Pancreas Function/Disorders Flashcards
which arteries supply the pancreas?
celiac and SMA
exocrine pancreas is ___% pancreatic mass
exocrine pancreas makes ______
85%
digestive enzymes, water, bicarb –> duodenum
pancreatic embryology
common variations in pancreatic duct anatomy
90%- Santorini and major duct connected
10% - fusion does no occur = pancreas divisium –> higher risk for pancreatitis
regulation of pancreas secretion
what determines bicarb secretion from the pancreas?
duodenal pH >4.5 - sensed in s/secretin cells
how does the pancreas avoid digesting itself?
pancreatic enzymes are stored in pancreas and secreted into duodenum as PROENZYMES. Enterokinase at brush border in duodenum converts trypsinogen –> trypsin. Trypsin makes the other zymogens –> active enzymes.
amylase and lipase are stored in active forms b/c there is no starch or TG in the pancreas to be digested
5 protective mechanisms in the pancreas
- synthesis of enzymes as inactive zymogens
- trypsin inhibitor packaged in zymogen granules
- segregation of enzymes in membrane bound compartments
- enterokinase restricted to small intestine
- acidic pH w/in zymogen inactivates Trypsin
Labs in acute pancreatitis
WBC: often elevated
Amylase: leaks from inflamed pancreas. high sensitivity, low specificity
Lipase: sensitive as amylase, but more specific , and remainvs elevated
Atlanta criteria for Acute pancreatitis
two or more of the following:
- abdominal pain consistent w/ acute pancreatitis: sudden onset upper abdominal pain, often radiating to upper back. steady pain w/ “boring” quality.
- elevated amylase or lipase >3x normal
- confirmatory finding on CT
normal amylase, high lipase - interpretation?
delayed presentation of acute pancreatitis
how do gallstones cause pancreatitis?
migrate to the cystic duct –> common duct –> can obstruct the ampulla of vater –> pancreatitis and/or cholangitis
which pancreatic hormone is most specific in dx pancreatitis?
lipase
lots of things can cause elevation of amylase
How do you assess the severity of pancreatitis?
Bedside eval
BISAP >2
- BUN>25, impaired mental status, SIRS, Age>60, pleural effusions
BUN >22
CRP >125 @48 hrs
SIRS persisting through 48 hours
what is SIRS?
presence of at least 2
- pulse >90 BPM
- RR >20 or PCO2<32mm Hg
- T> 100.4 or <96.8
- WBC> 12K or <4K
what are these and prognosis for each
left = interstitial
- very low mortality and infection (<1%)
right = necrotizing
- high infection rate (30-50%)
- mortality 10-30%
what causes acute pancreatitis?
- alcohol
- gallstones
- idiopathic
- other: high TGs, autoimmune, drugs, IBD, infectious, neoplasm, toxic, iatrogenic (ERCP), trauma, scorpion
inherited causes of pancreatitis
altered enzyme activity: trypsinogen mutations
abnormal ion movement: CFTR mutation
metabolic: familial hypertriglyceridemia (TGs <1000)
tx for acute pancreatitis
nothing to tx underlying pathophys
supportive care: IV fluids/lytes (EARLY and w/ Lactate Ringers), montioring, analgesia + antiemetics
other txs: Abx, NG tube, nutritional support, urgent ERCP (if gallstones)
systemic complications of acute pancreatitis
local complications of acute pancreatitis
fluid collection
necrosis
infection
ascites
erosion into adjacent structures
GI obstruction
hemorrhage
what is a pancreatic pseudocyst?
localized collection of pancreatic fluid that develops >4 wks after pancreatitis onset
how to distinguish from true pancreatic cysts: absence of epithelial lining
how to prevent infection in acute pancreatitis pt?
enteral feeding through jejunal tube! - to maintain gut barrier function
*abx use is controversial for prophylaxis
causes of death in acute pancreatitis
early <1 wk: SIRS, multiorgan failure
late: multiorgan failure, pancreatic infections/sepsis
features of chronic pancreatitis
- pain
- calcification
- pancreatic insufficiency
what causes chronic pancreatitis?
- cystic fibrosis
- hereditary pancreatitis (same conditions as acute)
- hypertriglyceridemia
- autoimmune
- fibrocalcific (equatorial countries)
course of chronic pancreatitis
gradually progressive
pain at presentation. decreases w/ longstandng disease.
calcification, malabsorption, and diabetes increase w/ progression
*increased risk of pancreatic cancer
name 5 causes of pain in chronic pancreatitis
- ischemia
- pseudocyst
- inflammation (general and neural)
- duodenal and common duct obstruction
- PD obstruction –> increased pancreatic pressure
at what point does pancreatic enzyme deficiency cause steatorrhea?
<10% lipase output
calcifications in chronic pancreatitis
tx for chronic pancreatitis
enzyme replacement and H2 blockers
pain tx: narcotics, neuro-modulators (antidepressants), anti-inflammatory drugs, somatostatin
surgical tx of chronic pancreatitis pain
lateral pancreaticojejunostomy
mild acute pancreatitis aka edematous or interstitial pancreatitis
separation of pancreatic lobules from eachother b/c edema. no evidence of necrosis in acinus.
severe acute pancreatitis
acinar tissue is totally necrotic and gone
acute pancreatitis w/ pseudocyst: area of pancreas has become liquefied and necrotic. no epithelial lining
wall of pseudocyst
chronic inflammation, fibrosis in chronic pancreatitis
atrophy of acinar tissue
pathogenesis of pancreatitis
- injury of acinar cells: activation of proenzymes
- duct obstruction w/ increased intraductal pressure –> leakage of pancreatic enzymes
- activation of trypsin and other proenzymes
necrosis-fibrosis hypothesis
one theory about pathogenesis of chronic pancreatitis
repeated episodes of acute pancreatitis –> focal necrosis, patchy scarring, duct distortion
this is probably happening in chronic alcoholics
PRSS1
mutant cationic trypsogen gene –> elimate trypsin last-resort off-switch
high incidence of pancreatic carcinoma
CF and pancreatitis
defect in electrolyte transport –> viscous material accumulates in ducts –> obstruction
lab findings, histology and tx in autoimmune pancreatitis
Labs: autoantibodies or high IgG
histology: CP w/ ductitis
tx: steroids NOT SURGERY
