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gastrointestinal system
- upper GI- mouth ends @ jejunum
- lower GI- ileum eands @ anus
accessory structures include peritoneum, liver, gallbadder, & pancreas
primary function- digestion & distrubution of food
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mouth, esophagus, stomach
mouth: contains enzyme salivary amylase which os secreted by salivary gland (moisten food), adds ptyalin enzyme 4 digestion of starched foods
- esophagus: starts @ pharynx & ends opening of stomach, has straied muscle @ proximal ends, straided & smooth muscle @ mid, & smooth muscle @ lower esophagus
- upper esphageal & hypopharyngeal sphincter prevents fluids from re-enterin pharynx
- stomach:
- lower esophageal/cardiac sphincter- between esophagus & stomach
- pyloric sphincter- between stomach & duodenum
- both are circular bands of muscle fibers
Gastric secretions: acidic b/c contain hydrochloric acid(HCI), this mixture with food is call chyme, & move by peristalisis 2 sm. intestine
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Sm. intestine
- primary function is 2 absorb nutrients from chyme, type of nutrient depends on site of sm. intestine (see pg 636, TBL-44-3)
- divided to 3 parts:
- duodenum- 10 in. long, 1st part of sm. intestine & where bile & pancreatic enzymes enter, which promote chemical breakdown of food, from chyme 2 a alkalin state
- jejunum & ileum- 23ft 2gether
- ileocecal valve- @ distal end, regulates flow of liquid content 2 lrg. intestine
- if any part diseased or removed absorption is reduced or lost
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lrg. intestine
- 4-5in long, 2inches in diameter
- recieves waste & sends it to anus
- absorbs water, eletrolytes, & bile acids
- parts of lrg intestine
- cecum- pouch-like, begining of lrg. intestine, appendix- narrow blind tube @ tip of cecum, no known use
- colon (3 parts)
- ascending, transverse, descending, sigmoid & rectum
- In colon unabsorbed material becomes fecal matter (water, food residue, microorganism, digestive secretion, & mucus), water reabsorbed by diffusion, when mixture reaches descending itz already a formed mass
- internal & external anal sphincters holds feces, when accumulates urge to defecate occurs, & sphincters are relaxed
if any part diseased/removed absorption is reduced/lost, leadin 2 loss stool, potential fuid & electrolyte imbalance, passage of stool that has bile salts lead to risk of skin breakdown, & if stool stays in lrg intestine too long it leads 2 constipation
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Accessory structures
- peritoneum:
- lines inner abd., encloses viscera & serous fluid it secretes, allows abd. organs 2 move w/o friction
- walls prevent gastric & intestinal content from escaping into peritoneal cavity
- peritonitis- when the content escape thru a perforation of wall
- live:
- largest glandular organ, weighs 1-1.5kg, in R upper abd. under diaphragm which serperates from R lung
- forms & releases bile, processes vit. proteins, fats, & carbs, stores glycogen, for blood coagulation, metabolizes & biotransforms chemical, bacteria & foreign matter, from antibodies & immunizing substances (gamma globulin)
- Gallbladder:
- attached to mid-portion in under surface of liver, has thin wall & holds 60ml of bile
- water & minerals absorbed
- triggered by ingested food (especially fats), causes bile to b released 1st by cystic duct then by common bile duct into duodenum where absorption of fats, fat-soluble vit., iron & calcium
- bile activates pancreas to release digestive enzymes & alkalin fluid that nuetralizes stomach acid that reach duodenum
- Pancreas:
- exocrine gland- releases secretions into duct or channel
- endocrine gland- releases substances directly to bloodstream
- endocrine organ releases insuline & glucagon
- exodrine organ- produces fats, protein, carb-digested enzymes
- panceatic emzyme- released in inactive form & transported to duodenum where activated
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HX Assessment
- b/c of GI disorders disturbances in ingestion, digestion, absorption, & elimination
- pt HX- c/o, focus on nutrition, metabolic & elimination patterns
- why pt needs tx & current symptoms, how long & cause
- foods that produce distress & when symptoms likely 2 occur
- ? pt does to releive symptoms
- pt appetite, problems w/ chewing/swallowing, ?/how much pt eats, any discomfort around consumption, any nutritional supplements
- wt gain/loss
- hx of medical/surgical procedures
- family health/death hx, family hx of digestive disorders
- work hx 2 exposure if chemical/toxins/radioactive materials
- allergy/med hx
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Physical assessment
- v/s, breathing pattern
- appearance w/ regard to age & body size
- hygiene
- energy
- emotional attitude, mental status
- skin:
- abnormal color (jaundice) in well lit room
- if dark skinned pt. inspect hard palate, gums, conjunctiva, & surroundng tissue 4 discoloration
- if jaundice, inspect sclera
- inspect skin of abd. & face (looking 4 spider angiomas- superficial red discoloration from blood vessels
- distended abd. veins (caput medusae), & scars
- oral dryness & skin turgor
- mouth:
- inspect lips 4 sores, cracks, lesions, abnormalities
- using tongue blade check 4 inflammation, discoloration
- quality of oral care, lookin 4 missin teeth, partial plates, dentures & ask if well fittin & if pt could eat reg. food
- abd: discribed in quads
- pt supine, knees flexed (helps 2 relax abd muscles)
- whether flat, round, concave, distended, & effort when breathing, (distention could cause dyspnea from upward pressue on diaphragm
- auscultation before palpation lower liver margin if tender liver may be enlarged (R lower rib cage) suggest liver disorder, gallbladder/intestinal disease or pancreatic disorder , mesurement of abd. girth
- percuss 4 changes in dullness over solid mass like liver
- Anus:
- hemorrhoid
- skin tags
- fissures (sm. tears), breaks, lesions, rash, inflammation, drainage
- stool characteristics
- (see pg 639 TBL. 44-4)
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barium swallow or upper GI series
used interchangeably
- barium swallow: flouroscopic observation
- faciliates identification of abnormalities of esophagus, swallowing dyfunctins & oral aspirations
- upper GI series: radiographic observation
- barium moving from stomach to 1st part of sm. intestine
- abnormalities in esophagus include tumors, peptic ulcers, gastric disorders
- if only barium swallow done takes 20min, but if stomach filling & emptyin then takes 1hr
- nurse teaching:
- pt needs to be on low-residue diet, NPO for 8-12hr before
- laxative given
- no smoking b/c it stimulates gastric mobility
- sometimes meds held like insuline & anticonvulsives
- barium is very constipating so after procedure pt needs fluids
- advise that stool may look white, streaky, clay color, of pt doesnt have bowel movement notify DR. b/c barium may cause blockage
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sm. bowel series
- flouroscope in sm. intestine after ingestion of contrast medium
- 2 identify inflammation/obstruction in jejunum or ileum
- like GI series but pt swallow more barium so sm. intestine could be well visualized
- if fissure or obstruction suspected substitute a water-soluble contrast medium like methylglucamine(gastrografin)
- takes 5hr till reaches lower portion of sm. intestine
- if series fails enteroclysis done
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enteroclysis/ sm. bowel enema
- nasal/oral placement of feedig tube, tip positioned @ proximal jejunum
- uses 2 contrast- 1st 750-1000ml of thin barium, then 750-1000ml of methylcellulose, both pass thru intestinal loop, DR. observes continuosly by flouroscopy & take some x-ray in sections
- takes up to 6hr
- nurse:
- if sedation ensure pt comfortable & monitor
- risk 4 aspiration especially if pt vomits while sedation
- position pt on side & have suction available
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barium enema or lower GI series
- 2 identify polyps, tumors, inflammation, strictures, abnormalities in colon
- radiographic tech, rectally instills 1000-1500ml barium
- observes rectum, sigmoid colon, & desending colon flouroscopically during fillin
- to facilitate process instruct to have multiple postion changes
- pt needs to retain bariun during test which takes 30 min
- pt may have abd. cramping & urge to defecate, nurse ensures pt thatmost pt could retain barium throughout test
- radiographs taken again after pt expels barium
- sometimes air instilled to compress barium residue against wall to help detect mucosal defect
- stool specimens not collected till barium expelled completely
- pt teaching to reduce formation of stool & remove residual stool:
- restrictions & process 24-48hr before barium enema
- low-residue diet 1-2 days before
- clear liquid diet evening before
- laxative evening before
- NPO after mid-night
- cleansing enema morning of (if not contraindicated b/c inflammation/active bleeding
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oral cholecytography or gallbladder series
- checks 4 stone, tummors, obstruction in gallbladder or common duct
- also checks gallbladders ability 2 concentrate/store dyelike iodine-based radiopaque contrast, after dye absorbed goes 2 liver excreted into the bile & passes into gallbladder makin it radiographic visible
- radiography should be done before GI exam w/ barium b/c it obscures image of gallbladder/ducts
- Nurse teaching:
- eat fat-free meal night before
- allergy to iodine, pt swallow 6 iodine tabs 1q5min after evenin meal bight before w/ 250ml of water, then pt needs to be NPO after mid-night
- if nausea/vomiting tell DR. so more tabs ordered or test rescheduled
- once radiography done, a fatty-test meal/fatty synthetic substance given 2 stimulate gallbladder contraction & emptying, checked by more radiography
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cholangiography
- performed in radiology or during surgery
- determines patency of ducys from liver & gallbladder
- used when gallbladder not seen w/ oral cholecystogram, vomite interferes w/ w/ retention of dye
- endoscopic retrograde cholangiopanceatography (ERCP):
- dye injected thru cath into pancreatic duct & common bile duct
- intraoperative cholangiography:
- contrast injected directly to bile dict during gallbladder surgery
- magnetic resonance cholangiopancreatography(MRCP):
- sees bile/pancreatic duct & gallbladder w/ no dye uses MRI, gives clear & detailed view
- percutaneous transhepatic cholangiogrphy:
- ultrasound used to guide needle into bile duct & directl injected
- no matter of dye given it travels into biliary system, x-ray taken to see narrowing/blackage
- nurse teaching:
- pt must sign consent
- ask about allergy to iodine/shellfish
- check orders for enema, & any food restrictions
- inform pt that warm feelng & nausea may happen when instilling dye
- pt may eat after procedure
- promote fluids for excretion of dye
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radionuclide imaging
- checks 4 lesions of liver or pancreas, & checks gastric emptying
- natural/synthetic, given IV or orally
- scanner used over body organ
- shows size of organ, & tumors, identifies site 4 bleeding/inflammation in GI tract
- have shorter half-lives lasting hr-days
dosed by wt, preg
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CT reffered to colonography
- tube inserted & air introduced & images done
- detect structual abnormalities of GI tract
- detect metastic lesions
- oral barium sulfate or IV calcium phosphate 4 contrast
- pt NPO 6-8hr before
- bowel cleansed
- med may be given to lower paristalisis or improve gastric motility
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MRI
- if test not good MRI done:
- check soft tissueGI disorders- abscess/bleeding
- Nurse:
- pt NPO 6-8 before
- remove metal objects
- pt w/ pacemakers need cardiologist consult 1st
- IV fluids, if req., by gravity
- inform that tunnel like maccin that makes load noises
- if claustrophobic- sedation needed
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magnetic resonance elastrography (MRE)
- low frequency sound waves (shear waves)
- checks firmness of liver , leads to prediction of fibrosis (scar tissue) & eventually cirrhosis (hardeni of liver)
- great promise like breast, muscle. & brain tissue
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ultrasound
- high frequency sound waves
- liver & pancreas
- shows size & location of orgns outlines stuctures & abnormalities like cholecytitis, cholelithiasis, pyloric stenosis, & disorders of billary system
- pt could have fluids but instructed not too, also no smoking chewing gum, they may swallow air distort sound waves
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percutanous liver biopsy
- checkin 4 malignant changes infectious & inflammatory process, liver damage (cirrhosis), & signs of liver rejection if transplant
- coagulation test done b/c biopsy could lead to bleeding, if @ risk give vit. k 2 promote coagulation
- CT 4 correct site of biopsy
- sedation & anesthics give 4 comfort & cooperation, monitor pt closley
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GI endoscopy
- visual exam of lumen
- flexible endoscope
- detects lesions
- nurse teaching:
- NPO
- bowel preps
- pt needs to spray & gargle anesthetic
- pt given anxiolytic 4 sedation
- monitor v/s, including pain, LOC, abd symptoms
- monitor signs of perforation like fever, abd distention, abd/chest pain vomiting blood, rectal bleeding
- pt may eat when gag reflex returns
- if sore throat gargle saline, ice chips, & cool drinks
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LABS
- CBC, urinalysis, serum bilirubin, cholesterol, ammonia level, PT, protein electrophorisis, & enzyme (amylase, lipase, aspertate aminotransferase, lactic acid dehydrogenase
- common tumor markers carcinoembryonic antigen & alpha-feto-protein
gastric analysis- activitiy of gastric mucosa, retention, NPO 8-12hr, nasogastric tube into stomach, content aspirated q15min for 1hr, checkin ph, volume, cytology
- H-pylori- 4 peptic ulcers,
- blood test, urea breath test, stool,
- more invasive biopsy could be done;
- raid ureas test (enzyme), histology (actual bacteria), culture(growing bacteria in tussue sample)
hydrogen brething test- collecting breath before & after ingestion of cardohydrate solution, detect types of malabsorption of lactose (most common)
- stool analysis- check WBC(inflammation), RBC(GI blood loss), fat(malabsorption), infection
- detects bacteria, parasites, ova
- hemocult test (blood)
- false + include red meat, iodine having antiseptic prep, asprin, & NSAIDS, alcohol
- false - include ascorbic acid (vit. C), iron supplements
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