GI Part 2 Lecture 4 PDF

Pathopharm GI part 2 Lecture 4 Images for educational purposes only, not for further distribution Helena Schaefer, MN GI terminology  ‘host flora’ – intestinal flora ◦ upto 500 species of intestinal bacteria  Colonization...

Pathopharm GI part 2 Lecture 4 Images for educational purposes only, not for further distribution Helena Schaefer, MN GI terminology  ‘host flora’ – intestinal flora ◦ upto 500 species of intestinal bacteria  Colonization – development of host flora  Anorexia – loss of appetite  Retching – rhythmic movement of abdominal muscles/diaphragm/chest wall  Emesis – vomiting (expulsion of GI contents)  Congenital – inborn  Dysphagia – difficulty swallowing  Serology – blood test, specifically antibody testing  Biopsy – sample of tissue for patho-analysis  Colonoscopy – viewing of lower GI tract  Endoscopy – viewing of upper GI tract Helena Schaefer, MN Upper GI: congenital malformation, e.g.: TEF (TE fistula) Helena Schaefer, MN GI: small intestine  20 feet long (6 m) ◦ 1 inch in diameter  3 parts ◦ duodenum ◦ jejunum ◦ Ileum (longest)  Associated organs  Major function: absorption of nutrients Helena Schaefer, MN Video, Dr. Mike  metabolism of fats, carbs, protein  https://www.youtube.com/watch?v=I-W- 1ihnoqc Helena Schaefer, MN GI: large intestine  5 feet long (1.5 m) ◦ 3 inch in diameter (7 cm)  4 parts ◦ Ascending colon ◦ Transverse colon ◦ Descending colon ◦ Sigmoid colon  Major functions: ◦ re-absorption of water (simple columnar cells) ◦ ‘host flora’ =Vit B & K synthesis Helena Schaefer, MN GI innervation review:  Intestinal motility affected by the nervous systems: ANS: Sympathetic Parasympathetic Enteric Nervous system; input from: ◦ Mechanoreceptors: GI stretch ◦ Chemoreceptors: food presence/osmolality/ pH/… ◦ ANS H. Schaefer, MN Innervation issues, e.g.: Hirschsprung disease Helena Schaefer, MN Helena Schaefer, MN Inflammatory disorders of GI, e.g. Common S&S: anorexia, diarrhea, nausea  Celiac disease Helena Schaefer, MN brainstorm  What are the stages of inflammation?  What are the s&s of inflammation related to these?  Which drug classes are used as tx of inflammation?  Does inflammation tx differ according to inflammatory mediator, the location, severity,…? Helena Schaefer, MN  Celiac disease ‘gluten sensitive enteropathy’  Gluten triggered immune disorder => overt T-cell mediated immune response to alpha-gliadin (gluten component) => inflammation => severe inflammation causes loss of villi  S&S: anorexia, bloating, diarrhea, malnutrition  Complications: malnutrition (e.g. weight loss, anemia, …)  Dx: serology; biopsy (endoscopic)  Tx: avoidance of gluten Helena Schaefer, MN Helena Schaefer, MN Helena Schaefer, MN Infectious diseases & GI, e.g.  C-dif (gram + bacterium) ◦ Tx?  E-coli (gram – bacterium) Helena Schaefer, MN brainstorm  What are the treatment options for C-dif?  What is a treatment option after abx? Helena Schaefer, MN E-coli infection (note: many strains of e-coli; some endogenous to GI tract in small numbers, some produced toxins)  Causes: ingestion of E-coli ◦ Sources: undercooked meat, contaminated vegetables, contaminated water, unwashed hands,…  S&S: diarrhea, pain, fever  Complications: bacterial toxin- caused ‘hemolytic uremic syndrome’ (life threatening) ◦ e-coli strain ◦ Toxin: Shiga-toxin destroys endothelial cells, platelets, RBCs, …  Tx: supportive Helena Schaefer, MN Video e-coli outbreak  https://www.cbc.ca/news/canada/calgary/e- coli-outbreak-calgary-ahs-daycares- 1.6962033 Helena Schaefer, MN HUS  https://www.youtube.com/watch?v=arKriOU PkBQ Helena Schaefer, MN kahoot Helena Schaefer, MN Diarrhea is a symptom!  increased frequency and fluidity of loose or unformed stool  caused by inflammation or infectious organisms ◦ e.g. food intolerances, intestinal disease, pathogens, drugs,…  Acute or Chronic ◦ Acute 4 weeks, related to longterm disease or drug tx  Complications: ◦ Electrolyte imbalance ◦ Dehydration ◦ Malabsorption H. Schaefer, MN Rehydration!! Rehydration is a MUST  In hospital: ◦ Isotonic IV solution (e.g. NS) ◦ Check serum electrolytes  At home: ◦ Rehydration solutions  Gastrolyte, Pedialyte  In no-mans-land: ◦ 1L water, 80 mL Glucose, 7 mL NaCL (salt) H. Schaefer, MN  Tx with Antidiarrheals Opioid-based  High efficacy: “Mu2” receptor agonism (in GI’s ENS) => decreased peristalsis  s/e: ◦ CNS depression in high doses ◦ addiction H. Schaefer, MN Drugs  Drugs: opioid + atropine ◦ Lomotil (diphenoxylate atropine)  diphenoxylate (opioid) + atropine ◦ Imodium (Loperamide HCl)  meperidine (Demerol) + atropine ◦ Note: Atropine: ‘antimuscarinic’ agent ◦ blocks parasympathetic system, stimulates SNS  Low doses OTC  High doses Rx H. Schaefer, MN  Fecal impaction  retention of hardened or putty-like stool in the rectum and colon  If not removed, it can cause partial or complete bowel Constipation is a symptom obstruction infrequent, incomplete or difficult passage of stool  Dietary: inadequate fluid or fiber intake  Peristalsis: alterations in peristalsis or intestinal innervation impacting colonic motor function ◦ E.g.: inactivity/bedrest; surgery; drugs; pain (e.g. Hemorrhoids); Hirschsprung disease; altered bowel routine H. Schaefer, MN  Tx: Laxatives (5 Types) 1) Bulk forming – pull water 2) Softeners – Pull water & fat into stool and add bulk to into stool stool.  E.g.:Colace (Docusate  E.g: Metamucil (psyllium) Sodium) ◦ Fiber = increases bulk and pulls in water  Prophylactic best ◦ Prophylactic best  Decreased straining ◦ 1 – 2 days to take effect  Good renal function for ◦ Water intake is a must ◦ Used long term in nursing homes excretion  Main use:  Most PO and some PR (suppository)  Post Myocardial Infarction  unscheduled  Post Surgery H. Schaefer, MN  Laxatives 3) Saline & Osmotic – 4) Stimulants – irritants – increase peristalsis pull water into stool  E.g.: Milk of  i.e., Dulcolax, Senna (Exlax, Magnesia, Lactulose, Senokot), Castor Oil GoLytely  s/e: N&V, cramping ◦ Pre-procedural best  If obstruction possible – DO ◦ Potent NOT USE because of ◦ Acts fast! 1 – 3 hours perforation  Milk of Magnesia  NOT first choice for renally excreted constipation   NOT first choice for pre- Lactulose not absorbed (contra. in surgery lactose intolerance) H. Schaefer, MN  Cathartics: Pre- procedure Bowel Laxatives Preparation  Cathartic = Enema 5) Miscellaneous – lubricating  Expansion of bowel  Fast evacuation  i.e., Mineral oil,  PR administration with Glycerine (PR)  patient lying on left side Water and electrolyte  Note: Adjunct combination treatment with constipation H. Schaefer, MN Bloating  “gas”  Tx abdominal discomfort caused by dietary ingestion, with appropriate drug:  Gas X (simethicone) ◦ Surfactant, breaks surface tension of bubbles, dissolves; not systemically absorbed  Beano (alpha-d- galactosidase) ◦ Carbohydrate enzyme to increase digestion into simple sugars Dietary choices? H. Schaefer, MN brainstorm:  Your patient has a GI disease that you haven’t studied: Gastroparesis.  You read about it: Gastroparesis, also called delayed gastric emptying, is a disorder that slows or stops the movement of food from your stomach to your small intestine, even though there is no blockage in the stomach or intestines.  Based on the above, what are the S&S that you anticipate, using all your current knowledge?  What are the concepts related to it, which will further guide your assessment & nursing process? Nausea & Vomiting Defence system! Brainstorm reasons for N&V: H. Schaefer, MN Physiology:  Medulla centers: ◦ Vomiting center (neuronal network)  receives stimuli from CTZ, organs, body regions,… ◦ CTZ  outside of BBB, exposed to blood contents, CSF  stimulus pathway for blood/CSF triggers  stimuli=> trigger GI & diaphragm contractions => emesis H. Schaefer, MN Receptors involved: H. Schaefer, MN Treat the cause & the symptoms! ◦ 1. tx nausea & vomiting  target most appropriate receptors  s/e: CNS (drowsiness, sedation, …) ◦ 2. tx the underlying cause:  Pain  Food poisoning  …. ◦ 3. tx the effects of perfuse vomiting  Dehydration = rehydrate  Electrolyte imbalances = correct: rehydration solutions H. Schaefer, MN  stimulus: motion induced, ‘morning’ sickness, anticipatory nausea target: H1 antagonism (antihistamines)  Antagonize receptors of vestibular excitation Drugs: ◦ dimenhydrinate (Gravol): diphenhydramine + chlorotheophyline ◦ meclizine (Dramamine) ◦ Diclectin: doxylamine + pyridoxine hydrochloride (vitamin B6) H. Schaefer, MN GINGER as a medication  Med: Ginger gravol  NHP (Herbal therapy) ◦ Increases intestinal emptying  Safe in moderate doses ◦ Overdose = bleeding, CNS depression H. Schaefer, MN  target: antimuscarinic anticholinergics  Reduce vestibular excitation ◦ Some affinity to H1 receptors  drugs: scopolamine (Hyoscine))  Transdermal patch  IV, PO H. Schaefer, MN stimulus: drug-induced & chemotherapy treatment; visceral pain target: 5HT3 (serotonin) antagonists  drugs: ◦ ondansetron (Zofran)  Prescription only  PO, IV H. Schaefer, MN stimulus: GI pain target: D2 receptor antagonism  stimulates GI motility  drug class: Phenothiazines  Drugs: ◦ metoclopramide (Maxeran, Reglan) ◦ prochlorperazine (Stemetil)  Prescription only  PO, IV, SC  s/e: sedation! H. Schaefer, MN  stimulus: chemotherapy; chronic disease; challenging cases target: CB1 & 2 agonism  Cannabinoids ◦ Active ingredients: THC (tetrahydrocannabinol) & CBD (cannabidiol) ◦ drugs:  Dronabinol (Marinol)  Cesamet /Nabilone  cannabis ◦ Agonism affects other neurotransmitters, dose dependent:  Serotonin  GABA  Dopamine H. Schaefer, MN