Ch. 12 Calculating parenteral injections Flashcards
Parenteral drugs are administered by these 4 types of injections:
intradermal, subQ, IM, and IV (filer also)
Giving parenteral drugs safely depends on choosing the right (2)
syringe and needle
Which layer of the skin do intradermal injections reach?
dermis aka the outermost layer
When are intradermal injections used?
to anesthetize the skin for invasive procedures, to test for allergies, TB, histoplasmosis, and other diseases.
Volume of a drug given by intradermal? Syringe used? Calibrated in? Needle size (diameter and length)? Bevels?
- less then 0.5 mL
- 1mL syringe
- calibrated in 0.01-mL increments
- 25-27G needle
- 3/8 in to 5/8 in long
- bevels usually short
Procedure for intradermal injection (4)?
- Clean skin with antiseptic swab
- Stretch skin taut with one hand
- With other hand, insert needle quickly @ 10-15 degree angle to a depth about 0.5 cm
- Inject drug. Small wheal forms.
SubQ injections are injected to which part of skin and what is the rate?
Into the subcutaneous tissue, beneath the dermis and above m. Faster rate of absorption d/t more capillaries
Which drugs are normally given subQ?
Insulin, heparin, tetanus, toxoid, and some opioid analgesics
Volume of a drug given by subQ? Needle size (diameter and length)? Bevel?
- 0.5-1mL
- 23G-28G
- 1/2 in to 5/8 long
- med. bevels
SubQ injection sites include:
- ant. aspect of thighs
- abdomen
- upper back
Procedure for subQ injection (5)?
- choose injection site
- clean skin with antiseptic swab
- If slim pt, pinch skin with index finger and thumb, insert needle @ 45 degree angle. If obese, insert needle into fatty tissue @ 90 degree angle.
- administer injection
- May apply pressure or massage site after removal of needle to enhance absorption. Unless heparin or insulin!
ALWAYS check facility’s policy
IM injections go into… used for drugs that need to be…
muscle… absorbed quickly, given in a large volume, or irritate tissues
Volume of a drug given IM
Needle size (length and diameter)? Bevel size?
- 0.5-3mL
- 1 to 3 in long
- 18G to 23G diameter
- bevels usually med
IM injection sites include (mention volume; 2 sites):
- ventral gluteal or vastus lateralis m. (3-mL).
- deltoid m. (less than 2mL)
Choice of injection site for IM injection depends on (3):
Pt’s m. mass and overlying tissue and volume of injection
Procedure for IM injection (6)?
- Choose injection site
- Clean skin with antiseptic swab. Some facilities use Z-track method.
- In quick, dart-like action, insert needle @ 75-90 degree angle.
- Before injecting, aspirate for blood.
- Push plunger and keep the syringe steady.
- Once injected, pull the needle straight out and apply pressure to injection site (may not be included in facility protocol).
What is the Z-track method (used in IM injections)?
With middle and index fingers, pull skin surrounding injection in opposite directions. Helps ensure med does not come back through the injection site once needle is removed.
How do we aspirate for blood when administering injections?
Pull back plunger and check plunger to see if blood has entered syringe
What are the 3 types of syringes used to administer parenteral drugs?
standard, Tuberculin, and prefilled.
Calibrated in cubic cm, drugs usually ordered in mL
dead space ( of syringe )
holds fluid that remains in syringe and needle after plunger is completely depressed. Not found in some, such as insulin syringes.
Strd. syringe available in 7 volumes:
3, 5, 10, 20, 30, 50, and 60mL
Parts of a syringe (6):
- plunger
- barrel
- hub
- needle
- safety device
- dead space
What is the most common type of syringe?
3-mL. Calibrated in tenths of a mL on the right and minims on the left. Large marks for every 0.5 mL on right.
Large volume syringes are calibrated in…
2 to 10 mL increments
These steps describe….
1. use aseptic technique
2. calculate the dose
3. draw the drug into the syringe
4. pull plunger back until the top ring of the plunger’s black portion aligns with the correct calibration mark
5. double-check the dose measurement
6. administer the drug
5.
6.
to administer drug
Usual adult dose of a parenteral drug can be contained in 1-3mL of soln. If more is needed…
Dose larger than 3mL should be given in 2 injections at 2 different sites to ensure proper drug absorption
Tuberculin syringes commonly used for…
intradermal injections and to administer small amnts of drugs (pediatrics or intensive care untis)
Tuberculin syringes are calibrated in…
hundredths of a mL, allowing you to accurately administer doses as small as 0.25mL.
Prefilled syringes
sterile syringe filled with a premeasured dose of a drug
When choosing a needle, consider (3):
gauge, bevel, and length
gauge refers to diameter of…. in a needle
inside. Smaller = larger diameter
Bevel refers to…
angle at which needle tip is opened
Bevel may be (3)…
short, medium, or long
length of a needle describes the…
distance from needle tip to needle hub. Ranges from 3/8 inches to 3 in
IV needle length, bevel size, diameter?
needles are 1-3in. long, are 14G to 25G in diameter
Filter needles are used for..
preparing a soln from a vial or ampule, not for injections
Filter needle length, bevel size, diameter?
1 1/2in long, med. bevel, 20G in diameter
