The purpose of this continuing education course is to enable the participants to safely administer IV Fluids.
After completing this continuing education course, the participant will be able to meet the following objectives:
The type of IV fluid seems very benign. It is not. The IV fluid that you hang must be correct. Otherwise, you can cause the patient to get worse, or die.
Homeostasis is the steady state of the body by which the internal systems of the body maintain a balance. It is maintained by adaptive responses that promote healthy functioning of the body.
One of the primary objectives of I.V. therapy is to maintain and/or restore the fluid and electrolyte balance in the body. Our bodies are composed largely of fluid. In fact, these fluids will account for about 60% of total body weight in an adult male, and 45%-50% in an adult woman. In infants, fluids account for about 80% of total body weight and will steadily decrease throughout childhood until it reaches adult percentages at around the age of 8.
Body fluids are composed of water and solutes. Solutes are classified as either electrolytes or nonelectrolytes. The nonelectrolytes are solutes without an electrical charge and include: glucose, proteins, lipids, oxygen, carbon dioxide, and organic acids. The electrolytes will be discussed later.
The body fluids are distributed between two major compartments: intracellular fluid is inside the cells; and extracellular is fluid outside of the cells.
The extracellular fluid occurs in two forms: interstitial fluid surrounding each cell and lymph gland: and intravascular fluid, which is blood plasma. Part of the interstitial fluid is also made up of the cerebrospinal, pleural, peritoneal, or synovial fluids, and the secretions from the salivary glands, pancreas, liver, and sweat glands. The distribution of fluids between these two compartments is constant when the body is healthy. The heart, kidneys, liver, adrenal and pituitary glands, and nervous system all play a part in maintaining fluid balance in the body.
If there is fluid accumulation in a compartment other than the intracellular or extracellular space, it is referred to as third-space fluid shifting. This happens when a cellular membrane allows water and fluid to enter but not exit. For example, with severe burns, fluids will pool in the burn site, causing depletion of the intracellular fluid (ICF) and Extracellular fluid (ECF). If pancreatitis fluids "leak out" into the peritoneal cavity this causes depletion in the ICF and ECF. Patients undergoing long and extensive surgeries will collect third-space fluids and will become intravascularly depleted despite the administration of large volumes of I.V. fluids and blood. Third-space fluid shifting can also occur due to acute bowel obstruction, ascites, and sepsis. These patients will experience tachycardia, hypotension, weight gain, low urine output, poor skin turgor, and hyponatremia.
Fluid balance is also affected by:
Distribution of fluids depends on the hydrostatic and colloid osmotic pressures in the capillaries. Fluid volumes and concentration are regulated by the interaction of two hormones antidiuretic hormone (ADH) and aldosterone.
ADH is secreted when plasma osmolarity increases or circulating blood volume decreases and blood pressure drops. ADH restores blood volume by reducing diuresis and increasing water retention.
Aldosterone is secreted when the serum sodium level is low, the potassium level is high, or the circulation volume of fluid decreases. It causes the kidneys to retain sodium and water.
Osmolarity is the concentration of a solution. Usually, the serum has the same osmolarity as other body fluids approximately 300 mOsm/L. If your patient has a serum osmolarity lower than this, they may have fluid overload. Whereas a higher serum osmolarity indicates the patient may be experiencing hemoconcentration of the fluid and dehydration.
Body fluids are in constant motion moving between the fluid compartments through membranes. Homeostasis is maintained when the solutes and fluids are distributed evenly on each side of the membrane. When there is an imbalance, these molecules will move between the compartments by various routes including:
|Electrolyte||Normal Value||Principal Functions||Signs of Imbalance|
Major cation in ECF
Maintains ECF osmolarity
Helps maintain BP
Influences water distribution
Helps regulate acid-base balance
Aids nerve/muscle fiber impulse transmission
Hypernatremia: Irritability, thirst, fever, decreased urine output, flushed skin, hypertension
Hyponatremia: Irritability, fatigue, muscle weakness, tachycardia, headache, hypotension, increased urine cutout
Major cation in ICF
Maintains fluid balance in cells
Maintains cell osmolarity
Contracts skeletal, cardiac, and smooth muscles
Major role is acid-base balance
Promotes cell growth
Hyperkalemia: muscle weakness, nausea, diarrhea, lethargy, bradycardia, hypotension, cardiac arrhythmias
Hypokalemia: fatigue, weakness, leg cramps, weak/irregular pulse, hypotension, hyperglycemia,
Major anion in ECF
Maintains serum osmolarity
Combines with other major cations to create important compounds: NaCl, HCI, KCI, CaCI
Hyperchloremia: stupor, rapid/ deep breathing, muscle weakness
Hypochloremia: increased muscle excitability, tetany, decreased respirations
99% found in bones and teeth
Enhances bone strength Maintains muscle tone
Maintains cell membrane structure, function, permeability
Enzyme co-factor for clotting
Affects activation, excitation, and contraction of cardiac and skeletal muscles
Hypercalcemia: anorexia, nausea, fatigue, constipation, dehydration, headache, hypertension, cardiac arrhythmias
Hypocalcemia: muscle spasms or cramping in calf muscles, tetany, positive Chvostek or Trousseau sign, hyperreflexia, laryngospasm, cardiac arrhythmias
Major anoin in ICF
Maintains cell integrity
Major role in acid-base balance as a urinary buffer
Essential to muscle, red blood cell, and neurologic functions
Hyperphosphatemia: anorexia, nausea, tetany, tingling, cramps, nervousness, cardiac arrhythmias
Hypophosphatemia: lethargy, stuttering/stammering, joint stiffness, memory loss, muscle pain
Major cation in ICF
Active in carbohydrate and protein metabolism
Facilitates sodium and
Influences calcium levels
Affects muscular irritability and contractions
Hypermagnesemia: muscle weakness, lethargy, nausea, hypotension, slow/weak pulse, bradycardia, decreased L.O.C.
Hypomagnesemia: dizziness, confusion, leg cramps, nausea, difficulty swallowing, cardiac
|Causes of Imbalance||Treatment|
There are three basic types of fluids that are utilized for IV therapy. They are:
Isotonic fluids have the same osmolality as the serum and other body fluids.1 It expands the intravascular compartment. It can be used to treat hypotension that is secondary to hypovolemia, or as maintenance fluids.
Isotonic fluids include:
Hypotonic fluids have a lower osmolality than the serum.1 When given they help hydrate the cells and can decrease the amount of fluid in the circulatory system. This is used when diuretic therapy dehydrates the cells, to lower serum sodium levels, in the treatment of diabetic ketoacidosis, and to treat hyperglycemic nonketotic syndrome.
Hypotonic fluids include:
0.45% NS (Half-normal saline)
0.33% NS (One-third saline)
O2.5W (Dextrose 2.5% in water)
Hypertonic solutions have a higher osmolality than the serum.1 These fluids pull fluid from the interstitial and intracellular compartments back into the blood vessels. Can be used to treat hypovolemia, low serum sodium levels, or to help reduce risk of edema and low blood pressure in post op patients.
Hypertonic fluids include: