7- Fluid Managment Flashcards
True False:
Females have more H2O by weight ?
False
Males= 60% H2O by weight
Females= 50% H2O by weight
What are examples of hypovlemia?
Vomiting, bleeding, diarrhea, sepsis, trauma
What are examples of hypervolemia?
CHF, renal impairment, weight gain
What are labs seen with hypovolemia?
Increasing hematocrit (dehydration)
concentration alkalosis then metabolic acidosis
Urine specific gravity over 1.010
Urine sodium less 10
urine osm over 450
hypernatermia
BUN:Cr > 10:1
what are labs seen with hypervolemia?
increased pulm vascular markings on chest xray
What are the two most common crystalloids?
NS
LR
What are the advantages of NS?
-preferred for diluting pRBCs due to no Ca2+ and no K+
-preferred in brain injuries
What are the disadvantages of NS?
-Large volumes produces hyperchloremic metabolic acidosis
- Hyperchoremia -> low GFR
What are advantages of LR?
-More physiologic
-Lactate is converted to HCO3- by liver
What are the disadvantages of LR?
Watch K+ in rental patients
CA2+ may cause clotting with pRBCs
What crystalloid does not have K+ and Ca2+?
NS
What crystalloid is given for its buffer in trauma pts?
LR
What is crystalloid is considered more acidic?
NS (PH: 5)
LR (PH: 6.6)
intact capillary membranes that contain colloids such as albumin expand plasma volume rather than ICE volume due to?
Oncotic pressure
In colloids, albumin concentration is, and how is it derived ?
5% or 25%
usually derived from pooled donated blood
Expensive
What is the composition of Colloid (Hetastarch)?
6% hydroxyethyl starch, HES
which is a solution of highly branched glucose chains
What is the down sides of using Hetastarch?
it can increase PTT (via factor VIII/ vWF) and clotting times
Anaphylactoid reactions with wheezing and urticaria may occur
may interfere with platelet function
What are some contraindications of Hetastarch?
Coagulopathy
Heart faliure
Renal faliure
In terms of fluid selection, what are the advantages and disadvantages of using a crystalloid?
Advantages:
-Lower cost
-Readily available
Disadvantages:
-Requires more volume for the same hemodynamic effect
-Shot IV t(1/2) (20-30 min)
-Dilutes plasma proteins-> peripheral/ pulmonary edema
In terms of fluid selection, what are the advantages and disadvantages of using a Colloid?
Advantages:
-Restores IV volume and HD with less volume, less time
-Longer IV t(1/2)
-Maintains plasma oncotic pressure
-Less cerebral edema (in healthy brain tissue)
-Less intestinal edema
Disadvantages:
-Expensive
-Coagulopathy (dextran >HRS)
-Potential renal complications
-May cause cerebral edema (in areas of injured brain)
How to calculate the fluid maintenance requirement?
4-2-1 Rule
-4ml/kg/hr for first 10kg
-2ml/kg/hr for next 10-20kg
-1ml/kg/hr for each additional kg (above 20kg)
* for pt over 20kg: add 40 to weight in kg
How to calculate fluid deficit?
-Multiply maintenance requirement by # of hours NPO
-Give 1/2 over 1st hr, 1/4 over 2nd hour, and 1/4 over 3rd hour
What are some ongoing losses to take into consideration when calculating for classical fluid losses?
- Evaporative & intestinal losses (capillary leak)
-Blood loss
-Urine output
What is a balanced fluid therapy?
-Balanced crystalloid solution
-1-3 ml/kg/hr
what is a goal directed fluid therapy?
-Use patient metrics to guide fluid titration
-Vitals (HR & BP trends), urine output, hematocrit, base deficit, serum lactate, response to fluid bolus, central venous variation, pulse pressure variation, respiratory variation of the a-line tracing, physical exam (i.e dry mucus membrane)
