Ch. 4 Medication Administration

Scrub Role​

Accepts medications from circulator​ Immediately labels those medications​ Passes medications to the surgeon If medications are not clearly identified, they should be discarded immediately.​

Caution

All medications delivered to the sterile field must be labeled immediately to avoid errors and to help ensure patient safety.

Medication Labeling ​on the Sterile Back Table

All medications must be labeled immediately after accepting from the circulator! This is the most important rule.​ Most drugs used in the sterile field are clear in color and easily confused if not clearly marked.​ The Joint Commission National Patient Safety Goal requires that all medication containers in the sterile field be labeled.

Right Patient (BOOK)

All surgical patients must be accurately identified before being transported into the operating room. Tools, such as The Joint Commission's Universal Protocol and the World Health Organization's Surgical Safety Checklist (Fig. 4-5), are used in The operating room to ensure that the correct surgical procedure will be performed on the correct patient. This process also includes relevant information about the patient, such as a history of drug allergies or hypersensitivity to a particular drug. The surgical procedure and operating surgeon are verified, and the preference card containing medication orders for that specific procedure is kept available in the operating room for reference. In addition, a surgical safety "time out" is conducted just before the incision to further verify that the intended surgical procedure is being performed on the correct patient. Diligence and care taken to properly identify the patient will help to ensure that the correct patient receives the medications intended for administration during a surgical procedure.

Caution

Always use a leading zero to accurately label medications in concentrations of less than 1%. For example, write "0.5% lidocaine" not ".5% lidocaine."

Quick NOTE: Surgical Technologist's Roles in Medication Administration

Circulator Role Obtain correct medication. Deliver medication to the sterile field using aseptic technique. Document all medications used from sterile field. Scrub Role Identify medication. Accept medication into the sterile field. Label the medication immediately. Pass the medication to the surgeon as requested. Say the drug name and strength aloud when passing.

Steps for Medication Identification

Circulator reads label. Circulator reads label aloud to scrub. Circulator shows label to scrub. Scrub states medication information aloud. Scrub accepts medication. Scrub labels medication containers immediately.

Medication Identification​

Circulator reads label. Circulator reads label aloud to scrub. Circulator shows label to scrub. Scrub states medication information aloud. Scrub accepts medication. Scrub labels medication containers immediately. Medication identification follows a distinct process, as listed in Box 4-3.​ Following a distinct, logical process is yet another way the medical team can help avoid mistakes.​ Remember the scrub and the circulator we talked about earlier? They share responsibility in this process.​ The circulator is responsible for early steps in the process, such as reading the medication's label and then reading the label aloud to the scrub (the first two steps in medication identification).

Right Dose

Correct amount (volume)​ 30 mL​ Correct strength (concentration)​ 1%, 2%, 0.5%​ The right dose is the amount multiplied by the strength. The second right of medication administration is "right dose."​ Dose is the factor of both its amount and strength.​ Written protocols may be instituted and posted to eliminate common confusions about some medications. Vital when mixing medications on back table​ Vital when multiple strengths of the same medication are on back table​ Label each medication carefully. Getting the dose right is vital. ​ The surgical technologist plays a key role in the prevention of administration of the wrong dosage of medication from the sterile field.

Tech Tip

Do not be embarrassed to admit ignorance or confusion, and always admit an outright error. Honesty and integrity are vital characteristics in health care professionals. If you make a medication error, acknowledge it at once so that corrective measures may be taken. Notify the surgeon immediately. Then follow institutional policy. Usually when a medication error occurs, the unit supervisor is notified and an incident or occurrence report is completed. Above all, immediate action is taken to correct the error. The surgical technologist's primary focus in medication administration is patient safety.

Tech Tip

Do not depend on hearsay or someone else's understanding or opinion regarding the limits of your practice. Use your computer competence and the easy availability of the Internet to read the pertinent legislative statutes for yourself. Ask for assistance at your facility's medical library or from the reference librarian at any public library. Remember, professional surgical technologists should be highly knowledgeable regarding their own practice.

Advanced Practices for the Surgical First Assistant: Chapter 4 (Cont.)

Drug-response relationships​ All medications have systemic effects on the patient.​ Duration of medication's effect is based on the half-life of the medicine. ​ Drug efficacy​ The degree to which a drug is able to produce its desired effects​ Drug potency​ Relative concentration required to produce that effect Elimination half-life (T) is also called biological half-life.​ Bioavailability is the extent to which an administered amount of a drug reaches its site of action and is available to produce the drug effects.​ Refer to Table 4-A in the textbook for a comparison of onset, peak, and duration of heparin when given subcutaneously and intravenously.

Supplies​

Figure 4-15 shows types of syringes. A, A 10-mL finger-control Luer-lock syringe. B, A 10-mL Luer-lock syringe. C, A 1-mL plain-tip tuberculin syringe. ​ The most common type of syringe tip used in surgery is the Luer-lock tip. By far, the most common syringe used in the operating room is a 10-mL syringe.​ 30-mL syringes are most frequently used to inject saline irrigation and contrast media into the common bile duct. Syringes used in surgery range from 1 mL to 60 mL.​

Advanced Practices for the Surgical First Assistant: Chapter 4​

Five more "rights" of medication administration​ Right patient assessment before administration​ Patient's right to education about the medication before it is administered​ Right evaluation of the medication's effect​ Patient's right to refuse the medication The Institute of Medicine estimated 7000 deaths occur annually because of preventable medication errors.​

Note

If a drug is in powder form in a vial, the circulator must reconstitute it, and the resulting liquid is withdrawn from the vial with a syringe and delivered to the sterile field, as described earlier.

Delivery to the Sterile Field (Cont.)

If a drug is in powder form in a vial, the circulator must reconstitute it.​ If a syringe is used to draw up and inject the reconstituting agent to withdraw the mixture, one must not touch the sides of plunger. Figure 4-9: Unsterile hands must not touch the syringe plunger. ​ If unsterile hands touch the plunger, the plunger contaminates the inside of the barrel as it moves down the barrel when injecting.

Right Time (BOOK)

In surgery the surgeon (or as delegated to the surgical first assistant) administers all medications at the surgical site. This practice prevents the vast majority of medication timing errors during surgery (for drugs administered from the sterile back table). The purpose of the drug, when stated on the preference card, often indicates the timing of administration. For example, if 1% lidocaine with epinephrine 1:100,000 is listed on the preference card for a local anesthetic, it will be administered before incision. In addition, it may be administered periodically throughout the procedure as needed (pro re nata [PRN]) for patient comfort. If 0.5% bupivacaine with epinephrine 1:100,000 is listed on the preference card for postoperative pain control, it may be administered at the beginning of the procedure or at the time of wound closure. Some routine medications (e.g., contrast media for cholangiography, antibiotics for irrigation, heparinized saline) are obtained and labeled during case setup and passed to the surgeon at the appropriate time. The surgeon may request a drug by verbal order during any procedure. In such case the medication is obtained, labeled, and passed to the surgeon from the sterile back table for administration as soon as requested.

Medication Administration from the Sterile Field

Intraoperative administration of medications to the surgical patient presents a unique situation unlike any other medical environment, especially for the advanced practitioner functioning as a surgical first assistant. Different personnel administer medications to the patient through several routes, often at the same time. Although the surgical first assistant might not perform the actual administration of medications, it is important that he or she be aware of the effects any medication can have on the patient. The process of administering medications at the sterile field requires a team effort. Medications will pass through at least two other people, the circulator and scrub person, before being delivered to the surgeon. The medication will almost always be in a container different from its original—usually a syringe, medicine cup, basin, or pitcher on the field. For the prevention of medication errors, strict policies and procedures have been developed for delivery of medications onto the sterile field (as described in this chapter). The surgeon and the surgical first assistant may be the last line of defense to avoid medication errors; therefore each should be aware of and follow all of these procedures. The person 62who administers the medication always has the right to question the procedure and decide whether the medication will be given or a new medication obtained. It is always in the best interest of the patient to discard any questionable medication (see Box 4-A).

Right Documentation

It is critical that medications be accurately recorded in the operative record.​ Surgical technologist must also maintain an accurate ongoing total of repeatedly administered drugs. Use a sterile marking pen on the field to keep a written tally of the amount of medications used during the procedure.​

Labeling​

Label intermediate container.​ Med cup, pitcher, basin​ Label administration item.​ Syringe Figure 4-13: Preprinted medication labels used in the sterile field. ​ This rule applies to all containers holding the medication: intermediate storage containers as well as delivery vehicles.​ Preprinted labels are the most accurate medication labeling method.

Scrub Role (Cont.)​

Labels medications immediately​ Figure 4-1, A and B show that the scrubbed surgical technologist is charged with labeling medications.​ Accurate identification and immediate labeling of all drugs accepted onto the sterile field is crucial.​ Explain what is done when medications are not clearly identified. (They should be discarded immediately and replaced with new samples.)

Advanced Practices for the Surgical First Assistant: Chapter 4 (Cont.)

Medication administration from the sterile field​ Different personnel administer medications to the patient through several routes, often at the same time.​ Process of administering medications at the sterile field requires a team effort.​ Surgeon and surgical first assistant may be the last line of defense to avoid medication errors. Personnel who fulfill the role of the surgical first assistant will have different educational and clinical backgrounds.​ Discuss the guidelines for administering medications from the sterile field found in Box 4-A of the textbook

Medication Identification (Cont.)

Medication label contains important information about the drug.​ Warning​ Do not accept any medication onto your back table without reading the label first. This slide includes an important reminder for medication administration: exercise caution.​ Medication should be accepted to the sterile field only after the steps for medication identification have been followed.

Right Route (BOOK)

Most medications administered in surgery are given intravenously, usually by the anesthesia care provider. However, many other medications may be injected or applied topically by the surgeon at the surgical site. Different administration routes may require different preparations and concentrations of a medication. The preference card should clearly state administration route or form, so that the proper form of the drug for a particular route may be obtained. For example, the preference card for cystoscopy may state that 2% lidocaine jelly is needed for local anesthesia (see Chapter 14). Although the preference card should clearly state "for topical application," it may also be safely assumed that properly educated surgical team members know that jelly, a semisolid form of the drug, is intended for topical application, not injection (Fig. 4-3). In a situation of a novice practitioner or a person with a knowledge deficit, careful reading of the medication label will reveal that this form of lidocaine is intended for topical use only. This situation also provides an excellent example of the importance of always reading the medication label carefully. When in doubt, the surgical technologist must clarify the information stated on the preference card. A crucial example of the importance of the right dose for the right route in surgery occurs during procedures on the middle ear. The surgical technologist must exercise particular caution when identifying, labeling, and handling medications for middle ear surgery because two significantly different strengths of epinephrine (a hormone that is a powerful vasoconstrictor, see Chapter 8) are present on the sterile back table.

Circulating Role​

Obtains correct medication​ Delivers medication​ Maintains asepsis during delivery to sterile field​ Documents all medications used from sterile field Medication administration from the sterile field is a team effort. ​ The surgical technologist may serve as the circulator or first scrub.​ The circulator has three main duties regarding medication administration from the sterile field.

Medication Labeling on the Sterile Back Table (BOOK)

Once a medication has been delivered to the sterile back table, it is no longer in its original container, so it must be labeled immediately. Most drugs used from the sterile field are clear in color; thus they are easily confused if not clearly marked. There are different methods of labeling medications on the sterile back table, but the most important point is that each medication must be labeled—in the intermediate storage container (such as pitcher or medicine cup) and in any delivery vehicle (such as a syringe). The Joint Commission National Patient Safety Goal 3, NPSG.03.04.01, requires that all medication containers in the sterile field be labeled. The most accurate medication labeling method is the use of preprinted medication labels available from sterile supply manufacturers (Fig. 4-13). If preprinted labels are not available, a sterile skin marking pen may be used to write on blank labels. If blank labels are not available, sterile skin adhesive strips may be used. Regardless of the labeling method used, proper identification of all medications in the sterile field is an absolutely crucial step in preventing medication administration errors. Occasionally the scrubbed surgical technologist may be replaced during a procedure (e.g., for shift change or lunch relief). All medications must be plainly labeled and reported to the new scrub. If there is any doubt as to the identity of a solution, it must be discarded and new medication must be obtained. There is no acceptable excuse for the presence of unlabeled (unidentified) medications on the sterile back table. Improper or inadequate labeling of drugs may be considered negligent.

Right Time

Per verbal order ​ Surgeon administers medications at the surgical site at the intended time. Other ways the surgical technologist can help keep patients free of errors is by heeding the fifth right of medication administration: "right time."​ This is not as difficult in surgery because the surgeon is present and administers the medications from the sterile field when he/she wants the drugs given.​ Medications given from the sterile table must be accurately recorded in the operative record.

Labeling Options​

Preprinted labels (most accurate)​ Write drug name and strength with skin marking pen on:​ Blank label​ Skin adhesive strips In terms of how medication is labeled, there is some flexibility. ​ Preprinted labels are the most accurate option, but labels can also be handwritten using a sterile skin marking pen on blank labels. Note​ Failing to label all medications on the sterile back table is unacceptable practice and probable negligence. The process of medication identification should never be compromised.​ As this slide shows, the consequences for failing to label medications properly can be serious for both the patient and the surgical technologist.

Delivery to the Sterile Field (BOOK)

Principles of asepsis (sterile technique) must be followed when delivering and receiving medications into the sterile field. Medications frequently used from the sterile back table are packaged 55in different types of containers, including vials and ampules (Fig. 4-7), and aseptic delivery methods vary by type of container. One of the most common containers is a glass or plastic vial with a rubber stopper encased in a metal cap and covered by an outer plastic cap. The plastic cap is popped off without touching the rubber stopper underneath. The circulator can draw up the drug (if in liquid form) with a syringe and hypodermic needle and then empty the contents of the syringe into a sterile medicine cup held by the scrub. The circulator should handle only the outside of the vial and should not touch the rubber stopper unless it is being removed. Alternatively, the circulator may hold the vial in an inverted position while the scrub withdraws the drug from the vial with a syringe and needle (Fig. 4-8). The scrubbed surgical technologist should first draw some air into the syringe, then puncture the rubber stopper with the needle and inject air into the vial, which will allow the contents of the vial to enter the syringe rapidly. In addition, the hypodermic needle used to puncture the vial should be a larger needle, such as 18 gauge, to permit rapid filling of the syringe. After the medication is in the syringe, the 18-gauge needle is removed and replaced with the correct gauge needle for injection (such as a 25-gauge needle).

Delivery to the Sterile Field​

Principles of aseptic technique must be followed when delivering and receiving medications.​ Medications are packaged in different types of containers. Medication should be accepted to the sterile field only after the steps for medication identification have been followed.

Right Drug

Read preference card and medication label carefully.​ Electronic or handwritten The first right of medication administration is "right drug."​ The surgeon's preference card and the medication's label help ensure the right drug is used. Say drug name when handing to surgeon.​ Keep vials in room. Saying the drug's name at handoff and keeping the vial in the room also help ensure that the correct medication is used.​ Medication vials serve as evidence that the proper medication was delivered to the field. CAUTION ​ Some drugs sound alike or are spelled alike, including:​ Pitocin/pitressin​ Epinephrine/ephedrine​ Tobrex/TobraDex Be careful when saying drug names.​ As this slide shows, some drugs sound—or are spelled—alike.

Handling Medications​

Some additional handling may be necessary.​ Some medications may be diluted before use.​ All containers must be labeled for the original medications.​ Administration container must be labeled with complete information on the mixture or dilution.

Delivery to the Sterile Field (Cont.)

Some medication vials and ampules are available in sterile packages.​ The scrub is responsible for showing the medication label and expiration date to the circulator. Glass ampule should be broken away from the body to help prevent injury. Figure 4-11: Breaking an ampule. Carefully break the neck of the ampule in a direction away from you. ​ Care must be taken to protect the gloved hands.

Supplies (Cont.)​

Special syringes are available for particular purposes.​ Figure 4-16 shows a Tubex syringe, glass carpule, and needle. ​ A carpule is a glass tube with a rubber cap that is penetrated by a special needle attached to the Tubex syringe. Hypodermic needles are used to draw up and administer drugs.​ A hypodermic needle has three basic parts:​ Hub (fits into syringe)​ Shaft​ Tip Needles vary in diameter and length.​ Most hypodermic needles used in surgery are disposable and color coded.​ The three needle sizes most frequently used at the sterile field are: 18 gauge (pink), 22 gauge (gray), and 25 gauge (blue).

Delivery to the Sterile Field (Cont.)

Sterile disposable spouts are commercially available.​ Figure 4-10: A sterile, disposable pour spout (decanter) is used to deliver medication contained in a bag of intravenous fluid. The bag decanter is grasped by the hub, and the prong is inserted into the injection port on the bag. ​ Decanters provide a greater margin of safety by increasing the distance between the circulator and the scrubbed surgical technologist during medication delivery.

Right Route

Surgeon administers medications at the surgical site.​ Surgeon determines route.​ Surgical technician in the scrub role (STSR) in the right route​ Correct formulation of drug Also vital to medication administration is the third right of medication administration: "right route."​ Most medications administered in surgery are given intravenously, usually by the anesthesia provider.​ Different administration routes require different preparations and concentrations of medications.​ The surgeon's preference card should state the administration route or form. For example, epinephrine strength for:​ Topical is 1:1000.​ Injectable is 1:100,000.​ Both are clear solutions. Here's an example of getting the drug form right.​ A careful reading of the medication label will provide information necessary to determining the right route.

Right Patient

Surgical "time out"​ Identify patient.​ Verify surgeon and procedure.​ Check preference card. The fourth right of medication administration is "right patient."​ This slide shows the ways the surgical technologist can help ensure medication is administered to the right patient.​ A history of drug allergies or hypersensitivity should be included in the patient identification.

Delivery to the Sterile Field (Cont.)

The circulator must take care not to lean over the sterile field.​ Medicine cups, pitchers, basins, or syringes may be used.​ Medications intended for topical administration should never be kept in a syringe on the back table. Some topical medications are fatal if injected.​

half-life

The duration of a medication's effect is based on the half-life of the medicine. Elimination half-life (T), also called biological half-life, is the time it takes for 50% of a drug to be cleared from the bloodstream. Each drug has a unique half-life dependent on its characteristics. Certain conditions, such as decreased liver or renal function, will alter the half-life of medications. It is important to note that a medication may go through many of its half-lives before it no longer has a therapeutic effect on the body. This must be recognized when calculating subsequent doses of the same medication to maintain a therapeutic level of its desired effects. Some half-lives are of short duration, such as those used in general anesthesia (a few minutes). Others may have a half-life of several days, such as those used to treat hypothyroidism. Therefore drugs with long half-lives are dosed less frequently than those with short half-lives. Essentially, drugs with short half-lives are said to leave the body quickly—in 4 to 8 hours. Drugs with long half-lives are said to leave the body more slowly—in more than 24 hours, and there is a greater risk for accumulation of these medications in the bloodstream and toxicity. A common example in the surgical setting is the administration of heparin sodium to achieve anticoagulation during vascular surgery. It has a relatively short half-life of approximately 60 to 90 minutes and so would have to be administered frequently to maintain its initial effect.

The Five "Rights" of Medication Administration (BOOK)

The five "rights" of medication administration have been established to help avoid medication errors (Box 4-2). Team members must work together to ensure that the right drug is given in the right dose, by the right route, to the right patient, and at the right time. It is also important to ensure that all medications given are accurately documented.

Note

The limits of legal authority for the surgical technologist to perform the indicated roles described in this text are controlled by each state through its statutes, case law, regulatory law, attorney general opinions, and medical licensing boards. Discussion of these sources of law is beyond the scope of this text. Except as otherwise noted, this book describes the general practice of surgical technology in the United States, not the legal authority for such practice. It is the surgical technologist's responsibility to consult the limitations in his or her area on acts described in this book.

Right Drug (Book)

The scrub person must always state the name and strength of the drug aloud as he or she hands it to the surgeon; this practice serves as confirmation that the medication is correct. The name of the drug should be spoken aloud even though the syringe (or other delivery container) is labeled. Using two processes, audible and visual, provides an additional level of patient safety. If there is ever any question as to the identity of a medication on the back table, it must be discarded and a new dose of the intended medication must be obtained, identified, and labeled.

Summary​

The surgical technician:​ Identifies medications​ Accepts medications​ Labels medications​ Passes medications​ All must be done correctly. The surgical technologist does all the things shown here—and much, much more.​ All roles of the surgical technologist demand accuracy, teamwork, and professionalism.

Circulating Role (BOOK)

The surgical technologist in the circulating role obtains medications as specified on the surgeon's preference card, delivers those medications to the sterile field as needed, and documents the medications used from the sterile field during an operation. The circulator must be sure that the medication obtained is the exact drug and strength specified on the preference card. The circulator must also inspect the container for integrity and expiration date. The circulator must maintain strict sterile technique when transferring medications to the scrub person. All medications must be properly identified, both by the scrub and by the circulator. The circulator is responsible for documenting all medications used from the sterile field according to institutional policy.

Scrub Role (BOOK)

The surgical technologist in the scrub role correctly identifies and accepts medications from the circulator, immediately labels (Fig. 4-1) those medications, and passes medications to the surgeon, as requested. Accurate identification and immediate labeling of all drugs accepted onto the sterile field are crucial. If medications are not clearly identified, they should be discarded immediately and a new dose should be obtained. This practice is essential to avoid possible drug administration error. The surgical technologist must clearly state the name and strength of a medication when passing it to the surgeon.

Right Documentation (BOOK)

Traditionally there are five "rights" of medication administration: right drug, right dose, right route, right patient, and right time. It is also crucial, though, that medications given from the sterile table be accurately recorded in the operative record. The circulator will document all medications delivered to the field, and the surgical technologist in the scrub role will verbally provide a final total of the amount of each medication administered for the circulator to note in the record. When a medication is repeatedly administered during a procedure, such as a local anesthetic, the scrubbed surgical technologist must also maintain an accurate ongoing total of the amount of medication being used throughout the procedure.

Sample Information Contained on a Medication Label

Type of Information Example - Name (brand and generic) bupivacaine HCl (Sensorcaine) Strength 0.5% Amount 50 mL Expiration date 01/2019 Administration route Injection Manufacturer AstraZeneca Storage directions Store at room temperature Warnings or precautions Federal law prohibits dispensing without prescription Lot number 1234567 Schedule (only if drug is a controlled substance) (C-I to C-V, see Chapter 2)

Tech Tip

Use a sterile marking pen on the field to keep a written tally of the amount of medications used during the procedure.

Sharps Safety​

Used needles must never be recapped.​ It is also dangerous, however, to leave an unsheathed hypodermic needle exposed on the sterile table during surgical procedure.​ Sometimes the same syringe/needle combination is used repeatedly during the course of a surgical procedure.​ For prevention of injury from needle while not in use, it must be recapped between injections. More than 10 mL of local anesthetic may be required, which necessitates refilling the syringe.​ Surgical technologist must use a one-handed recapping technique. Figure 4-18: If a needle must be recapped for protection for reuse during an operation, such as the periodic injection of local anesthetic for patient comfort, use a one-handed recapping technique. ​ Specialized self-shielding needles are also available for use from the sterile field.

Role of Surgical Technologist​

Varies state to state and differs from facility to facility​ Handling medications is a critical function.​ Each team member has a particular role in the process of medication administration. Varies state to state and differs from facility to facility​ Handling medications is a critical function.​ Each team member has a particular role in the process of medication administration.

Delivery to the Sterile Field (Cont.)

Vials (circulator) ​ Do not touch rubber stopper.​ Do not touch syringe plunger. Figure 4-8: The scrubbed surgical technologist may draw up medication from a vial held by the circulator. ​ Medications used in the sterile back table are packaged in different containers, including vials and ampules.​ Aseptic delivery methods vary by type of container.​ Circulators must use sterile technique when preparing vials for delivery to the back table.

Caution

When accepting a medication, especially an antibiotic or an iodine-based contrast medium, the scrubbed surgical technologist should ask the circulator if the patient has any medication allergies. This team effort helps to ensure that the patient does not get a medication to which he or she is allergic.

Note

When medications are administered from the sterile field, it is important to communicate to the anesthesia care provider the name of the agent and amount given. For example, when a local anesthetic agent that contains epinephrine is administered, the anesthesia care provider should be notified immediately and verbally advised as to the amount of the medication ultimately injected (which is also noted on the operative record). This is important because epinephrine acts as a vasoconstrictor and can affect the patient's blood pressure.

tech Tip

When placing the adhesive medication label on a syringe, be sure to place it on the syringe barrel opposite the volume markings so that you can always read the amount of medication used during the procedure.

Route/CAUTION!​

You must know the route and purpose for different epinephrine strengths.​ A mix-up can cause patient death.​ The scrubbed surgical technologist must observe the delivery of medications to the sterile field and immediately label each drug (identity and strength) as it is delivered to the field. Getting the drug route and purpose right are extremely important.​ Explain why this is the case. (Because an error could prove fatal.)

Efficacy

is the degree to which a drug is able to produce its desired effects.

Bioavailability

is the extent to which an administered amount of a drug reaches the site of action and is available to produce the drug effects (as described in Chapter 1). This is influenced by drug absorption and distribution to the site of action. Bioavailability is important in pharmacokinetics because it must be taken into consideration when calculating medication doses, especially those administered via nonintravenous routes. For intravenous administration, the bioavailability of the drug is considered to be 100% because it reaches systemic circulation immediately. Factors that affect bioavailability are form of the medication given (tablet, liquid, inhalation, etc.); route of administration (enteral, parenteral, etc.); gastrointestinal (GI) motility; food, herbals, and other drugs given; and liver function. Using heparin sodium as an example, see Table 4-A for a comparison of onset, peak, and duration when given subcutaneously and intravenously.

Potency

is the relative concentration required to produce that effect, as in how much of the drug is needed.

Guidelines for Administering Medications from the Sterile Field

• Always be aware of the process of delivering medications to the sterile field. • Always read the label on the device you receive which contains the medication. • Always confirm name and strength of the medication with the scrub person. • Always inform anesthesia personnel when administering medications. • Always be aware of any patient allergies. • Always be aware of the amount of the medication administered. • Never administer medications that are discolored or contain sediment. • Never administer medications that are contaminated with other materials from the sterile field. • Never administer a medication from any unlabeled container. • Never administer a medication when there is any doubt about its identification or strength.

The Five "Rights" ​of Medication Administration

• Right drug—What drug is required? • Right dose—How much of the drug is required in what concentration? • Right route—How will the drug be administered? • Right patient—Who will receive the drug? • Right time—When will the drug be administered?