Acute Abdomen1-急腹症1-英文版

Abdominal Series Indications:
Highest yield: Presentations suggestive of free air or obstruction • Not very good for masses, ascites, organomegaly, biliary tract disease, GI bleeding and vague abdominal complaints • Yield is higher in the elderly
Small Bowel Obstruction: Findings
• Step-ladder dilated bowel loops on supine view • Step-ladder air-fluid levels on erect/decubitus views • Stretch sign on supine view • String-of-pearls sign on erect/decubitus views
Don’t forget to look for pneumonia
GAS
In the gut, and elsewhere
PNEUMOPERITONEUM
FREE AIR: Perforated Gut
Free Air
• Best views: Erect chest and left lateral decubitus abdomen • Erect abdomen is less sensitive • Supine abdomen is insensitive
Free Air: Left Lateral Decubitus
• Right side up, left side down • Patient who can’t sit or stand • Air under right abdominal wall
Free Air: Left LBoth?
• Small bowel can be distended by either air or fluid or both • Fluid-filled bowel may be more significant than air-filled bowel, but often the significance is the same
OBSTRUCTION
Small bowel Colon
OBSTRUCTION
Small bowel obstruction much more common than colon: 70:30
Small Bowel Obstruction: Causes
• Adhesions 80% • Hernia 15% • Tumors, intussusception, midgut volvulus, etc.
• Air under the diaphragm • Usually on the right • Occasionally only seen on the left
Free Air: Erect Chest
Free Air: Erect Chest
Free Air: Erect Chest
• NONE
• None
• None • None
The Check List
• • • • • Bones and joints Calcifications Organs Fat Gas: In bowel and outside of bowel
A memory aid
• • • • “First organs, bones, and stones, Then masses, fat, and gas. Don’t forget the corner zones, And you’ll always cover your…subject”
Air Filled Small Bowel
Fluid Filled Small Bowel
Air-Fluid Levels
• Always abnormal in small bowel, but not specific; often normal in colon • The height of the fluid levels, same or different, is NOT helpful in distinguishing ileus from obstruction
How Big is Big?
• In an adult, any visible small bowel is abnormal, but small amounts often not significant. Kids normally have small amounts. • Jejunum over 3 cm and ileum over 2 cm diameter is very abnormal, but not specific for obstruction
Pneumoretroperitoneum
Air in Biliary System
Bile ducts Gall bladder
Air in Biliary System
• Usually secondary to surgery on bile ducts • Can be due to biliary-bowel fistula from infection or neoplasm • Rarely, can be due to infection
The Normal Abdominal Series
• • • • Chest Supine abdomen Erect abdomen Left lateral decubitus abdomen
Chest
Supine Abdomen
Erect Abdomen
Left Lateral Decubitus Abdomen
The Erect Chest
• Best for free air
• To evaluate for intrathoracic abnormalities presenting with abdominal complaints, especially pneumonia (more common in kids)
Small Bowel Air-Fluid Levels
What is Dilated?
• If small bowel and colon dilated equally, probably not small bowel obstruction: nonspecific ILEUS • If small bowel significantly more dilated than colon, suggests SBO • Some gas in colon does NOT exclude SBO
The ACUTE ABDOMEN
The role of the Plain Film Abdominal Series MI Zucker, MD
A dr Z Lecture
The Abdominal Series
• For all acute abdominal complaints where plain film imaging is indicated, get a COMPLETE abdominal series • Exceptions: Suspected renal calculus or foreign body, where a single view is OK • CT and ultrasound are often performed after plain films
How Sensitive?
• Plain films are 85% sensitive for free air
• Theoretical threshold is 2 cc
• CT is much more sensitive and is the “Gold Standard”
Free Air: Erect Chest
Free Air: Supine Abdomen
• Double bowel wall sign • Falciform ligament sign
Double Wall sign
Falciform Ligament sign
Pneumoretroperitoneum
• From perforation of posterior extraperitoneal portions of duodenum or colon • Extension from or through the mediastinum
Air in Bile Ducts
Air in Gall Bladder
Portal Venous Air
A sign of dead or dying bowel
Portal Venous Air
The GUT
Gas and Fluid Too Much and Too Little
The Gas Pattern
• • • • • Carcinoma of the colon 80% Volvulus 5% Diverticulitis 5% Fecal impaction 5% Everything else 5%
Colon Obstruction: Carcinoma
Colon Obstruction: Volvulus
Ileus
Classic Small Bowel Obstruction, Supine