What is the management plan for a patient with peritonitis after diverticulitis?

Management of Peritonitis After Diverticulitis

For patients with peritonitis secondary to perforated diverticulitis, immediate surgical intervention with source control is mandatory—both Hartmann's procedure and resection with primary anastomosis (RPA) are acceptable options, with RPA preferred in hemodynamically stable patients and Hartmann's reserved for unstable or high-risk patients. 1

Immediate Assessment and Stabilization

Hemodynamic status determines surgical approach. Patients presenting with peritonitis from perforated diverticulitis require urgent evaluation of vital signs, degree of sepsis, and physiologic reserve 1. Key clinical indicators include:

• Mannheim Peritonitis Index (MPI) score to stratify severity—scores >25 indicate higher mortality risk 1
• Presence of septic shock or hemodynamic instability mandates more conservative surgical approach 1
• Age, comorbidities (ASA score III-IV), and immunocompromised status influence surgical decision-making 1

Antibiotic Therapy

Broad-spectrum IV antibiotics covering gram-negative and anaerobic bacteria must be initiated immediately upon diagnosis of peritonitis 1, 2. First-line regimens include:

• Ceftriaxone PLUS metronidazole 2
• Piperacillin-tazobactam 2
• Amoxicillin-clavulanate 1200 mg IV four times daily 1

Duration of antibiotic therapy is 4 days postoperatively in immunocompetent patients with adequate source control, extending to 7 days in immunocompromised or critically ill patients 1, 3. The empiric regimen should be tailored based on patient risk factors for resistant organisms 1.

Surgical Management Algorithm

For Hemodynamically Stable Patients

Resection with primary anastomosis (RPA) is the preferred approach in stable patients without severe physiologic derangement 1, 4. Evidence demonstrates:

• RPA associates with fewer postoperative complications compared to Hartmann's procedure (P < 0.05) 4
• Anastomotic leak rate is approximately 11% with RPA, which is acceptable given the benefits of avoiding permanent stoma 4
• Emergency laparoscopic sigmoidectomy can be performed by experienced surgeons in selected stable patients with diffuse peritonitis 1

A diverting loop ileostomy may be added to RPA in cases of concern for anastomotic healing, particularly with:

• Purulent or fecal contamination 1
• Significant comorbidities 1
• Intraoperative concerns about tissue quality 1

For Hemodynamically Unstable or High-Risk Patients

Hartmann's procedure remains the safest option for patients with 1, 4:

• Hemodynamic instability or septic shock requiring vasopressor support
• Severe physiologic derangement (high MPI scores, multiple organ dysfunction)
• Significant comorbidities (ASA IV, advanced age with frailty)
• Fecal peritonitis with extensive contamination 1

Hartmann's procedure involves sigmoid resection with end colostomy and rectal stump closure, with potential for reversal in 50-90% of patients at 3-6 months 1, 5.

Damage Control Surgery (DCS) Approach

For patients with severe physiologic derangement who cannot tolerate definitive resection, DCS is a viable alternative 1. This involves:

• Emergency laparotomy with limited resection of diseased segment 1
• Peritoneal lavage and temporary abdominal closure with vacuum-assisted closure (VAC) 1
• Second-look operation within 24-48 hours for restoration of bowel continuity 1

DCS achieves bowel restoration rates of 71-83% without increasing mortality compared to traditional approaches 1. This strategy is particularly valuable in elderly patients (median age 68-70 years) with Hinchey III-IV disease 1.

Special Considerations for Elderly Patients

Age alone should not dictate surgical approach, but physiologic reserve and comorbidities must be carefully assessed 1. The 2022 WSES guidelines specifically address elderly patients:

• Both Hartmann's and RPA are reasonable options in elderly patients with generalized peritonitis 1
• DCS may be particularly beneficial in elderly patients with severe physiologic derangement 1
• Laparoscopic approach is feasible in stable elderly patients when performed by experienced surgeons 1, 5

Laparoscopic Peritoneal Lavage: A Cautionary Note

Laparoscopic lavage alone is NOT recommended as the preferred approach for peritonitis from perforated diverticulitis 1. While some older studies suggested feasibility 6, current guidelines recommend against this due to:

• Higher risk of failure to control the source of sepsis 1
• Lack of definitive source control compared to resection 1

However, laparoscopic lavage may be considered in highly selected cases of purulent peritonitis (Hinchey III) without fecal contamination, performed by experienced surgeons 6.

Postoperative Management

Transition from IV to oral antibiotics should occur as soon as the patient tolerates oral intake to facilitate earlier discharge 1. Monitoring includes:

• Daily assessment of clinical improvement: resolution of fever, decreasing leukocytosis, return of bowel function 1
• Surveillance for anastomotic leak in RPA patients: fever, tachycardia, abdominal pain beyond postoperative day 3-5 4
• Re-evaluation with CT imaging if clinical deterioration occurs 1

Critical Pitfalls to Avoid

Do not delay surgical intervention in patients with generalized peritonitis—prompt source control is essential for survival 1. Operating room latency >60 hours significantly increases mortality 1.

Do not attempt RPA in hemodynamically unstable patients—Hartmann's procedure is safer in this population despite the burden of stoma 1, 4.

Do not rely on laparoscopic lavage alone as definitive treatment for peritonitis—resection provides superior source control 1.

Do not extend antibiotics beyond 4-7 days in patients with adequate source control, as prolonged therapy does not improve outcomes and promotes resistance 1, 3.

Mortality and Outcomes

Overall mortality for emergent surgery ranges from 10-12% in patients with peritonitis from perforated diverticulitis 1, 2. This contrasts sharply with 0.5% mortality for elective resection 2, underscoring the importance of appropriate patient selection for elective surgery after initial episodes.

Specialization in colorectal surgery improves outcomes and increases the rate of one-stage procedures (RPA) over Hartmann's 4. When feasible, consultation with experienced colorectal surgeons should be obtained for surgical planning 1.