What treatment decreases the risk of perioperative adrenal crisis in a patient on chronic steroids?

“Stress-dose” steroids: 100 mg hydrocortisone administered preoperatively, continued postoperatively q 8 hours, and then tapered off

How should a CXR be read?

What CXR is better: P-A or A-P?

Classically, how much pleural fluid can the diaphragm hide on upright CXR?

How can CXR confirm that the last hole on a chest tube is in the pleural cavity?

How can a loculated pleural effusion be distinguished from a free-flowing pleural effusion?

How do you recognize a pneumothorax on CXR?

What x-ray should be obtained before feeding via a nasogastric or nasoduodenal tube?

What C-spine views are used to rule out bony injury?

Check the following:

Tubes and lines: Check placement

Patient data: Name, date, history number

Orientation: Up/down, left-right Technique: AP or PA, supine or

erect, decubitus

Trachea: Midline or deviated, caliber Lungs: CHF, mass

Pulmonary vessels: Artery or vein enlargement

Mediastinum: Aortic knob, nodes Hila: Masses, lymphadenopathy Heart: Transverse diameter should be

less than half the transthoracic diameter

Pleura: Effusion, thickening, pneumothorax

Bones: Fractures, lesions

Soft tissues: Periphery and below the diaphragm

P-A, less magnification of the heart (heart is closer to the x-ray plate)

It is said that the diaphragm can overshadow up to 500 cc

Last hole is through the radiopaque line on the chest tube; thus, look for the break in the radiopaque line to be in the rib cage

Ipsilateral decubitus CXR; if fluid is not loculated (or contained), it will layer out

Air without lung markings is seen outside the white pleural line—best seen in the apices on an upright CXR

Low CXR to ensure the tube is in the GI tract and not in the lung

CT scan

What is used to look for ligamentous C-spine injury?

What CXR findings may provide evidence of traumatic aortic injury?

How should a CT scan be read?

Chapter 30 / Surgical Radiology 185

Lateral flex and extension C-spine films, MRI

Widened mediastinum 8 cm (most common)

Apical pleural capping Loss of aortic knob

Inferior displacement of left main bronchus; NG tube displaced to the right, tracheal deviation, hemothorax

Cross section with the patient in supine position looking up from the feet

Anterior

How can you tell the difference between a small bowel obstruction (SBO) and an ileus?

What is the significance of an air-fluid level?

In SBO there is a transition point (cut-off sign) between the distended proximal bowel and the distal bowel of normal caliber (may be gasless), whereas the bowel in ileus is diffusely distended

Seen in obstruction or ileus on an upright x-ray; intraluminal bowel diameter increases, allowing for separation of fluid and gas

What are the normal calibers of the small bowel, transverse colon, and cecum?

What is the “rule of 3s” for the small bowel?

How can the small and large bowel be distinguished on AXR?

Use the “3, 6, 9 rule”:

Small bowel 3 cm

Transverse colon 6 cm

Cecum 9 cm

Bowel wall should be 3 mm thick Bowel folds should be 3 mm thick Bowel diameter should be 3 cm wide

By the intraluminal folds: The small bowel plicae circulares are complete, whereas the plicae semilunares of the large bowel are only partially around the inner circumference of the lumen

What does KUB stand for?

Kidneys, Ureters, and Bladder— commonly used term for a plain film AXR (abdominal flat plate)

What is the “parrot’s beak” or “bird’s beak” sign?

What is a “cut-off sign”?

Evidence of sigmoid volvulus on barium enema; evidence of achalasia on barium swallow

Seen in obstruction, bowel distention, and distended bowel that is “cut-off” from normal bowel

What is loss of the psoas shadow?

What is loss of the peritoneal fat stripe (a.k.a. preperitoneal fat stripe)?

What is “thumbprinting”?

What is pneumatosis intestinalis?

Loss of the clearly defined borders of the psoas muscle on AXR; loss signifies inflammation or ascites

Loss of the lateral peritoneal/preperitoneal fat interface; implies inflammation

Nonspecific colonic mucosal edema resembling thumb indentations on AXR

Gas within the intestinal wall (usually means dead gut) that can be seen in patients with congenital variant or chronic steroids

What is the best position for the detection of FREE AIR (free intraperitoneal air)?

If you cannot get an upright CXR, what is the second best plain x-ray for free air?

How long after a laparotomy can there be free air on AXR?

What is Chilaiditi’s sign?

When should a postoperative abdominal/pelvic CT scan for a peritoneal abscess be performed?

Upright CXR—air below the right diaphragm

Left lateral decubitus, because it prevents confusion with gastric air bubble; with free air both sides of the bowel wall can be seen; can detect as little as 1 cc of air

Usually 7 days or less

Transverse colon over the liver simulating free air on x-ray

POD #7 or later, to give time for the abscess to form

What U/S findings are associated with acute cholecystitis?

What type of kidney stone is not seen on AXR?

What medication should be given prophylactically to a patient with a true history of contrast allergy?

What is a C-C mammogram?

Gallstones, thickened gallbladder wall ( 3 mm), distended gallbladder ( 4 cm A-P), impacted stone in gallbladder neck, pericholecystic fluid

Uric acid (Think: Uric acid Unseen)

Methylprednisolone or dexamethasone; the patient should also receive nonionic contrast (associated with one fifth as many reactions as ionic contrast, the less expensive standard)

Cranio-Caudal mammogram, in which the breast is compressed top to bottom

What are the best studies to evaluate for a pulmonary embolus?

Spiral thoracic CT scan, V-Q scan, pulmonary angiogram (gold standard)

Why does lidocaine burn on injection and what can be done to decrease the burning sensation?

Why does some lidocaine come with epinephrine?

Lidocaine is acidic, which causes the burning; add sodium bicarbonate to decrease the burning sensation

Epinephrine vasoconstricts the small vessels, resulting in a decrease in bleeding and blood flow in the area; this prolongs retention of lidocaine and its effects

In what locations is lidocaine with epinephrine contraindicated?

What are the contraindications to nitrous oxide?

Fingers, toes, penis, etc., because of the possibility of ischemic injury/necrosis resulting from vasoconstriction

Nitrous oxide is poorly soluble in serum and thus expands into any air-filled body pockets; avoid in patients with middle ear occlusions, pneumothorax, small bowel obstruction, etc.

What is the feared side effect of bupivacaine (Marcaine®)?

What are the side effects of morphine?

Cardiac dysrhythmia after intravascular injection leading to fatal refractory dysrhythmia

Constipation, respiratory failure, hypotension (from histamine release), spasm of sphincter of Oddi (use Demerol® in pancreatitis and biliary surgery), decreased cough reflex

What are the side effects of meperidine?

Limit to the duration of Demerol® postoperatively?

What medication is a contraindication to Demerol®?

Similar to those of morphine but causes less sphincteric spasm and can cause tachycardia and seizures

Build up of the metabolites (normeperidine)

Monoamine oxidase inhibitor