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.
