Chapter 03: Infection Prevention and Control in the Perioperative Setting

Chapter 03: Infection Prevention and Control in the Perioperative Setting

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. Surgical site infections (SSIs) are most often caused by gram-positive cocci and may arise from the patient’s own endogenous sources. The most typical causative microorganism cultured from SSIs is:

ANS:  C

The organisms most commonly found in postoperative SSIs include staphylococcal, enterococcal, pseudomonal, and streptococcal species. S. aureus is the most frequently identified organism.

REF:   Page 48

2. A swab of a fluid collection from an edematous, red, and separating postoperative wound is sent to the microbiology lab for culture, sensitivity, and Gram stain. The surgeon expects that the result will show a gram-positive coccus. This Gram stain designation is based on the:

ANS:  B

Gram stain is a procedure for staining bacteria; it is the first step in classifying and differentiating bacteria into two large groups (gram-positive and gram-negative) based on the chemical and physical properties of their cell walls. A gram-positive microorganism has a thicker cell wall than a gram-negative microorganism.

REF:   Pages 48-49

3. The hospital epidemiologist was alerted when several cultures had recently revealed suspicious similarities. He was concerned about two unrelated patients with similar abscesses in similar body regions. Susan Grant, a 72-year-old diabetic patient taking immunosuppressive medications for chronic Crohn’s disease, had an incision and drainage of a perianal fistula. Shawn Ames, a healthy 22-year-old college student and motocross racer, had an incision and drainage plus excision of a pilonidal cyst. Both patients cultured out a new subtype of S. aureus. Susan’s specimen results showed a significant colony growth of S. aureus plus differential growth of coagulase-negative S. epidermidis, while Shawn’s specimen was a high colony growth coagulase-positive, similar subtype of S. aureus. The epidemiologist charged his department to be alert for this S. aureus subtype and cross-check for trends. He was most concerned about one of these patients in particular and pulled up the medical record for review. Which patient may be at higher risk with the more virulent strain and why?

ANS:  D

Coagulase-positive staphylococci are more virulent or pathogenic than coagulase-negative staphylococci. S. aureus is hemolytic, parasitic, pathogenic, and coagulase positive. S. epidermidis is parasitic, less pathogenic, and coagulase negative. Virulence is the potency of a pathogen measured in the numbers required to kill the host.

REF:   Pages 48-49

4. While antibiotics have been credited with saving lives, misuse of antibiotics has contributed to the evolution of multidrug-resistant organisms (MDROs). Antibiotic use is prolific in the perioperative setting. Select the antibiotic application has evidence to support it as a best practice and not, potentially, a misuse of antibiotics.

ANS:  A

Drug resistance from treatment-related causes is often the result of misuse (e.g., incorrect use, overuse, or underuse) of antibiotics. It is believed that 50% of all antibiotic use in the United States can be characterized by misuse in one form or another, and efforts to reduce surgical site infections include appropriate prophylactic antibiotic use in surgical patients. It is estimated that half of all antibiotic prescriptions written are not warranted. During antibiotic therapy, the patient may have retained a few resistant organisms. By natural selection, as the susceptible organisms are killed, the resistant organisms multiply and become predominant. Failure to perform sensitivity testing along with inappropriate dosing can contribute to resistance. Although some surgical complications are unavoidable, surgical care can be improved through decisions and subsequent care focusing on evidence-based practice recommendations. Research shows that delivering antibiotics to a patient within 1 hour of beginning surgery can dramatically decrease SSI rates, yet this practice is not followed in all situations.

REF:   Pages 55, 58

5. The Centers for Disease Control and Prevention (CDC) has identified pathogens that could pose a threat to national and world security and safety through bioterrorism. Select the four most probable agents that could be used to cause mass transmission, mortality, panic, and social disruption.

ANS:  B

The potential for bioterrorism is a reality in today’s world. The CDC has identified agents that may pose a risk to national security because of their (1) easy dissemination or transmission from person to person, (2) potential to cause high mortality and have a major public health impact, (3) potential to cause public panic and social disruption, and (4) necessity for special action for public health preparedness.