The yellow bird Recognizing biliary obstruction By Habiba A. Habib, BSN, RN, and Michael Saunders, MD As Mr. R, 66, is going about his daily activities, he experiences severe upper-abdominal pain. He describes the pain as a pressure that begins in the epigastrium and spreads in a 2.3 bandlike distribution to the left and right upper quadrants, ANCC CONTACT HOURS radiating to the upper back. It increases in intensity to 8 on a 0-to-10 scale over 1 to 2 hours. The pain is exacerbated by movement and associated with nausea, vomiting, chills, and rigors. Mr. R is jaundiced and his urine is dark amber. His liver function tests (LFTs), including serum bilirubin levels, are markedly elevated. Given Mr. R’s history and signs and symptoms, his healthcare provider suspects a biliary obstruction: a blockage of the flow of bile from the liver to the small intestine. A RELATIVELY COMMON disorder, biliary obstruction affects approximately 5 per 1,000 people.1 Jaundice (icterus) is a key sign of biliary obstruction. The word icterus derives from an ancient Greek word that also signified a yellow bird (see Recognizing the yellow bird of jaundice). This article describes the various possible causes of biliary obstruction, diagnostic studies and treatment options, and nursing considerations for patients with this disorder. NC , I What can go wrong? In biliary obstruction, the interruption of bile flow can ESEARCHERS occur at any level within the biliary system. (See How bile R travels to the duodenum.) Bile, the liver’s exocrine secretion, HOTO /P ARAZZI . P. M . P. R D 28 l Nursing2011 l October www.Nursing2011.com Copyright © 2011 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. of jaundice: www.Nursing2011.com October l Nursing2011 l 29 Copyright © 2011 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. is produced continuously by liver in the blood, it can be secreted by Recognizing “the yellow cells (hepatocytes). It contains the kidneys into urine, giving the water, cholesterol, bile salts, which bird” of jaundice urine a dark amber (“coca cola”) aid in the digestion of fats, and Jaundice was recognized by ancient color. waste products such as bilirubin, Greeks and Romans as a sign of disease. The normal serum total bilirubin which causes bile’s familiar yellow- The word jaundice stems from the Latin concentration is less than 1 mg/dL. green color. word galbinus, which described a light An accumulation of bilirubin in the Bilirubin is formed by the break- greenish yellow color. Icterus is a Lati- bloodstream (hyperbilirubinemia) down of hemoglobin from red blood nized form of the Greek word ikteros, and subsequent deposition in the which to the ancient Greeks signified cells as they pass through the spleen. skin and sclerae causes jaundice both jaundice and a “yellow bird.” The The process of bilirubin metabolism ancient treatment for jaundice included (icterus). Scleral icterus is generally can be affected by an alteration in the use of yellow birds as a cure, as is a more sensitive sign of hyperbiliru- the steps involving uptake, storage, described in Pliny the Elder’s Naturalis binemia than generalized jaundice. conjugation, and secretion. Historia XXX:XXVII (written in AD 77): Jaundice is a term often used inter- Unconjugated bilirubin (UCB) is “There is a bird called jaundice from its changeably with hyperbilirubine- minimally soluble in water and is color. If one with jaundice looks at it, mia, which may not be clinically transported in blood attached to they are cured of that complaint, and detected until bilirubin levels are at albumin, which limits renal excre- the bird dies.”2 least 3 mg/dL.3 tion and diffusion into tissues. UCB is cleared from the bloodstream both the small and large intestine Intrahepatic or extrahepatic? mainly by hepatocytes, which con- hydrolyze the conjugates, yielding Mr. R undergoes further evaluation to vert it to a water-soluble conju- UCB again. Colonic anaerobes then determine the origin of his signs and gated bilirubin (CB). This in turn is reduce UCB to urobilinogens that symptoms. secreted into bile. The secreted CB are eliminated mainly in the feces.2 Cholestasis, defined as obstruc- travels in bile down the biliary tree Bilirubin is normally absent in tion of biliary flow, can be caused by to the intestine, where bacteria in urine. But when excess CB is present mechanical factors, such as biliary How bile travels to the duodenum1 Half of the bile produced by the liver flows directly into the duodenum via a system of ducts, including the common bile duct (CBD). The remaining 50% is stored in the gallbladder. In response to a meal, this bile is released from the gallbladder via the cystic duct, which joins the common hepatic duct from the liver. The CBD courses through the head of the pancreas for approximately 2 cm before passing through the hepatopancreatic ampulla (ampulla of Vater) into the duodenum. Diaphragm Liver Gallbladder Spleen Cystic duct Common hepatic duct Common bile duct Hepatopancreatic Tail of the ampulla pancreas Duodenum Pancreatic duct Head of the pancreas 30 l Nursing2011 l October www.Nursing2011.com Copyright © 2011 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. strictures, or by metabolic factors throughout the biliary tree. In Mirizzi such as hepatotoxicity due to certain syndrome, an impacted cystic duct stone medications, pregnancy, and sepsis causes inflammation and compression (due to the effects of released cyto- of the common hepatic duct and thus kines). These processes can damage biliary obstruction.1 The vast majority or impair hepatocyte function, of stones, however, are smaller than resulting in hyperbilirubinemia (see 1 cm and don’t obstruct the ducts. Identifying causes of cholestasis). (See Hard facts about gallstones.) Cholestasis can also have either Other causes of intraductal cho- intrahepatic or extrahepatic etiologies. lestasis include: Intrahepatic cholestasis generally • benign biliary strictures caused by occurs at the level of the hepatocyte surgical anastomosis, operative injury, or biliary canalicular membrane. The or chronic pancreatitis. most common causes of intrahepatic • sphincter of Oddi dysfunction or cholestasis are hepatitis and cirrhosis.3 dyskinesia. Hepatitis is an inflammation of • PSC, a chronic disorder of unknown the liver characterized by diffuse or etiology characterized by inflamma- patchy necrosis. Causes of hepatitis Scleral icterus is generally tion, fibrosis, and stricturing of ducts include viruses, drugs, and alcohol. in the biliary tree. a more sensitive sign of • Cirrhosis is characterized by gener- hyperbilirubinemia benign and malignant neoplasms. alized disorganization of hepatic than generalized architecture with nodule formation jaundice. Assessing extraductal causes and scarring of the parenchyma. Malignant or benign neoplasms can Cirrhosis results from chronic liver also cause external compression of inflammation.2 the bile duct, resulting in obstruc- Primary biliary cirrhosis (PBC), than one million Americans are diag- tion. Causes of extraductal neoplastic another possible cause of intra- nosed with cholelithiasis (gallstones) obstruction include tumors arising hepatic cholestasis, is a chronic, auto- every year.5 Many factors increase locally from the gastrointestinal immune, granulomatous destruction the risk of developing gallstones, (GI) tract (such as pancreatic cancer) of the intrahepatic ducts.1 In contrast including: and metastatic cancers from outside to patients with other types of liver • advancing age the GI tract (such as breast cancer). disease, 95% of those with PBC are • gender; gallstones are more com- Benign extraductal causes of bili- women. Most patients with PBC are mon in women5 ary obstruction include acute and asymptomatic in the early stages of • family history and genetics chronic pancreatitis. disease; fatigue and pruritus are the • certain medications, such as most common presenting signs and estrogens Patient history and lab results symptoms at later stages.4 • obesity A former kitchen cabinet salesperson, Extrahepatic cholestasis can be • diet, especially a diet low in fiber Mr. R has been unemployed for the past subdivided into those that are intra- and high in saturated fats year and pays for his own insurance. ductal or extraductal. Intraductal • sedentary lifestyle. He’s proud to be with his wife of 42 causes include choledocholithiasis Gallstones can become lodged in the years. He reports drinking alcohol infre- (gallstone in the common bile duct CBD and cause complete obstruction, quently (one to three beers a month) and [CBD]), biliary strictures, primary with increased intraductal pressure denies any history of tobacco or illicit sclerosing cholangitis (PSC), sphincter of Oddi dysfunction, and neoplasms 2 such as cholangiocellular carcinoma. Identifying causes of cholestasis Extraductal obstruction caused by Intrahepatic cholestasis Extrahepatic cholestasis external compression of the biliary • hepatocellular injury • choledocholithiasis ducts may be secondary to neo- • hepatitis • neoplasms plasms, such as pancreatic carcinoma, • • pancreatitis, or cystic duct stones with primary biliary cirrhosis primary sclerosing cholangitis subsequent gallbladder distension.1 • drugs and toxins • pancreatitis • sepsis • biliary strictures Exploring intraductal causes • infiltrative diseases, such as amyloidosis • parasitic infections, such as ascaris Stone disease