Elimination Flashcards
What are 4 common clinical presentations of problems with elimination?
- Acidity
- Transition time (slow/fast)
- Nausea & Vomiting
- Liver disease
Slow transition time = ____ re-absorption of water
increased
Fast transition time = ____ re-absorption of water
decreased
What are gastric pits?
Indented depressions
What cells are gastric pits lined with?
Mucous + specialized gastric cells
What are 2 things gastric juice is composed of?
- HCl
2. pepsinogen
Which cells secrete HCl?
Parietal
Describe how pepsin is formed
- Gastric Chief cells secrete pepsinogen
2. Pepsinogen is activated by HCl into pepsin
What is the function of foveolar cells/ goblet cells
- Protection from gastric juice in esophagus
- Forms mucous and bicarbonate layer (endogenous protection)
How is the lower GI protected from gastric juice?
- Gallbladder secretion of bile
- Pancreatic bicarbonate
What is the function of gastric pits?
- Chemical digestion
- Direct contact w/ gastric capillaries
What is a proton pump’s function?
Releases HCl into stomach
What happens when food is digested in the stomach?
- G cells secrete gastrin
- Gastrin stimulates histamine
- Histamine binds to H2 receptors on parietal cells
- Increases HCl production
What are 2 examples of acidity problems?
- Reflux (& GERD)
2. Peptic Ulcer Disease (PUD)
Describe the 2 conditions that can result in reflux/GERD
- Weak lower esophageal sphincter allows reflux to occur
2. Delayed gastric emptying
What are some beverages that increase of reflux?
- Coffee
- Apple juice
- Carbonated drinks
What are 4 complications of GERD?
- Esophageal erosion
- Pain
- Inflammation
- Decreased appetite
What are 3 treatments for GERD?
- Decrease acidity
- Avoid irritants
- Surgery (fundoplication)
What are 3 causes of PUD?
- H. pylori (g- bacteria)
- NSAIDs
- Stress
What is the pathophysiology of PUD?
- Failure of endogenous protection
- Mucosal erosion
- Can extend into deep layers
____ ulcers have bloody vomit meanwhile ____ ulcers have bloody stool
Gastric, duodenal
How does H. pylori cause a PUD?
H. pylori produces ammonia, which damages the mucosa + neutralizes pH
How do NSAIDs cause PUD?
- Inhibit COX receptors (in charge of mucosa protection)
- Decreased protection of GI mucosa
- Decreased clotting (increases chance of bleeding)
What are 3 options for treating PUD?
- H2 receptor antagonists
- Proton pump inhibitors
- Antacids
How do H2 receptor antagonists decrease acidity?
H2 specific blockade to decrease HCl production
Are H2 receptor antagonists used for acute or chronic treatment?
Acute
What are 3 examples of H2 receptor antagonists?
- Ranitidine (Zantac)
- Cimetidine (Tagamet)
- Famotidine (Pepcid)
How do proton pump inhibitors decrease acidity?
Binds to enzymes on proton pump and prevents HCl secretion
Proton pump inhibitors have ____ efficacy and ____ half lives than H2 receptor antagonists
higher, longer
Are proton pump inhibitors used for acute or chronic treatment?
Chronic
What are 3 examples of proton pump inhibitors?
- Omeprazole (Losec)
- Lansoprazole (Prevacid)
- Pantoprazole (Pantoloc)
How do antacids decrease acidity?
Increase stomach pH
When are antacids used?
For symptom relief only
What are 3 examples of medications based on mineral elements?
- Aluminum hydroxide (Amphojel)
- Magnesium hydroxide (Milk of Magnesia)
- Calcium carbonate (Tums, Caltrate)
A side effect of aluminum is ____ while a side effect of magnesium is ____
constipation, diarrhea
What are 3 malabsorbed nutrients?
- Iron
- Calcium
- Magnesium
1st line therapy for PUD consists of: _ antibiotics + ____
3, PPI
What 3 antibiotics are in the 1st line of therapy for PUD?
- Amoxicillin
- Clarithromycin (if allergy, Tetracycline)
- Metronidazole
Bismuth therapy for PUD consists of: antibiotics + ____ ____
Bismuth subsalicylate (Pepto-bismol)
What is the small intestine responsible for versus the large intestine?
Small: absorption of nutrients
Large: reabsorption of water + vitamin B & K synthesis
Which nervous system innervates the bowel?
ANS, parasympathetic
What do mechanoreceptors do?
Peristalsis/GI stretch
What do chemoreceptors do?
Detect:
- Food presence
- Osmolality
- pH
Diarrhea occurs when the transition time is too ____
fast
What are 4 common causes of diarrhea?
- Infectious organisms
- Food intolerances
- Intestinal disease
- Drugs
Acute diarrhea is less than _ weeks and can either be ____ or ____
2, inflammatory, noninflammatory
What are 3 complications of diarrhea?
- Electrolyte imbalance
- Dehydration
- Malabsorption
Describe inflammatory diarrhea
- Infectious
- Pathogenic (invades mucosa)
- Fever + bloody stool (dysentery)
- LLQ cramps, urgency + tenesmus
Describe noninflammatory diarrhea
- Usually not infectious
- Effect mediated by toxins
- Watery stool
- N&V, bloating, periumbilical cramps
How do you treat Traveler’s Diarrhea?
- Treat infection first [Ciprofloxacin (PO, IV)]
2. Manage diarrhea symptoms
C. difficile is gram ____ and produces 2 toxins: ____ & ____
positive, enterotoxin, cytotoxin
What are the 4 signs and symptoms of a C. difficile infection?
- Severe diarrhea
- Blood or pus in stool
- Fever
- Abdominal pain
What are 2 causes of a C. difficile infection?
- Nosocomial
2. Long term antibiotic treatment
1st line of treatment for C. difficile infection: ____
2nd line of treatment for C. difficile infection: ____
Flagyl (PO)
Vancomycin (PO)
What are probiotics?
Live “good” bacteria
What is an example of a probiotic?
Lactobacillus acidophilus
Probiotics ____ + ____ normal flora
restore, protect
Chronic diarrhea is longer than _ weeks and can be ____, ____ or ____
4, osmotic, secretory, inflammatory
What causes osmotic diarrhea?
Too much solute stays in the intestine and water can’t be reabsorbed completely due to the hyperosmotic environment
ie) lactose intolerance
What are the 2 causes of secretory diarrhea?
- Body secretes too many electrolytes and causes water build up
- Too much bile acid in the colon, which causes secretion
What 5 chronic GI diseases are associated with chronic diarrhea?
- IBD
- IBS
- Malabsorption syndrome
- Endocrine disorders
- Radiation colitis
What are the 4 signs and symptoms of IBS being the cause of diarrhea?
- Abdominal pain
- Cramping
- Bloating
- Diarrhea/constipation
What are 4 potential triggers for IBS?
- Stress
- Menstruation
- Diet
- Food intolerances
What is the pathophysiology of IBS?
CNS dysregulation of normal motility
Opioids are the ____ effective treatment for diarrhea because they bind to __ receptors in the GI, which ____ peristalsis
most, Mu2, decrease
What are 2 side effects of opioids as antidiarrheals?
- CNS depression
2. Constipation
What are 2 cautions of using opioids as antidiarrheal?
- Pregnant women
2. Addiction
Atropines ____ parasympathetic system and ____ sympathetic system
block, stimulate
What are 2 examples of opioid + atropine medications?
- Lomotil (dyphenoxylate)
2. Imodium (loperamide HCl)
How do antidiarrheals work? (3 ways)
- Decreases peristalsis
- More fluid absorption
- Stool is more solid
How do we rehydrate a patient in the hospital vs at home?
Hospital: isotonic IV solution
Home: gastrolyte, pedialyte
Constipation occurs when transition time is too ____
slow
What are 3 common causes of constipation?
- Insufficient water and/or fibre intake
- Alterations in peristalsis
- Alterations in intestinal innervation
Describe Hirschsprung disease
Parasympathetic ganglion cells in the wall of large intestine don’t develop before birth (poop is stuck)
What are the 5 types of laxatives?
- Bulk forming
- Softners
- Saline & Osmotic
- Stimulants
- Lubricating
How do bulk forming laxatives work?
Pulls water into stool, increasing size
What is an example of a bulk forming laxative?
Metamucil (psyllium)
Describe metamucil
- Fibre powder
- Water intake is a must
- Prophylactic
How do softener laxatives work?
Pulls water + fat into stool
Describe softener laxatives
- PO
- Requires good renal function
- Used post MI or surgery
- Takes 1-3 days
What is an example of a softener laxative?
Colace (docusate sodium)
How do saline and osmotic laxatives work?
Pulls water into stool
What are 2 examples of saline and osmotic laxatives?
- Milk of magnesia
2. Lactulose
Describe saline and osmotic laxatives
- Pre-procedural is best
- Acts fast
- Potent
- Not systemic
How do stimulants/irritants work?
Increases peristalsis
What are 2 side effects of irritants?
- N&V
2. Cramping
What are 3 examples of irritants?
- Dulcolax
- Senna (Exlax, Senokot)
- Castor oil
What are the 3 conditions when you shouldn’t use stimulants/irritants?
- Perforation
- First choice for constipation
- Pre-surgery
What are 2 examples of lubricating laxatives?
- Mineral oil
2. Glycerine (PR)
What are cathartics?
Pre-procedure (bowel surgery or colonoscopy) preparation
> Expands bowel
> Clears contents
How to treat bloating?
Enzymes to increase carbohydrate digestion
ie) Gasex
How does the vomiting centre in the medulla work?
- Outside the BBB
- Receives sensory pathway signals OR senses toxins
- Triggers stomach contractions
What 5 receptors are involved in the N&V response?
- D2 = dopamine
- 5HT = serotonin
- H1 = histamine
- M = muscarinic
- CB1 = cannabinoid
What are the 3 steps in treating N&V?
1. Treat the N&V > Target receptors 2. Treat underlying cause > ie) pain, poisoning 3. Treat the effects of N&V > ie) dehydration, electrolyte imbalances
What are 3 examples of H1 antagonists/antihistamines?
- Dimenhydrinate (Gravol)
- Meclizine (Dramamine)
- Dilectin*
* For pregnant
What do H1 antagonists do to counter motion sickness?
Reduce vestibular excitation
What does ginger gravol do to combat nausea?
Increases intestinal peristalsis
What is an example of an antimuscarinic anticholinergic?
Scopolamine (Hycosine)*
*Transderm. patch, IV + PO
What do antimuscarinic anticholinergics do to combat nausea?
Reduce vestibular excitation
What are 2 uses of 5HT3 (serotonin) antagonists?
- Drug-induced & chemotherapy treatment
2. Visceral pain
What is an example of a 5HT3 (serotonin) antagonist?
Ondansetron (Zofran)*
*PO, IV
What are D2 receptor antagonists used for?
GI pain
How do D2 receptor antagonists counter GI pain?
Stimulate GI motility
What is are 2 examples of a D2 receptor antagonist?
Phenothiazines:
- Metoclopramide (Maxeran, reglan)
- Prochlorperazine (Stemetil)
What is a side effect of phenothiazines?
Sedation
What are the 3 uses for CB1 & 2 agonism?
- Chemotherapy
- Chronic disease
- Challenging cases
What are 3 examples of CB 1 & 2 agonists?
Cannabinoids:
- Dronabinol (Marinol)
- Cesamet/Nabilone
- Cannabis
Cannabinoids’ receptor binding ____ GABA and ____ sympathetic activity
stimulates, inhibits
What are the 2 active ingredients in cannabinoids?
- THC
2. CBD