Labs and Lytes 024
Author: Chris Sia
Reviewers: Sarah Yong and Chris Nickson
Q1. Describe the x-ray findings?
This is an AP supine abdominal x-ray.
Key findings include:
- Distended loops of small (5cm) and large (7.5cm) bowel
- Rigler’s sign is positive, suggesting intra-peritoneal free gas (red arrow)
- Nasojejunal tube in situ (yellow arrow)
- Contrast present in the colon and rectum from previous imaging (orange arrow)
Q2. What is Rigler’s sign?
Riglers sign (aka double-wall sign) is present when both sides of a bowel wall can be visualised, due to delineation by air on either side. It is a good indication of free intraperitoneal gas.
However, the sensitivity for detecting perforation on AXR is low and is best confirmed as subdiaphragmatic air on erect CXR or with a CT scan.
In this case the intraperitoneal gas was the result of a gastric perforation from anastamotic breakdown complicating a prior partial gastrectomy.
Q3. What is the size of normal small bowel, colon and caecum?
Apply the 3-6-9 rule:
- Small bowel < 3 cm
- Colon <6cm
- Caecum <9cm
Small bowel has a central location with valvulae conniventes visible. Large bowel is peripheral with haustra visible.