IV Fluids Flashcards
NS
Isotonic Crystalloid
increase circulating plasma volume when red cells are adequate
replaced losses without altering fluid concentrations
helpful for Na+ replacement
LR
Isotonic Crystalloid
Normal saline with electrolytes (K, Ca, Cl) and buffer (lactate)
replaced fluid and buffers pH
Often seen with surgery
D5-NS
HYPERtonic Crystalloid (volume expanders)
replaces fluid sodium, chloride, and calories
watch for fluid volume overload
D5-LR
HYPERtonic Crystalloid (volume expanders)
same as LR plus provides about 180 calories per 1 L
watch for fluid volume overload
D5
HYPOtonic Crystalloid (fluid shifts INTO cells; hydrate cells)
isotonic in the bag / physiologically hypotonic
raises total fluid volume
helpful in rehydrating and excretory purposes
provides 170-200 calories/1 L for energy
The dextrose is metabolized quickly so that only water remains - a hypotonic fluid
1/2 NS
HYPOtonic Crystalloid (fluid shifts INTO cells; hydrate cells)
raises total fluid volume
useful for daily maintenance of body fluid, but is of less value for replacement of NaCl deficit
helpful for establishing renal function
fluid replacement for patients who don’t need extra glucose (diabetics)
Colloids
Solutions that contain LARGE MOLECULES and don’t pass the cell membranes. They remain in the vascular compartment (in bloodstream outside of cells) and expand the vascular volume because they draw fluid from extravascular spaces via their higher oncotic pressures
VOLUME EXPANDERS (similar to hypertonic crystalloids but require less volume since they stay in the intravascular compartment only and stay there longer)
Albumin, Dextran, Hepspan, Hetastarch
D5-1/2 NS
HYPERtonic Crystalloid (volume expanders)
*clinically HYPOtonic
useful for daily maintenance of body fluids and nutrition, and for rehydration
most common postoperative fluid
Crystalloids
Solutions that contain small molecules that flow easily across the cell membranes, allowing for transfer from the bloodstream into the cells and body tissues. This will increase fluid volume in both the interstitial (space between cells in a given tissue) and vascular spaces (the extracellular portion of circulation).
Subdivided into: ISOTONIC (NSS, D5W, LR, Ringers), HYPOtonic (hydrate cells; D5W, 0.45% NS), and HYPERtonic (volume expanders; 3% NSS, D5NS)
Volume expanders
HYPERtonic (3% NSS, D5-NS)
volume expanders
Hydrate cells
HYPOtonic (0.45% NS, D5W)
fluid shifts INTO cells
Calculating hourly fluid rate for maintenance therapy
4-2-1 Rule
4 mg/kg for first 10 kg
2 mg/kg for next 10 kg
1 mg/kg for remainder of weight
Normal fluid intake/output
1500-2500 ml in 24 hours
Insensible Loss (sweating, breathing):
500-1000 ml/day
Possible Signs of Fluid Volume Deficit
High: BUN, Cr, HR
High or Low: Na
