Intravenous therapy. P&P cp 40 & Lewis cp 19 (w1&2) Flashcards
what is intracellular fluid (ICF)/ cytosol?
includes fluid w/in body cells (accounts for approx 60% of body fluid)
what is extracellular fluid (ECF)?
all fluid that is outside the cell and is divided in three compartments:
- interstitial fluid
- intravascular fluid
- transcellular fluid
what is interstitial fluid?
fluid between cells, and outside the blood vessels
-includes lymph
what is intravascular fluid?
is blood plasma
what is transcellular fluid?
separated from other fluids by epithelium
- includes cerebrospinal
- pleural
- peritoneal
- synovial fluid
- and fluids in the gastrointestinal tract
what does passive transport include?
- osmosis
- diffusion
- filtration
what is osmosis?
movement of water through a semipermeable membrane from an area of lower concentration of solute to a higher concentration of solute
what is osmotic pressure?
the pressure needed to counter the movement of water (solvent) across a semipermeable membrane from a low concentration to a high concentration of solutes
what are the 3 main classes of plasma proteins?
albumin, globulins, and fibrinogen
what pressure does albumin produce?
it exerts colloid osmotic pressure or oncotic pressure.
-oncotic pressure tends to keep fluid in the intravascular compartment by pulling water from the interstitial space back into the capillaries
what is diffusion?
movement of ions and molecules in a solution across a semipermeable membrane from an area of high concentration to an area of low concentration
how is the rate of diffusion affected?
by molecule size, concentration, and temperature of a solution
what is active transport?
it facilitates movement of molecules (solutes) across the plasma membrane across a concentration gradient using chemical energy (ATP)-adenosine triphosphate)
what is primary active transport?
a protein binds with a solute to carry it against a concentration gradient. there are three pumps
- uniport
- symport
- antiport
- the sodium-potassium pump (NA/K ATPase) is an antiport pump (transport solutes in the opposite direction across the plasma membrane)
what is filtration?
results of hydrostatic and colloid osmotic pressure
-a passive process whereby water moves into and out of the capillaries
what is hydrostatic pressure?
the force exerted by fluids w/in a compartment
what are the primary hormones that regulate fluid in our bodies?
- antidiuretic hormone
- angiotensin II
- natriuretic peptides
fluid output occurs with which four of our organs (water loss)?
- kidneys
- skin
- lungs
- gastrointestinal tract
what is sensible water loss?
includes water loss through urine and feces
what is insensible water loss?
a continuous, gradual loss of water from the respiratory and skin epithelium
- this water loss may increase in response to changes in respiratory rate and depth
- water loss from skin is regulated by our SNS activating sweat glands
- fevers may increase insensible water loss
what is paco2?
- is partial pressure of carbon dioxide
- measures how well the lungs are excreting CO2 by cells
- high PaCO2 indicates CO2 accumulation in blood (more carbonic acid) caused by hypoventilation; decreased PaCO2 indicates excessive CO2 excretion (less carbonic acid) through hyperventilation.
what does HCO-3 do?
HCO3– is concentration of the base (alkaline substance) bicarbonate, a measure of how well the kidneys are excreting metabolic acids. Increased HCO3– indicates that the blood has too few metabolic acids; decreased HCO3– indicates that the blood has too many metabolic acids.
what does Pa02 do?
PaO2 is partial pressure of oxygen (O2), a measure of how well gas exchange is occurring in the alveoli of the lungs. Values below normal indicate poor oxygenation of the blood.
what is the goal of intravenous fluid therapy?
- maintain fluid, electrolyte, and energy demands when pt’s are limited in their intake
- to prevent or correct fluid and electrolyte disturbances from excess losses
when are oral replacements of fluid contraindicated?
- pt has mechanical obstruction of the GI tract
- risk of aspiration
- impaired swallowing
what are crystalloids?
Small molecules that diffuse through capillary walls
-Depending on solute concentration, fluids may be:
-Isotonic – most nutrients, most common and least
irritating to the vein
-Hypertonic, hypotonic
-include dextrose, sodium chloride, and lactated Ringer’s solutions
what are colloids?
-they contain protein or starch which dose not cross semipermeable membranes and therefore remains suspended and distributed in the extracellular space (Larger molecules that can not diffuse through capillary walls)
primarily the intravascular space for several days
-colloids have been used to increase the osmotic pressure in the intravascular space to increase vascular volume in critical situations
-colloids are either semi-synthetic such as dextran, pentastarch, or hetastarch
or human plasma derivatives such as albumin, plasma proteins or blood
what are vascular access devices? (VADs)
-are catheters, cannulas, or infusion ports designed for repeated access to the vascular system. These devices include peripheral vascular access devices (PVADs) and central vascular access devices (CVADs) and allow for parenteral fluid and electrolyte replacement, par- enteral nutrition, and administration of medications.
name a cannula that is for short-term use?
peripheral cannulas
which cannula are used during long-term use?
central venous catheters (CVC)
-peripherally inserted central catheters (PICCs), tunnelled catheters (e.g., Hickman), and implanted ports are for long-term use or for administration of medications or solutions that are irritating to the veins
identify hypotonic solutions
- 0.225% sodium chloride (quarter normal saline; 14 0.225% NaCl)
- 0.45% sodium chloride (half normal saline; 12 NS; 0.45% NaCl)
- expands extracellular fluid volume (vascular and interstitial) and rehydrates cells
identify isotonic solutions
- Dextrose 5% in water (D5W)
- 0.9% sodium chloride (normal saline; NS; 0.9% NaCl)
- Lactated Ringer’s (LR)
- Expands extracellular fluid (vascular and interstitial); does not enter cells.
identify hypertonic solutions
- Dextrose 10% in water (D10W)
- 3% or 5% sodium chloride (hypertonic saline; 3% or 5% NaCl)-
- Dextrose 5% in 0.45% NaCl sodium chloride (D5 12 NS; D50.45% NaCl)
- Dextrose 5% in 0.9% sodium chloride (D5NS; D50.9% NaCl)
- Dextrose 5% in lactated Ringer’s (D5LR)
- dextrose enter cells rapidly and leaving % of fluid behind (i.e 0.45% sodium chloride) or draws water from cells into extracellular fluid by osmosis
what is a midline catheter?
- a catheter inserted into the upper arm and terminating distal to the shoulder
- is recommended for intermediate use (1-4 weeks) or when peripheral or central access is difficult or contraindicated
how long can transparent dressing remain intact?
5-7 days
what to assess at the insertion site?
- inspect for tenderness
- signs of infection
- erythema
- warmth
- edema
- infiltration, inflammation, clots, kinks/knots
- assessment should include palpation
- assess for engorged veins at the chest or neck
- assess any difficulty w/ movement
- assess for systemic infections (fever, chills, hypotension)
difference between maintenance fluids and replacement fluids
- maintenance: help to sustain normal levels of fluids and electrolytes- can also be used when pt is NPO
- replacement: ordered for a pt who lost fluid through-vomiting, diarrhea, or hemorrhage
what is primary IV line?
main source for IV fluids and electrolytes (i.e potassium chloride, sodium chloride, normal saline)
what are secondary IV lines?
- usually used to administer intermittent medication and are attached to the primary line at an injection port
- referred to ass IV piggyback (IVPB)
- must be hung higher than the primary so that it gives greater pressure allowing it to infuse first
blood can only be hung with what?
normal saline-to flush before and after the blood transfusion
what is the average dose for heparin lock?
10 units and NEVER exceeds 100 units
what is dose IV push refer to?
indicates that a syringe is attached to the port and the medication is pushed in
what is IV bolus?
indicates that a volume of IV fluid is infused over a specific period of time through an IV administration set