E2. L3. - Parenteral Vascular Access Devices Flashcards
Vascular access devices two classes
peripheral
central
Peripheral vascular access devices
Needle
Over-the-needle-catheter
Central vascular access devices
Peripherally-inserted central catheter (PICC)
Surgically implanted
-cannot just place in and pull out, must stay
Peripheral catheter: IV
IV catheter - vein on the limbs
-drip chamber
Y-site - piggyback
clamp - control flow rate
Now - use more and more pumps
-In emergency, may not have time to set up pump
Different Peripheral access devices
Metered burette
Partial-fill container
Partial fill premix
ADD-vantage
CRIS (only one not available today)
Drug manufacturer’s piggyback/Faspak
Vented syringe infusion
Syringe pump infusion
Basic set
One y site
Piercing spike, drop orifice, drip chamber, luer-lock adapter, roller clamp one y site
Add a line set
Two y sites
Some drugs do not like to mix w/anything = second y site while first one is being flushed to use later on again
Sometimes used to give quickly w/o coming into contact w/each other
Peripheral access: administration sets
Looks VERY similar to IV bag
Difference? - container that has marks for measurements
Need something that is a little more accurate - volume control set
Also can be used on patients who have restrictions
Peripheral access: ADD-Vantage
Media fill: USP At least once a year
Take liquid from a vial - transfer them
ADD vantage:
Vial (rubber seal, sterile inside)
Rubber bag also has rubber seal
remove stoppers and connect -> mixes with the liquid but does not matter because sterile and mixed in aseptic conditions (done in 30 seconds, risk of contamination is minimal)
Why don’t we use ADD-Vantage more often?
EXPENSIVE
Generic is much cheaper, have to go through ampule to vial, vial to bag
-Different ways of dosing
-Being tested for the most traditional
Macro vs micro drip
Macro: Larger quantities at faster rates
10, 15, or 20gtt/mL
Macro is the standard
Micro
Smaller amounts
~60 gtt/mL
Used in pediatrics or patients who need small or closely regulated amounts of IV solution
Drop conversion factor/drop number
For water, external degrees
Informed guess - will not be exactly 15, but good estimate
Drip chamber is NOT a corrective thing
Pumps are very smart machines now - programmed to say what dose to give HOWEVER they just push, do not know if it is going into the patient
Poiseullies Law
rate = driving force/resistance
Poiseuilles law verbal
Liquid law for whenever you are putting liquid into a patient
Numerator and denominator:
Driving force - push the liquid in
resistance
Entropy is pressure
N - viscosity
L - length of tubing
Know forces that are pulling one way or the other**
Components of resistance to flow: tubing
Macrobe vis microbe (thin diameter makes it harder to go through)
In line filter (may or may not be used)
Viscosity of IV fluid
Length of tubing venous backpressure
-Position of patient will make a difference on pressure
-Want to change flow rate? - move patient position
Volume fill
Take out of container to admix it
-Has impact
Container will tell you how much it contains
-Does not contain exact amount - some excess
0.5mL container - person who does compounding is able to pull out that volume (excess stays on corners)
-If liquid happens to be more viscous - we will have more excess
-more likely to stick to sides - does not want to come out
Smaller the volume - larger the difference will be
-Proportion of % of excess
Drop conversion factor - drop number
The drop conversion factor is an initial educated guess
It is seldom the exact conversion factor for actual parenteral preps
Actual number of drops/mL depends on:
-Viscosity of the CSP
-Surface tension
-Density
Peripheral access “butterfly” needle
Little wings
if patient moves hand - stays with motion of hand
wings fix it in place
Over-the-needle catheter
Longer
Metal part is used to pierce the vein
Plastic used to pull the needle
Flexible - does not hurt as much, risk of cutting/scratching vein is reduced
Central venous therapy
Lots of volume, lots of blood flow, large volume of fluid
Multiple infusions
Long-term infusion therapy
Infusion of irritating medications like potassium
Infusion of fluids of high osmolarity
-may not necessarily be lethal to cells
But not the norm - do not want it to be shrunk for a long time (shrink quickly, come back)
-Parenteral nutrition (PN)
Central lines - PICC
Peripherally inserted central catheter
Put through arm - goes all the way to the door of the heart
PICC line - easy or complex
COMPLEX PROCESS
Central venous access - functionality
Can go through uvular if needed (if patient has something blocking arm)
Central vein catheter - surgical implant
Multiple lumens - can give three different medications and they do not come into contact w/each other
Central lines common names
Hickman and Broviac
Like coke and pepsi of catheters
-PICC line is Dr. Pepper
Same function, designed by different doctors
Hickman catheter
Requires surgical insertion
Dacron cuff prevents excess motion
-Instead of going through arm, surgically inserted
-Starts in chest
-Put a little plug in there
-Prevents things from coming in: little complications w/infection
-Even if patient moves - affixed to the site of insertion
Central lines - vascular access port
Surgically implanted under the skin
-No exposure
-Aseptic
-Make sure it does not get destroyed - if destroyed, have to pull out and do again
Central lines - Vascular Access Port (VAP)
Non-coring needle
-Bent
-Cut rubber, but rubber can seal back after that
Advantages of Central Venous Therapy
Access to central veins
Rapid infusion of large amounts of fluid
A way to draw blood and measure CV pressure
Reduced need for repeated venipunctures
Reduced risk of vein irritation from infusing irritating substances
Risk of Central Venous Therapy
Sepsis
Thrombus formation
Perforation of vessel and adjacent organs
Air embolism (LARGE volume = LARGE bubble - very problematic)
Can accidentally pierce wrong vein
Disadvantages:
Cost
Requires more skill to insert than peripheral therapy
Risk associated w/infusion:
Complications from damage to the inner lining of the vein (intima):
Stenosis (narrowing)
Thrombus (clot)
Venous occlusion
Chemical inflammation (phlebitis) and pain
Instrumented flow control: controllers vs pumps
Controllers - rarely used anymore (use gravity as driving force)
Pumps - used all the time: powered devices
Instrumented flow: Control
Controls the speed, gravity based
Bag HAS TO BE above pump
-Technically pump could do without having bag above, but it would be harder
Infusion pumps
Powered devices
Pumps provide pressures in the range of 2-12 psi (100-600mmHg)LARGE. the high end of this pressure range is used for arterial infusions
Caution: the use of excessive infusion pressures can be a hazard w/respect to infiltration at the site of injection
A pump is a brute machine - if something is not working it will still keep pushing
Features of infusion pumps
Volumetric delivery, independent of vascular back-pressure, position of patient, composition of infusion solution, or tubing resistance
Position of patient - back pressure
Features of infusion pumps - safety (alarms)
Occlusion of line
Infusion complete
Air in line
Empty container
Flow rate error
-Becoming increasingly smart
T/F: use of infusion pumps turns the drip chamber into ornamental item
False - drip chamber is a window into what is happening
Syringe Pumps
Use commercial syringes
Smart machines
Especially useful for giving intermittent IV meds
Provide the best control for small volume infusions
Useful for pediatric patients
Know from brand name and volume what rate to move
Patient controlled analgesia (PCA)
Pain relief is generally obtained at a lower total dose of drug
-Press a button, release drug
-Potential for abuse
Ambulatory pumps
refers to size and weight of the pump, as well as ability to operate w/o an external power sourceI
Implantable pumps
Usually with reservoirs of ~50mL. Used for IV, intraspinal, and intra-arterial routes. Can deliver as low as 1 microliter/hour
When to use ambulatory vs implantable
How long it will be in patient
Do the same thing, one is just long term
