Anatomy Thorax Abdomen · Year 1 · from Anatomy Thorax Abdomen
Case 3: Pneumoperitoneum from Perforated Peptic Ulcer
Patient Demographics
- Age: 52 years old
- Sex: Male
- Occupation: Restaurant manager
Chief Complaint
Sudden onset of severe epigastric pain.
History of Present Illness
The patient reports the abrupt onset of severe, constant epigastric pain approximately 6 hours ago. He describes the pain as "like being stabbed" and rates it 10/10 in intensity. The pain has since spread to involve the entire abdomen. He is lying very still because any movement worsens the pain. He has a history of intermittent epigastric discomfort and burning for years, partially relieved by antacids, but never formally evaluated. He smokes one pack of cigarettes daily and takes ibuprofen regularly for chronic back pain. He denies recent vomiting or hematemesis.
Physical Examination
- Vitals: HR 118 bpm, BP 102/68 mmHg, RR 24, Temp 37.8C, SpO2 96% on room air
- General: Appears acutely ill, diaphoretic, lying motionless
- Abdomen: Board-like rigidity, diffuse tenderness with rebound, absent bowel sounds
- Rectal examination: No blood, no masses
Imaging Workup
- Upright chest radiograph: Free air (pneumoperitoneum) visible as a crescent of lucency beneath the right hemidiaphragm. This is the most sensitive plain radiograph for detecting free intraperitoneal air.
- Left lateral decubitus abdominal radiograph: Confirms free air overlying the lateral liver margin (used when patient cannot sit upright).
- CT abdomen/pelvis without and with contrast: Extensive pneumoperitoneum with free air surrounding the liver and spleen. Focal discontinuity of the anterior wall of the duodenal bulb consistent with perforation. Free fluid in the pelvis.
Clinical Image
Upright chest radiograph demonstrating free air beneath the right hemidiaphragm (arrow), indicating pneumoperitoneum from bowel perforation.
Image Source: Wikimedia Commons - Category:X-rays of pneumoperitoneum, Creative Commons Attribution-Share Alike 3.0
Diagnosis
Perforated duodenal ulcer with generalized peritonitis.
Anatomical Correlation
Free intraperitoneal air rises to the highest point in the peritoneal cavity. In an upright patient, this is beneath the diaphragm, making the upright chest radiograph the most sensitive plain film for detecting pneumoperitoneum. The right hemidiaphragm provides better contrast than the left because the liver creates a homogeneous density below it, whereas the gastric air bubble may mimic free air on the left. In patients who cannot sit upright, a left lateral decubitus film positions free air between the liver and the right lateral abdominal wall. CT is more sensitive than plain radiographs and can detect as little as 5 mL of free air, as well as localize the site of perforation. Duodenal ulcers typically occur in the duodenal bulb (first part of duodenum) and may perforate anteriorly into the peritoneal cavity or posteriorly into the lesser sac, potentially eroding into the gastroduodenal artery.
Treatment
- Immediate resuscitation: IV fluid bolus, vasopressors if needed
- NPO and nasogastric decompression
- Broad-spectrum IV antibiotics
- Emergent surgical repair: Primary closure with omental patch (Graham patch) or definitive ulcer surgery
- Post-operative H. pylori testing and eradication therapy