lOMoARcPSD| 13728229
lOMoARcPSD| 13728229
, lOMoARcPSD| 13728229
Chapter 01: Nursing Practice in Canada and Drug Therapy
rf rf rf rf rf rf rf rf
Sealock: Lilley’s Pharmacology for Canadian Health Care Practice, 5th Edition
rf rf rf rf rf rf rf rf rf
MULTIPLE CHOICE rf
1. Which is a judgement about a particular patient‘s potential need or problem?
rf rf rf rf rf rf rf rf rf rf rf
a. A goal rf
b. An assessment rf
c. Subjective data rf
d. A nursing diagnosis rf rf
ANS: D rf
Nursing diagnosis is the phase of the nursing process during which a clinical judgement is made about ho
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
th conditions and life processes or vulnerability for that response.
rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Knowledge rf rf
2. The patient is to receive oral furosemide (Lasix) every day; however, because the patient is unable to sw
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
medication orally, as ordered. The nurse needs to contact the physician. What type of problem is this?
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. A ―right time‖ problem rf rf rf
b. A ―right dose‖ problem rf rf rf
c. A ―right route‖ problem rf rf rf
d. A ―right medication‖ problem
rf rf rf
ANS: C rf
This is a ―right route‖ problem: the nurse cannot assume the route and must clarify the route with the pre
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
me‖ problem because the ordered frequency has not changed. This is not a ―right dose‖ problem because
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
inability to swallow. This is not a ―right medication‖ problem because the medication ordered will not c
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
3. The nurse has been monitoring the patient‘s progress on his new drug regimen since the first dose and ha
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
f possible adverse effects. What nursing process phase is the nurse practising?
rf rf rf rf rf rf rf rf rf rf rf
a. Planning
b. Evaluation
c. Implementation
d. Nursing diagnosis rf
ANS: B rf
Monitoring the patient‘s progress is part of the evaluation phase. Planning, implementation, and nursing
rf rf rf rf rf rf rf rf rf rf rf rf rf r
by this example.
rf rf
DIF: Cognitive Level: Application rf rf
4. The nurse is caring for a patient who has been newly diagnosed with type 1 diabetes mellitus. Which stat
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
utcome criterion for this patient? rf rf rf rf
a. The patient will follow instructions. rf rf rf rf
b. The patient will not experience complications.
rf rf rf rf rf
c. The patient adheres to the new insulin treatment regimen.
rf rf rf rf rf rf rf rf
d. The patient demonstrates safe insulin self-administration technique.
rf rf rf rf rf rf
ANS: D rf
Having the patient demonstrate safe insulin self-
rf rf rf rf rf rf
administration technique is a specific and measurable outcome criterion. Following instructions and avo
rf rf rf rf rf rf rf rf rf rf rf rf
pecific criteria. Adherence to the new insulin treatment regimen is not objective and would be difficult t
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
, lOMoARcPSD| 13728229
6. The nurse is working during a very busy night shift, and the health care provider has just given the nurse
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf r
e telephone, but the nurse does not recall the route. What is the best way for the nurse to avoid medicatio
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Recopy the order neatly on the order sheet, with the most common route indicated
rf rf rf rf rf rf rf rf rf rf rf rf rf
b. Consult with the pharmacist for clarification about the most common route
rf rf rf rf rf rf rf rf rf rf
c. Call the health care provider to clarify the route of administration
rf rf rf rf rf rf rf rf rf rf
d. Withhold the drug until the health care provider visits the patient
rf rf rf rf rf rf rf rf rf rf
ANS: C rf
If a medication order does not include the route, the nurse must ask the health care provider to clarify it. N
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
stration.
DIF: Cognitive Level: Application | Cognitive Level: Analysis
rf rf rf rf rf rf
7. Which constitutes the traditional Five Rights of medication administration?
rf rf rf rf rf rf rf rf
a. Right drug, right route, right dose, right time, and right patient
rf rf rf rf rf rf rf rf rf rf
b. Right drug, the right effect, the right route, the right time, and the right patient
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
c. Right patient, right strength, right diagnosis, right drug, and right route
rf rf rf rf rf rf rf rf rf rf
d. Right patient, right diagnosis, right drug, right route, and right time
rf rf rf rf rf rf rf rf rf rf
ANS: A rf
The traditional Five Rights of medication administration were considered to be Right drug, Right route, R
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
patient. Right effect, right strength, and right diagnosis are not part of the traditional Five Rights.
f rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
8. What correctly describes the nursing process?
rf rf rf rf rf
a. Diagnosing, planning, assessing, implementing, and finally evaluating rf rf rf rf rf rf
b. Assessing, then diagnosing, implementing, and ending with evaluating rf rf rf rf rf rf rf
c. A linear direction that begins with assessing and continues through diagnosing,
rf rf rf rf rf rf rf rf rf rf rf
planning, and finally implementing rf rf rf
d. An ongoing process that begins with assessing and continues with diagnosing,
rf rf rf rf rf rf rf rf rf rf rf
planning, implementing, and evaluating rf rf rf
ANS: D rf
The nursing process is an ongoing, flexible, adaptable, and adjustable five-
rf rf rf rf rf rf rf rf rf rf
step process that begins with assessing and continues through diagnosing, planning, implementing, and
rf rf rf rf rf rf rf rf rf rf rf rf rf
y then lead back to any of the other phases.
rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
9. When the nurse is considering the timing of a drug dose, which is most important to assess?
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. The patient‘s identification rf rf
b. The patient‘s weight rf rf
c. The patient‘s last meal rf rf rf
d. Any drug or food allergies rf rf rf rf
ANS: C rf
The pharmacokinetic and pharmacodynamic properties of the drug need to be assessed with regard to any
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
food interactions or compatibility issues. The patient‘s identification, weight, and drug or food allergies
rf rf rf rf rf rf rf rf rf rf rf rf rf
ming.
DIF: Cognitive Level: Application rf rf
10. The nurse is writing nursing diagnoses for a plan of care. Which reflects the correct format for her nursin
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Anxiety
b. Anxiety related to new drug therapy rf rf rf rf rf
c. Anxiety related to anxious feelings about drug therapy, as evidenced by s
rf rf rf rf rf rf rf rf rf rf rf
tatements such as ―I‘m upset about having to give myself shots‖
rf rf rf rf rf rf rf rf rf rf
d. Anxiety related to new drug therapy, as evidenced by statements such as ―I‘m
rf rf rf rf rf rf rf rf rf rf rf rf rf
upset about having to give myself shots‖
rf rf rf rf rf rf
, lOMoARcPSD| 13728229
Chapter 02: Pharmacological Principles
rf rf rf
Sealock: Lilley’s Pharmacology for Canadian Health Care Practice, 5th Edition
rf rf rf rf rf rf rf rf rf
MULTIPLE CHOICE rf
1. A patient is receiving two different drugs, which, at their current dose forms and dosages, are both absor
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
dentical amounts. Which term best denotes that the drugs have the same absorption rates?
rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Equivalent
b. Synergistic
c. Compatible
d. Bioequivalent
ANS: D rf
Two drugs absorbed into the circulation at the same amount (in specific dosage forms) have the same bio
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
oequivalent. ―Equivalent‖ is incorrect because the term ―bioavailability‖ is used to express the extent of
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
c‖ is incorrect because this term refers to two drugs given together whose resulting effect is greater than
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
h drug given alone. ―Compatible‖ is incorrect because this term is a general term used to indicate that tw
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
hemical reaction when mixed (or given, in the case of drugs) together.
rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
2. A patient is receiving medication via intravenous injection. Which information should the nurse provide
rf rf rf rf rf rf rf rf rf rf rf rf rf
a. The medication will cause fewer adverse effects when given intravenously.
rf rf rf rf rf rf rf rf rf
b. The medication will be absorbed slowly into the tissues over time.
rf rf rf rf rf rf rf rf rf rf
c. The medication‘s action will begin faster when given intravenously.
rf rf rf rf rf rf rf rf
d. Most of the drug is inactivated by the liver before it reaches the target area.
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
ANS: C rf
Intravenous injections are the fastest route of absorption. The intravenous route does not affect the numb
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
avenous route is not a slow route of absorption, and the intravenous route does not cause inactivation of
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
it reaches the target area.
rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
3. Which is true regarding parenteral drugs?
rf rf rf rf rf
a. They bypass the first-pass effect. rf rf rf rf
b. They decrease blood flow to the stomach. rf rf rf rf rf rf
c. They are altered by the presence of food in the stomach.
rf rf rf rf rf rf rf rf rf rf
d. They exert their effects while circulating in the bloodstream.
rf rf rf rf rf rf rf rf
ANS: A rf
Drugs given by the parenteral route bypass the first-
rf rf rf rf rf rf rf rf
pass effect, but they still must be absorbed into cells and tissues before they can exert their effects. Enter
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
not parenteral drugs, decrease blood flow to the stomach and are altered by the presence of food in the s
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
st be absorbed into cells and tissues from the circulation before they can exert their effects; they do not e
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
ating in the bloodstream.
rf rf rf
DIF: Cognitive Level: Analysis rf rf
4. A drug‘s half-life is best defined as
rf rf rf rf rf rf
a. The time it takes for the drug to elicit half its therapeutic response.
rf rf rf rf rf rf rf rf rf rf rf rf
b. The time it takes one- rf rf rf rf
half of the original amount of a drug to reach the target cells.
rf rf rf rf rf rf rf rf rf rf rf rf
c. The time it takes one- rf rf rf rf
half of the original amount of a drug to be removed from the body.
rf rf rf rf rf rf rf rf rf rf rf rf rf
d. The time it takes one- rf rf rf rf
half of the original amount of a drug to be absorbed into the circulation.
rf rf rf rf rf rf rf rf rf rf rf rf rf
ANS: C rf
lOMoARcPSD| 13728229
, lOMoARcPSD| 13728229
Chapter 01: Nursing Practice in Canada and Drug Therapy
rf rf rf rf rf rf rf rf
Sealock: Lilley’s Pharmacology for Canadian Health Care Practice, 5th Edition
rf rf rf rf rf rf rf rf rf
MULTIPLE CHOICE rf
1. Which is a judgement about a particular patient‘s potential need or problem?
rf rf rf rf rf rf rf rf rf rf rf
a. A goal rf
b. An assessment rf
c. Subjective data rf
d. A nursing diagnosis rf rf
ANS: D rf
Nursing diagnosis is the phase of the nursing process during which a clinical judgement is made about ho
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
th conditions and life processes or vulnerability for that response.
rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Knowledge rf rf
2. The patient is to receive oral furosemide (Lasix) every day; however, because the patient is unable to sw
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
medication orally, as ordered. The nurse needs to contact the physician. What type of problem is this?
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. A ―right time‖ problem rf rf rf
b. A ―right dose‖ problem rf rf rf
c. A ―right route‖ problem rf rf rf
d. A ―right medication‖ problem
rf rf rf
ANS: C rf
This is a ―right route‖ problem: the nurse cannot assume the route and must clarify the route with the pre
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
me‖ problem because the ordered frequency has not changed. This is not a ―right dose‖ problem because
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
inability to swallow. This is not a ―right medication‖ problem because the medication ordered will not c
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
3. The nurse has been monitoring the patient‘s progress on his new drug regimen since the first dose and ha
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
f possible adverse effects. What nursing process phase is the nurse practising?
rf rf rf rf rf rf rf rf rf rf rf
a. Planning
b. Evaluation
c. Implementation
d. Nursing diagnosis rf
ANS: B rf
Monitoring the patient‘s progress is part of the evaluation phase. Planning, implementation, and nursing
rf rf rf rf rf rf rf rf rf rf rf rf rf r
by this example.
rf rf
DIF: Cognitive Level: Application rf rf
4. The nurse is caring for a patient who has been newly diagnosed with type 1 diabetes mellitus. Which stat
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
utcome criterion for this patient? rf rf rf rf
a. The patient will follow instructions. rf rf rf rf
b. The patient will not experience complications.
rf rf rf rf rf
c. The patient adheres to the new insulin treatment regimen.
rf rf rf rf rf rf rf rf
d. The patient demonstrates safe insulin self-administration technique.
rf rf rf rf rf rf
ANS: D rf
Having the patient demonstrate safe insulin self-
rf rf rf rf rf rf
administration technique is a specific and measurable outcome criterion. Following instructions and avo
rf rf rf rf rf rf rf rf rf rf rf rf
pecific criteria. Adherence to the new insulin treatment regimen is not objective and would be difficult t
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
, lOMoARcPSD| 13728229
6. The nurse is working during a very busy night shift, and the health care provider has just given the nurse
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf r
e telephone, but the nurse does not recall the route. What is the best way for the nurse to avoid medicatio
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Recopy the order neatly on the order sheet, with the most common route indicated
rf rf rf rf rf rf rf rf rf rf rf rf rf
b. Consult with the pharmacist for clarification about the most common route
rf rf rf rf rf rf rf rf rf rf
c. Call the health care provider to clarify the route of administration
rf rf rf rf rf rf rf rf rf rf
d. Withhold the drug until the health care provider visits the patient
rf rf rf rf rf rf rf rf rf rf
ANS: C rf
If a medication order does not include the route, the nurse must ask the health care provider to clarify it. N
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
stration.
DIF: Cognitive Level: Application | Cognitive Level: Analysis
rf rf rf rf rf rf
7. Which constitutes the traditional Five Rights of medication administration?
rf rf rf rf rf rf rf rf
a. Right drug, right route, right dose, right time, and right patient
rf rf rf rf rf rf rf rf rf rf
b. Right drug, the right effect, the right route, the right time, and the right patient
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
c. Right patient, right strength, right diagnosis, right drug, and right route
rf rf rf rf rf rf rf rf rf rf
d. Right patient, right diagnosis, right drug, right route, and right time
rf rf rf rf rf rf rf rf rf rf
ANS: A rf
The traditional Five Rights of medication administration were considered to be Right drug, Right route, R
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
patient. Right effect, right strength, and right diagnosis are not part of the traditional Five Rights.
f rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
8. What correctly describes the nursing process?
rf rf rf rf rf
a. Diagnosing, planning, assessing, implementing, and finally evaluating rf rf rf rf rf rf
b. Assessing, then diagnosing, implementing, and ending with evaluating rf rf rf rf rf rf rf
c. A linear direction that begins with assessing and continues through diagnosing,
rf rf rf rf rf rf rf rf rf rf rf
planning, and finally implementing rf rf rf
d. An ongoing process that begins with assessing and continues with diagnosing,
rf rf rf rf rf rf rf rf rf rf rf
planning, implementing, and evaluating rf rf rf
ANS: D rf
The nursing process is an ongoing, flexible, adaptable, and adjustable five-
rf rf rf rf rf rf rf rf rf rf
step process that begins with assessing and continues through diagnosing, planning, implementing, and
rf rf rf rf rf rf rf rf rf rf rf rf rf
y then lead back to any of the other phases.
rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Application rf rf
9. When the nurse is considering the timing of a drug dose, which is most important to assess?
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. The patient‘s identification rf rf
b. The patient‘s weight rf rf
c. The patient‘s last meal rf rf rf
d. Any drug or food allergies rf rf rf rf
ANS: C rf
The pharmacokinetic and pharmacodynamic properties of the drug need to be assessed with regard to any
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
food interactions or compatibility issues. The patient‘s identification, weight, and drug or food allergies
rf rf rf rf rf rf rf rf rf rf rf rf rf
ming.
DIF: Cognitive Level: Application rf rf
10. The nurse is writing nursing diagnoses for a plan of care. Which reflects the correct format for her nursin
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Anxiety
b. Anxiety related to new drug therapy rf rf rf rf rf
c. Anxiety related to anxious feelings about drug therapy, as evidenced by s
rf rf rf rf rf rf rf rf rf rf rf
tatements such as ―I‘m upset about having to give myself shots‖
rf rf rf rf rf rf rf rf rf rf
d. Anxiety related to new drug therapy, as evidenced by statements such as ―I‘m
rf rf rf rf rf rf rf rf rf rf rf rf rf
upset about having to give myself shots‖
rf rf rf rf rf rf
, lOMoARcPSD| 13728229
Chapter 02: Pharmacological Principles
rf rf rf
Sealock: Lilley’s Pharmacology for Canadian Health Care Practice, 5th Edition
rf rf rf rf rf rf rf rf rf
MULTIPLE CHOICE rf
1. A patient is receiving two different drugs, which, at their current dose forms and dosages, are both absor
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
dentical amounts. Which term best denotes that the drugs have the same absorption rates?
rf rf rf rf rf rf rf rf rf rf rf rf rf
a. Equivalent
b. Synergistic
c. Compatible
d. Bioequivalent
ANS: D rf
Two drugs absorbed into the circulation at the same amount (in specific dosage forms) have the same bio
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
oequivalent. ―Equivalent‖ is incorrect because the term ―bioavailability‖ is used to express the extent of
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
c‖ is incorrect because this term refers to two drugs given together whose resulting effect is greater than
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
h drug given alone. ―Compatible‖ is incorrect because this term is a general term used to indicate that tw
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
hemical reaction when mixed (or given, in the case of drugs) together.
rf rf rf rf rf rf rf rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
2. A patient is receiving medication via intravenous injection. Which information should the nurse provide
rf rf rf rf rf rf rf rf rf rf rf rf rf
a. The medication will cause fewer adverse effects when given intravenously.
rf rf rf rf rf rf rf rf rf
b. The medication will be absorbed slowly into the tissues over time.
rf rf rf rf rf rf rf rf rf rf
c. The medication‘s action will begin faster when given intravenously.
rf rf rf rf rf rf rf rf
d. Most of the drug is inactivated by the liver before it reaches the target area.
rf rf rf rf rf rf rf rf rf rf rf rf rf rf
ANS: C rf
Intravenous injections are the fastest route of absorption. The intravenous route does not affect the numb
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
avenous route is not a slow route of absorption, and the intravenous route does not cause inactivation of
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
it reaches the target area.
rf rf rf rf
DIF: Cognitive Level: Comprehension rf rf
3. Which is true regarding parenteral drugs?
rf rf rf rf rf
a. They bypass the first-pass effect. rf rf rf rf
b. They decrease blood flow to the stomach. rf rf rf rf rf rf
c. They are altered by the presence of food in the stomach.
rf rf rf rf rf rf rf rf rf rf
d. They exert their effects while circulating in the bloodstream.
rf rf rf rf rf rf rf rf
ANS: A rf
Drugs given by the parenteral route bypass the first-
rf rf rf rf rf rf rf rf
pass effect, but they still must be absorbed into cells and tissues before they can exert their effects. Enter
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
not parenteral drugs, decrease blood flow to the stomach and are altered by the presence of food in the s
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
st be absorbed into cells and tissues from the circulation before they can exert their effects; they do not e
rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf rf
ating in the bloodstream.
rf rf rf
DIF: Cognitive Level: Analysis rf rf
4. A drug‘s half-life is best defined as
rf rf rf rf rf rf
a. The time it takes for the drug to elicit half its therapeutic response.
rf rf rf rf rf rf rf rf rf rf rf rf
b. The time it takes one- rf rf rf rf
half of the original amount of a drug to reach the target cells.
rf rf rf rf rf rf rf rf rf rf rf rf
c. The time it takes one- rf rf rf rf
half of the original amount of a drug to be removed from the body.
rf rf rf rf rf rf rf rf rf rf rf rf rf
d. The time it takes one- rf rf rf rf
half of the original amount of a drug to be absorbed into the circulation.
rf rf rf rf rf rf rf rf rf rf rf rf rf
ANS: C rf