What is the recommended treatment regimen for an adult male with peritonitis?

Treatment of Peritonitis in Adult Males

For an adult male with peritonitis, immediate fluid resuscitation and broad-spectrum antibiotics should be initiated, followed by urgent surgical source control for diffuse peritonitis. 1

Immediate Resuscitation and Stabilization

• Rapid fluid resuscitation should begin immediately to restore intravascular volume and promote physiologic stability, particularly in patients with septic shock 1
• For patients without volume depletion, intravenous fluid therapy should begin when intra-abdominal infection is first suspected 1
• Antimicrobial therapy must be administered as soon as possible—within 1 hour for septic shock patients 2

Empiric Antibiotic Selection

The choice of antibiotics depends on disease severity and patient risk factors:

For Mild-to-Moderate Community-Acquired Peritonitis:

• Single-agent options: Ertapenem, moxifloxacin, tigecycline, ticarcillin-clavulanate, or cefoxitin 1
• Combination regimens: Cefazolin, cefuroxime, ceftriaxone, cefotaxime, ciprofloxacin, or levofloxacin—each combined with metronidazole 1
• Piperacillin-tazobactam is recommended for non-critically ill, immunocompetent patients with adequate source control 2

For High-Risk or Severe Peritonitis:

• Single-agent options: Imipenem-cilastatin, meropenem, doripenem, or piperacillin-tazobactam 1
• These regimens are indicated for patients with severe physiologic disturbance, advanced age, immunocompromised state, or septic shock 1, 2
• For ESBL risk: Ertapenem or eravacycline should be used 2

Critical Pitfall to Avoid:

Do not use clindamycin, cefotetan, cefoxitin, or quinolones alone when Bacteroides fragilis is likely, as substantial resistance has been documented 1. Aminoglycosides lack anaerobic coverage and require combination with metronidazole 3.

Surgical Source Control

• Emergency surgical intervention is mandatory for patients with diffuse peritonitis, even if physiologic stabilization measures must continue during the procedure 1, 2
• Surgery should drain infected foci, control ongoing peritoneal contamination through diversion or resection, and restore anatomic function 1
• Percutaneous drainage is preferable to surgical drainage for well-localized abscesses when feasible 1
• For hemodynamically stable patients without organ failure, intervention may be delayed up to 24 hours if appropriate antimicrobials are given with close monitoring 1

Antibiotic Duration

• Short-course therapy (3-5 days) is recommended for patients with adequate source control 2
• Extended therapy (up to 7 days) is appropriate for immunocompromised or critically ill patients with adequate source control 2
• Antimicrobial levels should be maintained during source control procedures, potentially requiring additional dosing before the intervention 1

Microbiologic Evaluation

• Blood cultures are not routinely recommended for community-acquired intra-abdominal infections 1
• Blood cultures may be helpful if the patient appears clinically toxic or is immunocompromised, as bacteremia knowledge can guide therapy duration 1
• Routine Gram stain of infected material has no proven value for community-acquired infections 1
• For specimens from community-acquired infections, microbiologic workup should focus on identification and susceptibility testing of facultative and aerobic gram-negative bacilli 1

Special Considerations

Nosocomial or Tertiary Peritonitis:

• Imipenem plus amikacin is the reference treatment 4
• Antifungal therapy (fluconazine) is recommended for hospital-acquired infections and critically ill or severely immunocompromised patients until culture results are available 2, 4

Relaparotomy Approach:

• On-demand relaparotomy is recommended over mandatory scheduled relaparotomy in severe peritonitis, as it streamlines resources and reduces costs 2
• Mandatory relaparotomy is not recommended unless there is intestinal discontinuity, abdominal fascial loss preventing closure, or intra-abdominal hypertension 1

Highly Selected Patients:

• Patients with minimal physiological derangement and well-circumscribed infection (periappendiceal or pericolonic phlegmon) may be treated with antimicrobials alone without source control, provided very close clinical follow-up is possible 1