Infectious Diseases I

Answer: A

The patient has suspicion for MDR VAP, as evidenced by

the presence of clinical signs of infection, the patient’s

increased sputum production, and the patient’s having

been in the ICU for 5 days or longer. Empiric antibiotic

therapy should be initiated after obtaining a respiratory

culture and be based on patient-specific risk factors for

MDROs, together with local pathogen prevalence and

antibiotic susceptibility, to increase the likelihood of

providing timely appropriate antibiotic therapy (Answer

A is correct). Gram stain results can be used to help

guide empiric therapy as per GRACE-VAP, but antibiot-

ics should not be delayed 1–2 days awaiting Gram stain,

preliminary or final respiratory culture results, as well

as blood or urine cultures, may cause an unacceptable

delay in appropriate antibiotic therapy (Answers B–D

are incorrect).

Although this patient is suspected of having early-

onset VAP for the current admission, a history of

recent intravenous antibiotic therapy is a risk factor for

MDROs. Empiric antibiotic therapy for VAP in patients

with MDRO risk factors should include agents active

against P. aeruginosa and MRSA. Empiric combina-

tion therapy against P. aeruginosa is recommended to

increase the likelihood of appropriate antibiotic therapy

(Answer B is correct; Answers A and C are incorrect)

with a β-lactam antibiotic as one of the preferred agents

(Answer D is incorrect). Atypical bacteria coverage is

not necessary because their prevalence is low, although

consideration should be given if there is a poor response

to initial therapy.

Answer: B

Based on the PneumA trial and related meta-analyses,

the most recent IDSA VAP guidelines recommend

definitive antibiotic therapy duration of 7 full treatment

days for all patients. This is further emphasized in this

patient, who has VAP caused by Klebsiella spp., which

are lactose-fermenting gram-negative bacilli, and who

received appropriate empiric antibiotic therapy and had

an appropriate clinical response during therapy (Answer

B is correct; Answers A, C, and D are incorrect).

Answer: D

In the absence of other suspected sources (i.e., no

change in chest radiograph), CLABSI should be sus-

pected as the cause of new-onset fever and leukocytosis,

given the emergency placement and related duration

of the CVC (Answer B is incorrect). Although catheter

removal should strongly be considered, cultures should

be obtained before catheter removal for documentation

if the patient has a bloodstream infection (Answer C

is incorrect). Initiation of antibiotic therapy should be

considered, if appropriate, but only after cultures of the

suspected source are obtained (Answer D is correct;

Answer A is incorrect).

Answer: D

This patient, who is thought to have a CLABSI, has risk

factors for MDROs, given that the patient was hospi-

talized for 5 or more days. Empiric antibiotic therapy

choices should include agents active against MRSE

and MRSA as well as P. aeruginosa (Answer D is cor-

rect; Answer A is incorrect). Linezolid is active against

MRSA; however, it should be considered only for defini-

tive therapy because its empiric use in patients with a

CLABSI is associated with worse outcomes (Answer C

is incorrect). Fluconazole may be considered in addition

to antibiotic therapy, but monotherapy is not recom-

mended empirically (Answer B is incorrect).

Answer: B

The guideline recommendation for definitive antibiotic

therapy duration is 7–14 days from the first negative

blood culture in patients with uncomplicated gram-

negative CLABSI. Longer durations of therapy should

be considered in patients with persistent bacteremia

or if the patient has a poor clinical response. (Answer

B is correct; Answers A and C are incorrect). Patients

with complicated bacteremia (e.g., endocarditis, sep-

tic thrombus, chronic intravascular hardware) should

receive 4-6 weeks of therapy (Answer D is incorrect).

Answer: C

The presence of new fever and an elevated WBC in

conjunction with an indwelling urinary catheter and

pyuria on urinalysis is highly suggestive of a CAUTI

rather than worsening pneumonia (Answer B is incor-

rect). Similar to other ICU-related infections, empiric