Pathophysiology Nursing Final

Week 13

Digestive 

Common manifestations of digestive system disorders 

  • Anorexia, nausea, vomiting 

    • Systemic infection 

    • Uremia 

    • Emotional responses 

    • Motion sickness 

    • Pressure in brain 

    • Overindulgence of food, drugs 

    • Pain 

    • Can cause 

      • Dehydration, acidosis, malnutrition 

      • Anorexia often precedes nausea and vomiting 

      • Nausea: unpleasant subjective feeling, stimulated by distention, irritation, inflammation of digestive tract, stimulated by smells, visual images, pain and chemical toxins 

    • Vomiting 

      • Center located in medulla: activities involved in vomiting, protection of airway

      • Forceful expulsion of chyme from stomach (sometimes includes bile)

  • Vomiting center activation 

    • Distention or irritation in digestive tract 

    • Stimuli from various parts of brain 

      • Response to unpleasant sights or smells, ischemia 

    • Pain of stress 

    • Vestibular apparatus of inner ear (motion)

    • Increased intracranial pressure 

      • Sudden projectile vomiting without previous nausea 

    • Stimulation of chemoreceptor trigger zone (drugs, toxins, chemicals)

  • Vomiting reflex activities 

    • Deep inspiration 

    • Closing glottis, raising soft palate 

    • Ceasing respiration 

      • Minimizes risk of aspiration of vomitus into lungs 

    • Relaxing gastroesophageal sphincter 

    • Contracting abdominal muscles 

      • Forces gastric contents upward 

    • Reverse peristaltic waves 

      • Promotes expulsion of stomach contents 

  • Characteristics of vomitus 

    • Presence of blood - hematemesis 

      • “Coffee grounds” - brown granular material indicates action of HCl on hemoglobin 

      • Hemorrhage - red blood may be in vomitus 

    • Yellow or green stained 

      • Bile from duodenum 

    • Deeper brown color 

      • May indicate content from lower intestine 

    • Recurrent vomiting of undigested food 

      • Problem with gastric emptying or infection 

  • Diarrhea 

    • Excessive frequency of stools 

      • Usually of loose or watery consistency 

    • May be acute or chronic 

    • Frequently with nausea and vomiting when infection or inflammation develops 

    • May be accompanied by cramping pain 

    • Prolonged diarrhea may lead to dehydration, electrolyte imbalance, acidosis, malnutrition 

      • Common types of diarrhea 

        • Large volume (secretory or osmotic)

          • Watery resulting from increased secretions into intestine from plasma 

          • Often related to infection 

          • Limited reabsorption due to reversal of normal carriers for sodium and or glucose 

        • Small volume 

          • Often due to inflammatory bowel disease 

          • Stool may contain blood, mucus, pus 

          • May be accompanied by abdominal cramps and tenesmus 

        • Steatorrhea - fatty diarrhea 

          • Frequent bulky, greasy, loose stools 

          • Foul odor 

          • Characteristic of malabsorption syndromes 

            • Celiac disease or cystic fibrosis 

          • Fat usually the first dietary component affected 

            • Presence interferes with digestion of other nutrients 

          • Abdomen often distended 

  • Blood in stool 

    • Blood may occur in normal stools, with diarrhea, constipation, tumors or inflammatory conditions 

      • Frank blood: red - usually from lesions in rectum or anal canal 

      • Occult blood: small hidden amounts, may be cause by small bleeding ulcers

      • Melena: dark colored, tarry - may result from sig. bleeding in upper tract 

  • Gas

    • From swallowed air (drinking from a straw)

    • Bacterial action on food 

    • Foods or alterations in motility 

    • Excessive gas causes 

      • Eructation 

      • Borborygmus 

      • Abdominal distention and pain 

      • Flatus 

  • Constipation 

    • Less frequent bowel movements 

    • Small hard stools 

    • Acute or chronic 

    • May be due to decreased peristalsis (increased time for reabsorption of fluid)

    • Periods of constipation may alter with periods of diarrhea 

    • Chronic constipation may cause hemorrhoids, anal fissures or diverticulitis 

    • Causes 

      • Weakness of smooth muscle due to age or illness 

      • Inadequate dietary fiber

      • Inadequate fluid intake 

      • Failure to response to defecation reflex 

      • Immobility 

      • Neurologic disorders 

      • Drugs 

      • Some antacids, iron medications 

      • Obstructions caused by tumors or strictures 

  • Fluid and electrolyte imbalances 

    • Dehydration and hypovolemia are common complications of digestive tract disorders 

    • Electrolytes 

      • Lost in vomiting and diarrhea 

    • Acid base imbalances 

      • Metabolic alkalosis - results from loss of hydrochloric acid with vomiting 

      • Metabolic acidosis 

        • Severe vomiting causes a change to metabolic acidosis because of the loss of bicarbonate of duodenal secretions 

        • Diarrhea causes loss of bicarbonate 

Basic diagnostic tests 

  • Radiographs - contrast medium may be used 

  • Ultrasound - may show unusual masses

  • Computed tomographic (CT) scan 

  • Magnetic resonance imaging (MRI)

  • CT and MRI may use radioactive tracers - can be used for liver and pancreatic abn.

  • Fiberoptic endoscopy in upper GI - biopsy msy br done 

  • Sigmoidoscopy and colonoscopy - biopsy and removal of polyps 

  • Lab analysis of stool specimens - infections, parasites, bleeding, tumors, malabsorption 

  • Blood tests - liver, pancreatic function and cancer markers 

Disorders of the liver and pancreas 


Gallbladder disorders 

  • Cholelithiasis 

    • Formation of gallstones 

    • Solid material (calculi) that form in bile 

  • Cholecystitis 

    • Inflammation of gallbladder and cystic duct 

  • Cholangitis 

    • Inflammation usually related to infection of bile ducts 

  • Choledochonlithiasis 

    • Obstruction of biliary tract by gallstones 

  • Gallstones 

    • Form in bile ducts, gallbladder or cystic duct 

    • May consist of 

      • Cholesterol or bile pigment 

      • Mixed content with calcium salts 

    • Small stones - may be silent and excreted in bile

    • Larger stones - obstruct flow of bile in cystic or common bile ducts - cause sevre pain in right subscapular area 

    • Waves of pain, spasms  = biliary colic 

  • Risk for gallstones 

    • Women 2x more likely 

    • High cholesterol in bile 

    • High cholesterol intake 

    • Obesity 

    • Multiparity - multiple pregnancies 

    • Use of oral contraceptives or estrogen 

    • Hemolytic anemia 

    • Alcoholic cirrhosis 

    • Biliary tract infection 

  • Obstruction of duct by large calculi 

    • Sudden severe waves of pain - radiating pain 

    • Nausea and vomiting usually present 

    • Pain continues and jaundice develops 

      • Bile backs up into liver and blood - jaundice 

      • Risk of ruptured gallbladder if obstruction persists 

      • Pain decreases if stone moves into duodenum 

      • SLIDE 26

Indirect (conjugated) bilirubin - attached albumin going to liver 





Liver 

  • Glucose metabolism - impaired glycogen storage if not working right 

  • Converts ammonia to new proteins - if liver not working, ammonia too high (pt is confused)

  • Makes clotting factors 

  • Makes proteins 

  • Vit. A, B, D and iron stored in liver 

  • Drug metabolism - if not working = toxicity 

  • Excretes hormones - if not working = ADH and aldosterone too high 



Hepatitis C

  • Direct injury to liver - inflammation and necrosis 

  • Can become chronic 




Week 14


Digestive system disorders part 2 


Dysphagia 

  • Difficulty swallowing 

  • Causes 

    • Neurologic deficit 

      • Infection 

      • Stroke 

      • Brain damage 

      • Achalasia 

        • Failure of the lower esophageal sphincter to relax due to lack of innervation 

    • Muscular disorder 

      • Impairment from muscular dystrophy 

    • Mechanical obstruction 

      • Congenital atresia 

        • Developmental anomaly 

        • Upper and lower esophageal segments are separated 

      • Stenosis 

        • Narrowing of the esophagus 

        • May be developmental or acquired 

        • May be secondary to fibrosis, chronic inflammation, ulceration, radiation therapy 

        • Stenosis or stricture may also result from scar tissue 

        • May require treatment with repeated mechanical dilation 

      • Esophageal diverticula 

        • Outpouchings of the esophageal wall 

        • Congenital or acquired following inflammation 

        • Causes irritation, inflammation, scar tissue

        • Signs include dysphagia, foul breath, chronic cough, hoarseness 

      • Tumor - may be internal or external 

  • results/ presentation 

    • Pain with swallowing 

    • Inability to swallow larger pieces of solid material 

    • Difficulty swallowing liquids 



Hiatal hernia 

  • Part of stomach protrudes into thoracic cavity 

  • Sliding hernia 

    • More common type 

    • Portion and part of stomach and gastroesophageal junction slide up above diaphragm 

  • Rolling or paraesophageal hernia 

    • Part of fundus of stomach moves up through an enlarged or weak hiatus in the diaphragm and may become trapped 

  • Food may lodge in pouch of hernia 

    • Causes inflammation of mucosa 

    • Reflux of food up esophagus 

    • May cause chronic esophagitis 

  • Signs 

    • Heartburn or pyrosis 

    • Frequent belching 

    • Increased discomfort when lying down 

    • Substernal pain may radiate to shoulder and jaw 

Gastroesophageal reflux disease 

  • Periodic refluc of gastric contents into distal esophagus causing erosion and inflammation 

  • Often seen in conjunction with hiatal hernia 

  • Severity depends on competence of lower esophageal sphincter 

  • Delayed gastric emptying may be a factor 

  • Avoid 

    • Caffein, fatty/ spicy foods, alcohol, smoking, certain drugs 

  • Use of medication may reduce refluc and inflammation 

Gastritis - acute gastritis 

  • Gastric mucosa is inflamed 

  • May be ulcerated and bleeding 

  • May result from 

    • Infection by microorganisms 

    • Allergies to foods 

    • Excessive alcohol intake 

    • Ingestion of aspirin or other NSAIDs 

    • Ingestion of corrosive or toxic substances 

    • Radiation or chemotherapy 

  • Basic signs of gastrointestinal irritation 

    • Anorexia, nausea, vomiting may develop 

    • Hematemesis 

    • Epigastric pain, cramps or general discomfort 

    • With infection, diarrhea may develop 

  • Acute gastritis is usually self limiting 

    • Complete regeneration of gastric mucosa 

    • Supportive treatment with prolonged vomiting 

    • May require treatment with antimicrobial drugs 

Gastritis - chronic gastritis 

  • Characterized by atrophy of stomach mucosa 

    • Loss of secretory glands