11. Advanced Fluid Management - Editing Flashcards
hydrostatic pressure
pressure exerted against the capillary walls
intravascular hydrostatic pressure drives blood what way
out of blood vessel
interstitial hydrostatic pressure drives blood what way
into blood vessels
oncotic pressure
form of osmotic pressure exerted by proteins
pulls fluid towards itself
intravascular oncotic pressure drives fluid what way
into blood vessels
interstitial oncotic pressure drives fluid what way
out of blood vessels
oncotic pressure opposes?
oncotic pressure opposes hydrostatic pressyre
decreased intravascular oncotic pressure can lead to what
edema
why is there edema in pregnancy
incr plasma volume
decr plasma [albumin]
decr cap oncotic pressure
incr interstitial fluid (edema)
why is there edema in liver failure
decr plasma [albumin]
decr cap oncotic pressure
incr edema
capillary arterial end net filt pressure and direction
net filtration pressure of 13
OUT of blood vessels
venous end net filt pressure and direction
net filtration pressure 7
INTO blood vessels
INTO blood vessels
What happens to the 6 left in the interstitial fluid?
taken by lymphatic system back to lymph nodes
drains into subclavian vein
drain into subclavian vein
lymphatic system function
maintain fluid balance
protects body from infection
protect body from infection
moles
refer to compounds
NaCl
osmoles
refer to ions
Na+ Cl-
osmolality
number osmoles/kg solvent
osmolarity
number osmoles/L
plasma osmolarity
280-290 mOsm/L
what 3 things regulate osmolarity
hypothalamus
carotid baroreceptors
kidneys
what does the hypothalamus do to regulate osmolarity
osmolarity high=
tells posterior pituitary to:
secrete ADH
sense of thirst
what do the carotid and baroreceptor and kidneys do to regulate osmolarity
sense a decrease in blood volume
send message to brain to secrete ADH
molarity
how concentrated one solution is compared to another
hyperosmolar
higher conc of total solutes than other side of membrane
hypoosmolar
lower concentration of total solutes thatn other side of membrane
tonicity
which direction water moves
hypertonic
water moves toward the solution
hypotonic
water moves away from the solution
hypertonic IV solution definition
osmolarity of >375 mOsm/L
effects of hypertonic IV solution on the body
cells of the body shrink
blood volume incr/expands
blood volume increases
3 hypertonic IV solutions
mannitol
hypertonic 3% N/S
D5 Solution (except D5W)
mEq/L of 3% N/S
513 mEq/L
D5 solution
5% dextrose in bag or vial
D50 solution
50% dextrose in bag or vial
5% dextrose is what mg/mL?
50mg/mL
50% dextrose is what mg/mL
500mg/mL
pediatric dose of dextrose
0.25-0.5g/kg
adult dose of dextrose
0.5-1g/kg
3 indications for hypertonic fluids
3% N/S to correct plasma sodium conc.
glucose solution for maintenance for NPO or normalize sugar
mannitol for increase renal perfusion and neurosurgery to shrink brain cells
complications of hypertonic IV fluids
- if 3% N/S given too rapidly then the brain can have central pontine myelinolysis and death
- osmotic diuresis
- loss of electrolytes
- intracellular dehydration
- coma
hypotonic IV solution definition
osmolarity of <250mOsm/L
effects of hypotonic IV fluids on the body
cells of the body will expand
blood volume decr
blood volume decreases
3 hypotonic solutions
0.45% N/S
2.5% Dextrose in Water
D5W
is D5W really hypotonic?
starts isotonic but glucose is rapidly metabolized in the body and becomes hypotonic
indications for hypotonic IV fluids
hypernatremia (water deficit)
water deficit
2 complications of hypotonic fluids
cause phlebitis (go through central line) cerebral edema (contraindicated in pts with increased ICP)
isotonic solution definition
osmolarity of 250-375 mOsm/L
4 types of isotonic solution
LR
N/S 0.9%
normosol (plasmalyte)
5% albumin
osmolarity of LR
273 mOsm/L
slightly hypotonic
contents of LR
Na
K
Ca
Cl
lactate
what is lactate converted to by the liver?
bicarb and glucose
4 contraindications to LR
liver disease/liver failure neurosurgery incr ICP ceftriaxone (Rocephin)
questionable CI to LR
pts w/metabolic acidosis/pyloric stenosis
blood
diabetes
renal failure
why not hang LR with blood
Ca is clotting factor IV
calcium could chelate the citrate anticoagulant preservative and form clots
why not hang LR in liver failure
lactate builds up and cant be converted thus causing lactic acidosis (elevated anion gap metabolic acidosis)
why avoid LR in diabetes?
lactate is converted to glucose and exacerbates hyperglycemia
why avoid LR in renal failure?
LR contains potassium and renal failure pts are at risk for hyperkalemia
why avoid LR in neurosurgery?
slightly hypotonic fluid could incr ICP
why is ceftriaxone (rocephin) CI with LR for neonates?
risk of fatal ceftriaxone-calcium salt precipitation in the bloodstream
why is ceftriaxone (Rocephin) CI in pts > 28 days with LR?
cannot be given simultaneously because it may precipitate in IV line
why is LR CI in pts with pyloric stenosis?
pts with pyloric stenosis have met alkalosis
Lactate converts to bicarb = worsens alkalosis
osmolarity of 0.9% N/S
308 mOsm/L
slightly hypertonic to plasma/LR
slightly hypertonic
each L of 0.9% N/S contains how much mEq of sodium?
154mEq
what can large volumes of N/S 0.9% administration lead to?
non anion gap metabolic acidosis
osmolarity of normosol
294 mOsm/L
contents of normosol
Na, K, Mg, Cl
- doesnt have lactate or calcium
potassium conc in normosol
5mEq/L
potassium conc in LR
4mEq/L
indications for plasmalyte
blood transfusions
liver failure
liver failure
why is plasmalyte better for liver failure than LR
does not contain lactate
why is plasmalyte better for pts in metabolic acidosis?
plasmalyte is more alkalinizing than LR
conc bicarb normosol
50mEq/L
conc bicarb LR
28mEq/L
contraindications for normosol
none
most common colloid used in hypovolemic pts
5% albumin
5% albumin will expand the intravascular volume how much?
mL for mL
20-25% mannitol indication
large blood volume deficit
oncotic deficit
hypoproteinemia
Hespan
colloid used as alternative to albumin
6% hetastarch
what is the risk with hespan
black box warning increased mortality
when would you use hespan?
allergy to albumin
jehovah witness
Blood volume preterm infant
90-100mL/kg
blood volume pregnant pt at term
90-100 mL/kg
blood volume full term neonate
90mL/kg
blood volume infant
80mL/kg
blood volume male
70-75mL/kg
blood volume female
60-65mL/kg
blood volume elderly & obese
~15% less than adults
TBW males: healthy, obese, geriatric
healthy- 60%
obese- 50%
geriatric- 50%
TBW females: healthy, obese, geriatric
healthy- 50%
obese- 40-45%
geriatric- 40-45%
TBW neonate
80%
TBW infant
70%
intracellular fluid % of TBW
65%
extracellular fluid % of TBW
35%
extracellular: interstitial fluid
70-75%
TBW 25%
extracellular fluid: intravascular fluid
25-30%
TBW overall breakdown
intracellular: 65%
interstitial: 25%
intravascular: 10%
interstitial + intravascular =
extracellular = 35% of TBW
what % of total fluid in the human body is blood?
10%
as children grow into adults, TBW _______
decreases
as children grow into adults, % of intracelluar fluid ________
% of extracellular fluid ____________
% of intracellular incr
% of extracellular decr
lasix
loop diuretic
inhibits water and sodium reabsorption in LOH
indications for lasix 3
fluid overload
- edema
- pulm edema
- nephrotic syndrome
- CHF
chronic HTN
offsetting increased ADH in surgery
is lasix renal protective or increase renal blood flow?
no
mannitol
osmotic diuretic
increases osmolarity of blood, expands plasma volume
mannitol causes
incr blood osmolarity
incr plasma volume
cells shrink
mannitol indications
renal protection and perfusion
brain surgery (causes decr ICP)
brain surgery
does mannitol increase renal perfusion?
yes
spirolactone
usually at home mediations
potassium sparing
spironolacton is a _______ diuretic
potassium sparing diuretic
spironolactone SE
hyperkalemia
acetazolamide
carbonic anhydrase inhibitor
decrease bicarb and increase PaCO2
complication of acetazolamide
metabolic acidosis
hypokalemia
indications for acetazolamide
diuretic to treat heart failure edema
treat glaucoma and lower intraocular pressure
epilepsy
treat altitude sickness
nephrotic syndrome
kidney disorder that causes the body to excrete too much protein in urine, damage to nephrons
3 symptoms of nephrotic syndrome
proteinuria
hypoalbuminemia
fluid overload (edema)
treatment for nephrotic syndrome
finding and fixing underlying cause
adult major burn definition
> 20% of TBSA
kids and elderly major burn definition
> 10% TBSA
automatic major burn
face
airway
genitalia
what things make it a major burn regardless of TBSA?
burn to face
airway
genitalia
describe rule 9
head 9 front 18 back 18 arm 9 each leg 18 each genitalia 1
rule of 9 for peds
head 18
front 18
back 18
arm 9 each
leg 14 each
genitalia 1
patients with major thermal injury are expected to experience:
inflammatory response
massive vasodilation
fluid shift from IV INTO interstitial
injury to muscles
loss of skin protective barriers
physiology after thermal injury
- hypovolemia
- decr CO
- hTN
- massive edema
- hypothermia
- anemia/thrombocytopenia
- hypercoagulability
- altered pulm phys
- incr nicotinic Ach R
- hypermetabolic
why is there hypovolemia and decreased CO in burn pts
drainage and evaporation from wounds
relative hypovolemia from vasodilation
intense infammatory response leads to vasodilation
how is anemia and throbocytopenia caused in burn pts
bleeding from wounds
heat damage to RBC
fluid resuscitation
proliferation of nicotinic ach receptors causes what?
resistance to NDMB
sensitivity to Sux
sensitivity to succ
how long dose it take for proliferation of nicotinic Ach to occur?
24 hrs post burn
possible complications of altered pulm physiology include
decr pulm compliance
incr lung vascular and permeability incr PVR
possible carbon monoxide poisoning
what is the hypermetabolic phase caused by
massive surge of catecholamines and corticosteriods
what does the hypermetabolic phase lead to?
tachycardia
hypertension
incr myocardial o2 consumption
multisystem organ failure
when does the hypermetabolic phase develop?
can take several weeks
what is the first priority for anesthesia management in thermal injury?
secure the airway
safest option to intiubate burn pts?
awake fiberoptic intubation
when should you promptly intubate a burn pt
burns to face
neck
upper chest
inhalational burns
drug dosing initial burn shock phase (48hr)
vasodilation and low cardiac output = lower drug doses
hypermetabolic phase (48-72hr, lasting weeks or months) drug dosing
fluid overload can occur after capillary membrane integrity returns and fluid shifts
higher drug dose
MAC increased
succ in burn pts
safe in first 24 hr
avoided in 24-48 hr
consider using again after 1-2 yrs
does the magnitude of hyperkalemic response correlate to the magnitude of burn?
no
3 intraoperative goals burn pt
rapid and effective intravascular volume replacement (parkland formula)
low tidal volume (6mL/kg and PIP <30
minimize heat loss
parkland formula
(4mL)(%BSA)(kg)= volume of LR
half given first 8 hr
half given next 16 hr
colloids and burn pts
conflicting ideas
could leak from intravascular space and worsen edema
