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?