Lesson 1, Topic 1
In Progress

Section Three: Parenteral Medications

May 9, 2021

In 1987, in an effort to protect health care workers from exposure to human immunodeficiency virus (HIV), 85hepatitis B virus (HBV), and other bloodborne pathogens, the Centers for Disease Control and Prevention (CDC) issued recommendations for universal precautions for all health care workers to follow. They recommend that health care workers use gloves, gowns, masks, and protective eyewear when they are likely to be exposed to patient blood or body fluids, and that they consider that all patients might be infected. In 1988, an update from the CDC clarified the specific body fluids that may be a problem (Box 7-2). Evidence has suggested that only blood, semen, vaginal fluid, and possibly breast milk could carry HIV. These precautions also apply to a variety of other body fluids and tissues (see Box 7-2), although the risk from these is unknown. In 1996, the CDC published revised guidelines, called Standard Precautions, which are considered to be the primary ways to prevent the transmission of infections.

Box 7-2
Summary of Standard Precautions
Prevention of Transmission of Human Immunodeficiency Virus, Hepatitis B Virus, and Other Bloodborne Pathogens in Health Care Settings

Under Standard Precautions, blood and certain body fluids of all patients are considered to possibly contain human immunodeficiency virus (HIV), hepatitis B virus (HBV), and other bloodborne pathogens. Blood is the single most important source of transmission of HIV, HBV, and other bloodborne pathogens in health care settings. Infection control efforts for HIV, HBV, and other bloodborne pathogens must focus on preventing exposure to blood, as well as on delivery of HBV immunization.

Research has shown that only blood, semen, vaginal secretions, and possibly breast milk may transmit HIV. Although the risk is unknown, universal precautions also apply to tissues and the following fluids: cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, and amniotic fluid. Standard Precautions do not apply to feces, nasal secretions, sputum, saliva (except in situations in which contamination with blood is likely, such as dental settings), sweat, tears, urine, and vomitus unless they contain visible blood. The risk of transmission of HIV and HBV from these materials is extremely low to nonexistent.

Health care workers are at risk for exposure to blood from patients and must consider all patients as possibly infected with bloodborne pathogens. Therefore health care workers must always follow infection control precautions for all patients.

Precautions to Prevent Transmission of HIV
General Precautions

• Consider all patients potentially infected.
• Wear gloves when touching blood, body fluids containing blood, and body fluids to which Standard Precautions apply; for handling items or surfaces soiled with blood or other fluids; and for doing venipuncture or other procedures involving blood. Change gloves after each contact with a patient.
• Use masks, protective eyewear or face shields, and gowns or aprons when doing procedures that may produce blood or body fluid droplets or splashes.
• Wash hands and skin surfaces immediately and thoroughly with warm soap and water if they get splashed with blood or body fluid to which universal precautions apply; wash between patients and after removal of gloves even when they are not torn or punctured.
• Take precautions to prevent injuries from needles, scalpels, and other sharp instruments during procedures, when cleaning instruments, during disposal, or when handling. To prevent needlestick injuries, needles are not to be recapped, bent or broken by hand, or removed from disposable syringes. After they are used, disposable syringes and needles, scalpel blades, and other sharp items for disposal are to be placed in puncture-resistant containers located within the patient’s room.
• Use mouthpieces, resuscitation bags, or other ventilation devices when mouth-to-mouth resuscitation is likely to be performed in emergency situations.

Special Considerations
• Health care workers who have sore, draining lesions or wet skin conditions are not to be giving direct patient care and are not to handle patient care equipment until the condition resolves.
• Pregnant health care workers are not known to be at greater risk of getting HIV infection than health care workers who are not pregnant; however, if a health care worker is infected with HIV during pregnancy, the infant is at risk of infection from perinatal transmission. Because of this risk, pregnant health care workers must be especially familiar with and strictly follow precautions to lower the risk of HIV transmission.

Precautions for Invasive Procedures
An invasive procedure is defined as any surgical entry into tissues, cavities, or organs, or repair of major traumatic injuries. General blood and body fluid precautions listed earlier, combined with the following list of precautions, are the minimal precautions for all such invasive procedures.
• All health care workers who participate in invasive procedures must use appropriate barrier procedures to prevent skin and mucous membrane contact with all patients’ blood and other body fluids to which universal precautions apply.
• Gloves and surgical masks must be worn for all invasive procedures.
• Protective eyewear or face shields are to be worn for all procedures that commonly produce droplets or splashes of blood, body fluids containing blood, or other body fluids.
• Gowns or aprons made of materials providing a barrier are to be worn during an invasive procedure in which there is likely to be splashing of blood or other body fluids.
• All health care workers who perform or assist in vaginal or cesarean delivery are to wear gloves and gowns when handling the placenta or the infant until blood and amniotic fluid have been removed from the infant’s skin. Gloves are worn until postdelivery care of the umbilical cord.
• If a glove is torn or a needlestick or other injury occurs, the glove is removed and a new glove put on as promptly as patient safety permits; the needle or instrument involved in the incident should also be removed from the sterile field.
Data from Centers for Disease Control and Prevention: Recommendations for prevention of HIV transmission in health care settings, Morb Mortal Wkly Rep 36(suppl 25), 1987; Update universal precautions for prevention of transmission of human immunodeficiency virus, hepatitis B virus, and other bloodborne pathogens in health care settings, Morb Mortal Wkly Rep 37(24), 1988; and Morb Mortal Wkly Rep 38(suppl 6):9-18, 1989.

Standard Precautions recommend the use of puncture-resistant containers for disposing all needles 87and sharps. Scoop up the syringe with one hand. Do NOT put the cap back on a needle, because most needlestick injuries occur at this time. Do not break the needle off the syringe. If the syringe is supplied with a safety-cover system, be sure to slide the safety cover in place, per manufacturer instructions, before placing the whole syringe in the sharps container. If the syringe is supplied in a retractable needle system, simply place the whole syringe in the sharps container after use, because the needle will retract automatically after injection; in order to activate this system, be sure to administer the full volume of medication present in the syringe. With either product, if the safety feature does not activate or fails, be sure to place the whole device in the sharps container to minimize any risk of needle puncture. Place both needle and syringe in a well-marked “hazardous material” plastic canister directly after use. Research suggests that probably more needlestick injuries occur than are reported, and every effort should be made to prevent people from recapping used needles.

Parenteral Administration
The parenteral route (into the skin) of medication administration may be through intradermal (ID), subcutaneous (SubQ, SC), intramuscular (IM), or intravenous (IV) injections. Drugs are administered parenterally for the following reasons:

• The patient cannot take an oral medication.
• The action of the medicine is required quickly.
• The medication might be destroyed by gastric enzymes.
• The medication might be removed from the body on a “first pass” through the liver before it can get to the tissues in the body where it will act.
• The medication must be given at a steady rate to provide a constant blood level.
• The medication is not available in an enteral form.

For example, vomiting or unconscious patients may receive IM or IV antibiotics; IV medication may be given in a life-threatening emergency; or a patient may receive continuous IV medication to control heart dysrhythmias.
IM and subcutaneous injections require some time for the medication to reach the bloodstream, so the onset of action may be slower than if the medication were given intravenously. If an individual is filled with fluid (edema), has large quantities of fat, or has poor circulation (for example, if in shock), the rate of absorption may be unusually long for IM or subcutaneous injections.
IV injections or infusions may be needed when medication must go directly into the bloodstream because the action of these methods is rapid. IV medications may be effective for only a short time, requiring frequent doses. Overdosage errors of IV medications can be very serious. Also, the cost is generally higher for IV medication, even though the total dose may be smaller than if the medication were given orally.
Although all medication administration should be 100% accurate, the nurse giving parenteral medication has a special responsibility for careful and accurate administration because any errors in technique or dosage may have serious consequences. Once injected, the medication cannot be withdrawn. Precise administration of drug dosage is essential. Accurately locating the site of injection is required to avoid pain and damage to tissues, nerves, or blood vessels. Aseptic (sterile) technique must be followed to lessen chances of infection. A slow and gradual rate of injection of the medication into the tissues is important for most drugs. This will reduce pain, prevent overdosage, and decrease adverse reactions such as respiratory collapse or heart dysrhythmias.

Basic Equipment
Syringes
Syringes, or instruments for injecting liquids, come in 1-, 3-, 5-, 10-, 20-, and 50-mL sizes and in plastic or glass. Plastic syringes are the preferred equipment because they may be used once and thrown away. This makes them convenient in terms of packaging and disposal, but they are more expensive than glass and cannot be used with some medications; also, dosage lines or calibration may be more difficult to read. Reusable glass syringes cost far less, but they may break, may become loose with constant use, and must be cleaned, repackaged, and sterilized each time they are used. Needleless syringe systems are also now available for use, consisting of a high-pressured delivery device, a needleless syringe, and a cartridge of pressurized air that deliver the medication across the dermis. Needleless systems offer a pain-free alternative, although medications available for delivery through this method are limited. Cost and medication exposure (in the form of powdered or aerosolized compounds) are risks associated with the use of a needleless system (Figure 7-5).

FIGURE 7-5 Sample of a needle-free insulin delivery system.
Syringes are made up of three main parts (Figure 7-6). The tip is the portion that holds the needle. The needle screws onto the tip or fits tightly so it does not fall off. The barrel is the container for the medication. The calibrations are printed numbers on the barrel, and they indicate the amount or volume of medication in minims (m), milliliters (mL), units, or cubic centimeters (cc) (Figure 7-7). The plunger is the inner portion that fits into the barrel. The medication is forced out through the needle when the plunger is pushed into the barrel.

FIGURE 7-6 Parts of a syringe.

FIGURE 7-7 Comparison of different types of syringes.

Needles
The needle must be selected according to the needs of the medication. The needle is made up of the hub, or 88bottom part, which attaches to the syringe; the shaft, which is the hollow part through which the medication passes; and the pointed or beveled tip, which pierces the skin (Figure 7-8). The longer the pointed tip of the needle, the more easily the needle enters the skin. The diameter of the needle is called the gauge. The larger the number of the gauge, the smaller the hole. (For example, a 25-gauge needle is smaller than a 17-gauge needle.) Thick solutions require larger diameters for injection. The needle gauge is written on the needle hub and on the package. Needles also come in varying lengths, from inch to 3 inches. Generally, the smaller the needle (larger the gauge), the shorter the needle. The smallest needles are used for intradermal or subcutaneous injections because they do not need to go very far into the skin. Filter needles are also available for use when medication is drawn from an ampule to prevent uptake of glass shards and risk of injection. Needleless systems are a recent technology that allows the administration of medication through the dermis and into the bloodstream by way of a high-pressure needleless injection. Pressurized air drives aerosolized or powdered compounds through the skin, allowing for a pain-reduced or pain-free method of rapid administration. The needleless syringe or tip used in this procedure is disposable, since it does come in contact with the skin and is considered a one-time use component of the device.

FIGURE 7-8 Parts of the needle and various needle gauges.

There are also several specialized IV needles that are used when a needle is to be left in place in the vein for a long period (Figure 7-9). Short, small needles with plastic “wings” are used in infants and children, in the smaller veins of the hands in older adult patients, or in adults who are able to move around. These needles are referred to as scalp vein, butterfly, or wing-tipped needles, and all have small pieces of plastic on either side of the needle that can be pinched together when the needle is going in and then flattened against the skin and held in place with tape. These needles have a small, capped plastic tube attached to the hub that can be used when withdrawing blood specimens or injecting drugs such as heparin.

FIGURE 7-9 Over-the-needle catheters. Puncture the vein with a metal large-bore needle. Thread a 4- to 6-inch small-gauge plastic catheter inside and up into the vein before removing the metal needle. Use this type of needle when intravenous therapy must continue for several days.

The sizes of the needle and syringe are determined by how viscous (thick) the medication is and by the amount to be injected. For example, blood is very thick and requires a 15- to 19-gauge needle. Sometimes when the volume is very small and the dosage must be very accurate (as with heparin or insulin), a 89small-gauge needle (such as a 27 gauge) is used so no medicine is lost. If more than 3 mL of medication is to be given IM, the medication must be divided and given in two injections so that a large pool of medicine does not form in the tissue, which would irritate the tissue. The hub of the syringe is to be to inch above the skin surface when the drug is injected. This allows the needle to be easily grabbed and pulled out if the patient jerks or the needle breaks. (This rarely happens.) A general guide for choosing the best syringe and needle sizes is presented in Table 7-1.