Digestive System

1. Digestive System Chapter 56

2. Structures of Digestive System • Oral Cavity • Esophagus • Stomach • Small intestine • Large intestine • Pancreas • Gallbladder • Liver

3. Teeth, Gums and Mouth • Is the client capable of chewing • Do they have teeth? • What condition are the teeth in? • Are there sores in the mouth that make it painful to chew?

4. Oral Cavity • Chewing mechanically breaks food into smaller particles, which can be swallowed more easily and provide a larger surface area for enzyme action. • Saliva lubricates the food for easier swallowing and initiates the digestion of starches.

5. Esophagus • Can the client swallow? • Do they have a history of GERD, Hiatal hernia or esophageal stricture?

6. Esophagus • Main function is to move food from the pharynx to the stomach. • Secretes some mucous and has some peristaltic movement. • Two sphincters: • Upper sphincter prevents air from entering the esophagus during inspiration • Lower esophageal sphincter prevents reflux of acidic gastric contents into the esophagus

7. Secretions of Digestive System • Mucus • Saliva • Gastric juices • Mucous • Digestive enzymes • Hydrochloric acid • Electrolytes

8. Stomach • Serves as a reservoir • Churns and mixes the food with digestive juices: • Secretes mucous • Hydrochloric acid • Enzymes • Starts protein breakdown and secretes intrinsic factor for absorption of vitamin B12 from the ileum • Little absorption of any nutrients • Highly lipid-soluble substances - some drugs and alcohol – are absorbed • Gastric emptying time about 4 hours

9. Gastric Juices • Major digestive enzyme of gastric juice is pepsin, a proteolytic enzyme that functions best at a pH of 2 of 3. • Hydrochloric acid provides the acid medium to promote pepsin activity • Major function of gastric juice is to begin digestion of proteins.

10. Hydrochloric Acid • pH of 2 to 3 • Provides acid medium to promote pepsin activity.

11. Mucous • Mucous is secreted in the stomach to protect the stomach wall from the proteolytic action of pepsin. • When mucous is not secreted, gastric ulceration occurs.

12. Pancreatic Juices • Pancreatic juices are alkaline (pH of 8 or above) • Contains amylase for carbohydrate digestion, lipase for fat digestion, and trypsin and chymotrypsin for protein digestion. • Contains sodium bicarbonate a base that neutralizes the acid from the stomach.

13. Small Intestine • Consists of duodenum, jejunum, ileum • Pancreatic and bile ducts empty into the duodenum • Secretes digestive enzymes, hormones and mucous • Digestion and absorption occurs – including most orally administered drugs

14. Large Intestine • Consists of cecum, colon, rectum, and anus • Mainly due to elimination

15. Nutritional Support Products, Vitamins, and Mineral-Electrolytes Chapter 57

16. Nutrients • Water, carbohydrates, proteins, fats, vitamins and minerals are required to promote and maintain health and prevent illness. • Vitamins are required for normal body metabolism, growth, and development.

17. Nutritional Deficiency • Clients are unable to ingest, digest, absorb or not utilize sufficient nutrients to improve or maintain health.

18. Nutritional Products • Liquid enteral products • Intravenous fluids • Pancreatic enzymes • Vitamins • Minerals - electrolytes

19. Liquid Enteral Products

20. Liquid Formulas • OTC preparation for oral or tube feedings • Nutritionally complete except for water • Special formulas for clients with renal or hepatic failure • High protein for increased calories

21. Nursing Responsibilities • Read can to make sure the supplement ordered is correct • Calories per ounce and additives may differ • Make sure client drinks water • Especially important on clients dependant on care takers for fluid intake – gastrostomy tube feeds • With GT tube additional water will need to be given

22. Intravenous Solutions • Used when oral fluids or tube feedings are contraindicated • Used short term to provide fluids and electrolytes • Dextrose and sodium chloride major solution used • Most common: Dextrose 5% in 0.2 or 0.45 normal saline – additives may include potassium chloride or KCL at dosages of 2 meq / 100 mL of IV solution (KCL is considered a medication and needs to be charted on MAR)

23. Total Parenteral Nutrition • Long-term use from weeks to months to provide all nutrients required for normal body functions – growth and tissue repair • Usually administered through central line • Fluids often have high concentration of dextrose 5 or 10% along with extra minerals • Proteins and lipids are given IV through special filters • Must go in at prescribed rate – no catching up on fluids.

24. Pancreatic Enzymes • Amylase, protease and lipase needed for absorption of carbohydrates, protein and fat • In pancreatic dysfunction commercially prepared enzymes are given with each meal or snack

25. Vitamin Supplements • Most often self supplied • Billion dollar OTC industry • Preparations should not included more than recommended amounts of vitamin D, folic acid and vitamin A • Most are synthetic preparations • Most contain minerals – large doses of all minerals are toxic

26. Minerals - Electrolytes • 22 minerals • Calcium and phosphorus have major role in bone metabolism • Electrolytes - Body must contain equal number of negative and positive charges • Adequate amounts contained in protein foods so extra intake is not needed if diet is adequate • Most common dietary deficiency: calcium and iron

27. Calcium - Iron Calcium supplements - most adolescent and adult females would benefit from calcium supplements (1000 to 1300 mg daily) Iron supplements – often used during periods of increase need – pregnancy Iron should not be taken otherwise due to high risk for accumulation and toxicity

28. Drugs to Aid Weight Management Chapter 58

29. Overweight / Obese Adults • 60% of adults are overweight or obese • Etiology • Physiologic factors • Genetic factors • Environmental factors • Psychosocial factors - depression

30. BMI • BMI = weight (pounds) divided by height (inches) x 704.5 • Desired BMI is 18.5 to 24.9 • Extremes may represent underweight or overweight / obese

31. Diseased Related to Obesity • Cancer • Cardiovascular disease • Diabetes type II • Dyslipdemias • Gallstones

32. Drug Therapy • BMI greater than 30 • Part of a weight management program – exercise – decrease in calorie intake • Once drugs stopped weight gain tends to re-occur

33. Drugs Used in Weight Loss • Appetite suppressants - • Phentermine – short term use only – use with caution in clients with hypertension • Sibutramine – most commonly prescribed drug – inhibits reuptake of serotonin and norepinephrine in brain • Fat blockers • Orlistat – decreases absorption of dietary fat from the intestines – recommended for persons clinically obese

34. Drugs Used for Peptic Ulcer and Acid Reflux Disorders Chapter 59

35. Peptic Ulcer Disease • Ulcer formation in the esophagus, stomach or duodenum • Mucous exposed to gastric acid and pepsin • Imbalance between cell-destructive and cell-protective effects • Gastric acid and pepsin • H. pylori – infectious process

36. Peptic Ulcer Disease

37. Gastric Ulcers • Associated with stress • NSAID ingestion • H. pylori • More likely to occur in older adults

38. Duodenal Ulcer • Associated with H. pylori and NSAIDs • Higher incidence in smokers

39. GERD • Most common disorder of esophagus • Characterized by regurgitation of gastric contents into esophagus and exposure of esophageal mucous to gastric acid and pepsin. • Main symptom is heart burn - occurs after eating • Cause is thought to be incompetent lower esophageal sphincter

40. GERD

41. Treatment of acid-peptic disorders • Promote healing of lesions and prevent recurrence of lesions by decreasing cell-destructive effects or increasing cell- protective effects

42. Antacids • Alkaline substances work primarily in the stomach • Work to raise the pH to 3.5 and inhibits conversion of pepsingogen to pepsin • Common antacid products: • Maalox • Mylanta • Gelusil • Amphojel

43. Helicobacter pylori Agents • Multiple drug therapy to treat the H. pylori organism and heal related ulcers • Antimicrobial • Amoxacillin • Clarithromycin • Metronidazol • Tetrocycline) • Histamine2 Receptor Antagonists

44. Histamine2 Receptor Antagonists • Histamine causes strong stimulation of gastric acid • Histamine 2 receptor blocks this action • Cimetidine or Tagamet – most widely used • Famotidine or Pepcid • Nizatidine or Axid • Ranitidine or Zantac – more potent than Tagamet

45. Proton Pump Inhibitors • Strong inhibitors of gastric acid secretion • Nexium • Prevacid • Prilosec • Aciphex • Cytotec • Carafate

46. Use in Special Populations • Pediatrics – will be given to prevent GI bleeding • Asthmatics on IV or po corticosteroids • Head trauma on IV dexamethasone for cerebral swelling • Older Adults – calcium carbonate antacids like “Tums” due to decreased side effects • Renal impairment – magnesium containing preparations (Mylanta, Maalox) contraindicated – need good kidney function to eliminate magnesium • Critical care units may use to prevent GI bleeding

47. Laxatives and Cathartics Chapter 60

48. Laxatives and Cathartics • Used to promote bowel elimination • Laxatives implies mild effects and elimination of soft, formed stool • Cathartics implies strong effects and elimination

49. Indications for Use • Relieve constipation in pregnant women and elderly clients • To prevent straining of clients with coronary artery disease • To empty the bowel in preparation for a surgery or diagnostic procedure • To accelerate elimination of toxic substance • To reduce serum cholesterol

50. Bulk Forming Laxatives • Substances that are largely unabsorbed from the intestine • When water is added the substances swell and become gel like • Added bulk and size of the fecal mass stimulates peristalsis and defecation