Which of the following is the goal of monitoring peak and trough levels during antibacterial therapy?

A. Decision to administer either a bactericidal or bacteriostatic drug:

Culture and sensitivity tests provide information about the susceptibility of the microorganism to specific antimicrobial agents. Based on this information, healthcare providers can choose between bactericidal (agents that kill bacteria) or bacteriostatic (agents that inhibit bacterial growth) drugs. For example, if the culture indicates that the microorganism is susceptible to a bactericidal drug, such as penicillin, the healthcare provider may choose to administer that type of drug.

B. Microbial susceptibility to an anti-infective:

This option accurately describes one of the primary purposes of culture and sensitivity tests. These tests determine whether the microorganism causing the infection is susceptible or resistant to specific antimicrobial agents. This information guides the selection of the most appropriate anti-infective therapy to effectively treat the infection.

C. Duration of the antibacterial drug therapy:

While culture and sensitivity tests provide valuable information about microbial susceptibility to antimicrobial agents, they do not specifically determine the duration of antibacterial drug therapy. The duration of therapy is often determined based on factors such as the type and severity of the infection, the patient's response to treatment, and clinical guidelines, rather than solely on the results of culture and sensitivity tests.

D. Decision to administer empiric therapy:

Empiric therapy involves the initiation of antimicrobial treatment based on clinical judgment and knowledge of likely pathogens before culture and sensitivity results are available. Culture and sensitivity tests help confirm the causative microorganism and guide subsequent treatment decisions, including adjustments to therapy based on the results. Therefore, while culture and sensitivity tests inform decisions regarding antimicrobial therapy, they do not directly determine whether empiric therapy should be initiated.

A. By assessing the temperature every 4 hours:

Monitoring temperature every 4 hours is a common practice in hospitalized patients to detect fever, which could indicate an infection or an inflammatory response. However, this method does not directly assess the therapeutic blood levels of vancomycin. Fever alone does not provide specific information about the effectiveness or concentration of the antibiotic in the bloodstream.

B. By repeating a culture and sensitivity test on day 3:

Culture and sensitivity tests involve taking a sample from the patient (such as blood, urine, or sputum) and growing the microorganisms in a laboratory to identify the causative organism and determine its susceptibility to antibiotics. While this test is essential for identifying the appropriate antibiotic therapy initially, repeating it on day 3 does not directly monitor therapeutic blood levels of vancomycin. It also doesn't provide real-time information about the concentration of vancomycin in the bloodstream.

C. By obtaining drug peak and trough levels:

This choice involves measuring the highest (peak) and lowest (trough) concentrations of vancomycin in the bloodstream. Peak levels are typically measured about 1 hour after the completion of a vancomycin infusion, while trough levels are measured just before the next dose is administered. These measurements allow healthcare providers to ensure that the drug concentration remains within the therapeutic range to effectively treat the infection while minimizing the risk of toxicity.

D. By assessing for breathlessness:

Assessing for breathlessness is important for monitoring respiratory status, particularly in patients receiving vancomycin, as rare side effects like red-man syndrome or anaphylaxis can cause respiratory distress. However, this method does not directly monitor therapeutic blood levels of vancomycin.