Welcome, PharmD students, to this MCQ quiz on the Pharmacotherapy of Surgical Prophylaxis! Administering antibiotics before surgery is a critical intervention to prevent surgical site infections (SSIs), a significant cause of postoperative morbidity. Understanding the principles guiding appropriate antimicrobial selection, timing, dosing, and duration, as well as the specific recommendations for different types of procedures, is essential for pharmacists involved in optimizing surgical patient care and promoting antimicrobial stewardship. This quiz will test your knowledge on these vital aspects of surgical prophylaxis. Let’s begin!
1. The primary goal of surgical antimicrobial prophylaxis (SAP) is to:
- a) Treat established infections at the surgical site.
- b) Prevent postoperative surgical site infections (SSIs) by reducing microbial burden at the incision site.
- c) Eradicate all normal flora from the patient’s body.
- d) Replace the need for sterile surgical technique.
Answer: b) Prevent postoperative surgical site infections (SSIs) by reducing microbial burden at the incision site.
2. For most surgical procedures, the first dose of intravenous prophylactic antibiotics should ideally be administered within what timeframe before the surgical incision?
- a) 4 hours
- b) 2 hours
- c) 60 minutes (or 120 minutes for vancomycin or fluoroquinolones)
- d) Immediately after the incision is made.
Answer: c) 60 minutes (or 120 minutes for vancomycin or fluoroquinolones)
3. Which of the following is a key principle for selecting an antimicrobial agent for surgical prophylaxis?
- a) Choose the broadest spectrum antibiotic available, regardless of the procedure.
- b) Select an agent that is effective against the most likely pathogens to contaminate the surgical site for that specific procedure.
- c) Always use an oral antibiotic for convenience.
- d) Pick the newest antibiotic on the market.
Answer: b) Select an agent that is effective against the most likely pathogens to contaminate the surgical site for that specific procedure.
4. Cefazolin, a first-generation cephalosporin, is a common choice for surgical prophylaxis in many clean and clean-contaminated surgeries primarily due to its effectiveness against:
- a) Pseudomonas aeruginosa and anaerobes.
- b) Common skin flora such as Staphylococcus aureus (MSSA) and Streptococci.
- c) Fungi and viruses.
- d) Only Gram-negative enteric organisms.
Answer: b) Common skin flora such as Staphylococcus aureus (MSSA) and Streptococci.
5. For most surgical procedures, the recommended duration of postoperative antimicrobial prophylaxis is generally:
- a) At least 7 days.
- b) 3-5 days.
- c) A single dose, or discontinued within 24 hours postoperatively.
- d) Continued until the patient is discharged from the hospital.
Answer: c) A single dose, or discontinued within 24 hours postoperatively.
6. Intraoperative redosing of prophylactic antibiotics may be necessary in which of the following situations?
- a) For all surgical procedures lasting longer than 30 minutes.
- b) If the surgical procedure is prolonged (e.g., exceeds two half-lives of the antibiotic) or if there is excessive blood loss.
- c) Only if the patient develops a fever during surgery.
- d) If the surgeon requests it based on preference.
Answer: b) If the surgical procedure is prolonged (e.g., exceeds two half-lives of the antibiotic) or if there is excessive blood loss.
7. Vancomycin is an appropriate prophylactic antibiotic choice in which of the following scenarios?
- a) For all routine clean surgeries in healthy patients.
- b) In patients with a documented IgE-mediated (anaphylactic) allergy to beta-lactam antibiotics, or for procedures with a high risk of MRSA infection.
- c) As a broad-spectrum agent to cover Gram-negatives.
- d) When a rapid infusion is required.
Answer: b) In patients with a documented IgE-mediated (anaphylactic) allergy to beta-lactam antibiotics, or for procedures with a high risk of MRSA infection.
8. For colorectal surgery, prophylactic antibiotic regimens typically need to provide coverage against:
- a) Only Gram-positive cocci.
- b) Aerobic Gram-negative bacilli and anaerobic organisms commonly found in the colon.
- c) Fungi only.
- d) Viruses only.
Answer: b) Aerobic Gram-negative bacilli and anaerobic organisms commonly found in the colon.
9. Which of the following agents or combinations would be appropriate for prophylaxis in colorectal surgery?
- a) Cefazolin alone.
- b) Vancomycin alone.
- c) Ertapenem, or Cefoxitin/Cefotetan, or Ceftriaxone plus Metronidazole.
- d) Amoxicillin alone.
Answer: c) Ertapenem, or Cefoxitin/Cefotetan, or Ceftriaxone plus Metronidazole.
10. What is a potential risk associated with prolonged or inappropriate surgical antimicrobial prophylaxis?
- a) Decreased incidence of surgical site infections.
- b) Promotion of antimicrobial resistance and increased risk of Clostridioides difficile infection.
- c) Reduced healthcare costs.
- d) Enhanced patient immune response.
Answer: b) Promotion of antimicrobial resistance and increased risk of Clostridioides difficile infection.
11. The timing of vancomycin administration for surgical prophylaxis is critical. Due to its longer infusion time (to prevent Red Man Syndrome), it should generally be started within _______ before the surgical incision.
- a) 30 minutes
- b) 60 minutes
- c) 120 minutes (1-2 hours)
- d) Immediately at the time of incision.
Answer: c) 120 minutes (1-2 hours)
12. For patients undergoing cardiac surgery, cefazolin is a common prophylactic choice. If a patient has a true beta-lactam allergy, an alternative might be:
- a) Ampicillin/sulbactam.
- b) Vancomycin or clindamycin.
- c) Piperacillin/tazobactam.
- d) Ceftriaxone.
Answer: b) Vancomycin or clindamycin.
13. The pharmacist’s role in surgical antimicrobial prophylaxis includes all of the following EXCEPT:
- a) Ensuring appropriate antibiotic selection based on guidelines and patient factors.
- b) Verifying correct dosing, timing, and duration of prophylaxis.
- c) Performing the surgical incision.
- d) Assessing for patient allergies and potential drug interactions.
Answer: c) Performing the surgical incision.
14. For orthopedic procedures involving implantation of prosthetic material (e.g., total joint replacement), _______ is a crucial pathogen to cover with prophylaxis.
- a) Escherichia coli
- b) Staphylococcus aureus (including consideration for MRSA in high-risk settings/patients) and Coagulase-Negative Staphylococci.
- c) Candida albicans
- d) Pseudomonas aeruginosa (unless specific risk factors).
Answer: b) Staphylococcus aureus (including consideration for MRSA in high-risk settings/patients) and Coagulase-Negative Staphylococci.
15. If a surgical procedure lasts 5 hours, and the prophylactic antibiotic given (e.g., cefazolin) has a half-life of 1.5-2 hours, when should an intraoperative redose typically be considered?
- a) It is not necessary for procedures under 6 hours.
- b) After approximately 3-4 hours from the initial preoperative dose (i.e., after two half-lives).
- c) Only at the end of the surgery.
- d) 30 minutes after the initial dose.
Answer: b) After approximately 3-4 hours from the initial preoperative dose (i.e., after two half-lives).
16. Which factor is generally LEAST important when selecting an antibiotic for routine surgical prophylaxis in a patient with no allergies and no MRSA risk?
- a) Activity against likely pathogens for the specific surgery type.
- b) Evidence-based guidelines.
- c) The antibiotic’s ability to penetrate the surgical site.
- d) The availability of a novel, very broad-spectrum investigational agent.
Answer: d) The availability of a novel, very broad-spectrum investigational agent.
17. For hysterectomy (abdominal or vaginal), prophylactic antibiotics typically target common vaginal and skin flora. A common single-dose agent is:
- a) Gentamicin
- b) Cefazolin (or cefoxitin/cefotetan if broader anaerobic coverage is desired for certain cases)
- c) Doxycycline
- d) Fluconazole
Answer: b) Cefazolin (or cefoxitin/cefotetan if broader anaerobic coverage is desired for certain cases)
18. The Surgical Care Improvement Project (SCIP) guidelines emphasize which aspects of surgical prophylaxis to reduce SSIs?
- a) Using antibiotics for at least 72 hours postoperatively.
- b) Appropriate antibiotic selection, timing of the first dose, and timely discontinuation postoperatively.
- c) Administering prophylactic antibiotics only after the surgery is completed.
- d) Relying solely on skin preparation without antibiotics.
Answer: b) Appropriate antibiotic selection, timing of the first dose, and timely discontinuation postoperatively.
19. If a patient is already receiving an appropriate antibiotic for an existing infection that also covers the likely pathogens for a planned surgery, is additional surgical prophylaxis generally needed?
- a) Yes, a different prophylactic antibiotic should always be added.
- b) No, if the therapeutic antibiotic is given within the appropriate window before incision and covers the likely surgical pathogens, additional prophylaxis is usually not needed.
- c) Yes, but only a topical antibiotic at the incision site.
- d) Surgical prophylaxis is contraindicated in this scenario.
Answer: b) No, if the therapeutic antibiotic is given within the appropriate window before incision and covers the likely surgical pathogens, additional prophylaxis is usually not needed.
20. Metronidazole is often added to prophylactic regimens for surgeries involving the gastrointestinal tract or female genital tract because of its excellent activity against:
- a) Aerobic Gram-positive cocci.
- b) Pseudomonas aeruginosa.
- c) Anaerobic bacteria.
- d) Fungi.
Answer: c) Anaerobic bacteria.
21. Why is a single preoperative dose (or short course) of antibiotics generally preferred over prolonged postoperative prophylaxis for most surgeries?
- a) Prolonged use is cheaper.
- b) Prolonged use is more effective at preventing all types of infections.
- c) Prolonged use increases the risk of antibiotic resistance, C. difficile infection, and adverse drug effects without providing additional benefit for SSI prevention in most cases.
- d) Single doses are not effective.
Answer: c) Prolonged use increases the risk of antibiotic resistance, C. difficile infection, and adverse drug effects without providing additional benefit for SSI prevention in most cases.
22. For patients with a history of MRSA colonization or infection undergoing procedures with high MRSA risk, prophylaxis might include:
- a) Cefazolin alone.
- b) Vancomycin (often in addition to an agent like cefazolin, depending on the procedure and local guidelines).
- c) Amoxicillin.
- d) No antibiotics are effective.
Answer: b) Vancomycin (often in addition to an agent like cefazolin, depending on the procedure and local guidelines).
23. The dose of cefazolin for surgical prophylaxis in obese patients (e.g., BMI > 30-40 kg/m² or weight > 120 kg) often needs to be:
- a) Decreased due to reduced clearance.
- b) The standard adult dose regardless of weight.
- c) Increased (e.g., 2g or 3g instead of 1g) to ensure adequate tissue concentrations.
- d) Administered orally only.
Answer: c) Increased (e.g., 2g or 3g instead of 1g) to ensure adequate tissue concentrations.
24. Which of these is NOT a primary goal of pharmacotherapy in surgical prophylaxis?
- a) Achieving adequate antibiotic concentrations in the serum and tissues at the time of incision.
- b) Maintaining therapeutic concentrations throughout the duration of the surgery.
- c) Eradicating pre-existing infections.
- d) Minimizing the risk of surgical site infection.
Answer: c) Eradicating pre-existing infections. (Prophylaxis is for prevention, not treatment of existing infection).
25. Clindamycin is a common alternative for surgical prophylaxis in patients with beta-lactam allergies. It provides good coverage against:
- a) Most Gram-negative aerobes including Pseudomonas.
- b) Gram-positive cocci (including some MRSA strains, though resistance varies) and many anaerobic bacteria.
- c) Only Enterococci.
- d) Only atypical bacteria.
Answer: b) Gram-positive cocci (including some MRSA strains, though resistance varies) and many anaerobic bacteria.
26. The term “clean surgery” (e.g., thyroidectomy, hernia repair without mesh in a non-contaminated field) implies:
- a) High risk of infection, always requiring broad-spectrum prophylaxis.
- b) Infection rates are low, and prophylaxis is often targeted mainly at skin flora if indicated, or sometimes not indicated at all for very clean procedures.
- c) The surgical field is sterile.
- d) Only anaerobic bacteria are a concern.
Answer: b) Infection rates are low, and prophylaxis is often targeted mainly at skin flora if indicated, or sometimes not indicated at all for very clean procedures.
27. “Clean-contaminated surgery” (e.g., elective GI surgery, hysterectomy) involves entry into a colonized viscus under controlled conditions. Prophylaxis here aims to cover:
- a) Only skin flora.
- b) Likely endogenous flora from the entered viscus in addition to skin flora.
- c) Only fungal pathogens.
- d) Only viral pathogens.
Answer: b) Likely endogenous flora from the entered viscus in addition to skin flora.
28. If a patient experiences an anaphylactic reaction to penicillin, which prophylactic agent would generally be considered unsafe due to potential cross-reactivity?
- a) Vancomycin
- b) Clindamycin
- c) Most cephalosporins (especially first and some second generation with similar side chains, though actual cross-reactivity is lower than once thought for many).
- d) Gentamicin
Answer: c) Most cephalosporins (especially first and some second generation with similar side chains, though actual cross-reactivity is lower than once thought for many). (This is a cautious approach; specific agent and reaction type matter).
29. For very long surgical procedures, why is intraoperative redosing of prophylactic antibiotics important?
- a) To increase the risk of side effects.
- b) Because the initial dose will be fully metabolized within one hour.
- c) To maintain adequate antibiotic concentrations in the serum and tissues above the MIC for likely pathogens throughout the period of contamination risk.
- d) It is only done if the patient complains of pain.
Answer: c) To maintain adequate antibiotic concentrations in the serum and tissues above the MIC for likely pathogens throughout the period of contamination risk.
30. Which factor is most critical in ensuring the success of surgical antimicrobial prophylaxis?
- a) Using the most expensive antibiotic.
- b) Administering the antibiotic at the correct time before incision to achieve adequate tissue levels when contamination is most likely.
- c) Continuing the antibiotic for several days post-surgery for all cases.
- d) Choosing an oral antibiotic.
Answer: b) Administering the antibiotic at the correct time before incision to achieve adequate tissue levels when contamination is most likely.
31. The selection of a prophylactic antibiotic should ideally be based on:
- a) The surgeon’s favorite color.
- b) National or local evidence-based guidelines and local hospital/institutional antibiograms if available.
- c) Pharmaceutical company marketing.
- d) What was used for the previous patient.
Answer: b) National or local evidence-based guidelines and local hospital/institutional antibiograms if available.
32. For urologic procedures involving entry into the urinary tract, prophylaxis may target common uropathogens like:
- a) Staphylococcus aureus only.
- b) Gram-negative bacilli (e.g., E. coli) and sometimes Enterococci.
- c) Anaerobic bacteria only.
- d) Fungi only.
Answer: b) Gram-negative bacilli (e.g., E. coli) and sometimes Enterococci.
33. What is the primary reason vancomycin requires a slower infusion (e.g., over 60-120 minutes)?
- a) To enhance its antibacterial activity.
- b) To prevent Red Man Syndrome (an infusion-related histamine release).
- c) It is very unstable if infused quickly.
- d) It is very viscous.
Answer: b) To prevent Red Man Syndrome (an infusion-related histamine release).
34. In cases of significant intraoperative blood loss (>1500 mL in adults), redosing of prophylactic antibiotics may be needed because:
- a) Blood loss increases antibiotic metabolism.
- b) The antibiotic concentration can be significantly diluted or lost, potentially falling below therapeutic levels.
- c) Anemia enhances antibiotic efficacy.
- d) Blood loss inactivates all antibiotics.
Answer: b) The antibiotic concentration can be significantly diluted or lost, potentially falling below therapeutic levels.
35. The pharmacist’s review of a surgical prophylaxis order should verify that the chosen agent provides adequate coverage against ________ for that specific procedure type.
- a) all known bacteria, viruses, and fungi
- b) the most common and expected surgical site pathogens
- c) only MRSA
- d) only anaerobic organisms
Answer: b) the most common and expected surgical site pathogens
36. For procedures where skin flora are the primary concern (e.g., clean orthopedic surgery without implant), which part of cefazolin’s spectrum is most important?
- a) Its activity against Pseudomonas aeruginosa.
- b) Its activity against Staphylococcus and Streptococcus species.
- c) Its activity against anaerobes.
- d) Its activity against atypical bacteria.
Answer: b) Its activity against Staphylococcus and Streptococcus species.
37. If a surgical procedure is cancelled or significantly delayed after the prophylactic antibiotic has been administered, what is a key consideration?
- a) The antibiotic will remain effective indefinitely.
- b) The antibiotic should be redosed if the delay is long enough that concentrations will be sub-therapeutic by the time the incision is made.
- c) No further antibiotic is needed regardless of the delay.
- d) A different antibiotic should be chosen.
Answer: b) The antibiotic should be redosed if the delay is long enough that concentrations will be sub-therapeutic by the time the incision is made.
38. Which of the following would generally NOT be a first-line agent for surgical prophylaxis due to concerns about resistance development and broader spectrum?
- a) Cefazolin
- b) Vancomycin (used appropriately for MRSA risk/allergy)
- c) A broad-spectrum carbapenem for routine clean surgery in a patient without specific risk factors for resistant organisms.
- d) Clindamycin (for appropriate beta-lactam allergic patients)
Answer: c) A broad-spectrum carbapenem for routine clean surgery in a patient without specific risk factors for resistant organisms.
39. The concept of “timing” in surgical prophylaxis refers not only to pre-operative administration but also to:
- a) The time of day the surgery is scheduled.
- b) The appropriate discontinuation of antibiotics post-operatively (usually within 24 hours).
- c) How long the pharmacist takes to verify the order.
- d) The patient’s age.
Answer: b) The appropriate discontinuation of antibiotics post-operatively (usually within 24 hours).
40. Which statement accurately describes a principle of antimicrobial selection for surgical prophylaxis?
- a) The chosen antibiotic must have 100% oral bioavailability.
- b) The antibiotic should achieve bactericidal concentrations in serum and tissue during the period of potential contamination.
- c) The antibiotic should have the longest possible half-life, regardless of the procedure duration.
- d) Patient allergies are not a concern for single-dose prophylaxis.
Answer: b) The antibiotic should achieve bactericidal concentrations in serum and tissue during the period of potential contamination.
41. For a patient with a documented non-anaphylactic rash to penicillin, which cephalosporin might be considered for surgical prophylaxis with caution, or an alternative selected?
- a) Any cephalosporin is absolutely contraindicated.
- b) A cephalosporin with a dissimilar side chain to the offending penicillin might be used cautiously, or a non-beta-lactam alternative chosen.
- c) Vancomycin is the only option.
- d) No prophylaxis is needed.
Answer: b) A cephalosporin with a dissimilar side chain to the offending penicillin might be used cautiously, or a non-beta-lactam alternative chosen.
42. One of the goals of ASHP (American Society of Health-System Pharmacists) guidelines on surgical prophylaxis is to:
- a) Promote the use of more expensive antibiotics.
- b) Standardize practices and provide evidence-based recommendations to optimize antibiotic use and reduce SSIs.
- c) Eliminate the pharmacist’s role in prophylaxis.
- d) Encourage prolonged postoperative antibiotic use.
Answer: b) Standardize practices and provide evidence-based recommendations to optimize antibiotic use and reduce SSIs.
43. If a patient is undergoing a “dirty” or “infected” surgical procedure (e.g., incision and drainage of a large established abscess, repair of perforated viscus with gross contamination), the antimicrobials administered are considered:
- a) Prophylactic only.
- b) Therapeutic (treatment of an existing infection), not just prophylactic.
- c) Optional.
- d) Only for viral coverage.
Answer: b) Therapeutic (treatment of an existing infection), not just prophylactic.
44. The ideal prophylactic antibiotic should possess which pharmacokinetic property?
- a) Poor tissue penetration to minimize side effects.
- b) Adequate penetration into the surgical site to reach effective concentrations.
- c) A very short half-life requiring frequent intraoperative redosing for all procedures.
- d) Elimination solely through hepatic metabolism.
Answer: b) Adequate penetration into the surgical site to reach effective concentrations.
45. Which of the following is a critical aspect of communication for effective surgical prophylaxis?
- a) Ensuring the surgical team does not communicate with the pharmacy.
- b) Clear communication between surgery, anesthesia, and pharmacy regarding patient allergies, antibiotic choice, timing of administration, and need for redosing.
- c) Using only verbal orders for prophylactic antibiotics.
- d) Documenting antibiotic administration only after patient discharge.
Answer: b) Clear communication between surgery, anesthesia, and pharmacy regarding patient allergies, antibiotic choice, timing of administration, and need for redosing.
46. What is the rationale for generally not recommending broad-spectrum agents like carbapenems for routine surgical prophylaxis in most clean surgeries?
- a) They are less effective than cefazolin.
- b) To preserve their utility for treating multidrug-resistant infections and to minimize selection pressure for resistance (antimicrobial stewardship).
- c) They are too inexpensive.
- d) They have no activity against skin flora.
Answer: b) To preserve their utility for treating multidrug-resistant infections and to minimize selection pressure for resistance (antimicrobial stewardship).
47. For neurosurgical procedures (e.g., craniotomy), prophylaxis often targets skin flora. _______ is a common agent.
- a) Metronidazole
- b) Cefazolin or Vancomycin (if MRSA risk/allergy)
- c) Gentamicin
- d) Doxycycline
Answer: b) Cefazolin or Vancomycin (if MRSA risk/allergy)
48. The pharmacist can contribute to successful surgical prophylaxis by developing and implementing institutional guidelines and protocols that are:
- a) Intentionally vague and flexible.
- b) Based on the oldest available literature.
- c) Evidence-based, regularly updated, and tailored to local epidemiology and surgical practices.
- d) Designed to maximize antibiotic usage.
Answer: c) Evidence-based, regularly updated, and tailored to local epidemiology and surgical practices.
49. A key principle in surgical prophylaxis is that the antibiotic should be present at the surgical site _______ contamination occurs.
- a) long after
- b) at the time
- c) just before closure only
- d) only if signs of infection develop
Answer: b) at the time (i.e., during the period of incision through closure when microbial contamination is most likely).
50. Failure to adhere to appropriate surgical prophylaxis guidelines can lead to:
- a) Decreased healthcare costs.
- b) Increased rates of surgical site infections, longer hospital stays, and increased patient morbidity.
- c) A reduction in antimicrobial resistance.
- d) Shorter surgical procedure times.
Answer: b) Increased rates of surgical site infections, longer hospital stays, and increased patient morbidity.