Fluids & Electrolytes Pt 3 Flashcards
IV Fluids
- Purposes
> Maintenance - When oral intake is not adequate
> Replacement
- When losses have occurred
- Types of fluids categorized by tonicity
Tonicity - osmotic pressure of fluid r/t to the conc of electrolytes in fluid
> Hypotonic, isotonic, hypertonic
?
Provides more water than electrolytes
> Pure water lyses RBCs
- Water moves from ECF to ICF by osmosis
- Usually maintenance fluids
- Monitor for changes in mentation
Hypotonic
Hypotonic
- 0.45% NaCl
> Additional electrolytes may be added to maintain normal lvls (i.e., KCl)
! Can cause cellular swelling so monitor for changes in mentation like cerebral edema
?
Expands ONLY ECF
* No net loss or gain from ICF
* Ideal to replace ECF volume deficit
Isotonic
?
Initially expands & raises the osmolality of ECF
Require frequent monitoring of BP, lung sounds, serum Na+ lvls (b/c inc risk for intravascular fluid volume excess)
Hypertonic
- LRD (Lactated Ringer’s w/dextrose)
- D 5 1/2 NS
- D 10% H2O
D5W
Hypo/Iso/Hyper-tonic ?
- Provides 170 cal/L
- Prevents ketosis assoc w/starvation
- Free water (moves into ICF; increases renal solute excretion)
- Used to replace water losses & treat hypernatremia
! Does not provide electrolytes
Isotonic
Normal Saline (NS or NSS)
Hypo/Iso/Hyper-tonic ?
- More NaCl than ECF
- Expands IV volume
> Preferred fluid for immediate response
> Risk for fluid overload higher - Also monitor for hyperchloremic acidosis
Isotonic
- 0.9% NaCl
- No free water, no calories
- No additional electrolytes
- Blood products (! NS is only IV solution that can be used w/blood)
- Compatible w/most rx’s
Lactated Ringer’s Solution
Hypo/Iso/Hyper-tonic ?
- Similar in composition to plasma except contains no Mg
- Expands ECF - treat burns & GI losses
! Contraindicated w/hyperkalemia & lactic acidosis [the body has a dec’d ability to convert lactate to bicarbonate] - No free water or calories
Isotonic
- Contains Na+, Cl-, K+, Ca+, & lactate (the precursor of bicarbonate)
D5 1/2 NS
Hypo/Iso/Hyper-tonic ?
- Common maintenance fluid
- Replaces fluid loss
- KCl added for maintenance or replacement
Hypertonic
- Provides free water in add’n to Na+ & Cl-
D10W
Hypo/Iso/Hyper-tonic ?
- Provides 340 kcal/L
- Provides free water but no electrolytes
- Limit of dextrose concentration may be infused peripherally
Hypertonic (glucose solution)
> 10% dextrose is the highest conc of dextrose than can be administered through a peripheral line; need a central line to infuse higher conc (i.e., parenteral nutrition)
Plasma Expanders
- Stay in vascular space & inc osmotic pressure
- Colloids (protein solutions)
> Plasma, albumin [avail in 5 & 25% sol’n], commercial plasmas [Plasmanate]
- Dextran (a complex synthetic sugar)
- Hetastarch (Hespan; works like Dextran to expand plasma volume)
- Blood (loop diuretics may be given w/blood to prevent manifestations of fluid vol excess)
