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Intravenous therapy

Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein.

Or

Intravenous therapy, also referred to as ‘IV therapy’, constitutes the administration of liquid

substances directly into a vein and the general circulation through venepuncture (Mosby

1998).

• Replace fluids and replace imbalances. • Maintain fluid, electrolyte and acid-base balance. • Administer blood and blood products. • Administer medication. • Provide parenteral nutrition. • Monitor cardiac function. • Immediate results • To provide avenue for dialysis/apheresis • To provide avenue for diagnostic testing • Predictable therapeutic effects • There are more than 200 types of commercially prepared IV fluids

PRINCIPLES USED FOR MOVEMENT OF FLUID IN AND OUT OF

CELL ARE (OSMOSIS and DIFFUSION)

• In Osmosis,

• Fluid moves passively

from areas with more

fluid to areas with less

fluid

• FLUID MOVES

• In Diffusion,

• Solutes (particles) move

from an area of high

concentration to an area

of lesser concentration.

• This process mainly occurs

in gases, liquids and

solutions

• PARTICLES MOVE

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Osmolarity is the measure of solute concentration, defined as the number

of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L).

The osmolarity of a solution is usually expressed as Osm/L

Osmolarity vs. tonicity

Osmolarity and tonicity are related, but different concepts. Thus, the terms ending in -osmotic (isosmotic, hyperosmotic, hyposmotic) are not synonymous with the terms ending in -tonic (isotonic, hypertonic, hypotonic).

The terms are related in that they both compare the solute concentrations of two solutions separated by a membrane.

The terms are different because osmolarity takes into account the total concentration of penetrating solutes and non-penetrating solutes, whereas tonicity takes into account the total concentration of only non-penetrating solutes.

Penetrating solutes can diffuse through the cell membrane, causing momentary changes in cell volume as the solutes "pull" water molecules with them. Non-penetrating solutes cannot cross the cell membrane, and therefore osmosis of water must occur for the solutions to reach equilibrium.

A solution can be both hyperosmotic and isotonic. For example, the intracellular fluid and extracellular can be hyperosmotic, but isotonic – if the total concentration of solutes in one compartment is different from that of the other, but one of the ions can cross the membrane, drawing water with it and thus causing no net change in solution volume.

Functionally, total body water can be divided into two major compartments:

Extracellular fluid (ECF)

Approximately 80% of extracellular fluid is interstitial, which occupies the microscopic spaces between cells. Approximately 20% of extracellular fluid is plasma, which is the liquid portion of blood

Intracellular fluid (ICF).

This is also known as cytosol and is the fluid within cells. • Within the body it is essential that substances move around. • Substances will move from areas of ‘high’ concentration to ‘low’ concentration and a

‘concentration gradient’ will exist between the two. • No energy is required for these physiological movements as they are described as ‘passive’. • Movement is facilitated through processes of ‘osmosis or diffusion’.

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• COLLOIDS • Always hypertonic

1. Volume expanders

• CRYSTALLOIDS • Isotonic • Hypotonic • Hypertonic

• Crystalloids

Crystalloids Solutions with small molecules that flow easily from the bloodstream into cells

and tissues. A clear aqueous solution of mineral salts and other water–soluble molecules, for example 5% Dextrose Solution.

Isotonic solutions have a concentration of dissolved particles equal to that of intracellular fluid.

A solution whose osmolarity falls within the range of 250 and 375 mOsm/Litter is considered isotonic.

• Osmotic pressure is the same both inside and outside the cell. • Cells neither shrink nor swell with fluid movement. • Same tonicity as plasma • Isotonic solution containing electrolytes such as NaCl, KCl, CaCl, and sodium lactate

Hypotonic solutions have less particles than does intracellular fluid. Fluid flows into cells

• Osmotic pressure is greater than that of intracellular fluid. Hypertonic solutions have a large concentration of solutes (particles).

• Water is drawn from the cells to equalize the concentration, which causes the cells to shrink.

• Hypotonic solution containing glucose to provide calories for metabolism • Glucose moves into cells rapidly • Inappropriate use can cause fluid overload and pulmonary edema

Hypertonic solutions have a greater concentration of dissolved particles than does intracellular fluid. Fluid is pulled from cells

• Osmotic pressure is less than intracellular fluid • Water is drawn into the cells from the extracellular fluid causing them to swell

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• Inappropriate use can result in increased ICP and cardiovascular collapse from volume depletion.

• May cause blood cells to burst

Isotonic Solutions (250-375 mOsm/L)

EXAMPLES

Action Indications Nursing

Interventions/Concerns

■ 5% dextrose in

water

■ 0.9% sodium

chloride

Solution (Normal Saline)

■ Ringer’s injection

■ Lactated

Ringer’s Solution

Will hydrate the extracellular compartment; replaces fluid volume without disrupting the intracellular and interstitial volumes

Treatment of vascular dehydration; replaces sodium and chloride

• 5% dextrose in water is isotonic when infused but becomes hypotonic when the dextrose has been metabolized.

• Use cautiously in patients who are fluid-overloaded or who would be compromised if vascular volume would increase, such as renal and cardiac patients.

Hypotonic solutions (<250 mOsm/L)

EXAMPLES

ACTION Indications Nursing

Interventions/Concerns

■ 2.5% dextrose in

water

■ 0.25% sodium

chloride solution

■ 0.33% sodium

chloride solution

■ 0.45% sodium

chloride Solution

Will hydrate the cells; pulls fluid from the vascular space into the cellular space

Treatment of hypertonic dehydration

• These solutions may further exaggerate hypotension due to fluid shifting out of vascular space.

• Do not administer these solutions to hypotensive patients.

Hypertonic Solutions (>375 mOsm/L)

EXAMPLES

Action Indications Nursing

Interventions/Concerns

■ 5% dextrose in

0.45% sodium chloride solution

■ 5% dextrose in

0.9% sodium chloride solution

■ 5% dextrose in

lactated Ringer’s solution

■ 10% dextrose in

water

■ 20% dextrose in

water

■ 50% dextrose in

Will draw fluid out of intracellular space, leading to increased extracellular volume both in vascular and interstitial space

Treatment of hypotonic dehydration; treatment of circulatory collapse; increase fluid shift from interstitial space to vascular space

• These solutions can be very irritating to veins, so observing the IV site for inflammation is imperative.

• May cause circulatory overload, so these solutions should be infused slowly to prevent this in vulnerable patients.

• May increase serum glucose in patients with glucose intolerance, which would make more frequent glucose monitoring an important nursing intervention

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water

• 0.9% Sodium Chloride ( Normal Saline ) • Lactated Ringers • Dextrose 5% in Water (D5W)

0.9% Sodium Chloride Normal Saline

Uses Special considerations

• Shock • Resuscitation • Fluid challenges • Blood transfusions • Metabolic alkalosis • Hyponatremia • DKA

• Use with caution in patients with heart failure, edema, or hypernatremia

• Can lead to overload

Lactated Ringers

Uses Special Considerations

• Dehydration • Burns • GI tract fluid loss • Acute blood loss • Hypovolemia

• Contains Potassium, can cause hyperkalemia in renal patients

• Patients with liver disease cannot metabolize lactate

• Lactate is converted into bicarb by liver

Dextrose 5% in Water (D5W)

Uses Special Considerations

• Fluid loss and dehydration • Hypernatremia

• Solution becomes Hypotonic when dextrose is metabolized

• Do not use for resuscitation • Use cautiously in renal and cardiac patients

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• 0.45% Sodium Chloride (1/2 normal saline)

0.45% Sodium Chloride (1/2 normal saline)

Uses Special Considerations

• Gastric fluid loss • Cellular dehydration from

excessive diuresis • Hypertonic dehydration • Slow rehydration

• Do not give to patients at risk for ICP • Not for rapid rehydration • Electrolyte disturbances can occur

• 5% Dextrose in 0.9% Sodium Chloride(D5NS) • 5% Dextrose in Lactated Ringers (D5LR) • 5% Dextrose in 0.45% Sodium Chloride (D51/2NS)

5% Dextrose in 0.9% Sodium Chloride(D5NS)

Uses Special Considerations

• Heat related disorders • Fresh water drowning • Peritonitis

• Should not be given to patients with impaired cardiac or renal function

• Draw blood before administering to diabetics

5% Dextrose in Lactated Ringers (D5LR)

Uses Special Considerations

• Hypovolemic Shock • Hemorrhagic Shock • Certain cases of acidosis

• Do not administer in patients with cardiac or renal dysfunction

• Monitor for circulatory overload

5% Dextrose in 0.45% Sodium Chloride (D51/2NS)

Uses Special Considerations

• Heat exhaustion • Diabetic disorders • TKO solution in patients with

renal or cardiac dysfunction

• Not for rapid fluid replacement

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• COLLIDES

Colloids - contain large insoluble particles which are referred to as solutes, such

as gelatine. Blood is a colloid

Colloids are made up of much larger solutes than are crystalloids

Used if crystalloids do not improve blood volume Colloids pull fluid into the bloodstream, remember they are always Hypertonic

Watch for increased BP, Dyspnea, and bounding pulse For Example:

o Blood, or blood products. o Albumin o Plasma Protein fraction o Dextran o Hetastarch

Plasma Expanders

EXAMPLES

Action

Indications Nursing

Interventions/Concerns

■ Dextran 70

(isotonic)

■ Dextran 40

(isotonic)

■ 10% mannitol

(hypertonic)

■ 20% mannitol

(hypertonic)

■ 5% albumin

■ 25% albumin

■ 6% hetastarch in

0.9% sodium chloride

■10% hetastarch

in 0.9% sodium chloride

Increases volume in the vascular space. Will draw fluid out of intracellular space, leading to increased extracellular volume both in vascular and interstitial space

Emergency treatment of shock due to fluid or blood loss. Treatment of hypotonic dehydration. Treatment of circulatory collapse. Increase fluid shift from interstitial space to vascular space

• Monitor patients carefully for circulatory overload.

• Monitor for hypersensitivity reactions.

• medications should not be given with or added to these solutions

• These solutions can be very irritating to veins, so observing the IV site for inflammation is imperative.

• May cause circulatory overload, so these solutions should be infused slowly to prevent this in vulnerable patients.

• May increase serum glucose in patients with glucose intolerance, which would make more frequent glucose monitoring an important nursing intervention.

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2. Buffer solutions:

Buffer solutions are used to correct acidosis or alkalosis. Lactated Ringer's solution also has some buffering effect. A solution more specifically used for buffering purpose is intravenous sodium bicarbonate.

3. Other medications

Medications may be mixed into the fluids mentioned above. Certain types of medications can only be given intravenously, such as when there is insufficient uptake by other routes of administration such as enterally. Examples include intravenous immunoglobulin and propofol.

4. Other

Parenteral nutrition is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulas containing salts, glucose, amino acids, lipids and added vitamins.

Drug injection used for recreational substances usually enters by the intravenous route.