Tension Pneumoperitoneum in the Child: A Report of Two Cases with the Radiologic Features

Case 1

This is a report of a 4 -year-old male child referred from a peripheral health care facility for plain abdominal radiographs in erect and supine views on account of fever, abdominal pain, discomfort and tenderness, vomiting, constipation, dyspnea, loss of weight and irritability.

The patient was conscious and alert but ill-looking, wasted, febrile, not pale, mildly dehydrated, anicteric, in respiratory distress, distended and tender abdomen, and mild pedal swelling. The plain abdominal radiographs (erect and supine views) demonstrate abdominal distension with free intraperitoneal air beneath both hemi-diaphragm (Cupola sign) with inferior and medial displacement of the liver (saddlebag sign) and spleen denoting severe pneumoperitoneum (Figure 1). Other features of pneumoperitoneum which include; Rigler’s sign (air outlining both sides of the bowel wall), foot-ball sign (central lucencies surrounded by fluid), air tracking the paracolic gutters (Figure 2), and continuous diaphragmatic sign (air tracking beneath the central tendon of the diaphragm; Figure 1) were also demonstrated. Dilated bowel loops noted centrally with air-fluid levels with ground-glass opacity distally due to free fluid were also noted (Figure 1). Complementary ultrasonography demonstrated focal hyperechogenic thickening of the peritoneum (enhanced peritoneal stripe sign) with associated posterior dirty shadowing and comet tail appearance in keeping free intraperitoneal air. Turbid free intraperitoneal fluid with dilated and collapsed bowel loops with diminished peristaltic activity, mild-moderate hepatomegaly and splenomegaly were also demonstrated (Figure 3).

A diagnosis of tension pneumoperitoneum following perforated bowel loop in this patient with clinical and laboratory features of typhoid fever. The patient had needle decompression, intravenous fluid for resuscitation and an exploratory laparotomy for the repair of perforations at the terminal ileum located on the antimesenteric border, the patient later got better post-operatively, and discharged home after three weeks for follow-up visits.

Case 2

This is a report of a 5-year-old male child referred from a peripheral health care facility for plain abdominal radiographs in erect and supine views on account of fever, abdominal pain, discomfort and tenderness, vomiting, constipation, dyspnea, loss of weight and irritability.

The patient was conscious and alert but ill-looking, wasted, febrile, not pale, mildly dehydrated, anicteric, in respiratory distress, distended and tender abdomen, and mild pedal swelling.

The plain abdominal radiographs (erect and supine views) demonstrate abdominal distension with free intraperitoneal air beneath both hemi-diaphragm (Cupola sign) with inferior and medial displacement of the liver (saddlebag sign) and spleen denoting severe pneumoperitoneum (Figure 4). Other features of pneumoperitoneum which include continuous diaphragmatic sign (air tracking beneath the central tendon of the diaphragm; figure 4) were also demonstrated. Dilated bowel loops noted centrally with air-fluid levels with ground-glass opacity distally due to free fluid were also noted (Figure 5).

A diagnosis of tension pneumoperitoneum following perforated bowel loop in this patient with clinical and laboratory features of typhoid fever. The patient also had needle decompression, intravenous fluid for resuscitation and an exploratory laparotomy for the repair of perforations at the terminal ileum located on the antimesenteric border, and later got better post-operatively, and discharged home after two weeks for follow-up visits. 

Discussion

Pneumoperitoneum is a well-known consequence of gastrointestinal perforation, mechanical ventilation and abdominal operation and in vast majority of cases, about 90% follows an intra-abdominal viscus perforation often requiring acute surgical intervention. The cases under review had perforation of abdominal viscus; Typhoid perforation, thereby conforming to these literatures.

Perforation and hemorrhage being complications of typhoid fever, hemorrhage appears to be the most common, though both occur in the terminal ileum following necrosis of Payer’s patches (in the antimesenteric border) at least 2-3 weeks after commencement of the illness. The patients under review had onset of fever for about two weeks, this was followed by abdominal distension, vomiting, constipation and abdominal pain with tenderness, they were reported to have had perforations at the terminal ileum intra-operatively, thereby conforming to these literatures. Typhoid fever with perforations is basically detected following a detailed clinical assessment of the patients presentations, detection of the gram-negative bacillus in the blood and stool of the patient and also clinical imaging which are either ultrasonography, plain abdominal radiography (Erect and supine projections), and computerized tomography scan [18-20]. The index cases were also diagnosed following detailed clinical examination, positive titer on widal test, and detection of pneumoperitoneum following perforation from ultrasonography and plain radiography, thereby conforming to these literatures.

Plain radiograph most especially the erect view, has been regarded the most sensitive in diagnosis of pneumoperitoneum, some of the features of pneumoperitoneum detected are Cupola sign, Rigler’s sign, falciform ligament sign, lucent liver sign, football sign, urachus sign, to mention a few [21,23]. The cases under review had most of these signs, thereby conforming to these literatures.

Tension pneumoperitoneum is diagnosed following clinical signs and abdominal radiograph demonstrating free intraperitoneal gas with upward displacement of the diaphragm and medial displacement of the liver; the so-called saddlebag sign [3,6]. The index cases had the clinical signs with presence of free air beneath both diaphragms displacing the liver (saddlebag sign) and spleen inferior and medially, thereby conforming to these literatures. The patients with TP usually present with abdominal fullness, tenderness, distant bowel sounds and dyspnea [3,26], the index cases also had similar presentations, thereby conforming to most literatures.

Tension pneumoperitoneum (TP) leads to abdominal compartment syndrome (ACS), which is a sustained intra-abdominal pressure of greater than 20mmHg with evidence of organ dysfunction and manifested by respiratory failure following compression of the diaphragm and obstructive shock, which is the result of compression of the intra-abdominal veins². The index cases had no feature of organ dysfunction, but presented with dyspnea and respiratory distress most likely from compression of intra-abdominal veins following compression of the hemi-diaphragms bilaterally, though the intra-abdominal pressure was not measured due to lack of facility.

The prompt treatment of tension pneumoperitoneum patients especially the unstable ones, regardless of the cause should be percutaneous catheter insertion or if time permits drain placement to relieve the intraperitoneal pressure. This intervention usually results in immediate hemodynamic and ventilation improvement [3,24]. This intervention is followed by treatment of the specific cause for example surgical repair(laparotomy) for gastrointestinal perforations [3,25]. The cases under review had percutaneous needle insertion to relieve the tension pneumoperitoneum, they subsequently had exploratory laparotomy, thereby conforming to these literatures.