Flow rate computation, week 3
page 3
Vit c most anti-cancer at ½ gram/min
if have 15 gm in bag what is ideal delivery rate?
30 mins
if 1000 ml fluid
100 gram vit c
½ gram/min-->200 minutes
if know total fluid and time can calculate flow rate
1000ml/200min = 5ml/min
the vit c stock vial has 500mg/ml
30mls have 15grams
drop rate usu 20 drops/ml but use larger tubing for vit C to deliver a ml in 10 drops
can't start high dose vit c at 100gram, too much
start with 15 grams first time
at 1/2 gram/min that's 30 minutes
don't need a lot of fluid
she chose 300ml for bag volume
30ml vit c solution + and 270 sterile water
larger tubing allows a flow rate of 10ml/min
100 drops/min, divide by four for how many drops you count in drip chamber in 15 seconds
50 drops/15 sec is too many to count, that's why the bigger tubing is nice
*never give potassium via an iv push
IV solutions revisited
skpping page 1, hitting high points
hypertonic expansion-->circulatory overload risk
cystalloids = substances that form true solutions, truly dissolve up to saturation point (salt, glucose)
colloid solution is not a true solution, substance can't dissolve in carrier
could give starchy solution to patient who needs fluids while waiting for blood
sometimes called plasma blood expanders
carrier solutions containing glucose
by convention
D5W is solution containing 5% dextrose in water
assume 1ml water weighs 1 gram, figure out how to make D5W if needed
a liter = 1000ml would contain 50g dextrose
G10W
100g gluc / L water
insulin carries potassium into cells
can induce serum hypokalemia
normal saline .9%
half saline is .45%
lactated ringers
variation on physiol saline
less sodium, more goodies (calcium potassium)
don't use with liver dz, addison's, metabolic acidosis or alkalosis, profound hypovolemia, shock or cardiac failure
B12
maybe better IM, not cleared so fast by kidneys
2-3ml of nutrient prob don't need IV
above 3ml consider a push, up to 60mL-->at least 30 mins, time to consider drip because of your time pushing
Fat Soluble vits
tricky
practical perspective, vit A only one she gives by IV
must add emulsifier to disperse it in aqeous medium
she can't get an osmolarity for any other fat soluble vitamin, not comfortable using them
emulsified intended for IM use and manufacturers won't talk about IV use
she uses A for infx, healing, finds it's useful
vit K is very dicey by IV, she would never use it, can cause anaphylaxis
biotin
a tweener
from chem perspective more fat than water soluble
want to minimize adsorption on plastic of IV bag and tubes
mix formula in glass to save formula, can't do anything about tubes
B12 cyano, hydroxy and methyl cobalamin
methyl best for nervous system because it crosses BBB
folic acid
is buffered to pH of around 8
the other vits are buffered to acidic pH's
folic does not play well in sandbox unless sandbox is big
not dilute enough-->will see "chunkies" (B12/folic precipitates) forming in solution
500ml bag mb big enough
she uses fresh syringe for folate
vit c
a few CI, look these up
calcium chloride and calcium gluconate
gluconate is from shells, if pt has extreme shellfish allergy beware!
CI with digitalis
tables
don't give vit A in liver dz
vit K IM only
vit D
no reason to give IV
adequate repletion orally
125OH is active form, has half life of 30 mins
testing is for 25OH, 5 weeks half life
copper infusions
lowers chol
also lowers zinc
KCl never in IV push
MgSo4 for mm cramps and asthma
no concern re: sulfa drug allergies
Magnesium too much too fast-->resp arrest, vasodil and sm mm relaxer
antidote: calcium gluconate
iron
Dr osborne never talked about
can cause anaphylaxis, iron destran mc used, sugar moeity is immunogenic
give IM unless btw rock and hard place--complete malabsorption pts
block box warnings
she has done IV iron but doesn't like it, and it's expensive
pts ferritin is 3, hgb is 9, will need transfusions
or do z track IM injx to avoid sensitizing her
needs management by hematologist
2ml vial = $27