Acute Pancreatitis

Etiologies

• Common alcohol (30% of cases, typically in men): usually chronic, with acute flares gallstones (35% of cases, typically in women): usually small (<5 mm) stones are culprit

Obstructive: ampullary or pancreatic tumors. ? pancreas divisum

Metabolic: hypertriglyceridemia (TG need to be 1000 and usually 4500: seen w type I and type V familial hypertriglyceridemia), hypercalcemia Drugs: furosemide. thiazides, sulfa, didanosine. protease inhibitors, estrogen. 6-MP.

azathioprine.ACE-l (occur via hypersensitivity, toxic metabolite, or direct toxicity) Infection: echovirus. coxsackievirus, mumps, rubella. EBV. CMV, HIV. HAV. HBV. Ascaris Trauma: blunt abdominal trauma. post-ERCP (35-70% with T amylase. -5% with clinical, overt pancreatitis) Familial: autosomal dominant with variable penetrance (PRSS1. CFTR, SPINK 1 genes) Ischemia: vasculitis, cholesterol emboli, hypotension, hemorrhagic shock Scorpion sting (in Trinidad): mechanism believed to be hyperstimulation of pancreas I • Idiopathic 20% (many cases probably due to microlithiasis)

Clinical manifestations

• Epigastric abdominal pain, radiating to back, constant, some relief w leaning forward

• Nausea and vomiting: fever is common

• Ddx: biliary disease, perforated viscus. intestinal obstruction, mesenteric ischemia. IMI.

AAA leak, distal aortic dissection, ruptured ectopic pregnancy Physical exam

• Abdominal tenderness and guarding, i bowel sounds (adynamic ileus)

• palpable abdominal mass; * jaundice if biliary obstruction

• Signs of retroperitoneal hemorrhage (Cullen s - periumbilical; Grey Turner's flank) rare

• r hypotension or shock

Diagnostic studies (/AMA 2004.291:2865)

• Laboratory t amylase: levels >3 x ULN very suggestive of pancreatitis, but level * severity false ©: acute on chronic (eg. alcoholic); hypertriglyceridemia (1 amylase activity) false other abd. or salivary gland process, acidemia, renal failure, macroamylasemia (amylase binds to other proteins in serum, cannot be filtered out) t lipase: may be more specific than amylase false ©: renal failure, other abd. process, diabetic ketoacidosis. HIV. macrolipasemia ALT >3 x ULN — gallstone pancreatitis (AmjCostn 1994.8* 1863); A<J>. bili not helpful other labs depending on severity: TWBC. I Hct, 1 BUN. I Ca. t glucose

• Imaging studies abdominal CT not required in Pts at time of dx. Obtain if needed to exclude other dx. stage severity, r o complic. Assessment of necrosis req. IV contrast, which may want to avoid for 1st few days b c theoretical concern of f necrosis (and spont. necrosis may not be radiographically apparent for 48-72 h) abdominal ultrasound to evaluate for gallstones. CBD dilatation, ascites, pseudocyst pancreas often obscured by bowel gas; if seen diffusely enlarged, hypoechoic MRCP can be used to assess for gallstones & pancreatic ductal disruption endoscopic U S (EUS) most Se test for gallstones; limited role in acute pancreatitis

• CT-guided abscess drainage or fine-needle aspiration to r o infection if Pt w persistent fevers. T WBC. or organ failure and pancreatic necrosis present on CT (96% Se. 99% Sp); has risk of seeding sterile necrosis

Treatment (Lancet 2003:361 1447; NEJM 2006:354 2142)

• Supportive therapy fluid resuscitation (may need up to 10L d if hemodynamically severe pancreatitis) enteral nutrition: i infectious complications and disease severity, and trend toward

I mortality c wTPN (8/vy 2004:328:1407). ideally via NJ tube, but NG acceptable, analgesia with IV meperidine, morphine (theoretical risk of sphincter of Oddi spasm, but has not been shown to adversely affect outcome), or hydromorphone

• Prophylactic systemic antibiotics (eg. imipenem) of unclear benefit and remain controversial (Gaiuo 2007:1312019); if used, reserve for severe necrotizing pancreatitis (>30% necrosis by CT) for no more than 14 d

• ERCP • sphincterotomy, may 1 biliary sepsis in severe gallstone pancreatitis if performed w in 72 h (N£/m 1993:328:228); no effect on local or systemic pancreatitis complications; most effective if obstructive jaundice (bili -5) and or cholangitis (nejm 1997:336:237; Ann Surg 2007. 24S: 10)

• Surgery debridement indicated if infected necrosis (usually after confirmation of infection by FNA); up to 65% mortality if surgery performed w in first few days (ftmotot 2002.1565); should be delayed -2 wks unless Pt worsening cholecystectomy if gallstones (as soon as Pt recovers and inflammatory process i)

Complications

• Systemic shock. ARDS. renal failure. Gl hemorrhage. DIC

• Metabolic: hypocalcemia, hyperglycemia, hypertriglyceridemia

• Acute fluid collection (30-50%): seen early, no capsule, no Rx required

• Pseudocyst (10-20%): fluid collection, persists for 4-6 wks. encapsulated suggested by persistent pain & elevation of amylase or lipase, or mass on exam most resolve spont.; if >6 cm or persists >6 wks • pain -» endo perc surg drainage

• Sterile pancreatic necrosis (20%): area of nonviable pancreatic tissue

Rx conservatively with prophylactic antibiotics (eg. imipenem; ne}m 1999;34<H412) if severe necrosis & supportive measures for as long as possible; surgery if Pt unstable

• Infection (5% of all cases. 30% of severe): fever and t WBC; usually 2° enteric GNR

infected pancreatic necrosis (aspiration -»© bacterial culture): antibiotics • surgical debridement (100% mortality w o debridement; HcpaogoumetMcmiog/ 1991:38:116) pancreatic abscess: circumscribed collection of pus (usually w o pancreatic tissue) treat with antibiotics + drainage (CT-guided if possible)

• Pancreatic ascites or pleural effusion: indicates disrupted pancreatic duct; consider early

ERCP with stent placement across duct

• Scarring of pancreatic duct -♦ stricture chronic pancreatitis

Prognosis

• Severe pancreatitis organ failure or local complications (necrosis, abscess, pseudocyst)

• Scoring systems: Apache II. Ranson's criteria. CT Severity Index (CTSI; Balthazar grade score • necrosis score)

APACHE II: assigns points for age. previous health status, temp. HR. RR. MAP. P.02. pH. K. Na. Cr. Hct.WBC. GCS - severe pancreatitis if -8 (>13 ttt mortality) advantage: can be used on admission (before 48 h) and on daily basis Ranson's: severe pancreatitis when -3 criteria; takes 48 h to compute CT Severity Index: most helpful to assess severity; combine with Ranson's

Ranson's Criteria

Prognosis

At diagnosis

At 48 hours

U of criteria

Mortality

age >55

Ha 1 >10%

s2

<5%

WBC 16.000 mm1

BUN ! >5 mg dl

3-4

15-20%

glucose >200 mg dl

base deficit 4 mEq L

5-6

40%

AST >250 U L

Ca <8 mEq L

>99%

LDH >350 U L.

P.O; < 60 mmHg

fluid sequestration >6 L

(Am J Cosuocnteml 1982:77:633)

CT

Description

Points

Necrosis

Points

Total

Mortality

Grade

Index

A

Normal pancreas c w mild pancreatitis

0

33%

2

0-3

3%

B

Enlarged pancreas but w o inflammation

1

33-50%

4

4-6

6%

C

Pancreatic or peripancreatic inflammation

2

>50%

6

7-10

Î7X"

D

Single peripancreatic fluid collection

3

E

-2 Peripancreatic fluid collections or gas in the pancreas or retropericoneum

4

(Radiology 1990:174:331)

(Radiology 1990:174:331)

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  • eden
    What are 5 clinical manifestations of acute pancreatitis?
    6 months ago

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