IV Fluids Flashcards
Total body water =
60% total body weight
ICF: 2/3
ECF: 1/3
Who will have more body water; normal weight ind. or obese ind.?
normal weight pt
Ways that we get water input? output?
fluid intake, H20 in food, metabolically produced H20
insensible loss, sweat, feces, urine
input = output
What are some causes of hypovolemia?
GI losses, renal losses, sweat losses (sweats, burns), sequestration without loss
What are some examples of sequestration without loss?
Intestinal obstruction, pancreatitis, rhabdomyolysis
Clinical features of hypovolemia
Increased thirst, decreased sweating
Decreased skin turgor & drymm
Oliguria
CNS depression
Weakness and muscle cramps
Decreased BP; postural
hypotension/dizziness
tachycardia
What is third spacing?
fluid getting into spaces where its not supposed to be
fluid accumulation in the interstitium of tissues
- ascites
- pleural effusions
- edema assoc. with burns
third spacing can causes…
relative hypovolemia
What are the types of replacement IVF?
crystalloids
colloids
blood and blood products
What are crystalloids?
fluids that contains crystal-forming elements (electrolytes) which easily pass through vascular endothelial membrane barriers followed by water, leading to their equilibrating between the intravascular & extracellular space
What are colloids?
Fluids that contain both large organic marcomolecules and electrolytes
What are blood and blood products?
RBC’s are similar to colloids because they stay in vascular space
What are some examples of crystalloids?
normal saline
LR
plasma-lyte
What are the different types of crystalloids?
isotonic crystalloids
hypertonic crystalloid
hypotonic crystalloids
Describe isotonic crystalloids
NaCl
They distribute uniformly throughout the ECF space.
Internists tent to prefer NS and surgeons LR…intensivists prefer Plasma-Lyte.
What are isotonic crystalloids used for?
for tx of dehydration/hypovolemia
What is hypertonic crystalloid?
3% NS
use very cautiously!
- good in situations where there is life-threatening hyponatremia
- also somestimes used in neurosurg pts to decrease cerebral edema
When you use hypertonic crystalloid need to be careful not to cause….
central pontine myelinolysis
-Overly rapid correction of sodium can lead to osmotic demyelination
How do hypotonic crystalloids work?
distribute throughout the total body water, used for maintenance fluids
not used for tx of dehydration/hypovolemia- not really used in general
What is D5W?
another type of crystalloid
5% dextrose in water
used to tx hypoglycemia
used in hypernatremia with a free water deficit
Describe colloids
More likely to expand vascular compartment
Used when crystalloids fail to sustain plasma volume due to low osmotic pressure
-when there is sig. protein loss
What are the dif. types of colloid fluids?
Albumin** used clinically
Dextran
Hydroxyethyl Starch
When do we use Albumin?
Used in edematous patients to mobilize interstitial fluid into the vascular space
-not really used if albumin is norm.
Which pts are albumin helpful in?
in patients with liver disease, peritonitis or burns or surgical patients experiencing “third spacing”
Crystalloid v. Albumin
Albumin temporarily increases MAP
BUT no dif. in mortality
What are the dif. types of blood products?
Packed red blood cells (PRBCs)
Platelets
Fresh frozen plasma (FFP)
Cryoprecipitate
Most commonly used blood product?
PRBCs
Describe PRBCs
prepared from whole blood, remain entirely within vascular space
used for blood transfusions
- improves oxygen delivery to tissues
- need to type and screen/cross
I unit of PRBCs should increase Hgb by…
1g
When do we transfuse blood?
if: actively bleeding, sxs or Hgb <7
When are platelets used?
in patients with thrombocytopenia or impaired platelet function to prevent or treat bleeding
What is fresh frozen plasma (FFP)? What is it used for?
Contains all factors of the soluble coagulation system
Used to correct major bleeding complications in patients on warfarin and/or with a vitamin K deficiency
When do you give FFP?
when INR is elevated?
What is another agent that works similar to FFP?
PCCs
prothrombin complex concentrates
What is cryoprecipitate?
Prepared by thawing fresh frozen plasma and collecting the precipitate.
-It contains high concentrations of factor VIII & fibrinogen
When are cryoprecipitate used?
in pts with low fibrinogen, typically in the setting of massive hemorrhage or consumptive coagulopathy.
What are the dif ways that we can give IVF (time wise)?
bolus
maintenance
replacement
Describe Bolus IVF
NS, LR, and Plasma-Lyte can be given as a bolus depending on the clinical situation
can give 250ml-IL
caution in pts with HF
How do you determine how much fluids to give?
depending on how dry they are
can give a L at a time, reassessing btwn each
(Assuming no HF or other concern from volume overload)
Describe maintenance IVF
Maintains/accounts for ongoing losses of water and electrolytes under normal physiologic conditions via urine, sweat, respirations, and stool
goal is to provide water and lyte balance
When are maintenance IVF used?
when pts are not eating/drinking norm.
What are some common fluids for maintenance?
NS, plasma-lyte, LR
D5/0.5NS +/- 20 meg KCL
What can we used to determine rate for maintenance IVF?
“the Kg method” (body weight) to determine water needs
How are calculated maintenance IVF different for peds as opposed to adults
“Kg method”
but children require less sodium than adults
What are the 3 most common rates for maintenance fluids in adults?
75ml/hr, 100ml/hr, 125ml/hr
maintenance IVF & potassium can be used to tx…
hypokalemia or for maintenance fluids if pt NPO
Role for replacement IVF?
Corrects any existing water and electrolyte deficits caused by GI, urinary, skin, or blood losses or “third-spacing”
amount of replacement fluids in surg pts should be determine based on?
UOP and vitals
Replacement fluids in burn pts?
use parkland formula
-total fluid required during 1st 24 hrs
(percentage of 2nd/3rd deg burns) x (body weight in kg) x 4ml
How do you determine percentage of body burned?
rule of nines
