Intravenous Therapy IV Infusion Preparations

Fluid and Electrolytes

Sasha A. Rarang, RN, MSN

Intravenous (IV)Therapy :

Definition: Infusion of a fluid into a vein to prevent or treat fluid &/or electrolyte

imbalance(s) to deliver medications to deliver blood products

VENIPUNCTURE: technique of accessing a vein via insertion of a needle or catheter sterile procedure because skin integrity is

broken

Purposes of Infusion Therapy:

Provide fluids when PO intake not possible replace fluids/lytes

Maintain normal electrolyte balances Provide glucose as energy source Provide access for administration of meds Administer blood products Emergency access Maintain urine output

Distribution of Body Fluids & Electrolytes:

Typical adult 60% body weight consists of fluid (water & lytes) varies with body fat content, age, sex

– ex. fat cells contain little water; lean tissue is rich with water

– ex. infants have a high body fluid content (approx 70 - 80% of body weight)

Fluid Distribution:

INTRACELLULAR (ICF) within the cells approx 2/3 of total fluid found within ICF

EXTRACELLULAR (ECF) outside the cells approx 1/3 of total fluid found within ECF ECF: 2 compartments

– Intravascular Within a vessel; Plasma– Interstitial/Extravascular Between & around the

cells; Tissue Fluid

Electrolytes:

A substance that develops an electrical charge when dissolved in water

Electrolyte content of ICF is different from ECF Major electrolytes in ICF: Potassium;

Phosphate; Magnesium Major electrolytes in ECF: Sodium;

Chloride; Bicarbonate; Calcium

Movement of Fluids:Normal mvmt of fluids through capillary walls depends on 2

forces

Hydrostatic Pressure - pressure exerted by the heart; pressure of blood volume in vessels

Oncotic Pressure - pressure exerted by plasma proteins such as albumin Water is pulled toward higher oncotic

pressure

Movement of Fluids:

When solutions are separated by a membrane impermeable to dissolved substances, a shift of water occurs through the membrane from an area of low solute concentration to higher solute concentration Magnitude of this force dependent on the

number of particles dissolved OSMOLALITY: number of dissolved particles

– TONICITY; OSMOLARITY– amt of solutes (ex sugar, Na+, protein) in a liter of

solution

Intravenous Infusion Preparations

Osmolality – osmotic pull or pressure exerted by all particles by unit of water

( expressed in milliosmoles per kilogram)

Osmolarity- is the osmotic pull by all particles per unit of solution. Unit of osmotic pressure – osmole ( Osm) and the milliosmole is mOsm is 1/1000th of an osmole. Osmotic cpressure determines osmotic activity.

Osmotic pressure determines osmotic activity.

Osmolality

Influience by the quantity of dissolved particles that exerts an osmotic pull in the intracellular and extracelluar fluids.

Primary solutes – serum sodium, urea, and glucose. Plasma (intravascular compartment ) contains protein

and slightly higher osmolality than fluid in other areas. 25% concentration only that found in the ICF. Interstitial fluid has little to no protein. It is the responsibuility of the nurse to knowwherther a

prescribed infusate is hypertonic, hypotonic, or isotonic.

Osmolality:

The more solute present; the higher the osmolality

ISOTONIC solutions have the same osmolality as body fluids

HYPOTONIC solutions have a lower osmolality as body fluids

HYPERTONIC solutions have a higher osmolality as body fluids

Isotonic Solutions:same osmotic pressure as that found in the cell

Will not alter intracellular fluid compartments

ex. Normal Saline (NS): used to expand ECF compartments

ex. Lactate Ringers (LR): similar to plasma content (Na, K, Ca, Cl, Lactate); used to correct ECF deficits

Hypotonic Solutions:less osmotic pressure as that found in the cell

have lower osmolality than body fluids within the cell (ICF)

cause fluids to shift out of the vasculature (ECF) & into the cells (ICF)

used to provide water, cellular hydration ex. 0.45% NS (“half Normal Saline”) ex. D5W (“5% dextrose water”)

Hypertonic Solutions:greater osmotic pressure as that found in the cell

HIGHER osmolality than body fluids causes fluids to shift out of the cells (ICF) into

the vascular space rapid shift fr ICF into the ECF/ vascular beds

given to treat specific problems can potentially have serious side effects

– ex. CHF, PE, overload

ex. Hypertonic saline (3% or 5% NS) ex. TPN ex. 50% dextrose

Classification of Infusates

Crystalloid Colloids Hydrating Solution Electrolyte Solution Dextrose Solution

Crystalloids

Materials that are capable of crystallization.

Solution that when place on solvent , homogeneously mixed with and dissolved into a solution and cannot be distinguished from the resultant solution.

Can be isotonic, hypertonic, or hypotonic.

Hydrating Solution

Provide free water for maintenance or hydration.

When used chemical make-up or rate of administration is adjuted so the equilibria of fluids are not disturbed.

E.g. glucose solution are most often used. Dextrose 21/2 % in 0.45 % saline Dextrose 5% in water Dextrose 5% in 0.45 saline Sodium Chloride 0.45% Dextrose 5% in 0.2% saline.

Electrolyte Solution

Substance capable of ionization such as sodium chloride

Dextrose solutions

Are frequently used as infusates, are manufactured as percentage solutions expressed the numberof grams per 100 g of solvent,.

A 5% dextrose in water (D5W) infusions contains 5 g of dextrose in 100 ml of water 1 ml of water equals 1 gr.

Colloids Are glutinous substances whose particles,

when submerge into a solvent, cannot form a true solution because their molecules when thoroughly dispersed no not dissolve, but remained uniformly suspended and distributed throughout the fluid.

Can raise osmotic pressure. Plasma or volume expander. E.g. dextran, plamanate, and artificial blood

substitute, hetastarch.

Indications for IV Therapy

Fluid Volume maintenance Fluid Volume replacement Medication Administration Blood and Blood Producct Donation and

administration Nutritional support.

Equipment and Supplies

Infusate container – glass Plastic – flexible Semiregid Infusate administration container Drop factor Primary administration set Secondary administration set Volume control administration set Blood and Blood product administration set Accessory Devices for use with administration set Needleless Systems and Needlestick Safety System