: perforated diverticulitis with abscess <4 cm, peri-appendiceal phlegmon, small perforated peptic ulcer with minimal contamination, or CT findings of pericolic air only 1

Absolute contraindications to non-operative management:

• Distant free air 1
• Hemodynamic instability 1
• Diffuse peritonitis 1

Step 5: Duration of Antibiotic Therapy

• Limit antibiotics to 3-5 days post-operatively in patients with adequate source control 1
• No post-operative antibiotics needed for uncomplicated appendicitis or cholecystitis with definitive source control 1
• If signs of peritonitis persist beyond 5-7 days, investigate for inadequate source control or tertiary peritonitis 1

Critical Pitfalls to Avoid

• Do not delay surgical intervention for additional imaging in unstable patients—clinical diagnosis is sufficient 1
• Do not continue antibiotics beyond 5 days without investigating for inadequate source control 1
• Do not use narrow-spectrum antibiotics in hospital-acquired peritonitis—resistance patterns demand broader coverage 1
• Do not forget antifungal coverage in nosocomial cases 1, 3
• Adjust antibiotic dosing based on renal function in critically ill patients 1

Prognosis

• Overall mortality from secondary peritonitis is 6%, but rises to 35% in patients with severe sepsis 5
• Mortality from peritonitis secondary to bowel perforation or anastomotic complications ranges from 4-10% even with appropriate management 1
• Patient outcomes depend heavily on time to diagnosis and intervention, adequacy of source control, and patient physiologic reserve 1