4 IV Fluids Flashcards
Three main types of replacement IVF
Crystalloids (most common) - solutions that contain SODIUM as the main osmotically active particle
Colloids - solutions that contain high-molecular weight substances that do not migrate easily across capillary walls (more likely to stay in vascular compartment)
Blood and blood products
Solutions with the same salt concentrations as normal cells of the body
Isotonic crystalloids
Normal saline (0.9% NS) Lactated Ringer (LR) Plasma-lyte
A solution with higher salt concentration than normal cells of the body and blood (3% NS)
Hypertonic crystalloids
Solutions with lower salt concentration than normal cells of the body
Hypotonic crystalloids
- 5% NS
- 25% NS
Other non-tonic crystalloids
D5W (5% dextrose in water) - useful for someone who is hypoglycemic
What is a lactated ringer solution?
Contains lactate, K+ and Ca2+ in addition to NS
What is plasma lyte?
Contains less chloride than NS
Thought to be the most physiologic solution
All isotonic crystalloids…
Distribute uniformly throughout the ECF space
Internists tend to prefer NS and surgeons LR
Isotonic crystalloids are used for…
Treatment of dehydration/hypovolemia
Severe hypovolemia should be corrected as rapidly as possible to correct intravascular volume depletion
Why do we use hypertonic crystalloids cautiously?
Most valuable in situations where there is life-threatening hyponatremia with significant water excess (to prevent hyponatremic seizures)
BUT must calculate replacement rate (and double check) because overly rapid correction could lead to osmotic demyelination or central pontine myelinolysis (CPM) — IRREVERSIBLE!
When are hypotonic crystalloids use?
For maintenance fluids to prevent hypernatremia when one continuous fluids (ie - a patient who is NPO for several days)
INADEQUATE for replacing intravascular volume deficits (ie dehydration)
What do colloids do to the vascular compartment?
Typically expand it
Used when crystalloids fail to sustain plasma volume due to low osmotic pressure
Perfect examples of when colloids should be used
Patients with burns, peritonitis, or liver disease, where there is considerable protein loss from the vascular space
What is the most common type of colloid?
Albumin preparations
5% albumin
25% albumin
Other types: Dextran (40 or 70) Hydroxyethyl starch (Hetastarch)
Albumin colloids are not useful if patient’s serum albumin is …
> 2.5mg/dL
What is third-spacing?
Physiological concept that body fluids collect in a third body compartment that isn’t normally perfused with fluids
Patient becomes edematous very quickly (ie ascites) so crystalloids will just make it worse
Colloids put the fluids in the right place
What is Dextran?
A synthetic glucose polymer which expands intravascular volume equal to the amount infused
Used less frequently as an alternative to albumin
What is hydroxyethyl starch?
A glycogen-like synthetic molecule that increases the vascular volume to an amount ≥ the volume infused
Less expensive than albumin
Colloid more frequently used intra-operatively
Hydroxyethyl starch (hetastarch)
What are the three relative blood products?
Packed RBCs
Platelets
Fresh frozen plasma
How are PRBCs used?
Used with crystalloids to expand intravascular volume
Remain entirely within the vascular space
Used for blood transfusions
• Hemorrhage, severe anemia
• Patients must be typed and screened/crossed in order to determine blood type and antibodies prior to transfusion
When do we use platelets?
In patients with thrombocytopenia or impaired platelet function to prevent or treat bleeding
Watch out in condition with accelerated consumption of platelets
(ITP, DIC, TTP, hypersplenism, AIDS, sepsis, CABG)
What do we use fresh frozen plasma for?
To correct major bleeding complications in patients on warfarin and/or with a vitamin K supratherapeutic INR
Also consider prothrombin complex concentrates
What fluids can be used for boluses?
NS, LR, Plasma-lyte, PRBCs
Can give 250ml to 1L bolus
Use with caution in patients with HF