Chapter 39 Alterations of Digestive Function Mosby items

Clinical Manifestations of Gastrointestinal Dysfunction Anorexia Ø A lack of desire to eat despite physiologic stimuli that would normally produce hunger Vomiting The forceful emptying of the stomach and intestinal contents through the mouth Ø Several types of stimuli initiate the vomiting reflex Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 2

Clinical Manifestations of Gastrointestinal Dysfunction Nausea A subjective experience associated with a number of conditions Ø Common symptoms: hypersalivation and tachycardia Ø Retching Ø Nonproductive vomiting Projectile vomiting Ø Spontaneous vomiting that does not follow nausea or retching Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 3

Clinical Manifestations of Gastrointestinal Dysfunction Constipation Infrequent or difficult defecation Ø Pathophysiology • Neurogenic disorders, functional or mechanical Ø conditions, low-residue diet, sedentary lifestyle, excessive use of antacids, changes in bowel habits Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 4

Clinical Manifestations of Gastrointestinal Dysfunction Diarrhea Increased frequency of bowel movements Ø Increased volume, fluidity, weight of the feces • May be protective Ø Major mechanisms of diarrhea • Osmotic diarrhea • Secretory diarrhea • Motility diarrhea Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 5

Clinical Manifestations of Gastrointestinal Dysfunction Systemic effects of GI dysfunction Ø Manifestations of diarrhea • Dehydration, electrolyte imbalance, metabolic acidosis, and weight loss Manifestations of acute bacterial or viral infection • Fever, with or without cramping pain Ø Manifestations of inflammatory bowel disease • Fever, cramping pain, bloody stools Ø Manifestations of malabsorption syndromes • Steatorrhea (fat in the stools) and diarrhea Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 6

Clinical Manifestations of Gastrointestinal Dysfunction Abdominal pain A symptom of a number of GI disorders Ø Parietal pain Ø Visceral pain Ø Referred pain Ø Biochemical mediators of the inflammatory response (histamine, bradykinin, and serotonin) stimulate organic nerve endings producing abdominal pain Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 7

Clinical Manifestations of Gastrointestinal Dysfunction GI bleeding Upper GI bleeding • Esophagus, stomach, or duodenum Ø Lower GI bleeding • Below the ligament of Treitz, or bleeding from the Ø jejunum, ileum, colon, or rectum Hematemesis Ø Hematochezia Ø Melena Ø Occult bleeding Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 8

Disorders of Motility Dysphagia Difficulty swallowing Ø Types • Mechanical obstructions • Functional obstructions Ø Achalasia • Denervation of smooth muscle in the esophagus and Ø lower esophageal sphincter relaxation Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 9

Disorders of Motility Gastroesophageal reflux disease (GERD) The reflux of chyme from the stomach to the esophagus Ø If GERD causes inflammation of the esophagus, it is called reflux esophagitis Ø A normal functioning lower esophageal sphincter maintains a zone of high pressure to prevent chyme reflux Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 10

Disorders of Motility Gastroesophageal reflux disease (GERD) Conditions that increase abdominal pressure can contribute to GERD Ø Manifestations • Heartburn, regurgitation of chyme, and upper abdominal Ø pain within 1 hour of eating Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 11

Gastroesophageal Reflux Disease Mosby items and derived items © 2010, 2006 by Mosby, Inc.

Disorders of Motility Hiatal hernia Sliding hiatal hernia Ø Paraesophageal hiatal hernia Ø Mosby

Hiatal Hernia Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Disorders of Motility Pyloric obstruction The blocking or narrowing of the opening between the stomach and the duodenum Ø Can be acquired or congenital Ø Manifestations • Epigastric pain and fullness, nausea, succussion splash, Ø vomiting, and with a prolonged obstruction, malnutrition, dehydration, and extreme debilitation Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 15

Disorders of Motility Intestinal obstruction and ileus An intestinal obstruction is any condition that prevents the flow of chyme through the intestinal lumen or failure of normal intestinal motility in the absence of an obstructing lesion Ø An ileus is an obstruction of the intestines Ø Manifestastions • Colicky pain, vomiting, distention, hypovolemia, Ø metabolic acidosis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 16

Disorders of Motility Intestinal obstruction and ileus Simple obstruction Ø Functional obstruction Ø Small intestinal obstruction Ø Large bowel obstruction Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 17

Intestinal Obstruction Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Gastritis Inflammatory disorder of the gastric mucosa Acute gastritis Ø H. pylori, NSAIDs Chronic gastritis Chronic fundal gastritis Ø Chronic antral gastritis • Signs and symptoms of chronic gastritis often do not Ø correlate with the severity of the disease Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 19

Peptic Ulcer Disease A break or ulceration in the protective mucosal lining of the lower esophagus, stomach, or duodenum Acute and chronic ulcers Superficial Ø Erosions Deep Ø True ulcers Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 20

Chronic Peptic Ulcer Mosby items and derived items © 2010, 2006 by Mosby, Inc.

Peptic Ulcer Disease Duodenal ulcers Most common of the peptic ulcers Ø Developmental factors • H. pylori infection Ø • • Toxins and enzymes that promote inflammation and ulceration Hypersecretion of stomach acid and pepsin Use of NSAIDs High gastrin levels Acid production by cigarette smoking Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 22

Duodenal Ulcer Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Gastric Ulcer Tends to develop in the antral region of the stomach, adjacent to the acid-secreting mucosa of the body Pathophysiology The primary defect is an increased mucosal permeability to hydrogen ions Ø Gastric secretion is normal or less than normal Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 24

Gastric Ulcer Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Stress Ulcer Stress ulcer is a peptic ulcer that is related to severe illness, neural injury, or systemic trauma Ischemic ulcers Ø Cushing ulcers • Ulcers that develop as a result of a burn injury Ø Manifestastions • Bleeding most common Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 27

Dumping Syndrome Rapid emptying of chyme from surgically created residual stomach into small intestine A clinical complication of partial gastrectomy or pyloroplasty surgery Developmental factors Ø Loss of gastric capacity, loss of emptying control, and loss of feedback control by the duodenum when it is removed Late dumping syndrome Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 28

Postgastrectomy Syndromes Alkaline reflux gastritis Afferent loop obstruction Diarrhea Weight loss Anemia Mosby items

Malabsorption Syndromes Inadequate digestion Pancreatic insufficiency Lactase deficiency Bile salt deficiency Gluten-sensitive enteropathy Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 30

Malabsorption Syndromes Pancreatic insufficiency Insufficient pancreatic enzyme production • Lipase, amylase, trypsin, or chymotrypsin Ø Causes: pancreatitis, pancreatic carcinoma, pancreatic resection, and cystic fibrosis Ø Fat maldigestion is the main problem, so the person will exhibit fatty stools and weight loss Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 31

Malabsorption Syndromes Lactase deficiency Inability to break down lactose into monosaccharides and thus prevent lactose digestion and monosaccharide absorption Ø Fermentation of lactose by bacteria causes gas (cramping pain, flatulence, etc. ) and osmotic diarrhea Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 32

Malabsorption Syndromes Bile salt deficiency Conjugated bile salts needed to emulsify and absorb fats Ø Conjugated bile salts are synthesized from cholesterol in the liver Ø Result from liver disease and bile obstructions Ø Poor intestinal absorption of lipids causes fatty stools, diarrhea, and loss of fat-soluble vitamins (A, D, E, K) Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 33

Malabsorption Syndromes Fat-soluble vitamin deficiencies Vitamin A • Night blindness Ø Vitamin D • Decreased calcium absorption, bone pain, osteoporosis, Ø fractures Vitamin K • Prolonged prothrombin time, purpura, and petechiae Ø Vitamin E • Uncertain Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 34

Inflammatory Bowel Diseases Chronic, relapsing inflammatory bowel disorders of unknown origin Genetics Ø Alterations of epithelial barrier functions Ø Immune reactions to intestinal flora Ø Abnormal T-cell responses Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 35

Ulcerative Colitis Chronic inflammatory disease that causes ulceration of the colonic mucosa Ø Sigmoid colon and rectum Suggested causes Ø Infectious, immunologic (anticolon antibodies), dietary, genetic (supported by family studies and identical twin studies) Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 36

Ulcerative Colitis Symptoms Ø Diarrhea (10 -20/day), bloody stools, cramps Treatment Broad-spectrum antibiotics and steroids Ø Immunosuppressive agents Ø Surgery Ø Increased colon cancer risk demonstrated Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 37

Crohn Disease Granulomatous colitis, ileocolitis, or regional enteritis Idiopathic inflammatory disorder; affects any part of the digestive tract, from mouth to anus Difficult to differentiate from ulcerative colitis Ø Similar risk factors and theories of causation Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 38

Crohn Disease Causes “skip lesions” Ulcerations can produce longitudinal and transverse inflammatory fissures that extend into the lymphatics Anemia may result due to malabsorption of vitamin B 12 and folic acid Treatment is similar to ulcerative colitis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 39

Ulcerative Colitis and Crohn Disease Mosby items and derived items © 2010, 2006 by

Crohn Disease Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Diverticular Disease of the Colon Diverticula Ø Diverticulosis Ø Asymptomatic diverticular disease Diverticulitis Ø Herniations of mucosa through the muscle layers of the colon wall, especially the sigmoid colon The inflammatory stage of diverticulosis Manifestations Ø Low abdominal pain, diarrhea, constipation, fever, leukocytosis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 42

Appendicitis Inflammation of the vermiform appendix Possible causes Ø Obstruction, ischemia, increased intraluminal pressure, infection, ulceration, etc. Manifestations Epigastric and right lower quadrant pain, rebound tenderness Ø Nausea, vomiting, fever, leukocytosis Ø Most serious complication is peritonitis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 43

Vascular Insufficiency Blood supply to the stomach and intestine Celiac axis Ø Superior and inferior mesenteric arteries Ø Two of three must be compromised to cause ischemia Ø Mesenteric venous thrombosis Acute occlusion of mesenteric artery blood flow Chronic mesenteric insufficiency Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 44

Obesity is an increase in body fat mass Ø Body fat index >30 A major cause of morbidity, death, and increased health care costs Risk factor for many diseases and conditions Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 45

Obesity Hypothalamus Hormones that control appetite and weight Ø Insulin, ghrelin, peptide YY, leptin, adiponectin, and resistin Leptin resistance Hyperleptinemia Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 46

Anorexia Nervosa and Bulimia Nervosa Characterized by abnormal eating behavior, weight regulation, and disturbed attitudes toward body weight, body shape, and size Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 47

Anorexia Nervosa and Bulimia Nervosa Anorexia nervosa Person has poor body image disorder and refuses to eat Ø Person can lose 25% to 30% of ideal body weight due to fat and muscle depletion Ø Can lead to starvation-induced cardiac failure Ø In females, characterized by absence of three consecutive menstrual periods Ø Binge eating/purging Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 48

Anorexia Nervosa and Bulimia Nervosa Bulimia nervosa Body weight remains near normal but with aspirations for weight loss Ø Findings • Recurrent episodes of binge eating • Self-induced vomiting • Two binge-eating episodes per week for at least 3 Ø months • Fasting to oppose the effect of binge eating, or excessive exercise Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 49

Anorexia Nervosa and Bulimia Nervosa Bulimia nervosa Continual vomiting of acidic chyme can cause pitted teeth, pharyngeal and esophageal inflammation, and tracheoesophageal fistulae Ø Overuse of laxative can cause rectal bleeding Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 50

Anorexia Nervosa and Bulimia Nervosa Starvation Decreased caloric intake leading to weight loss Ø Short-term starvation • Glycogenolysis • Gluconeogenesis Ø Long-term starvation • Marasmus • Kwashiorkor Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 51

Manifestations of Liver Disease Portal hypertension Ascites Hepatic-encephalopathy Jaundice Hepatorenal syndrome Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 52

Liver Disorders Portal hypertension Ø Abnormally high blood pressure in the portal venous system due to resistance to portal blood flow • Prehepatic • Intrahepatic • Posthepatic Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 53

Liver Disorders Portal hypertension Ø Consequences • Varices • • • Lower esophagus, stomach, rectum Splenomegaly Ascites Hepatic encephalopathy Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 54

Varices Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an

Hepatic Encephalopathy Accumulation of toxins related to liver failure cause disruption of neurotransmission Ammonia-bacterial urease acting on gut proteins Ø Neurotoxins: result from hepatic failure Ø Symptoms Personality changes Ø Confusion Ø Memory loss Ø Stupor, coma, death Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 56

Liver Disorders Jaundice (icterus) Obstructive jaundice • Extrahepatic obstruction • Intrahepatic obstruction Ø Hemolytic jaundice • Prehepatic jaundice • Excessive hemolysis of red blood cells or absorption of a Ø hematoma Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 57

Jaundice Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an

Hepatorenal Syndrome (HRS) Renal failure demonstrating oliguria, sodium and water retention, hypotension, and peripheral vasodilation due to advanced liver disease Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 59

Hepatorenal Syndrome Renal failure associated with liver failure Ø Ø Ø Hypovolemia Hypotension Decreased renal blood flow Intrarenal vasoconstriction Decreased GFR and urine output Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 60

Viral Hepatitis Systemic viral disease that primarily affects the liver Hepatitis A • Formally known as infectious hepatitis Ø Hepatitis B • Formally known as serum hepatitis Ø Hepatitis C, D, E, G Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 61

Hepatitis A Can be found in the feces, bile, and sera of infected individuals Usually transmitted by the fecal-oral route Risk factors Crowded, unsanitary conditions Ø Food and water contamination Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 62

Hepatitis A Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Hepatitis B Transmitted through contact with infected blood, body fluids, contaminated needles Maternal transmission if the mother is infected during the third trimester Hepatitis B vaccine prevents transmission and development of hepatitis B Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 64

Hepatitis B Mosby items and derived items © 2010, 2006 by Mosby, Inc. ,

Hepatitis C Responsible for most cases of posttransfusion hepatitis Also implicated in infections related to IV drug use 50% to 80% of hepatitis C cases result in chronic hepatitis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 66

Hepatitis D Ø Depends on hepatitis B for replication Hepatitis E Fecal-oral transmission Ø Developing countries Ø Hepatitis G Recently discovered Ø Parenterally and sexually transmitted Ø Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 67

Hepatitis Sequence Incubation phase Ø Prodromal (preicteric) phase Ø Icteric phase Ø Recovery phase Ø Chronic active hepatitis Fulminant hepatitis Ø From impairment or necrosis of hepatocytes Acute hepatic failure Ø Acetaminophen overdose Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 68

Cirrhosis Irreversible inflammatory disease that disrupts liver function and even structure Decreased hepatic function from nodular and fibrotic tissue synthesis (fibrosis) Biliary channels become obstructed and cause portal hypertension; due to the hypertension, blood shunted away from the liver, and a hypoxic necrosis develops Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 69

Cirrhosis Alcoholic Ø Oxidation of alcohol damages hepatocytes Biliary (bile canaliculi) Cirrhosis begins in bile canaliculi and ducts Ø Primary biliary cirrhosis (autoimmune) Ø Secondary biliary cirrhosis (obstruction) Ø Postnecrotic Ø Consequence of chronic disease Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 70

Cirrhosis Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an

Disorders of the Gallbladder Cholecystitis Gallstones Ø Cholesterol stones form in bile that is supersaturated with cholesterol. Theories: • Enzyme defect; increases cholesterol synthesis • Decreased secretion of bile acids to emulsify fats • Decreased resorption of bile acids from the ileum • Gallbladder smooth muscle hypomotility, stasis • Genetic predisposition • Combination of any or all of the above Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 73

Disorders of the Pancreas Pancreatitis Inflammation of the pancreas Ø Associated with several clinical disorders (alcohol intake and cholelithiasis) • Caused by injury or damage to pancreatic cells and ducts, Ø causing a leakage of pancreatic enzymes into the pancreatic tissue Ø These enzymes cause autodigestion of pancreatic tissue and leak into the bloodstream to cause injury to blood vessels and other organs Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 74

Disorders of the Pancreas Pancreatitis Ø Manifestations and evaluation • Epigastric pain radiating to the back • Fever and leukocytosis • Hypotension and hypovolemia Enzymes increase vascular permeability • Characterized by an increase in a patient’s serum amylase level Ø Chronic pancreatitis • Related to chronic alcohol abuse Mosby items and derived items © 2010, 2006 by Mosby, Inc. , an affiliate of Elsevier Inc. 75