16. Pancreas: Acute, Chronic, and AI Pancreatitis Flashcards
What is the annual incidence for acute pancreatitis?
Overall mortality
4.9 to 35 per 100,000
5%
What are the main causes of mortality from AP in the first two weeks?
SIRS: systemic inflammatory response syndrome
Organ failure
What is the definition of SIRS?
Two or more abnormalities in the temperature, HR, respiration, or WBC count NOT related to infection
What is the main cause of mortality from AP after the first two weeks?
Sepsis and its complications
What are the main causes of AP?
Gallstones *** Smoking Alcohol Hypertriglyceridemia Pancreas divisum Autoimmune pancreatitis Hypercalcemia Post-ERCP Genetic Intraductal papillary nucinous neoplasm and pancreatic cancer Drugs Trauma Ischemia Pregnancy
What is the most common cause of AP in the world? (25-40% of all cases)
Gall stones
What % of people with gallstones develop pancreatitis?
3-7%
What % of alcoholics develop pancreatitis? What % of cases in the US?
10%
30%
**usually after MANY years of alcohol abuse
What level of TGs is a RF for AP? What % of AP cases?
> 1000 mg/dl
1-4% of AP cases
What is pancreas divisum?
Congenital condition where the dorsal and ventral drainage is separate and the major drainage is through the minor papilla
What % of people with pancreas divisum develop pancreatitis?
Less than 5% (not a major risk factor)
Why is risk for pancreatitis increased post-ERCP (Endoscopic retrograde cholangiopancreatography)
Pancreatic duct can be disrupted due to proximity to the bile duct
**pancreatitis in 3-5% of ERCPs w/o manometry
What are four mutations that can increase the risk for pancreatitis?
- PRSS1 (Serine protease 1)
- CFTR (cytic fibrosis transmembrane conductance regulator)
- SPINK1 (serine protease inhibitor Kazal type 1)
- CTRC (Chymotrypsin C)
How does alcohol act as an inciting event for AP?
- Increased effect of CCK on activating TFs, NF-kB, and protein-1
- Acetaldehyde and ox stress activate pancreatic stellate cells
- Generation of acetalehyde and and fatty acid ethyl esters
- Sensitization of acinar cells to premature activation of zymogens by CCK
How do gallstones act as an inciting event for AP
- Reflux of bile into the pancreatic duct
2. Ampullary obstruction from stones or edema
How does hypertriglyceridemia act as an inciting event for AP?
Free fatty acid release by pancreatic lipase
How do genetics act as inciting events for AP?
Premature activation of pancreatic zymogens
- CTFR gene mutations, more concentrated and acidic pancreatic juice production -> ductal obstruction or altered acinar cell function
What are the main early acute changes in AP that all inciting events lead to?
- Intraacinar activation of proteolytic enzymes
- Microcirculatory injury
- Leukocyte chemoattraction
- Release of cytokines and oxidative stress
What does intraacinar activation of proteolytic enzymes involve?
- Generation of large amounts of active trypsin within the pancreas
- Vacuoles containing active trypsin rupture
- Overwhelming of natural defense mechanisms
- Pancreatic autodigestion from intrapancreatic release of active enzymes
What are the normal defense mechanisms that are overwhelmed in the setting of intraacinar activation of proteolytic enzymes?
- Pancreatic secretory trypsin inhibitor
- Autolysis of prematurely activated trypsin
- Mesotrypsin and enzyme Y lysis of trypsin
- Nonspecific antiproteases (A1AT, alpha2 macroglobulin)
What is involved in the microcirculatory injury seen in early acute changes in AP
- Damage of vascular endothelium and pancreatic interstitium
- Vasoconstriction, capillary stasis, ischemia, and decreased oxygen saturaiton
- Increased vascular permeability and pancreatic gland swelling
- Possible role of ischemia-reperfusion injury
What is involved in leukocyte chemoattraction seen as an early acute change in AP?
Complement activation and C5a release
What is involved in release of cytokines and oxidative stress as early acute changes in AP?
TNF IL-1, 6, 8 Prostaglandins, PAF, leukotrienes Proteolytic and lipolytic enzymes Reactive oxygen metabolites
What are the components of the systemic response in AP?
- SIRS
- Renal failure
- Myocardial depression
- Bacterial translocation from the gut
What are the clinical manifestations of AP?
Acute onset of persistent, severe epigastric abdominal pain Pain radiating to back in 50% of cases Nausea and vomiting in 90% of cases No pain in 5-10% of cases Ileus can be present (gut hypomotility)
What are the laboratory findings in AP?
- Amylase elevated in 6-12 hours
2. Lipase elevated in 4-8 hours, peaks at 24
When does lipase return to normal after AP?
8-14 days
What are two inflammatory markers that will rise along with amylase and lipase in AP?
CRP
Leukocytosis
What is the best way to look for the MCC of AP?
Abdominal ultrasound: evaluate for gallstones in the gallbladder (cholelithiasis) and bile duct (choledocholithiasis)
**visualization can be obscured by bowel gas
What modality is good for detecting necrosis related to AP but NOT gallstones?
CT
What has a higher sensitivity to early AP than CT, with a better visualization of the bile duct and pancreatic duct?
MRI
Diagnosis of AP required at least 2 of the following:
- Constant epigastric or LUQ pain with radiation to the back or flanks
- Serum amylase and/or lipase > 3 x the upper range of normal
- Characteristic abdominal imaging findings
What % of people with AP have local or systemic complications?
20%
What are the two main local complications or AP?
Acute peripancreatic fluid collection ( pseudocysts (>4wk)
Acute necrotic collection ( walled off necrosis (>4wk)