GI and ENT Flashcards
qwhat is the difference between a colloid and crystalloid?
crystalloids are the most common and are based on electrolytes to approximate the mineral content of human plasma; colloids have extra colloidal stuff in them that can’t freely diffuse across a membrane but these are more expensive
water is __ % of body wt in men, ___ in women
60%; 50%
total body water is __/3 intracellular and ___/3 extracellular
2; 1 most of the extracellular fluid is in the intersititum
obligatory fluid intake of adults, how much is ingested, how much is in water and how much is from oxidation?
2600mL; 1400; 850 in food, 350 from oxidation
how is water excreted?
urine, skin, respiratory tract, and stool
what causes volume depletion?
loss of Na or water from vomiting, diarrhea, bleeding; diuretics, osmotic diuresis, salt wasting nephropathies and hypoaldosteronism; skin and respiratory losses, burns, third space sequestration from intestinal obstruction, crush injury, fracture or acute pancreatitis
what are the common sx of volume depletion?
lassitude, easy fatiguability, thirst, muscle cramps, postural dizziness, concentrated urine, dry mucuous membranes; if really severe it can lead to and pain, chest pain, lethargy and confusion from ischemia
skin tenting, dry or clammy skin, dry buccal mucosa and parched or crackedl lips and deep set or sunken eyes signifies fluid loss from where?
intersitial volume
how can you tell if someone has lost plasma volume?
decreased BP and decreased venous pressure in jugular veins, may be tachycardia, lower cap refill
electrolye and acid base imbalances of dehydration can cause?
muscle weakness from hypokalemia or hyperkalemia, polyuria and polydipsia from hyperglycemia or severe hypokalemia and lethargy, confusion, seizures, coma from hyponatremia, hypernatremia or hyperglycemia
for which cases of dehydration is correcting via the oral route ok?
mild cases
what can provide a reasonable estimate of fluid loss?
wt if pre and post wt are known
if wt is not know–how do you estimate fluid losses?
BP, skin burger, urine output, urine sodium excretion and osmolality
what is the req’d rate of repletion for severe depletion or hypovolemic shock?
1-2 liters of normal saline given as rapidly as possible to restore tissue perfusion, then continue at a rapid rate until normalized clinical signs like BP, urine output, mental status
what is the req’d rate of repletion for mild to moderate hypovolemia?
50-100 ml per her in excess of continued losses
overly rapid correction of plasma sodium conc can lead to potentially irreversible?
neurological damage
what pt pops are at risk of fluid overload?
renal, cardiac, or hepatic failure, older adults
what 4 components are considered in maintains tx in healthy euvolemic pts?
water, na, K,carbs
how much body water is lost for each degree above 37C?
100-150/day
replacement of insensible losses should be with what kind of solution?
5% dextrose or hypotonic saline
diarrhea causes ____ times as many losses of fluids as vomiting
2x
what should you monitor when giving fluid?
VS, daily wits, clinical appearance, urine output and specific gravity, serum electrolytes
Histamine receptor antagonists: MOA indicaiton generic/trade AE drug intx adjust for renal?
MOA ; competitively inhibit histamine at H2 receptors on parietal cells leading to decreased gastric acid secretion
generic/trade ranitidine zantac
indicaiton: PUD
AE ; usu well tolerated, D/N/V, rare BM suppression, confusion, hallucinations, with cimetidine: seizures with IV, gynecomastia, impotence with prolonged doses
drug intx CYP450 substrate inhibitor and increases Cp of anticoagulants, theophylline, phenytoin. tolerance may develop with chronic use
adjust for renal? yes
propton pump inhibitors MOA indication generic/trade AE drug intx adjust for renal?
generic/trade omeprazole prilosec
MOA: inhibits H/K/ATPase of parietal cell which decreases gastric acid secretion; more powerful than H2RA, only inhibits actively secreting proton pumps
indication
AE: well tolerated, occasional D/N/C/, HA, dizziness, skin rash, rebound acid hypersecretion is a possibility so taper or step down to H2RA. Overuse risks: fracture risks from decreased calcium absorption (add supps if needed), increased r/o pneumonia or c.diff diarrhea, low Mg, low B12 take 30-60 min before am meal.
drug intx: inhibits CYP450 2C19 which decreases the metabolism of clopidogrel and also its active metabolite and thus its antiplatelet activity by up to 1/2, also alters other absorption of some meds.
adjust for renal?
mucosal protectatnt MOA indication generic/trade AE drug intx adjust for renal?
generic/trade sucralfate carafate
MOA: forms a “pink blanket” in stomach which is a protective barrier and weak acid neutralizer
indication PUD
AE constipation, safe in preg
drug intx :chelation of phenytoin, warfarin, quinolones, thyroxine
adjust for renal? no
prostaglandins MOA indication generic/trade AE drug intx adjust for renal? ci
generc/trademisoprostol cytotec
MOA: it is a synthetic prostaglandin E1 analog and replaces lost/dysfcnal protective PGs.
indication PUD
generic/trade
AE: diarrhea in 30-40% (start with low dose and titrate), uterine contractions, abd pain, nausea, flatulence
ci: preg
drug intx may increase effect of oxytocin
adjust for renal?
bismuth preps MOA indication generic/trade AE drug intx adjust for renal?
bismuth subsalicylate pepto-bismol
MOA: local gastroprotective, stimulates prostaglandins and suppresses H. pylori
indication
AE: black stool or tongue. May cause salicylate sensitivity. Caution In children, influenza or herpes zoster from reye’s syndrome
drug intx: toxicity of ASA, warfarin or hypoglycemics may be increased. May decrease GI absorption and bioavailability of tetracyclines
adjust for renal? caution in older pts or renal pts
antacids MOA indication generic/trade AE drug intx adjust for renal?
MOA local gastroprotective, stimulates prostaglandins and suppresses H. pylori
indication GERD
generic/trade bismuth subsalicylate pepto-bismol
AE black stool or tongue. May cause salicylate sensitivity. Caution In children, influenza or herpes zoster from reye’s syndrome
drug intx toxicity of ASA, warfarin or hypoglycemics may be increased. May decrease GI absorption and bioavailability of tetracyclines
caution in older pts or renal pts
adjust for renal?
promotility MOA indication generic/trade AE drug intx adjust for renal?
MOA increases rate of gastric emptying by unclear mechanism, sensitive tissues to the action of acetylcholine
indication GERD not rec’d anymore b/c of AE and low efficacy
generic/trade metoclopramide reglan
AE occasional extrapyramidal effects: use diphenydramine (benadryl) for prophylaxis or pRN. Restlessness, drowsiness, fatigue, nausea, diarrhea. Black box warning for tardive dyskinesia ( irreversirble psuedoparkinsonism)
drug intx increased risk of HTn with MAOI, incresaes toxicity with antipsychotics, decreased absorption of many drugs
adjust for renal? no
what are the 4 diff PUD etiologies?
NSAIDS, h. pylori, stress related mucosal damage, zollinger ellison syndrome, decreased mucosal blood flow
what are some of the protective factors of the stomach?
PGs, mucous, bicarb
what are the non pharm ulcer txs?
stop NSAIDS, reduce etoh and smoking
what is the general rule for how ulcers should be treated?
ulcer healing rx+ specific ulcer tx +/- maintenaince
what is important to ask pts before testing for H. pylori?
ask about recent abx (last 4 wks) and recent PPi use (last 2 weeks) NOTE: with tests (except antigen detection) for HP can get false - if took abx or bismuth within 4 wks and PPI within 2 weeks.
what role do PPI/H2R2s have in std tx for h. pylori?
they augment h. pylori eradication, relieve ulcer sx and contribute to ulcer healing
what must every regiment to eradicate h. pylori contain?
> or = to 2 abx + a PPI (best) or H2R2
what does the 1st line sequential tx consist of? what is its eradication rate?
PPI for 4 wks throughout. AND amoxicillin 1 gm PO bid x5 days then clarithromycin (or levo) ) 500 mg and tinidazole 500 mg bid x 5 days.eradication rate is 90%.
what are important pieces of pt ed for people on h. pylori eradication tx?
DON’T DRINK if on tinidazole or metronidazole. important to finish tx to eradiacate and prevent resistance, important to keep going with the PPI after you feel better (or if you feel crummy from the abx..important to keep taking them) because it can take 4 wks to heal an ulcer even though you will see sx relief in about 1 wk
what step do you want to take when they re done with h. pylori tx?
do a stool antigen test or urea breath test >8 wks after tx to make sure h. pylori is eradicated (need to give that 4 wk gap after abx so you don’ get a false -)
how do ulcers irritate gastric epithelium?
they are weak acids and directly irritate and they block prostaglandin syntehsis
what are the established RFs for ulcers and GI complications from NSAID use?
These are generally additive RFs: ASA use, age >60, also using anticoagulants, preexisting coagulopathy (elevated INR or thrombocytopenia), also using corticosteroids or SSRI, previous PUD or pUD complications(bleeding or perf), CV disease or other chronic diseases, multiple NSAID use, >1 mo use of NSAID, high dose NSAID use, NSAID related dyspepsia, smoking
is aspirin an NSAID?
YES
which NSAIDs have the lowest GI toxicity?
COX-2 inhibitors are lowest, then ibuprofen. ketorolac has the highest risk of GI bleed.
what factors are included in deciding how to protect peoples GI systemics from adverse effects of LT NSAID use?
based on the RFs. if no RFs, can give normal NSAIDS. if 1-2 RFs, give NSAIDS+PPI or COX-2 or misoprostol. If 3 RFs, give NSAIDS or COX-2 + PPI or misoprostol. If full blown ulcers or previous ulcers give NSAIDS/COX2 + PPI or misoprostol and consider concomitant use with misoprostol.
what can you tell someone if they having been taking NSAIDS and now have ulcer problems?
first heal them with PPI, sucralfate or H2R2. tx h. pylori if that is there as well. tell them they can take acetaminophen instead and that they can either switch to a less toxic one like a partially selective NSAID or cox-2 and that they could also try lowering the dose.
when are PPIs tx of choice for ulcer healing in NSAID induced ulcers?
if NSAID must be continued or if H. pylori positive.
what is the primary mechanism by which stress causes ulcers?
usu d/t mucosal ischemia which means less blood flow and less prostaglandins getting to the area and more damage from gastric acid.
what is the DOC for stress related mucosal damage?
H2RA or PPIs IV, also keep good perfusion going for them.
when is ulcer maintenance tx indicated?
Use maintenance tx if frequent ulcer recurrences, hx of ulcer related bleeding, healed refractory ulcer, failed hP eradication, heavy smokers or continuous nSAID tx.
what are some of the typical sx of GERD/
“heart burn” 30-60 min after eating or when supine, regurgitation, dysphagia (“stuck”), +/-atypical/extraesophageal signs: asthma, chronic cough, chronic laryngitis, sore throat, hoarseness, globus sensation, noncardiac chest pain, or dental erosions.
what are some of the typical alarm signs of heartburn that required further eval?
continual pain, dysphagia, odynophagia, bleeding, unexplained weight loss >5%, unexplained anemia, choking
what are some of the foods, meds, and other things that can decrease lower esophageal sphincter tone?
tobacco, etoh, fatty foods, overeating, tight clothing, obesity, hiatal hernia, pregnancy. Foods that decrease lower esophageal spincter tone: fats, chocolate, peppermint, spearmint, smoking, meds (CCBs, estrogens, theophylline, progesterone, nitrates, narcotics, nicotine, anticholinergics, barbituates, dopamine, caffeine, ethanol, etc), hormones, pregnancy, chalasi (decreases sphincter tone), scleroderma, direct irirtatns like spicy foods, oj, etc
what are the non pharm things to do to tx GERD?
pharm: empirically w/ antisecretory tx or antacids or oral H2 receptor blockers and lifestyle mods. Heal esophagitis if present. Prevent complications. Non pharm: Elevated head of bead 6 inches, no food/drink for 2-3 hrs before bedtime, stop smoking, decrease etoh, modify diet to smaller portions, less fat and avoid foods that decrease LES like peppermint, spearmint, chocolate, and directly irritating foods liek citrus juices, tomato, etoh, coffee, tea, cola, spicy foods, lose wt. avoid NSAIDs, tight fitting clothes, meds that promote reflex (CCB, nitrates, theophylline) if they don’t respond to tx: can do nissen fundoplicaiton surgery
how is tx for GERD staged based on patient presentation?
mild/intermittent gets antacids +/- OTC PPI/H2R2 day; symtomatic or unresponsive to 1st level gets rx strength PPI or H2Ra for 4-8 or 6-12 wks, respectively . severe or to heal erosive esophagitis gets PPIs for 4-16 wks. all should have lifestyle modifications. if sx persist tx on lowest maintenance dose or pRN.
what can influence the cerebral cortex to send signals to medulla to vomit?
sights, smells, emotions
what receptors are associated with the chemoreceptor trigger zone?
5HT3, D2, NK1
what receptors are associated with the vestibular apparatus?
H1, muscarnic
what receptors are associated with the GI tract?
5HT3, D2, NK1
which 2 drugs act at dopamine receptors of CTZ?
PHENOTHIAZINES, butyrophenones
which drug is Very effective for prevention or treatment of CINV, PONV and is generally well tolerated with AE of
constipation, HA, somnolence, diarrhea most common;
All except palonosetron can prolong QT interval?
5ht3 antagonists, these are the big guns. try other stuff first before jumping to these
which drug acts centrally with an unknown mechanism?
cannabinoids
which drugs are safe for use in PONV?
pyridoxine (vitamin B6) +/- doxylamine (unisom and a antihistamine) and if sx persist you can add promethazine (a phenothiazine) or metoclopramide or trimethobenzamide (benzamides) or ondansetron (but must avoid 1st trimester to use this one or r/o of cardiac abnormalities)
which drugs are indicated for motion sicknesses they work at the H1 or M1 receptors in the vestibulocochlear apparatus?
scopolamine and antihistamines like dimenhydrainate (dramamine)
which drug is best for anticipatory N/V? and why?
lorazepam (a benzodiazepine); it has a slight amnesia effect
which drugs are used for highly emetogenic or moderate chemotherapy N/V?
5Ht3 antagonists + dexamethasone (corticosteroid) +aprepitant ( Nk1 antagonist)–note NK1 is most effective with those other two
which drugs are used for moderately emetogenic chemo?
5ht3 antagonist +dexamethasone
which drugs are used for low emetogenicity?
dexamethasone
which drugs are best for post operative N/V?
the 5Ht3 antagonists , dexamethosaone (corticosteroid), droperidol
what drugs are indicated for refractory N/V?
use indicated tx for etiology and ADD chlorpromazine, prochlorperazine (phenothiazines), methylprednisone, lorazepam, metoclopramide, dexamethasone or dronabinol if needed. consider around the clock doxing.
which is the most common cause of acute gastroenteritis?
unidentified source, then viral, then bacterial
What is the DOC for salmonella? (if illness is mild no tx if indicated)
cipro or levo
What is the DOC for shigella?
cipro
What is the DOC for C. diff?
metronidazole
What is the DOC for shiga toxin E. coli?
NONE! need to let the toxin out
what tx most often causes c. diff?
clindamycin
which antidiarrheal can actuallyworsen dehydratin/
calcium polycarbophil: the adsorbent class
which antidiarrheal is very effective for tx of acute diarrhea?
loperamide (anti peristaltic)
which antidiarrheal works by blocking GI fluid flow? what’s a major contraindication of it?
antisecretories like pep bismol . B: Potential for salicylate toxicity; may darken tongue and stools. Do not use in children with influenza or Chicken pox due to risk of Reye’s syndrome
what does the pt ed for constipation include?
increaes fiber to 20-25 gm/day, increase fluids, increase exercise, d/c constipation inducing drugs
which laxative is used for bowerlprep for surgery?
go lately-PEG solution
which stool softeners have an effect in 1-6 hours?
PEG, saline cathartics
which stool softeners have an effect in 6-12 hours?
diphyenylmethane derivatives like bisadocyl po, and anthraquinone derivatives like senna
which are the best stool softeners for prevention of chronic constipation?
bulk forming (psyllium) and emollients (docusate)
how do disaccharides like sorbitol and lactulose work?
Metabolized to low molecular weight acids and increase paristalsis; osmotic agent
what is the most commonly dx childhood illness and most common reason for antibiotic rx in kids?
acute otitis media
which is most likely the cause of AOM? bacteria and virus, bacteria alone, virus alone
bacteria + virus
what makes a kid more prone to resistant S. pneuma infections/
daycare,
which common AOM pathogen is 100% beta lactase producing?
m cat
what are the controllable RFs for AOM?
allergies, anatomic defects like cleft palate, GERD, immunodeficiency, male sex, native american or inuit ethnicity, + FM HX or genetic predisposition, siblings, viral rest tract infection/winter season, young age at first dx
what are the not controllable RFs for AOM?
day care attendance, lack of breastfeeding, pacifier use, smoke exposure, low ses
what is the req’d painkiller for kids with AOM?
acetaminophen or ibuprofen is best
what sx are considered “severe in AOM”?
toxic appearing kid, persistent otalgia >48 hous, temp >39 in past 48 hours or uncertain access to follow up if observation chosen
what is the only scenario where you wouldn’t give abx to a 6 mo-2 yo with AOM?
if unilateral and no otorrhea
what are things to consider when rx ing abx for AOM?
coverage of common pathogens, available formulations, cost, freq of doses, taste, concomitant dz states, age (can’t use tetra
What drug is req’d for AOM and what is the back up if they were on it within the last 30 days?
rec’d is amoxicillin 80-90 mg in 2 divided doses or amoxicillin + clavulanate if they were on it within the last 30 days
if PCN allergic, what abx can a kid with AOM take?
cefdinir, cefuroxime, cefpodoxime, ceftriaxone
what drug is rec’d for initially failed tx for AOM in first 48-72 hours?
amoxicillin + clavulanate or ceftriaxone
what is the rec’d duration of tx for AOM a kid
10 days or if severe sx
what is duration of tx for AOM kids 2-5 and kids >6?
7 days and 5-7 days, respectively
when should sx start to stabilize and improve for AOM?
stabilize in 24 hours, improve in 48
what features are suggestive of bacterial vs. viral pharyngitis?
not to be followed to a T but is helpful: some signs and sx indicative of GABS: sudden onset of ST, age 5-15, fever, HA, nausea, vomiting, abdom pain, tonisllopharygneal ifnlammaion, patchy tonsillpharyngeal exudates, palatal petechiae, anterior cervical adenitis, winter and early spring presentation, hx of exposure to strep pharyngitis, scarlatiniform rash. features suggestive of viral : conjuctivitis, coryza, cough, diarrhea, hoarseness, discrete ulcerative stomaitits, viral exanthema.
how do you tx epiglottis? what’s the rec’d abx therapy?
rec’d abx: cefotaxime or ceftriaxone + vancomycindo not leave unattended in exam room! Establish and maintain airway. Give abx and corticosteroids to reduce edema.Tx all in householdwith rifampin if they have any other members that are immunocompromised, or if they are not yet completely vaccinated.
what’s the tx for acute viral URI?
analgesics, decongestant (avoid in children
what’s the DOC for allergic rhinitis?
nasal corticosteroids
what pt ed things should pts know before starting nasal corticosteroids?
onset in 12 hours but peak response in 1-2 wks, must clear nasal passages with decongestant or saline irrigation before inhaling to make sure med penetrates–if they say its not working–check this and adherence! Avoid sneezing or blowing nose for 10 minutes afterwards.
which drug provides symptomatic relief of allergic rhinitis but dries out?
anticholinergics: ipratropium nasal spray (atrovent)
oral antihistamines MOA, indications, not rec’d
bind to h1 receptors wihtout activating them so histamine can’t bind. May affect release of histamine and influx of inflammatory cells. 1st line preventing allergic rhnitis. Not rec’d for viral URI or sinusitis
nasal and oral decongestants, examples, MOA, and indications, not rec’d
nasal: oxymetazoline (afrin), oral pseudoephedrine (sudafed). MOA: sympathomimetic activity on adrenergic receptors (alpha 1 antagonist) in the nasal mucosa, producing vasoconstriction to shrink swollen mucosa and improve ventilation + pseudoephedrine is also a B1 and B2 agonist which bronchodilates and increases HR. 2nd line for allergic rhinitis. Not rec’d for sinusitis.
which drugs have few AE and are especially safe for children for AR?
mast cell stabilizers and leukotriene receptors antagonists
which drug is especially useful for people with both AR and asthma?
luekotriene receptor antagonist (montelukast)
what are the criteria for an immunological mediated drug run?
rxn is not an pharm effect, rxn stops when drug stops and is reproduced by starting it, rxn fits into other immune mediated rxns like anaphylaxis, etc. presence of eosinophilia. lag time between first exposure and rxn.
