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10.2: Intestinal Perforation- Pneumoperitoneum

  • Page ID
    14845
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    Case 1

    Pneumoperitoneum

    Clinical:

    History – This patient was stabbed in the abdomen outside the neighbourhood bar.

    Symptoms – Pain associated with a knife wound in the left lower abdomen.

    Physical – A single linear, puncture wound was seen in the left lower abdomen. No active bleeding. Hemodynamically stable. No other findings.

    DDx:

    Abdominal Wall Laceration

    Perforated Viscus

    Solid Organ Laceration

    Imaging Recommendation

    Trauma Imaging

    Chest x-ray

    Abdominal x-ray

    ODIN Link for Chest and Supine Abdomen images, Figure 10.2A and B: mistr.usask.ca/odin/?caseID=20170119170923860

    GI-2-1-1.jpg
    Figure 10.2A Abdominal x-ray displaying possible perforated viscus, Rigler’s sign in right upper quadrant.
    GI-2-2-837x1024.jpg
    Figure 10.2B Lateral chest x-ray displaying sub-diaphragmatic free gas.

    Imaging Assessment

    Findings:

    Abdominal x-ray – There was a positive Rigler sign in in the right upper quadrant. No other findings.

    Chest x-ray – Pneumoperitoneum was seen beneath the hemidiaphragms.

    Interpretation:

    Probable perforated hollow viscus.

    Diagnosis:

    Pneumoperitoneum. Perforated hollow viscus.

    Discussion:

    Causes for pneumoperitoneum:

    • Perforated hollow viscus
    • Recent surgery
    • Recent drainage procedure – needle aspiration or drainage tube insertion
    • Gas forming organism in peritoneal fluid
    • Vaginal route
    • Inflammatory bowel disease
    • Pneumothorax
    • Mechanical ventilation
    • Peritoneal dialysis

    X-ray findings may include:

    There are three major signs of free intraperitoneal gas, arranged below in the order in which they are most commonly seen:

    • Air beneath the diaphragm
    • Visualization of both sides of the bowel wall (Rigler Sign)
    • Visualization of the falciform ligament

    Air Beneath the Diaphragm ·

    • Gas will rise to the highest part of the abdomen.
    • In the upright position, free gas will usually reveal itself under the diaphragm as a crescentic lucency that parallels the under surface of the diaphragm.
    • The size of the crescent will be roughly proportional to the amount of free gas.

    Visualization of both sides of the bowel wall

    • On the normal abdominal radiograph, we visualize air only inside the lumen of the bowel, not outside the bowel wall. This is because the bowel wall is soft tissue density and is surrounded by tissue of the same density.
    • The introduction of gas into the peritoneal cavity enables us to visualize the wall of the bowel itself since the wall is now surrounded on both inside and outside by gas (Rigler sign).

    Visualization of the falciform ligament

    • The falciform ligament courses over the free edge of the liver anteriorly. It contains a remnant of the obliterated umbilical artery. It is normally invisible, composed of soft tissue and surrounded by tissue of similar density.
    • When free gas is present and the patient is in the supine position, the free gas may rise over the anterior surface of the liver, surround the falciform ligament, and render it visible.

    Case 2

    Large Pneumoperitoneum

    Clinical:

    History – This patient was just discharged two days previously after laparoscopic appendectomy.

    Symptoms – Generalized abdominal pain and bloating.

    Physical – The patient’s abdomen was distended and tympanitic. He had mild peritoneal irritation. He was hemodynamically stable. He had a mild fever of 38.5C. No other findings.

    DDx:

    Post-operative adynamic ileus

    Perforated Viscus

    Dehiscence of the appendectomy stump

    Bowel obstruction

    Imaging Recommendation

    Chest x-ray

    Abdominal x-ray

    ODIN Link for Massive Pneumoperitoneum images (Chest x-ray and 3 Views of the Abdomen), Figure 10.3A and B: mistr.usask.ca/odin/?caseID=20110921160717536

    GI-3-1-1024x1019.jpg
    Figure 10.3A Chest x-ray displaying massive pneumoperitoneum
    GI-3-2-1024x1021.jpg
    Figure 10.3B Decubitus Abdominal x-ray displaying massive pneumoperitoneum

    Imaging Assessment

    Findings:

    Chest x-ray – Pneumoperitoneum was seen beneath the hemidiaphragms.

    Abdominal x-ray – Massived pneumperitoneum was seen. No evidence of bowel obstruction or ileus. No evidence of post-operative abscess. No other findings.

    Interpretation:

    Probable dehiscence of the appendectomy stump.

    Diagnosis:

    Pneumoperitoneum, dehiscence of appendectomy closure.


    Attributions

    Figure 10.2A Abdominal x-ray displaying possible perforated viscus, Rigler’s sign in right upper quadrant by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.

    Figure 10.2B Lateral chest x-ray displaying possible perforated viscus, sub-diaphragmatic free gas by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.

    Figure 10.3A Chest x-ray displaying massive pneumoperitoneum by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.

    Figure 10.3B Decubitus Abdominal x-ray displaying massive pneumoperitoneum by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.


    This page titled 10.2: Intestinal Perforation- Pneumoperitoneum is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Brent Burbridge and Evan Mah via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.