Parenteral Medication Administration

• Parenteral medications are administered via injection.

Objectives:

• Verbalize the advantages and disadvantages of parenteral medications.
• Differentiate between types of syringes used for medications.
• Identify the parts of a syringe and needle.
• Discuss the importance of using different needle sizes and gauges on client populations.
• Identify sites for subcutaneous injections.
• Discuss the importance of proper aseptic technique when administering parenteral medications.
• Demonstrate proper safety techniques before and after administering parenteral medications.

Medication Administration:

• Enteral medications travel through the GI tract and liver before absorption.
• Examples include oral liquids, NG tubes, rectal, sublingual, and buccal medications.
• Parenteral medications are administered by injection, bypassing the liver.
• Examples include subcutaneous, intradermal, intramuscular, IV, and intrathecal injections.
• Topical medications are applied to the skin, including transdermal patches, eye/ear drops, vaginal creams, nasal sprays, and nebulization.

First-Pass Metabolism:

• Oral medications are metabolized by the liver, decreasing their effect.
• The first-pass metabolism can be bypassed by using sublingual, buccal, and parenteral routes.

Advantages of Parenteral Administration:

• Bypasses the gastrointestinal tract, causing no GI irritation.
• Results in rapid onset compared to the oral route.
• Administration is easier for uncooperative or unconscious patients.
• Absorption is better for drugs that are poorly absorbed through the oral route.

Disadvantages of Parenteral Administration:

• Is invasive and uncomfortable for the patient.
• More expensive than oral medications.
• Additional supplies and equipment are required.
• Requires qualified personnel to administer.
• Carry a risk of infection and nerve injury.
• The parenteral route means a route of drug administration other than oral or through the gastrointestinal tract.

Parenteral Administration Equipment:

• All syringes contain a barrel, a plunger, and a tip or hub.
• Syringes are calibrated in milliliters (mL), cubic centimeters (cc), units (U).

Parts of a Needle:

• Shaft: The hollow tube through which medication passes; varies in length.
• Lumen: The oval-shaped opening at the end of the needle.
• Tip: The sharpened end of the needle.
• Bevel: The flat slanted surface on the point.
• Hub: The part of the needle that attaches to the syringe.
• Gauge: Determined by the diameter of the lumen, ranging from 16gu to 30gu.
• The larger the number, the thinner the needle and the smaller the diameter.

Needle Length:

• Needles come in various lengths and gauges.
• Shaft: This is the length of the needle.
• The length varies from 0.5 to 3.0 inches
• Filter needles are used when withdrawing medication from a glass ampule.

Needle Gauge:

• Refers to the width of the needle/ size of the hole.
• The smaller the number, the larger the diameter.
• Common gauges range from 18G to 27G needles.
• Insulin pens often have very tiny needle gauges and lengths, typically 4mm-12mm in length and 29-31 gauge.
• Remember that the smaller gauge needle(diameter) has a higher number.
• A #16-gauge needle is a larger diameter and is a smaller gauge number.
• A #31-gauge needle is a smaller diameter and is a larger gauge number.

Common Syringe and Needle Sizes:

• Intradermal (tuberculin) injections use a 1 mL syringe calibrated in 0.01 mL or in minims, with a 25-27 gauge needle, ½- to 5/8-inch.
• Subcutaneous injections use a 1, 2, 2.5, or 3 mL syringe calibrated in 0.1 mL, with a 23-26 gauge needle, 5/8- or ½-inch.
• Insulin injections (subcutaneous) use a 1 mL syringe calibrated in units, with a 25-27 gauge needle, ½- or 5/8-inch.
• Intramuscular injections use a 3 or 5 mL syringe calibrated in 0.2 mL, with a 20-23 gauge needle, 1½- or 2-inch.
• Needle length and gauge depend on the type of medication you are giving, the thickness/viscosity of the medication, the age/size/weight of the patient, the amount of subcutaneous fat/muscle mass, and which injection sit

Recapping Clean Needles:

• For a CLEAN needle, put the needle cover back on.
• Use the 1 handed scoop method.
• Never recap a dirty needle.
• After administering an injection, do not recap the needle cover.
• If a safety mechanism exists, use the 1-handed technique to apply the safety mechanism.
• Place the used needle into the biohazard sharps container to be incinerated.
• Safety injection equipment avoids needlestick injuries and reduces the risk of blood-borne diseases such as Hepatitis B, Hepatitis C, or AIDS.
• Equipment includes plastic needle shields, needles that retract into the syringe.
• Gas-pressured devices inject medications without needles.
• The syringe barrel holds the medication; the plunger withdraws and instills the medication; the tip/hub attaches the needle.

Drug Preparations:

• Ampule: Sealed glass drug container.
• Vial: Glass or plastic container of parenteral medication with a self-sealing rubber stopper.
• Reconstitution: The process of adding liquid, known as diluent, to a powdered substance.
• Single-dose vials are used for only one patient and thrown away after they have been accessed.
• Multi-dose vials need to be labeled multidose.
• If possible, multi-dose vials should be dedicated to only one patient.
• For multidose vials used on multiple patients, keep in the med area, never in a patient treatment/operating room, and record the date the vial was first opened.
• Vials have 2 expiration dates: the manufacturer's expiration date and the open date/opened expiration date after 28 days.
• Discard vials after the manufacturer's expiration date.
• Vials need to be labeled with the date they are opened.
• Discard opened vials within 28 days of opening, unless the manufacturer recommends a different expiration period, and always err on the side of caution, when in doubt, throw it out.
• Filter needles, reconstitution methods, and prefilled cartridges affect drug preparation.

Other Drug Preparations:

• Prefilled cartridges: Sealed glass cylinders of parenteral medication
• Cartridge: These come with an attached needle, and the cylinder is made to fit in a specially designed syringe.
• Combining meds in one syringe: Exact amounts must be withdrawn from each drug container since, once in the barrel of the syringe, there is no way to expel one without expelling some of the other.

Injection Sites:

• Select the correct location for parenteral medication administration based on the type of injection and to optimize the absorption of the medications.
• Injecting medication into the correct location prevents injury to the tissues, nerves, and bones, at different angles for injections.

Needle Insertion Angle:

• The needle should be inserted all the way to the hub, using a smooth and quick continuous motion, reducing discomfort; use a "Dart Like Motion".
• Withdraw the needle at the same angle it was inserted.

Subcutaneous Injection Sites:

• Medication is instilled between the skin and muscle; beneath the skin by above the muscle.
• Medication is instilled between the skin and muscle and absorbed rapidly. Commonly used to administer insulin and heparin.
• The most common site is the abdomen, at least 2 inches away from the belly button.
• Other sites include the back of the upper arm and the anterior aspect of the thigh.
• Document the site per facility policy.
• Injection sites for insulin are rotated to avoid complications.
• Lipoatrophy: the breakdown of subcutaneous fat at repeated insulin injection sites.
• Lipo-hypertrophy: the buildup of subcutaneous fat with repeated insulin injections.
• The nurse inserts the needle at a 45° angle for thin clients.
• For obese clients and intramuscular injection administration, insert the needle at a 90° angle.
• For intradermal injections, instill the medication shallowly at a 10° to 15° angle of entry.
• Equipment depends on the type of prescribed medication, for example, insulin is prepared in an insulin syringe, while heparin is prepared in a tuberculin syringe.

Insulin Syringe:

• Measured in units; often has an orange cap; always verify you have an insulin syringe.

Tuberculin Syringe:

• Measured in mL most often.
• Contains only 1mL, starting with 0.1.

Administering Heparin Subcutaneously:

• Assessment is needed before and after medication administration.
• Before: All medications require assessment prior to administration to ensure the patient is receiving the correct medication for the correct reason (review of lab values, pain, respiratory or cardiac assessment, etc.).
• After: Assessment helps determine if medication is having its intended effect and to determine possible adverse reactions.
• Nurses select the appropriate needle gauge and length based on the medication ordered, the type of injection, the anatomical location, the patient's body mass, body weight, age, the amount of adipose tissue or the muscle mass. The needle must be long enough to do its intended action, and must have a large enough gauge to inject.
• Check the medication in the vial to ensure it is not contaminated, is the correct color, and has no floaties, flecks, specks, discoloration, cloudiness (if the med is supposed to be transparent.
• Check the vial for leakage or damage, and the syringe for any form of damage.
• Do not use Rapid or Long-acting insulins if they do not appear "clear".
• (rapid- and long-acting insulins) such as Glulisine (Apidra), Lispro (Humalog), Aspart (NovoRapid), Determir (Levemir) or Glargine (Lantus).
• If it becomes "cloudy" or straw-colored, or contains solid particles that are floating around.
• Do not use “cloudy” intermediate-acting insulin (such as Humulin-N or Novolin-NPH) if you see particles or lumps are floating around after mixing.
• Solid pieces stick to the bottom or sides of the bottle.
• To use, roll the bottle between your palms 10 times, and do not shake.
• Heparin, an anticoagulant, prolongs blood clot time, and is given subcutaneously and intravenously.
• Heparin is irritating to the tissue or the vein, so consider changing the needle.

Nursing Considerations with Heparin:

• When given in large doses, monitor the labs (aPTT - activated partial thromboplastin time; PTT - partial thromboplastin time).
• Remember the “ Rule of 10”: Heparin has 7 letters + PTT has 3 letters = 10 letters
• Note that there are other nursing considerations with heparin.
• The antidote for heparin is protamine sulfate (think pms- the p is in heparin).
• Heparin is always given in the abdomen, staying 2" away from the umbilicus.
• Do not massage the injection site.
• LPN's can only give 5000 units (low dose) of heparin at most facilities.
• Heparin can cause bruising and bleeding at the injection site.
• Rotate injection sites to prevent tissue injury or bleeding/bruising.
• Do not aspirate the plunger once the needle is inserted in place for subcutaneous injections.
• Administer the injection slowly over 5-10 seconds, holding the plunger for 10 seconds, and withdraw the needle at the same angle it was inserted.
• Lovenox (low molecular weight heparin): Given subcutaneously only in the abdomen, used in home care and subacute care, and is usually administered by LPN's (may vary at different facilities).
• Coumadin (Warfarin) is an oral medication, an oral anticoagulant, is similar to heparin but has a delayed onset, is well-suited for long-term prophylaxis, and labs need to be monitored.
• Monitor the patient's PT (prothrombin time) and INR (international ratio).
• Remember the rule of 10 again: Coumadin (8 letters) and PT (2 letters) = 10 The antidote for Coumadin is Vitamin K (the "c" sound in Coumadin will help you remember that vitamin k is the antidote).