Massive hydropneumoperitoneum secondary to duodenal ulcer perforation

A 59 year-old woman presented with a 3-day history of dyspnea and fatigue after two episodes of alimentary vomits. Past medical history included epiglottis cancer, hepatitis B, COVID-19 and pulmonary tuberculosis. Physical examination revealed signs of mild dehydration. Blood tests revealed leucocitosis (12300 cells/mm3) and C-Reactive protein of 11.19 mg/L. She was admitted with a presumed diagnosis of bacterial gastroenteritis complicated with dehydration, oral intolerance and acute renal failure and initiated empiric antibiotic therapy (ciprofloxacin).

Chest X-ray revealed small nodular opacities bilaterally, probable tuberculous granulomas. Abdominal ultrasound showed signs of chronic hepatopathy and a thin left peri-renal fluid layer.

On day 2 of admission with a presumed diagnosis of bacterial gastroenteritis she showed signs of respiratory distress and abdominal distention. Repeated chest X-ray (Fig. 1) revealed massive pneumoperitoneum. Abdominal X-ray (Fig. 2) showed a gas-fluid level, also shown on ultrasound as intra-abdominal gas centrally and moderate volume of peritoneal fluid.

Subsequent computer tomography (CT) detected a large pneumoperitoneum and a moderate quantity of free fluid (Figs. 3,4). A small discontinuity in the anterior aspect of the duodenal bulb and adjacent wall thickening and edema were found, highly suggestive of duodenal perforation.

Urgent surgical intervention confirmed a perforated justapyloric ulcer measuring 1,5 cm in the first portion of duodenum with ischemic borders. A pyloroplasty and peritoneal lavage were done. Afterwards, she developed signs of septic chock and ischemic hepatitis and despite optimal supportive and therapeutic measures she passed away at day 3 of admission.

Most cases of pneumoperitoneum are secondary to gastric/duodenal ulcer perforation, a life-threatening complication with 10-40% mortality rate. Perforation may also be secondary to bowel obstruction, inflammatory or neoplasic conditions, ischemic bowel, trauma or iatrogenic. Immediate postoperative status, peritoneal dialysis, gas-forming bacterial infection and mechanical ventilation are other causes of pneumoperitoneum and it may be an isolated asymptomatic finding. [1-5]

Clinical presentation of peptic ulcer perforation is variable and dependent on factors such as the time since perforation, its size and extent of gastroduodenal contents extravasation. Most commonly patients show clinical signs of peritonitis, although symptoms may be mild or absent in older or immunocompromised patients. [5]  Tension pneumoperitoneum occurs when gas compression results in decreased venous return and cardiac output. [6] Differential diagnosis include other causes of acute abdomen such as acute pancreatitis, cholecystitis or appendicitis. [5]

Free abdominal air is most commonly detected in upright chest x-rays as subdiaphragmatic crescent air densities. Specific signs in supine abdominal x-ray include linear subhepatic collection of air, gas outlining the falciform ligament and the Rigler sign (air on both sides of bowel wall). When fluid is also present, an abdominal air-fluid level in seen. [1,2,4]

CT is valuable in cases of small amounts of air and may reveal its cause and location (specially if oral contrast is given) and additional findings such as free fluid, fluid collections, inflammatory signs and gastric or duodenal wall thickening. [6]

A large amount of intraperitoneal air suggests gastroduodenal perforation or bowel perforation secondary to obstruction or endoscopic procedures. Perforations in retroperitoneal portions of duodenum (descending and horizontal) manifest as pneumoretroperitoneum, which spreads less freely than intraperitoneal gas. [7] The absence of retroperitoneal air in our patient was consistent with the site of perforation, demonstrating the usefulness of the extraluminal air distribution on CT in locating gastrointestinal perforations.

Ultrasonography isn’t usually chosen given that gas is a reflector that hinders the transmission of ultrasound, although it can detect free fluid, inflammatory masses, fluid collections, extraluminal gas bubbles close to the perforation site and other signs of perforation (gas bubbles extending beyond wall’s contour and sometimes a cleft or defect on the outer surface outlined by fluid). [3,5,6]

Urgent surgical intervention is mandatory in most cases of peptic ulcer perforation. [3] Few cases may be treated conservatively, including those asymptomatic, contained or diagnosed within 8 hours. [6]

Our case was clinically unsuspected until a massive hydropneumoperitoneum was found on x-rays done because of respiratory distress. CT revealed a discontinuity in duodenal wall, motivating urgent surgical intervention. Despite optimal surgical and medical treatment measures, patient succumbed after developing a septic shock, illustrating this condition’s poor outcome.

This report serves as an unfortunate reminder that, despite the overwhelming number of daily visits to the emergency department, one must always be prepared to be confronted with cases of dramatically fast unfavourable progression after an initial seemly innocent presentation.

Take-Home Message

Pneumoperitoneum is most frequently result peptic ulcer perforation, a life-threatening complication requiring urgent surgical intervention in most patients.

One must always keep high levels of clinical and imaging suspicion and offer aggressive treatment when ominous signs are found, such as pneumoperitoneum, not always as massive and rapidly progressive as the one described.

Written informed patient consent for publication has been obtained.