How should a patient with free intraperitoneal air under the right hemidiaphragm on a plain X‑ray be managed?

Management of Free Air Under the Right Diaphragm

The presence of free intraperitoneal air under the right hemidiaphragm requires immediate surgical consultation in all cases, with emergency surgery indicated for patients showing signs of peritonitis, hemodynamic instability, or clinical deterioration. 1, 2

Initial Clinical Assessment

The critical first step is determining whether this represents a surgical emergency:

• Assess for peritonitis signs: Evaluate for diffuse abdominal tenderness, guarding, rigidity, and rebound tenderness 1
• Check hemodynamic stability: Monitor blood pressure, heart rate, and signs of shock 2
• Look for systemic inflammatory response: Fever, tachycardia, altered mental status 1
• Obtain laboratory markers: White blood cell count, lactate, C-reactive protein, and procalcitonin to assess severity of inflammation and potential sepsis 1, 2

Imaging to Determine Source and Extent

CT scan with contrast is strongly recommended as it provides superior sensitivity for detecting the perforation site, determining the extent of contamination, and identifying complications such as abscess formation. 1, 2

• CT scan can distinguish between surgical and non-surgical causes of pneumoperitoneum and help predict the operative scenario 2
• Plain radiographs alone are insufficient, as they miss up to 15-70% of perforations and cannot characterize the source 1
• However, if the patient has clear signs of diffuse peritonitis or hemodynamic instability, do not delay surgical exploration to obtain imaging 2

Treatment Algorithm

For Hemodynamically Unstable Patients or Those with Peritonitis:

Proceed immediately to emergency surgical exploration without delay 1, 2

• Initiate aggressive fluid resuscitation 1
• Start broad-spectrum intravenous antibiotics immediately 1
• Obtain surgical consultation emergently 1
• The presence of free air with peritoneal signs is sufficient justification for surgical exploration 1

For Hemodynamically Stable Patients Without Peritonitis:

Conservative (non-operative) management may be appropriate in highly selected cases only 1

This approach requires ALL of the following criteria:

• Localized pain only (not diffuse) 1
• No fever 1
• Hemodynamically stable 1
• Minimal free fluid on imaging 1
• Small, sealed-off perforation suspected (such as from therapeutic colonoscopy with good bowel prep) 1

Conservative management protocol includes:

• Serial clinical and imaging monitoring every 3-6 hours 1
• Absolute bowel rest (NPO status) 1
• Intravenous fluids for hydration 1
• Broad-spectrum intravenous antibiotics 1
• Close multidisciplinary team follow-up to detect any development of sepsis or peritoneal signs 1

Critical Caveats and Pitfalls

The sole presence of subdiaphragmatic free air does NOT constitute an indication for urgent surgery—clinical status determines management 1

However, several important warnings apply:

• Early success with conservative treatment does not eliminate the potential need for surgery 1
• If clinical deterioration occurs or the patient progresses to sepsis or peritonitis, surgical treatment must not be delayed 1
• Patients who fail conservative management and require delayed surgery have significantly higher complication rates and longer hospital stays than those treated surgically from the outset 1
• When surgical treatment is delayed, peritonitis and bowel wall inflammation worsen, requiring more invasive surgery with poorer prognosis 1
• The decision to pursue surgery should ideally be made as early as possible 1

Special Considerations

Specific Patient Populations Requiring Surgery:

Even with minimal symptoms, surgical management is recommended for:

• Immunosuppressed patients 1
• Transplant recipients 1
• Patients with concomitant colonic diseases requiring surgery 1

Non-Surgical Pneumoperitoneum:

Rarely, pneumoperitoneum occurs without visceral perforation (spontaneous pneumoperitoneum), but this diagnosis can only be considered in completely asymptomatic patients without any peritoneal signs, fever, or leukocytosis 3, 4, 5

In summary: Obtain immediate surgical consultation, assess clinical stability and peritoneal signs, perform CT scan if stable, and proceed to emergency surgery for any patient with peritonitis or instability—conservative management is only for the rare, highly selected stable patient with localized findings and requires intensive monitoring with low threshold for surgical intervention.