Infectious Diseases I

Definitive antibiotic therapy should be focused on the causative pathogen(s) identified on lower

respiratory tract culture.

Pathogen-specific definitive antibiotic choices should be based on antibiotic susceptibilities and, if

possible, available evidence supporting efficacy and safety in patients with VAP.

MRSA: Vancomycin or linezolid; daptomycin is not indicated for pneumonia because of direct

inhibition by pulmonary surfactant. Although not included in the guidelines, ceftaroline is

also a potential treatment of MRSA HAP/VAP.

ii.

P. aeruginosa

results is recommended in immunocompetent patients not in septic shock and not at a

high risk of dying. Concomitant aminoglycoside or antipseudomonal fluoroquinolone is

recommended in immunocompromised patients and those in septic shock or at a high risk

of dying. Combination therapy can be de-escalated to monotherapy β-lactam once septic

shock resolves.

not be used to for both P. aeruginosa and MSSA), piperacillin/tazobactam, imipenem,

meropenem, ceftolozane-tazobactam, ceftazidime-avibactam, or cefiderocol

iii.

Acinetobacter spp.: Sulbactam-durlobactam, ampicillin-sulbactam (sulbactam is active agent),

carbapenems (eg, imipenem or meropenem), minocycline, or cefiderocol

iv.

Stenotrophomonas maltophilia: The combination of 2 of the following agents:

sulfamethoxazole-trimethoprim, levofloxacin, minocycline, or cefiderocol. For cultures

exhibiting metallo-β-lactamase, the combination of ceftazidime-avibactam and aztreonam

can be used.

Extended-spectrum β-lactamase (ESBL)-producing organisms: Carbapenem (e.g., ertapenem;

imipenem; meropenem)

vi.

Since the 2016 IDSA guidelines, cefiderocol, ceftolozane/tazobactam, ceftazidime/avibactam,

imipenem/cilastatin/relebactam, and sulbactam/durlobactam have been FDA approved for

the treatment of VAP. These agents can be considered for certain multidrug-resistant (MDR)

pathogens (e.g., ESBL; specific carbapenemases) in concert with an antimicrobial stewardship

program.

vii.

In 2024, IDSA updated its guidance document in the treatment of antimicrobial-resistant

gram-negative infections (Clin Infect Dis. 2024 Aug 7:ciae403).

Duration of definitive antibiotic therapy is recommended to be 7 days for all patients rather than

longer durations. Pathogen-based recommendations for duration of definitive antibiotic are no

longer indicated in VAP guidelines.

The PneumA trial was a pivotal noninferiority study that evaluated 8 days (7 full treatment

days) versus 15 days (14 full treatment days) for duration of definitive antibiotic therapy in

patients with bacteriologically diagnosed VAP. The primary noninferiority outcome was VAP

recurrence. All patients included in the study received appropriate empiric antibiotic therapy

not caused by non–lactose-fermenting gram-negative bacilli (e.g., P. aeruginosa).

8-day group more often had VAP recurrence. This was primarily seen in patients with

P. aeruginosa, but also included other lactose-non-fermenters (e.g., Acinetobacter,

Stenotrophomonas, and Burkholderia spp.).