Van Bockern - IV Fluids Flashcards
what are the 2 fluid compartments
intracellular: 60% of body weight
extracellular: 20% of body weight
extracellular fluid consists of
intravascular: 80% of ECP
interstitial: 20% of ECP
both fluid compartments account for __% of our body weight
intracellular: 60% of body weight
40L
intracellular ions
K+
phosphoric acid (-)
non-penetrating anions: proteins, organic anions
extracellular ions
Na+
Cl-
BMP
what is third spacing
-shift of fluid from intravascular to interstitial space
-increased vascular permeability
4 conditions associated w. third spacing losses
pancreatitis
hypoalbuminemia (cirrhosis)
surgery
sepsis
3 goals of IV fluids
replacement/resuscitation
maintenance
electrolyte balance
4 considerations in IVF management
how much
assessment of volume status
sources of loss
maintenance
3 ways to assess fluid volume status
JVP - Janice’s fave
peripheral edema
crackles
6 sources of fluid/lyte loss
renal
respiratory
hemorrhage
GI
skin
third spacing
most significant cause of skin fluid/lyte losses
burns
normal water losses
urine: at least 0.5 L/day
stool: 200 mL/day
insensible (skin/resp): 400-500 mL/day
endogenous metabolism: 250-350 mL/day
total: 1400 mL/day
minimum fluid required for maintenance
60 mL/hr
what type of fluid loss increases w. rr, metabolic state, and body temp
insensible (skin/resp)
daily lyte requirements
Na+: 75-175 mEq
K+: 20-60 mEq
daily CHO requirements
100-150 g/day dex
maintenance dosing for NS
D5 1/2 NS w. 20 mEq/L KCl @ 75 mL/hr = 1.8 L
1.8 L of D5 1/2 NS w. 20mEq KCl maintenance fluids adds how much K+, Na+, and dex
K+: 36 mEq
Na+: 139 mEq
dex: 90 g
4 considerations of volume status management
clinical assessment
daily weights
intake vs output
SCr
3 clinical assessment tools that Janice likes to assess hypervolemia
jvp
body weight
orthopnea
5 sx of hypovolemia
hypotn
tachycardia
oliguria
decreased skin turgor
dry mm
2 types of crystalloid fluids
NS
LR (balanced crystalloid)
colloid fluid
albumin
NS content compared to plasma
NS contains more Na and Cl -> can cause:
-hyperchloremic metabolic acidosis
-chloride mediated renal vasoconstriction
study that janice referenced showed better outcomes (3) when what type of fluid was used
better outcomes w. LR:
-death from any cause
-new renal replacement therapy
-persistent renal dysfxn
what is added to LR to provide buffer
sodium lactate
compared to plasma, LR contains __ Na
and __ K+
less
equal
3 problems w. LR
-falsely high serum lactate measurements
-ionized Ca can cause clots
-4 mEq of K -> hyperkalemia in renal insufficiency
moa for colloids (albumin)
high molecular wt -> increase plasma oncotic pressure
which fluid lasts longest in intravascular space
colloids (albumin) - 16 hr vs 30-60 min
3 types of dex containing fluids
-D5W: 50 g dex in 1L free water (5%dex)
-D5NS: 50 g dex in 1L NS
-D10LR: 100 g dex in 1 L LR
benefit of dex containing solutions
non-protein calories -> prevent protein catabolism
indication for dex containing solutions
ongoing hypoglycemia
what do you need to calculate in order to treat hypernatremia
free water deficit
goal of maintenance fluid
maintain homeostasis in euvolemic pt who cannot accomplish maintenance w. oral intake
how do you adjust maintenance fluid for pt w. CHF, CKD etc
decrease to 50 mL/hr
many healthy pt’s can tolerate __ mL/hr of maintenance fluids
100-125
goals of replacement fluid (2)
maintain hemodynamic stability
replenish intravascular volume
what dosing of replacement fluid does Janice like
bolus:
1L
500 mL
250 mL
bolus dosing considerations for sicker pt
smaller bolus needed
3 conditions that require aggressive IVF
sepsis
acute pancreatitis
DKA/HHS (hyperosmolar hyperglycemic state)
initial replacement fluid for sepsis
crystalloid bolus of 30 mL/kg
in sepsis, fluid adjustments are guided by (2)
serum lactate
hypotn
initial replacement fluid for acute pancreatitis
always LR bolus:
initial fluid bolus of 20 mL/kg given over 30 min, followed by 3 mL/kg/hr for 8-12 hr
consequence of inadequate fluids in acute pancreatitis
necrotic pancreas
initial replacement fluids for DKA/HHS
15-20 mL/kg/hr for first 2 hr, or approx 1L/hr
250-500 mL next few hr, reduce to 150 mL/hr
how do you monitor effectiveness of IVF in DKA/HHS
BMP -> make sure gap is closing
2 conditions that require serious caution w. fluid replacement
acute pulmonary edema
CHF
for CHF, fluid bolus should be at most
250 mL
consequence of over aggressive fluid replacement in CHF
acute pulmonary edema
what do you need to do every single time before fluid bolusing CHF pt
echo
K+ replacement rule of thumb based on serum K+
-serum K+ 3.0-3.4: 10 mEq = serum increase by 0.1 mEq
-serum K+ < 3.0: do PO + IV replacement - frequent recheck
-whole body K+ deficit: often more severe than serum K+ reflects -> replete past nl on BMP
lab value to always check w. hypokalemia
Mg -> can not correct hypokalemia in setting of hypomagnesemia
s.e of IV K+
how do you avoid this
phlebitis: painful burning sensation
avoid: limit to 10 mEq q 2 hr through peripheral IV
use __ IV access for rapid K+ repletion
central
route of admin for Mg repletion
always IV: 1-4 g at a time
oral absorption is poor
goals for K+ and Mg in heart disease
K+: > 4.0
Mg: > 2.0
route of admin for phos repletion
PO tabs
IV
hypophosphatemia is mc seen w. what 3 conditions
malnutrition
refeeding
alcoholics
A 38 year old male with PMH of ETOH use disorder presents to the hospital in EtOH withdrawal and severe electrolyte depletion.
On exam his vitals are: HR: 109, RR 18, BP 90/70, Pulse Ox 95%
Gen: ill appearing male, HEENT: Dry CV: Tachy RR
Labs: Na: 131, K: 3.0
What do you want to do?
-give NS bolus 1000 mL
-replete K+ w. 60 mEq to get him to 3.6 (each 10 mEq = 0.1 mEq increase)
pt from previous card develops severe epigastric pain that radiates to his back - what do you do?
order cbc, lft’s, lipase, and continue IVF
worried about pancreatitis
what lab always needs to be ordered if you are concerned for pancreatitis
lipase
pt from previous card has lipase 3x upper nl and bili is elevated - hgb is normal
what do you do
start LR 150 mL/hr
start IV pain control
obtain CT abd
what lab elevation is concerning for gallstone related pancreatitis
elevated bilirubin
2 mc causes of acute pancreatitis
gallstones
etoh
diagnostic criteria for acute pancreatitis
2 of the following:
-acute epigastric pain radiating to back
-lipase 3x unl
-acute pancreatitis on CT/MRI/US
tx for acute pancreatitis (3)
LR
NPO
pain control
what is FENa
what does it tell you
-fractional excretion of sodium
-tells you if renal dz is pre vs post vs intrinsic -> guides you in terms of fluid type
indication for calculating FENa
elevated SCr
contraindication for FENa
pt on diuretics
use FEUrea instead
first thing you do in pt w. AKI
order BMP and UA to calculate FENa
components of FENa (4)
serum Na
urine Na
serum Cr
urine Cr
FENUrea uses __ instead of urine Na
urine urea
