Slide 1: Which of these patients has a worse prognosis? Let’s discuss acute pancreatitis – the different types and prognosis.

Slide 2: First we need to understand normal pancreatic appearance. The pancreas should be nice and skinny with barely perceptible pancreatic duct.

Notice how the normal pancreas has a lobulated contour with pristine peri-pancreatic fat.

The splenic vein is nice and patent.

Slide 3: The most common form of pancreatitis is interstitial edematous pancreatitis.

This is highlighted by a giant, swollen pancreas with peri-pancreatic standing.

Notice how the fat around the pancreas is all stranded (increased attenuation, brighter) from edema.

The prognosis is quite favorable in these patients, with a mortality around 5%. Major complications to look out for include pseudocyst formation, splenic vein thrombosis and SMA aneurysm.

The pancreas is so swollen that it has lost its nice lobulated edge!

Slide 4: The more severe form of pancreatitis is necrotic pancreatitis.

This can be identified by hypo-enhancement of the pancreatic body or presence of complex fluid collection in or around the pancreas.

These patients are more complicated and have a much higher mortality rate of around 25%. The danger of these necrotic collections is the risk of infection. Watch out for air bubbles inside that signal gas-forming bacteria.

Look how the body of the pancreas is much darker than the adjacent head, a sign of necrosis!

Slide 5: How do we assess peri-pancreatic fluid collections? Necrosis is typically irregularly shaped with much more internal complexity (arrow marks partially digested pancreas). These collections are more often eventually infected.

Pseudocysts are organized collections of simple fluid and are often well-circumscribed. These do not become infected as often.

Typically peri-pancreatic collections will resolve over time without treatment. Just be on the lookout for dreaded superinfection!

Slide 6: Let’s review! The radiographic characteristics of pancreatitis can inform risk stratification.

Pancreatitis. Type. Interstitial edematous. Mortality. Decreased. 5%. Key findings. Loss of lobular pancreatic border. Peripheral fat stranding. Type. Acute necrotic. Mortality. Increased. 25%. Hypo-attenuation/complex fluid collection within the pancreas.

Fluid collections. Type. Pseudocyst. Infection. Decreased. Key findings. Organized collection. Well circumscribed. Type. Necrotic collection. Infection. Increased. Key findings. Irregularly shaped. Internal complexity.

Interstitial edematous pancreatitis for greater than 4 weeks is a pseudocyst. Acute necrotic pancreatitis for 3 to 5 days is a necrotic collection.

Slide 7: Bonus clinical pearl: Should I give antibiotics?
Routine prophylaxis. Antibiotics are not routinely recommended in patients with pancreatitis – even if presenting with severe necrotic pancreatitis.

Signs of infection. Pancreatitis is pro-inflammatory, thus typical SIRS criteria are not reliable markers for infection. Think pancreatic infection in patients with necrosis on imaging who fail to improve after 7 to 10 hospital days. Signs may include increased leukocytosis, pro-calcitonin, abdominal pain/distension.

Gas on imaging. The presence of gas in the retro-peritoneum or fluid collections should be presumed to represent superinfection. Antibiotics should be promptly started. Strongly consider referral for intervention.