From the Guidelines
Air under the diaphragm, also known as pneumoperitoneum, is most commonly caused by a perforation in the gastrointestinal tract, with recent evidence suggesting that iatrogenic colonoscopy perforation is a significant concern 1.
Causes of Pneumoperitoneum
The causes of pneumoperitoneum can be varied, but they often involve a breach in the integrity of the gastrointestinal tract, allowing air to escape into the abdominal cavity. Some of the most frequent causes include:
- Perforated peptic ulcers
- Perforated appendicitis
- Diverticulitis with perforation
- Traumatic injury to the abdomen
- Recent abdominal surgery, particularly laparoscopic procedures 1
Diagnosis and Detection
Pneumoperitoneum is typically detected on imaging studies such as upright chest X-rays or CT scans. The presence of air under the diaphragm on an upright chest X-ray is a classic sign of pneumoperitoneum. CT scans can provide more detailed information about the location and extent of the air, as well as potential sources of the perforation 1.
Clinical Implications
Pneumoperitoneum is a medical emergency in most non-surgical cases, requiring prompt evaluation and often surgical intervention to repair the perforation and clean the abdominal cavity to prevent peritonitis and sepsis. The clinical presentation of pneumoperitoneum can vary widely, depending on the size of the perforation, the type of etiologic agent, and the patient’s general status 1.
Management
The management of pneumoperitoneum depends on the underlying cause and the patient's clinical condition. In cases of iatrogenic colonoscopy perforation, the diagnosis is based on clinical, laboratory, and radiologic findings, and treatment may involve surgical intervention or non-operative management, depending on the severity of the perforation and the patient's overall condition 1.
From the Research
Causes of Air Under the Diaphragm
- Air under the diaphragm, also known as pneumoperitoneum, is typically an indication of a perforated abdominal viscus that requires surgical intervention 2
- However, in some cases, pneumoperitoneum may not be caused by an intra-abdominal perforation and may not require laparotomy, this is referred to as spontaneous or nonsurgical pneumoperitoneum 2
- The presence of air under the diaphragm can be caused by various factors, including:
- Perforation of the gastrointestinal tract 3
- Pneumomediastinum and pneumothorax 3
- Mechanical ventilation 3
- Chilaiditi syndrome, a condition where the large bowel is transposed between the liver and the diaphragm 4
- Faulty technique during continuous ambulatory peritoneal dialysis (CAPD) 5
- Colonic perforation 5
Diagnosis and Treatment
- A thorough history, physical examination, and workup are necessary to determine the cause of pneumoperitoneum and the necessary treatment 6
- Diagnostic imaging, such as plain chest/abdominal radiograph or computed tomographic scan of the abdomen, can be used to confirm the presence of pneumoperitoneum 3
- Treatment may involve surgical intervention or nonsurgical conservative observation, depending on the cause and amount of free air 3