Critical Care Medicine-Pulmonary Disorders>>>>>Pulmonary Infections
Question 1#

A 68-year-old woman with a history of hypertension and poorly controlled diabetes mellitus presents to the emergency department (ED) with fevers and 5 days of progressive shortness of breath and cough. She presented to her primary care physician 3 days ago and was prescribed amoxicillin. Despite this treatment, her symptoms worsened; she has no other associated symptoms. On arrival to the ED, her vital signs are notable for :

• T 38.4°C
• blood pressure (BP) 118/75 mm Hg
• heart rate (HR) 90 beats per minute
• respiratory rate 14 breaths per minute
• SpO₂ 83% breathing ambient air

She is placed on high-flow nasal cannula at 60 L/min and FiO₂ 0.6 in the ED, and vancomycin and cefepime administered. She is subsequently admitted to the intensive care unit (ICU) for severe community-acquired pneumonia (CAP).

Which of the following is the BEST next step in her management?

A. Perform flexible bronchoscopy and bronchoalveolar lavage to obtain bacterial culture
B. Add levofloxacin to her antibiotic regimen
C. Send quantitative respiratory cultures and blood cultures
D. Change her antibiotic regimen to ceftriaxone and azithromycin
E. Change vancomycin to linezolid

Correct Answer is B

Comment:

Correct Answer: B

The patient presents with severe CAP. Common pathogens explaining this presentation include S. pneumoniae, H. influenzae, Legionella, Enterobacteriaceae species, S. aureus, and Pseudomonas. The narrowest recommended antibiotic regimen for patients admitted to the ICU with CAP must include:

1. an antipneumococcal beta-lactam antibiotic and
2. either a macrolide (eg azithromycin) or a respiratory fluoroquinolone

For patients with risk factors for S. aureus and Pseudomonas infection (which include outpatient antibiotic failure, past healthcare exposure, structural lung disease, and recent IV antibiotic exposure), empiric coverage is recommended. Given this patient’s recent antibiotic exposure and failure of outpatient antibiotic therapy, empiric treatment for methicillin-resistant S. aureus and Pseudomonas species is appropriate (answer D is incorrect). However, addition of a macrolide or fluoroquinolone is recommended to cover atypical pathogens including Legionella—at least 20% of severe pneumonia is thought to be because of atypical bacterial pathogens (answer B is correct). There are no data to support the use of bronchioalveolar lavage over routine respiratory gram stain and culture for CAP (answer A is incorrect). Additionally, although blood cultures are recommended for patients who are hospitalized with CAP, there is no additional value of quantitative respiratory cultures over routine respiratory gram stain and cultures. There is no indication for empiric treatment of vancomycin-resistant species such as Enterococcus (answer E is incorrect).

Reference:

1. Mandell LA, Wunderink RG, Anzueto A, et al. Infectious diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007;44(suppl 2):S27-S72.