Review of the Pancreatobiliary System What Every GI Nurse Needs to Know Joyce Flueckiger, APRN, BC, CGRN

Liver

• The liver is the largest organ in the body – Weighs 3-4 pounds – Extends from the fifth intercostal space in the midclavicular line to the right costal margin – Glisson’s capsule covers the liver – contains blood vessels and lymphatics – Serosa covers the Glisson’s capsule

Liver

• • • • • • Two lobes – right - 6 times larger than the left One million hepatic lobules – functioning unit of the liver Each lobule – Hepatocytes → secrete bile Each portal triad → hepatic artery, hepatic vein, bile duct Sinusoids → lie between each row of cells Kupffer cells → phagocytosis

Blood Supply to Liver

• • • • • 1500 ml of blood flow into the liver every minute Portal vein supplies 75% Hepatic artery supplies 25% Cells can regenerate within 3 weeks Can function with 90% damage for short time

Functions of Liver

• • • • Bile production – up to 1000 ml per day Storage of vitamins, minerals – A, D, B 12 and iron in form of ferritin Coagulation – production of clotting factors → fibrinogen and prothrombin Detoxification and excretion of many drugs and hormones

Primary Sclerosing Cholangitis

• • • More common in males 50-75% associated with ulcerative colitis Monitor progression of disease with liver function tests, cholangiography

Portal Hypertension

• • • Portal vein resistance is increased → collateral circulation Splenomegaly, varices, hemorrhoids, dilated cutaneous umbilical veins Jaundice, bleeding, edema, palmar erythema, fetor hepatics, spider nevus

Complications of Liver Disease

• • • • Varices Ascites Hepatorenal syndrome Hepatic encephalopathy – Mild → severe

Hepatitis A

• • • HAV – RNA virus, fecal – oral, contaminated food Symptoms – low-grade fever, fatigue, nausea, anorexia, myalgias, dark urine, light stools, right upper quadrant pain or discomfort Self-limiting

Hepatitis B

• • • • • HBV – DNA virus, bloods, saliva, semen Incubation period up to 6 months HBsAg is positive, ALT and AST 5-20 above upper limits normal HBsAb – when disease clears Hepatitis vaccine

Hepatitis C

• • • HCV – IV drug use, blood transfusions, most common Interferon therapy Now close to being treated with medications, will soon be treated by PCP

Other Diseases of the Liver

• • • • • NASH Wilson’s disease – autosomal recessive – excess copper stores Porphyria – hereditary disorder affects synthesis of heme Hemochromatosis – autosomal recessive – excess iron stores Gilbert’s syndrome

Gallbladder

• • • Size – 3” x 1” Capacity – 50 ml of bile Alkaline greenish-yellow fluid – Bile – – Bile salts Fatty acids – Lipids (cholesterol & lecithin) – Inorganic substances – Conjugated bilirubin – 90% of water is removed from bile from the liver → cystic duct → gallbladder

Anatomical Divisions of Gallbladder • • • • Cystic duct Hepatic duct Common bile duct Sphincter of Oddi – Arrangement of smooth muscles

Gallbladder has Three Layers

• • • Outer serosa derived from peritoneum Middle layer which contains longitudinal & spiral smooth muscle and fibrous tissue Inner mucosa which is simple columnar epithelium arranged in folds similar to rugae in the stomach

Diseases of the Gallbladder

• • • Cholelithiasis – the presence of stones or calculi in the gallbladder Two types of stones – Cholesterol – contain pure cholesterol – Mixed – cholesterol, bile acids, calcium salts, fatty acids, protein, phospholipids Pigment – Black contain bilirubin polymers, inorganic calcium salts – Brown contain primarily calcium bilirubinate and organic fatty acid salts of calcium

Symptoms of Cholelithiasis

• • • • 50% of gallstones do not cause symptoms Biliary colic – usually within 30 minutes of meal, lasting up to or greater than one hour Location of pain – right upper quadrant, right subscapular, back May be associated with nausea and vomiting

Diagnosis of Cholelithiasis

• • • • Ultrasound – may miss very small stones MRI/MRCP EUS ERCP – want to be sure stones are present before doing this procedure

Choledocholithiasis

• • • Stones in the common bile duct Patients may be asymptomatic Symptoms associated with choledocholithiasis – Biliary colic with constant right upper quadrant pain, epigastric pain – Obstructive jaundice and pruritus – Cholangitis – urgent or emergent situation manifested with fever, right upper quadrant pain, jaundice (Charcot triad), +/- rigors – Gallstone pancreatitis

Acalculous Cholecystitis

• • May occur in hospitalized patients not receiving oral intake resulting in gallbladder stasis Right upper quadrant pain, guarding, nausea and vomiting

Cholangitis

• • • • Bacterial infection of the bile duct Associated with choledocholithiasis, strictures, neoplasms, cysts, fistulas Symptoms – acute fever, chills, rigors, dark urine, often abdominal pain Acute, emergent situation – ERCP

Acute Calculous Cholecystitis

• • • 90% associated with a stone impacted in the cystic duct Symptoms include midepigastric or right upper quadrant pain, radiation of pain to shoulders and back Nausea, vomiting, fever, leukocytosis

Gallbladder Cancer

• • • • • More common in older women 80% have gallstones Gallbladder polyps >1 cm in size raise the risk of gallbladder cancer Vague symptoms of pain, anorexia, weight loss, nausea, vomiting 80% of tumors are adenocarcinoma – rarely are gallbladder tumors benign

Bile Duct Cancers

• • 30% associated with gallstones Maybe associated with long-standing UC, Crohn’s, PSC, choledochal cysts

Pancreas

• • • The pancreas is 6-8 inches long Lies posterior to the stomach Segments – Head, body and tail

Exocrine Cells – Approximately 99%

• • • Acinar cells – majority of pancreatic tissue Groups of acinar cells form lobules (acinus) Pancreatic juice with enzymes drains into the main pancreatic duct

Endocrine Cells – Remaining 1%

• Loculated in islets of Langerhaus – in the connective tissue between the lobules, mostly in the tail

Endocrine Cells

• • • Alpha → glucagon Beta → insulin Delta → somatostatin

Exocrine Acinar Cells

• • • 500-1000 ml daily (pancreatic juice) pH 8.5

Contains water, enzymes, electrolytes, bicarbonate

Exocrine Acinar Cells

• • • 500-1000 ml daily (pancreatic juice) pH 8.5

Contains water, enzymes, electrolytes, bicarbonate

Exocrine Acinar Cells

• • • 500-1000 ml daily (pancreatic juice) pH 8.5

Contains water, enzymes, electrolytes, bicarbonate

Pancreatic Enzymes

• • • Amylase → CHO 3 into glucose and maltose Lipase → pancreatic lipase and phospholipase A, important in early fat digestion Proteases → trypsinogen, then trypsin which break amino acids into active forms

• • • • • • Secretin and Cholecystokinin-Pancreozymin Hormones which stimulate pancreatic secretions Rest → bicarbonate 2% of maximum; enzymes 15% of maximum Cephalic phase → sight and smell of food stimulate the flow of digestive enzymes Gastric phase → increasing amounts of enzymes secreted still low in bicarbonate Intestinal phase → food entering the duodenum stimulates pancreatic enzyme secretion at 70% of maximal rate Bicarbonate output increases as the pH of meal decreases and acid increases

Diseases/Conditions of the Pancreas • • • • • Cystic fibrosis Pancreatic exocrine insufficiency – Associated with chronic pancreatitis – Malabsorption of fat, protein, and carbohydrates → quantitative – 72 hour fecal fat test (>7%) – Treat with pancreatic enzymes and acid suppression Pancreatic rest Pancreatic divisum – in 7-10% of general population Annular pancreas

Tumors of the Pancreas

• • • • Cystic – fluid filled, most often in head of pancreas – – Serous cystadenoma Cyst adenocarcinoma – – Mucinous cystadenoma Cyst adenocarcinoma IPMN – intraductal papillary mucinous neoplasm Carcinoma Endocrine tumors

Acute Pancreatitis

• • Inflammation of enzymatic digestion Etiology – alcohol, gallstones, trauma, family history, genetic abnormalities, medications, tumors, anatomic variants, hypercalcemia

Symptoms of Pancreatitis

• • • • Epigastric pain radiating to back, left blank Nausea and vomiting Low-grade fever Abdominal distention, ileus

Treatment of Acute Pancreatitis

• • • • • Aggressive hydration Analgesics and antiemetics Antiobiotics - ?

Nasojejunal feedings ERCP - ?

Chronic Pancreatitis

• • • • Not defined only by chronic pain Criteria on endoscopic ultrasound Criteria on pancreatography Intraductal secretin test – HCO 3 < 105, volume < 3 ml/min

Manifestations of Chronic Pancreatitis • • • • • Chronic abdominal pain Weight loss Steatorrhea Nausea and/or vomiting Obstructive jaundice

Treatment of Chronic Pancreatitis

• • • • • • Analgesics Enteral feeding tube Octreotide/sandostatin Pancreatic enzymes Celiac plexus block Intrathecal pain pump