Pneumoperitoneum

<Presentations>

<Index>

 

 

Definition

-  Gas in the peritoneal cavity typically detected radiographically not clinically

 

Features

-  Usually seen on x-ray

-  Small amounts often missed

-  CT is gold standard for detection

-  Can detect down to 5cm3

-  W or wo peritonitis

-  Perforation less likely wo peritonitis unless silent

 

Causes

-  Perforation of GIT

-  Abdominal surgery, incl laparoscopy for up to 3/52

-  Anastamotic leak

-  Peritoneal dialysis

-  Vaginal insuflation

-  Bronchopleural fistula

 

DDx

-  Chilaiditi syndrome: bowel between diaphragm & liver

-  Linear atelectasis

-  Pneumatosis coli from Necrotising enterocilitis

-  Subphrenic abscess

 

Ix

-  2+ x-rays required

-  Supine AXR

-  + Erect CXR OR

-  + Left lateral decubitus AXR

-  AXR

-  RUQ

-   Ant. subhepatic space gas

-   Doges Cap sign: free gas in Morrisons pouch

-   Gas ant. to ventral surface of liver

-   Falciform ligament sign

 

 

 

-  The Cupola: gas under central tendon of diaphragm

-  Continuous diaphragm sign

-  Double bubble: gastric bubble + gas under left diaphragm

-  Supine: Football sign (more common in infants)

-  Supine: Riglers sign

-   Gas present intra & extraluminally outlines bowel wall

 

 

-  Decubitus: gas outlined against liver/flank

 

 

-  CXR - Erect: gas under the diaphragm

 

 

-  CT – Abdo

-  US

 

Mx

-  Post surgical pneumoperitoneum resolves 3-6/7 (upto 24/7)

-  Mx as per cause