GI E2- Study Guide

What condition?

• transmitted by food and water; 12-72 hr incubation

• profuse watery diarrhea that is prolonged but self limited (1-2 wks)

  • *can be longer if immunocompromised

• look at hx & environmental factors for diagnosis

Acute infectious diarrhea

What pathogen for acute infectious diarrhea does recent hospitalization or abx use suggest?

C. diff

What pathogens for acute infectious diarrhea do recent foreign travel suggest?

Salmonella, shigella, campylobacter, e. coli or v. cholerae

What pathogen for acute infectious diarrhea does an undercooked hamburger suggest?

E. coli 0157:H7

What pathogen for acute infectious diarrhea does an outbreak in a longterm care facility, school, or on a cruise ship suggest?

Norovirus

What pathogen for acute infectious diarrhea does the consumption of fried rice suggest?

B. cereus toxin

What is the treatment for acute infectious diarrhea?

Routine abx not recommended → most self limited

Fluid/elyte replacement, oral glucose rehydration soln, antiemetics

Antibiotics for acute infectious diarrhea could be helpful for with pathogens?

Shigella or campylobacter infections

Acute infectious diarrhea caused by which pathogens would antibiotics worsen the disease?

E. coli 0157:H7 (risk developing HUS)

C. diff (prolongs disease)

What pathogen?

• affects all ages, esp kids

• MC in summer

• transmission: ingestion of contaminated food, drink

• vector: domestic pets (dogs, cats, turtles)

• large numbers must be ingested to produce illness

Salmonella (salmonellosis)

What are sources that can contain salmonella?

Unpasteurized milk, turkey, chicken, duck, eggs (esp raw), hollandaise sauce, homemade eggnog, caesar salad dressing

What can decrease the possibility of salmonella infection but doesn’t eliminate it?

Cooking contaminated foods (might not reach lethal temperature range / deep in foods like large turkeys or soft cooked eggs)

In general, what amount of shigella is sufficient to induce symptoms?

10-100 bacteria

What pathogen?

• Worldwide distribution; common in countries w/o effective sanitation

• fecal oral route

• source: food or water contaminated with human feces

Shigella aka bacillary dysentery

What pathogen?

• infx MC in children and elderly

• produces cytotoxin (shiga toxin/STEC) → endothelial damage, hemolysis and renal damage

• uncomplicated infx resolves spontaneously in 5-10 days

E. coli 0157:H7 (enterohemorrhagic)

What have E. coli 0157:H7 outbreaks been attributed to?

Undercooked ground beef, unpasteurized apple juice and milk, raw fruits and vegetables

What are complications of E. coli 0157:H7?

Hemolytic uremic syndrome (HUS), esp in kids < 5 y/o

Why are antibiotics contraindicated in e.coli 0157:H8 infx?

increases risk of HUS

What does the CDC recommend for all patients with bloody diarrhea or HUS?

Test for E. coli 0157:H7

What condition?

• mostly caused by enterotoxigenic e coli, shigella species, or c. jejuni

• onset 5-15 days, can occur w/in 2-10 days of travel, esp in area of poor sanitation

• contaminated foods or drinks- unpeeled fruits, leafy vegetables, unsanitary drinking water or ice

Traveler’s diarrhea

What is there a significant risk of developing with traveler’s diarrhea?

IBS

What sx are associated with traveler’s diarrhea?

Watery diarrhea (≥ 10 loose stools/day), nausea, abd cramping, fever

Are stool cultures needed for travelers diarrhea?

Nope- no blood or leukocytes present

What is the treatment/prevention for traveler’s diarrhea?

Antimicrobials (cipro/levo/ofloxacin, azithro, or rifaximin) to take if diarrhea occurs during trip

Loperamide 4mg loading dose following by 2mg after each loose stool (max 16 mg/day)

Peptobismol

What condition is a toxin mediate disease caused by C. diff that causes severe inflammatory response with formation of pseudomembranes & is transmitted by fecal oral route?

Pseudomembranous colitis (PMC)

Who is PMC most commonly seen in?

Hospitalized patients receiving abx → ampicillin, lincosamides (clindamycin), 3rd gen cephalosporins, FQs

What pathogen is an obligate anaerobe, gram positive, spore forming bacilli?

C. difficile

Describe the toxins associated with PMC

Raised yellowish-white plaques (pseudomembranes) in patches loosely adherent to the colonic mucosa, destroying it

*Can occur in any part of colon but MC in rectosigmoid

The following sx are associated with what condition?

• mild-mod greenish, foul smelling, watery diarrhea

  • 5-15 stools/day

• lower abd cramping, LLQ tenderness

• positive for mucous in stool but no blood

PMC

What is the diagnostic workup for PMC?

Cytotoxicity assay (definitive), EIA, rapid PCR, fecal WBC, flex sig

What is the treatment for PMC?

D/c offending antibiotic

Vancomycin PO or fidaxomicin (if both not available → flagyl)

Fecal microbiota transplant

*avoid antimotility agents & narcotics → delays clearance of toxin

What is the treatment for a relapse of PMC?

Retreat with same therapy

Multiple relapses → 7 week tapering regimen of vancomycin & concomitant probiotics

What condition is caused by rotaviruses or norovirus and is spread fecal-oral, with water/food borne outbreaks being common?

Viral gastroenteritis

Rotavirus or norovirus (Norwalk)?

• MC winter months

• infants & children 6-24 mos

• 24-72 hr incubation

• abrupt onset of watery diarrhea, V, low fever, ± abd pain

Rotavirus

Rotavirus or norovirus (Norwalk)?

• family & community wide outbreaks, esp on cruiseships

• school age children, family contacts, and adults

• 1-3 day incubation

• abrupt onset of D, N, V, mild abd cramps

Norovirus (Norwalk)

What pathogen?

• Causes protozoal gastroenteritis

• 1-3 wk incubation

• prevalent in areas with poor water treatment → water contaminated w/ cyst-infested feces from humans or animals

• MC after camping or backpacking trip (mountainous west)

Giardia lamblia

What is the presentation/diagnosis for protozoal gastroenteritis caused by Giardia lamblia?

Pale, explosive diarrhea & cysts or trophozoites found in stool

What is the treatment for protozoal gastroenteritis?

Tinidazole (TOC) or metro

*tx empirically, tx close contacts, report to board of health

What AST-ALT ratio suggests alcohol injury / alcohol hepatitis?

≥ 2:1

What is a useful marker to diagnose specific liver diseases?

AST-ALT ratio

What level of AST-ALT elevations would be due to ETOH alone?

< 300 IU/L

What common digestive disease consists of gallstone and is most often asymptomatic and found incidentally during abd sonography?

Cholelithiasis

What are RF for cholelithiasis in adults (> 40)?

Fat, forty, female, fertile

What are RF for cholelithiasis in children?

CF, sickle cell disease

The following ssx are associated with what condition?

• biliary colic- steady epigastric or RUQ pain that radiates to R scapula or shoulder

  • lasts 15min-5 hrs

  • often develops after eating fatty foods

• nocturnal awakening is common

• N, +/- V

• most will have recurrent attacks (stone usually returns back to GB after attack)

Cholelithiasis

How is uncomplicated symptomatic gallstone disease characterized?

Episodes of biliary pain < 5 hrs

How is complicated gallstone disease characterized?

Biliary pain lasts > 5 hours + findings might indicate acute cholecystitis, acute biliary pancreatitis, or biliary obstruction

What is the diagnosis for cholelithiasis

Preferred: abd US → GB wall thickening, cystic duct dilation

Other: HIDA scan (GB contractility), CT, ERCP, PTC

What condition is an acute GB wall inflammation due to mechanical, chemical, or bacterial causes and can be a complication of cholelithiasis?

Acute cholecystitis

The following PE findings are seen in what condition?

• progressively worsening biliary colic localizes to RUQ

• N, V

• palpable gallbladder, peritoneal inflammation

• Murphys sign

• Triad: RUQ pain, fever, leukocytosis

Acute cholecystitis

What is the triad for acute cholecystitis?

RUQ pain, fever, leukocytosis

What sign?

• Pt exhale → place hand below costal margin on right side at MCL → pt inhale

• positive = pt stops breathing in & winces w/ a catch in breath

  • d/t inflamed gallbladder palpated as it descends → acute cholecystitis

Murphy’s sign

What is the dx for acute cholecystitis?

Abd US, leukocytosis, mild elevation in AST/ALT, amylase, bili

What condition is chronic inflammation of the GB wall that results from repeated attacks of acute/subacute cholecystitis OR mechanical irritation of GB mucosa by gallstones?

Chronic cholecystitis

What condition?

• Calcium salts are deposited w/in wall of chronically inflamed GB (comp of chronic cholecystitis)

• Dx: plain films

• Rx: cholecystectomy

Porcelain gallbladder

What does porcelain gallbladder have a high association with?

Carcinoma of gallbladder

What is an acute necroinflammatory disease of the GB, presents with NO gallstone, & has a high morbidity/mortality?

Acalculous cholecystitis

Who is acalculous cholecystitis MC in?

Males over 50

What is acalculous cholecystitis associated with?

Major surgery, critical illness, burns, trauma, TPN

*GB stasis & ischemia → local inflammatory response, distension, necrosis, secondary infx

What condition is characterized by calculus in the common bile duct (CBD) from gallstones or formed spontaneously in CBD s/p cholecystectomy?

Choledocholithiasis

The following presentation is associated with what condition?

• MC “silent”- no sx unless obstruction

• Frequently occur in pts w/ hx of biliary colic episodes

• +/- abd tenderness

• Jaundice develops later on

Choledocholithiasis

How is choledocolithiasis diagnosed?

Labs: elevated LFTs & GGT, later → elevated ALP & bili

Imaging: abd US, ERCP

What diagnostic modality is highly sensitive & specific for choledocholithiasis, allows for stone extraction, & is completed preoperatively or if cholangitis or acute pancreatitis is also present?

ERCP

What condition is a bacterial infection superimposed over an obstructed biliary tree due to a gallstone, stricture, or neoplasm (uncommon, can develop after ERCP)?

Acute cholangitis

What is the triad associated with acute cholangitis?

Charcot’s triad → RUQ pain, jaundice, fever w/ chills

What is a complication of acute cholangitis?

Acute suppurative cholangitis (pus in biliary ducts)

What is the pentad associated with acute suppurative cholangitis?

Reynold’s pentad → charcot’s triad + hypotension + mental confusion

What is the treatment for acute cholangitis?

Emergent ERCP, cholecystectomy, or percutaneous cholecystectomy if others can’t be done

What condition is pancreatic inflammation due to the passage of stones through the CBD during acute cholecystitis or in patients with choledocholithisis?

Biliary pancreatitis

What condition is an autoimmune destruction of intrahepatic bile ducts by antimitochondrial antibodies (AMA) & cholestasis?

Primary biliary cholangitis (PBC)

Who is PBC MC in?

Middle aged women

The inflammation & fibrosis associated with PBC can lead to what?

Portal HTN and eventual cirrhosis (in 10-12 yrs)

What is the onset of PBC?

Insidious- often asx and found incidentally w/ inc LFTs on annual labs

The following symptoms are associated with what condition?

• insidious onset, often asx

• Fatigue, dry eyes & mouth

• pruritus (excoriations)

• unexplained RUQ discomfort → hepatomegaly

• xanthelasma- yellow plaques around eyes

  • d/t dec LDL receptors in damaged hepatocytes

• late finding → jaundice

PBC

What is the dx for PBC?

Cholestatic LFT pattern → 3-4x inc ALP

Positive AMA & ANA, liver bx (dz not uniform throughout)

What is the first line and only proven therapy for PBC?

Ursodiol (URSO) → decreases ALP

What are additional treatment options for PBC?

Cholestyramine for pruritus, Osteoporosis agents (Ca, Vit D), vaccines, hepatology referral, no alcohol

What is the only effective treatment for end stage PBC?

Liver transplant

What condition is a progressive, inflammatory, sclerosing & obliterative disease of the extrahepatic and/or intrahepatic bile ducts, in which the progression of the disease cannot be halted?

Primary sclerosing cholangitis (PSC)

Who is primary sclerosing cholangitis MC in?

Men 20-50 y/o & often associated with UC (check in pts w/ IBD + persistent & unexplained elevated ALP)

What are PSC patients at an increased risk for developing?

Cholelithiasis, choledocholithiasis, cholangitis, & cholangiocarcinoma

The following ssx are associated with what condition?

• often asx

• fatigue & pruritus are common

• RUQ pain

• progressive jaundice

• anorexia, indigestion

• acute cholangitis

PSC

The following diagnostic workup is for what condition?

• cholestatic LFT pattern → 4-10x inc ALP

• liver bx → fibrous obliteration of connective tissue in onion skin pattern

• fibroscan

• MRCP (preferred) & ERCP→ narrowing & beading of bile ducts

PSC

What is the tx for PSC?

Ursodiol (URSO), cholestyramine for pruritus, ERCP (to distinguish from PBC), liver transplant if advanced

Quick reference PBC vs PSC

What is the most common gallbladder carcinoma?

Adenocarcinomas

What RF are associated with GB carcinoma?

Hx chronic cholecystitis, porcelain gallbladder** (calcification of GB itself)

MC in elderly women

The following ssx are associated with what condition?

• early → usually asx, incidental finding

• advanced → RUQ pain & mass, wt loss, malaise, jaundice

• dx w/ radiologic imaging

GB carcinoma

What condition is an acute, reversible pancreatic inflammation with enzymatic release into the parenchyma, which activates enzymes that lead to autodigestion of the pancreas?

Acute pancreatitis

What is the “I get smashed” mnemonic for causes of acute pancreatitis?

Idiopathic

Gallstones

Ethanol

Trauma

Steroids

Mumps

Autoimmune

Scorpion sting

Hypercalcemia or Hypertriglyceridemia (serum TG > 1000 mg/dl)

ERCP

Drugs (cannabis, codeine, enalapril, furosemide, 5ASA, metro, simvastatin)

At what serum TG levels would hypertriglyceridemia associated pancreatitis occur?

≥ 1000 mg/dL

The following ssx are associated with what condition?

• Epigastric / LUQ pain that radiates to the back

  • steady, boring pain, increases in intensity

• often bends forward or pulls knees to chest

• N, V, abd distension, restless, ± fever

• very tender to palpation

• dec bowel sounds

Acute pancreatitis

What is Cullen’s sign?

Blue discoloration to umbilicus form retroperitoneal bleeding in pancreatic necrosis

What is Grey Turner’s sign?

Green brown discoloration to flanks seen with severe, necrotizing pancreatitis

How might a patient with acute pancreatitis appear on physical exam?

Cullens & Grey turners sign, erythematous nodules (fat necrosis), dec/absent bowel sounds, rales/atelectasis/effusions, pt may appear anxious or shocky

The following labs are likely to be seen in what condition?

• Amylase & lipase elevated >3x upper limit

  • lipase preferred

• Hypocalcemia bc necrotic fat binds calcium

• ALT > 150 (highly specific for stones)

• possible protein casts in UA

Acute pancreatitis

What is the preferred lab test for acute pancreatitis because it is most specific, sensitive, & remains elevated the longest?

Lipase

What should you think of with increased ALP & bilirubin?

Biliary disease

What are the imaging studies used to dx acute pancreatitis?

Abd CT (gold standard), flat plate (shows ileus & sentinel loop), US

What are the different criterias used in the evaluation of acute pancreatitis?

Ranson’s criteria (predict mortality), APACHE II (ICU mortality), & BISAP (preferred, assess severity)