The identification of pneumoperitoneum on abdominal imaging has been always considered a surgical emergency requiring prompt surgical intervention. Yet, with the recognition of spontaneous pneumoperitoneum, the management of such can be altered to a more benign course, avoiding the burden of surgery and general anaesthesia on the weak newborns.
While cases of non-surgical pneumoperitoneum have been well documented in adults, evidence within the pediatric population is lacking. It was believed that pneumoperitoneum in children almost always resulted from a perforated viscus as in the case of necrotizing enterocolitis .
There are numerous documented causes of non-surgical pneumoperitoneum, which are categorized into thoracic, abdominal, gynaecological, idiopathic, and pseudo-pneumoperitoneum, it can also be a complication of cardiopulmonary resuscitation, mechanical ventilation, gynaecologic manipulation, peritoneal dialysis, and gastrointestinal endoscopic procedures [10, 11]. Previous abdominal surgeries are also an obvious cause of pneumoperitoneum. However, 97% of cases of post-operative free air resolves within 5 days .
In children, the most common causes of non-surgical pneumoperitoneum are peritoneal dialysis, endoscopic gastrointestinal procedures, pneumatosis cystoides intestinalis, and mechanical ventilation . In the paediatric population, pneumoperitoneum occurs in 1–3% of infants who are mechanically ventilated . In our series, our reported cases have developed pneumoperitoneum following positive pressure ventilation or ambu bagging, which we believed was the most likely because of their pneumoperitoneum, given that no other source of perforation or infection was identified.
Subclinical perforations may be an expected route for the development of idiopathic pneumoperitoneum, but those perforations are thought to resolve without surgical intervention .
Plain chest or abdominal radiography is the most common imaging modality for the diagnosis of intraperitoneal free air in the emergency setting , but abdominal CT is a more sensitive method of diagnosing pneumoperitoneum and identifying the cause of acute abdomen . In our series, all of the patients did not get a CT scan because there were on respiratory support and were unstable for the transfer to CT rooms. Moreover, modern technology with multidetector CT is highly accurate for predicting the site of GI tract perforation . In our hospital, the upper GI contrast study was done bedside in the NIC Units with serial portable X-rays.
While imaging modalities have greatly aided in our detection of pathologies requiring emergent surgery, the clinical picture of the patient needs to remain the primary determinant of the need for operative intervention.
In clinical practice, once pneumoperitoneum is found, it is difficult to avoid emergency surgical exploration, because it is needed to rule out visceral perforation, especially when the patients show signs of sepsis and abdominal exam finding suggesting NEC which is the most common cause of perforation. However, Karaman et al. developed an algorithm for evaluation of pneumoperitoneum; it includes a thorough history taking concerning cardiopulmonary resuscitation, intubation, and ventilator use, a physical examination to investigate subcutaneous emphysema, and a number of diagnostic procedures such as paracentesis or peritoneal lavage . Regarding our cases, case 1 radiological contrast study that showed evidence of leak led the clinical decision to exploration. While in case 2, the progression of the clinical condition led us to early exploration. In case 3, we applied the suggested algorithm.
In conclusion, spontaneous pneumoperitoneum should be considered in every neonate with a similar presentation, which when recognized requires no further surgical intervention but close observation and supportive care. we recommend every treating physician facing such cases evaluate each case individually, to consider conservative management every time the patient condition allows and not rush for unnecessary surgery.
Ethical approval was obtained from the institution review board for reviewing the cases’ medical records and imaging.