What is the initial step in managing a patient with peritonitis, fever, severe abdominal pain, guarding, and free air under the diaphragm on chest X-ray (CXR)?

Initial Management of Peritonitis with Free Air

The initial step is IV fluid resuscitation, which must begin immediately and continue concurrently with preparation for emergency laparotomy. 1

Algorithmic Approach to Initial Management

Step 1: Immediate Fluid Resuscitation (FIRST ACTION)

• Rapid restoration of intravascular volume must begin immediately upon diagnosis of peritonitis, even before surgical intervention 1
• For patients with fever and diffuse peritonitis (as in this case), IV fluid therapy should start the moment intra-abdominal infection is suspected 1
• This resuscitation continues during the surgical procedure itself—do not delay surgery to achieve complete physiologic stabilization 1, 2

Step 2: Concurrent Actions (While Resuscitating)

• Initiate broad-spectrum antibiotics immediately in the emergency department, ideally within 1 hour if septic shock is present 1
• Prepare for emergency laparotomy—surgical consultation and operating room notification should occur simultaneously with fluid resuscitation 1

Step 3: Emergency Laparotomy (As Soon As Possible)

• Patients with diffuse peritonitis and free air under the diaphragm require emergency surgical intervention as soon as possible 1, 2
• Surgery should not be delayed for complete physiologic stabilization—ongoing resuscitative measures continue during the procedure 1, 2
• Further diagnostic imaging is unnecessary when obvious signs of diffuse peritonitis are present and immediate surgery is planned 1

Why This Sequence Matters

The evidence strongly supports that fluid resuscitation is the true "initial" step, not surgery itself. The Surgical Infection Society and IDSA guidelines explicitly state that patients should undergo rapid restoration of intravascular volume and that for patients with diffuse peritonitis, emergency surgery should occur "as soon as is possible, even if ongoing measures to restore physiologic stability need to be continued during the procedure" 1. This language clearly indicates that resuscitation begins first and continues through surgery.

Critical Timing Considerations

• Delaying surgical intervention while attempting complete physiologic stabilization increases mortality 2
• However, starting surgery without any resuscitation is equally dangerous—the guidelines emphasize that physiologic stability measures should be initiated and then continued during surgery 1, 2
• The median time from presentation to surgery should be minimized, but not at the expense of initiating fluid resuscitation 1

Common Pitfalls to Avoid

Pitfall 1: Choosing Surgery Without Resuscitation

• Never proceed directly to laparotomy without initiating IV fluids first 1
• Patients with peritonitis are typically volume depleted from third-spacing, fever, and decreased oral intake 3
• Starting fluids takes only seconds and dramatically improves surgical outcomes 1

Pitfall 2: Delaying Surgery for Complete Stabilization

• Do not wait for complete hemodynamic normalization before surgery 1, 2
• Ongoing peritoneal contamination from the perforation continues to worsen sepsis with each passing hour 4, 5
• Resuscitation should continue in the operating room 1, 2

Pitfall 3: Ordering Additional Imaging

• With obvious diffuse peritonitis and free air on CXR, CT scanning is unnecessary and delays definitive treatment 1
• The diagnosis is already confirmed—further imaging provides no additional benefit 1

Pitfall 4: Considering Reassurance

• Reassurance is completely inappropriate for a patient with peritonitis and pneumoperitoneum 1
• This represents a surgical emergency requiring immediate intervention 1, 2
• Conservative management is only appropriate for highly selected patients with localized findings, minimal physiologic derangement, and no free air 1

Practical Implementation

In the first 5 minutes:

1. Establish large-bore IV access (two lines preferred) 1
2. Begin rapid crystalloid infusion (initial bolus 20-30 mL/kg) 1
3. Draw blood for labs and cultures 1
4. Administer broad-spectrum antibiotics 1
5. Contact surgical team for emergency laparotomy 1, 2

The answer to this question is IV fluid (Option A), as it represents the true initial step that must occur before and during emergency laparotomy. 1